I want to share with you how I prepare forecasts on a daily basis. Forecasts of mine appear on channel weather: asheville, www.angelfire.com/ga/mrsweather/atlweather.html, and the UNCA Weatherline Friday afternoons. The way I go about preparing the forecasts is the same for all three. First, I go outside to feel what the air is like. Many times, a forecaster would neglect to recognize this but I feel it is an essential and very important part to the initialization of the forecast. Without knowing what it is doing now, how can you possibly know what is coming up? So I go outside first. Next, I go onto my website to look at what the current conditions are whereever I am and what's going on weatherwise across the region and across the country. Again, initializing myself to get ready for the forecast. Then I get into the nuts and bolts of it all, the forecast computer models. A good website to find those on is Unisys Weather where they have the models run by the National Centers for Environmental Prediction (NCEP) which are made available to all forecasters and the general public. The models I look at are the ETA, NGM, AVN, MRF, ECMWF, and RUC and all have their biases. ETA model tends to be the more accurate of the models but tends to also have a cold bias. The NGM model is usually the outlier among the models and the most inaccurate because it has the least grid points making it inferior to the other models' capability. The AVN is an accurate model too although it has a bias of putting out too much precipitation and overdeveloping tropical systems but it is the newest of the six with good grid coverage. The MRF is two of the long range models that go out in the long range. It goes out 10 days. The only other model to give that much range would be the ECMWF which is run out of the United Kingdom and that model goes out 6 days. ECMWF is usually right with winter storms more than the MRF and the MRF tends to overdo precipitation. Finally, the RUC model goes out to 12 hours and is the only mesoscale model that I look at. It is especially good during severe weather sitations but can look transparent and not accurate at times. These quarks must be taken into account when forecasting. After looking at the models, I have a good idea what I am going to forecast. However, I like to compare what my idea is with NCEP and the National Weather Service (NWS) forecast offices so I go online and read their discussions. Most times, my thoughts are right along with them but there have been lots of instances where I have gone against what their philosophy is. Keep in mind, different people see different things different ways and that's the same with forecasting. Just because they have a government name attached to them, doesn't mean that they're the almighty. Besides, not all of the people at a company think alike anyway so I am careful of what the forecasters say. After reading their discussions, I check out other forecasts on my page and compare them with the philosophy I have. If perhaps I am a little confused on something, I can look at what another forecast outlet is going with and resign myself to close to what they are thinking. It doesn't happen often because I have too much pride for what I do. Next, I look at Model Output Statistics (MOS). Those are stats directly from the models: ETA, NGM, AVN and MRF, that are qualatative analysis ranging from going out every 3 hours to 48 hours or as far as 7 days. The same quarks apply to their MOS guidance and that all it really is, is guidance to help make the forecast. MOS hasn't always been around for forecasters as it made it's debut in the late 1970s. People then predicted that the numbers would replace real people doing the weather but that's not the case. Those MOS guidance numbers can be highly varied and as a forecaster, you have to make a decision on which ones will guide your forecast. Finally after that process, the forecast is made and put to print but it isn't over. Now you must verify yourself and that means I look at climate data over the next few days to make sure my forecasts were as accurate as possible. It's the only way to get better and will help in future forecast preparation. Forecast Preparation By A TV Meteorologist Former Weather Channel meteorologist for 18 years, Bruce Edwards moved on to local television in 2000. Serving the Cleveland TV market, his home town, he changed his on air name back to his original name, Bruce Kalinowski. I emailed him and asked him how he prepares a forecast: Now I work Mon-Fri. I come in at 2p.m....take an hour to look over the
data
and compose a short 24-hr forecast, which I call over to a local radio
station at about 3:15. Then its look at the data, come up with my
forecast...decide how I want to present the show...then start creating
the
graphics. The alpha-numeric graphics are the ones I up-date. The sat
loops, radar loops and temp maps automatically update. If weather is
going
to be a story, I tell the producer of the newscast & maybe have an
extra
slot for weather closer to the top of the show...and maybe a final
forecast
at the end. I usually cut a show intro...some days cut a :30 weather
briefing that they run on the Jumbotron at Jacobs Field or Gund Arena
at
5:30...update or web page weather...slap on some make-up and do the
6:00
show.
After the show...cut 2 weather teases that they'll run during the
evening...grab some dinner....adjust & adapt the cast for the 10 p.m.
news
on Channel 43. Finish that show at 10:45...then have 15 minutes to
reload
& adjust for the 11:00 news on ch19. All newscasts have their own
producers
and different formats...so I deal with three different producers,
daily. At
11:35...I shut down the equipment, scrape off the make-up...and go home
and
have a tall cold Jack & Water !!! The weather dictates the severity of
the
work day...some are quiet and easy...others are hectic, and stressful. National Weather Service Style Forecast You can always be assured of the following in a National Weather Service forecast: Different authors have different styles of writing. Forecasters are also authors, all with unique ways of penning a discussion. Forecast discussions are issued four times a day and here's a few of examples of these: I like to have an explanation of my forecasts as well on my site and with the UNCA Weatherline. While I am not a meteorologist, I know enough to explain why I am forecasting what and the philosophy behind it. So here are my forecast discussions from the last couple of years:
Can you believe it, my time is done in Atlanta for the summer. So this is your final forecast report until I come back home for December and the Christmas and New Years break. So let's get to it taking it slide by slide and the first slide shows the cloudiness or lack there of over the southeast this early Wednesday morning. The remenants of Barry look to be over the bootheel of Missouri, they had been over Memphis providing a very beautiful shot on radar and satellite earlier Tuesday afternoon of showers and thunderstorms revolving around the city. Even we got into the act with some scattered showers and storms, mainly west of town on the outer circulation of what once was Barry. I say mainly west because we have high pressure to our northeast nosing down providing the city on eastward more stable air and acting as a block to the precipitation. Also notice the build up of cloudiness over the Gulf coast, we have plenty of tropical moisture over the southeast and you see on the next slide dewpoints are in the 70s everywhere! So one of those slow to cool nights where it will be hard to sleep. Not much on the current map, the L denotes where our former tropical storm is with a few showers associated with it. They'll blossom once again with daytime heating later in the afternoon but like today, should mainly stay on the west side of town. Next slide is the jet stream, which is running well to the north. We're having some of the hottest weather of the season over the Midwest and Northeast. Not here though, we've only hit 90 6 times this season, it's been noticably milder than previous summers. We haven't had this few of 90 plus days since at least 1984 and the extended keeps us 90 free. But the jet stream will take a buckle and in the next slide, that's the forecasted jet by Friday morning. Notice it's still well to the north of us and we're under a ridge with light winds aloft. The next slide shows the precip map by Friday morning and it's looking like we could have a line of thunderstorms over the Midwest with the remenants of Barry increasing our rain chances ahead of the cold front that shouldn't make too much southward progress...i.e. shouldn't move through us. It looks to stay to our north and sort of stall and since we'll stay south of it and remain in the warm tropical air, a chance for scattered storms each day through the weekend looks the best. Some of the storms will be locally heavy, this air is very moist, very juicy so if you're under one, it'll be like a monsoon. And finally the next slide shows our temperatures, still 2 degrees below our average high for this time of year.
I'm done, I hope you enjoyed these forecast updates all summer long. I will keep the maps and everything up through the fall. I'm going back to school next week in Asheville, NC and if you're just dying to see my forecasts up there just click here. A new look, new graphics, new format debuts there a week from today. And much of what you'll eventually see there will be incorporated here. I've had fun forecasting for Atlanta, much less of a challenge than Asheville but still tough everyday. I worked at The Weather Channel this summer and it limited the amount of time that I had to forecast on this page. I still hope you found everything useful for your lives and I'm glad you chose to depend on me for your forecast. Thanks to that one person who voted for me down in the poll, that means a whole lot to me, it really does. One day, you'll see me on TV and maybe I'll get more votes with the increased visibility. Anyway, you all take care, see ya in December!
(From August 8, 2001 the Atlanta Weather Report) Notice the difference in type from the NWS discussions and mine. I don't do all caps, I think it looks bad. Almost like you are yelling. Yes, this was my last forecast for the summer in Atlanta last August before I came to school. I like trying to incorporate historical data in my forecasts to give those who read a sense that maybe this hasn't happened before and it's pretty significant and I like putting in streaks should they be occuring. Also, probably the most important thing a forecaster for their region should know is the geography and how that affects the weather. Often times, just going a few miles will drastically vary the weather conditions.
That from the afternoon discussion from the Greenville/Spartanburg NWS where they had a blast up call with virtually every forecast office within 100 miles. So you know at this point that all of Western North Carolina is under a winter storm watch. Looking at up to 10 inches of snow here in Asheville, 1 to 2 feet of snow above 4000 feet, ya know the normal high elevation places like Mitchell, Pisgah, Grandfather, Sugar to name a few. They'll be measuring the snow in feet. But wait, wait, let's not be hasty here! Let me set the scene.
I want you to put out of your mind the fact that we reached 53 degrees for a high today. You may say, we got so warm today that we just won't get cold enough for snow. Folks, that doesn't tell the whole story. It could have gotten 5 degrees warmer and I'd still be saying this. The air is very dry! Dewpoints are in the 10s this evening. Once that precipitation reaches us, it'll fall in that dry air, evaporational cooling will take place and temps will crash. As of 7pm, heavy rain in Atlanta and it's 42 degrees. They reached 54 today. See with heavy rain, you're going to get the temp to plummet even further than just a light shower coming in with dry air. So for that reason, we will be cold enough for the snow.
"THERE SHOULD BE SUFFICIENT DYNAMIC COOLING OCCURRING IN ADVANCE OF THE UPPER LOW TO LEAD TO SOME LOCALLY HEAVY SNOWFALL IN THE HIGHER ELEVATIONS OF ERN TN...WRN NC...AND NWRN SC MAINLY ABOVE 2500 FEET. ISOLATED AMTS ON SOME OF THE HIGHER MTN LOCATIONS COULD APPROACH 6-8 INCHES BUT OVERALL MOST AREAS WILL PROBABLY SEE 4-6 INCHES."
That from NCEP's heavy snowfall discussion this afternoon. I'd like to point out the sufficent dynamic cooling. If you've seen any upper air maps, thickness maps, you'll see how unusual this storm situation is shaping up to be. They have critical thickness values that would be low enough for snow going all the way into the Northern Gulf of Mexico! No it's not going to snow down there but that'll tell you how dynamic this storm system is. The upper low will bring it's own cold air with it. There'll be plenty of cold air aloft for snow and as the snowfalls, the temperatures will drop. Oh but there is forecast to be loads of lifting with this system and as you saw, it should be ahead of the upper low. So we could be in a situation where the whole event is snow. Like later tonight, we could see heavy, wet snow falling with temperatures well above freezing then of course those temps plummet. And when I say plummet, we aren't going into the single digits and teens. Not even the 20s. We're going to be around freezing for this event at our lowest.
"STRONG DIFFLUENCE AHEAD OF THE UPPER LOW WILL CONTRIBUTE TO POTENT UVVS AND THIS COMBINED WITH CONTINUED STRONG EASTERLY INFLOW WILL BRING SOME IMPRESSIVE SNOW AMTS PARTICULARLY TO WRN NC WHERE ACCUMULATIONS COULD APPROACH 8-12 INCHES ON THE HIGHEST PEAKS THERE."
Also from NCEP's heavy snowfall discussion. This will be a miller type A storm as the surface low moves from the northeast Gulf northeastward to South Georgia with a secondary low forming off the Georgia coast. The easterly flow will overwhelm the mountains with an abundance of moisture and will keep the cool air entrenched. I would like to point out this. This will be snow, no mixing, no freezing rain, very low potential for sleet. But if you go east, places like Morganton, Hickory, Statesville, warm air aloft from that flow off the Atlantic could mix the snow with sleet there tomorrow. All snow Asheville.
My snowfall prediction, 5-10 inches for Asheville through tomorrow night. Tricky thing is, do we stay all snow into Wednesday or do we change to rain tomorrow night? We'll have to see on that, tune back here periodically, I'll update the forecast around midnight or so for my best guess at this storm. I must say, it's amazing the awareness people are having due to this impending snowstorm. It's been the buzz all over the city all day today. Oh and one more thing. Winds will be up to 30 mph, we'll be in near blizzard like conditions at times tomorrow and if we get any kind of convection with the snow, then add a few more inches to my snowfall prediction. I'll update later tonight! (From March 19, 2001 the Asheville Weather Report) My favorite part of forecasting is during storm situations because things can change so rapidly and whatever happens affects the lives of many. That's probably my main reason that I am pursuing a degree in atmospheric sciences. So this was my 7:30pm update which was unusually late due to the circumstances--a big snowstorm coming our way--normally I wouldn't delay for that long but I had a lot to say and there were uncertainties up to that point that I wanted to make sure were clear. You can tell the excitement in my discussion in transitioning from the first to the second paragraph. Forecasters should be careful in not getting too excited over severe weather events even though they are beautiful and are interesting, they can be extremely dangerous and hazardous to all of us. But during storm events like this, I provide round the clock coverage on my site and made several more forecast reports during the duration of the storm. By the way, my prediction of 5-10 inches of snow for Asheville was in the ballpark with 6.1 inches officially at the airport and 6.5 inches at UNCA. (From February 22, 2002 the UNCA Weatherline) Now this is more like NWS style which is what our forecasts are suppose to be styled after on the Weatherline. I usually have a lot to say so my forecasts are long and to limit the length, I put in abbreviations as well. Like the Met. equals meteorological. Not so much in this one but in others I've done that. Also, I like adding teases which would be especially important for forecasting in the media which reel the viewer in and keeps them locked and interested in what you have to say. Look at the following forecasts from the model output statistics using data collected at 8am for Asheville, NC:
Ok, so which numbers are right? That's what forecasters are faced with every day. These are meant to be used as guidance, not just a copy and paste kind of thing into your forecast. All these initialize at the same time (except the MRF which initializes 12 hours earlier) but definetly have different solutions. Explaining the categories and numbers for you. For the AVN, ETA, NGM, and MRF, the top lines explain what station the forecast is for in this case it is KAVL which is Asheville, NC, also which MOS they are and the date and time they were initialized, UTC time (4 hours ahead of EDT and 5 hours ahead of EST) that is. For the AVN, ETA, and NGM MOS the next line shows what dates the forecasts go out to. Next line shows the hours of the day in UTC time. Next line shows the high temperatures and low temperatures based on periods between 12-00 UTC and 00-12 UTC respectively. Note that the high for the day may not occur during daylight hours and the low may not neccessarily occur in the morning and a forecaster has to keep that in mind or else the forecast could be blown. After that line comes the line where the temperatures forecasted for the certain time is such as with the AVN MOS, the forecasted temperature at 11pm on May 8 (0300 UTC May 9) should be 69 degrees F. In fact, all temperatures are in Fahrenheit on MOS. Line below is the dewpoint then below it is the cloud cover denoted by a CL for clear, SC for scattered, BK for broken, and OV for overcast. Under that line is the line for wind direction which is in degrees with the last 0 cut off. For instance at 11pm on May 8 (0300 UTC May 9), ETA MOS forecasts a wind direction of 250 degrees. Below that is the wind speed in knots. Next line shows the precipitation probablilities for the 6 hour periods like on the NGM MOS between 06-12 UTC or 2am-8am EST on May 9, there is an 11% chance of precipitation. Following that line is the probability for precipitation for the 12 hour period like on NGM MOS again from 00-12 UTC May 9 or 8pm-8am EST on May 8-9, there would be an 18% chance of precipitation for the period. What follows that line are the QPF or quantitative precipitation forecast for the 6 and 12 hour periods giving in categories from 0 to 5. Category 0 is for a trace or less of precip, category 1 is from .01 to .10 inch, category 2 is from .11 to .24 inch, category 3 is from .25 to .49 inch, category 4 is from .50 to .99 inch, and category 5 is from 1.00 inch and beyond. For the NGM the first half of the / is the 6 hour QPF with the other side being the 12 hour QPF. Under that for the NGM and AVN are the thunderstorm probabilities for 6 and 12 hours. The number in front of the / is the possibility of thunderstorms and that other number is the possibility that if there are thunderstorms they could turn severe like in the NGM for 00-12 UTC on May 10 there is a 52% chance of thunderstorms with a 41% chance of those storms becoming severe. The next lines for the AVN are the probability of frozen precipitation and probability of snow. Again, that doesn't mean those would be the actual chances of snow but if it were to precipitate, that would be the chances for snow or freezing precipitation. Same goes for the NGM but it is below the PTYPE which for both means precipitation type with R meaning rain, Z meaning freezing precipitation, RS meaning rain and snow, and S meaning snow. Ceiling, visibility, and obstruction to vision categories follow and those can be explained as well as the other things I mentioned on the NWS Website With the MRF, the concepts are the same. X/N though mean the day's high and low temperature. There are no conditional probabilities for severe thunderstorms just the possibilities that there will be thunderstorms. Big difference is, these numbers go out farther in time because the MRF is a long range model. So after explaining this all to you, based on these MOS, what would you forecast for May 9?
Model Forecasts So you want to try your hand at forecasting? Well here are some forecast models to start help you on your way: ETA Model
Forecast Preparation
Bruce Kalinowski is the chief meteorologist for WOIO/WUAB-TV Cleveland
The Craft Of Forecasts
IAZ063>068-076>078-090830-
CEDAR IA-CLINTON IA-IOWA IA-JOHNSON IA-KEOKUK IA-LOUISA IA-
MUSCATINE IA-SCOTT IA-WASHINGTON IA-
INCLUDING THE CITIES OF...BETTENDORF...DAVENPORT...CLINTON...
IOWA CITY...MARENGO...MUSCATINE...SIGOURNEY...TIPTON...WAPELLO...
WASHINGTON
1026 PM CDT SUN APR 8 2001
...TORNADO WATCH UNTIL 1 AM...
.OVERNIGHT...THUNDERSTORMS DEVELOPING...SOME MAY BE SEVERE WITH LARGE
HAIL AND DAMAGING WIND. LOW NEAR 50. SOUTH WIND AROUND 10 MPH. CHANCE
OF RAIN 80 PERCENT.
.MONDAY...MOSTLY CLOUDY WITH A CHANCE OF SHOWERS AND THUNDERSTORMS.
HIGH 70 TO 75. SOUTHWEST WIND AROUND 10 MPH BECOMING WEST. CHANCE
OF RAIN 40 PERCENT.
.MONDAY NIGHT...PARTLY CLOUDY WITH A CHANCE OF EVENING SHOWERS AND
THUNDERSTORMS. LOW IN THE MID 40S. WEST WIND 5 TO 10 MPH. CHANCE OF
RAIN 30 PERCENT.
.TUESDAY...PARTLY SUNNY. HIGH IN THE MID 60S.
.TUESDAY NIGHT...MOSTLY CLOUDY WITH THUNDERSTORMS LIKELY. HEAVY RAIN
POSSIBLE. LOW IN THE MID 40S. CHANCE OF RAIN 70 PERCENT.
.EXTENDED FORECAST...
.WEDNESDAY...SHOWERS AND THUNDERSTORMS LIKELY. HIGH IN THE LOWER 60S.
.THURSDAY...A CHANCE OF SHOWERS AND THUNDERSTORMS. LOW IN THE MID
40S. HIGH AROUND 60.
.FRIDAY...DRY. LOW IN THE MID 40S. HIGH AROUND 60.
.SATURDAY...A CHANCE OF SHOWERS. LOW AROUND 40. HIGH IN THE LOWER
60S.
.SUNDAY...A CHANCE OF SHOWERS. LOW AROUND 40. HIGH IN THE LOWER 60S.
$$
State abbreviation and zone numbers
County names with names of selected cities
Time and date of issuance
If there are any warnings, they'd be highlighted above the forecast
A 48 hour forecast followed by the extended forecast that goes out to 7 days
In the forecast in order of importance: significant weather, cloud cover, high or low temperature, wind forecast, probability of precipitation
Forecasts are issued by the National Weather Service in the early morning (2-5am), late morning/midday (9am-1pm), late afternoon (3-5pm), and in prime time (7-11pm). Forecasts are made later when there is significant weather (winter storms, severe weather, tropical weather) in the forecast or if it is imminent.
Forecast DiscussionsAREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
248 PM EDT SUN APR 8 2001
SEE LITTLE DAY TO DAY CHANGE OVER THE AREA THROUGH THE MIDDLE OF THE
UPCOMING WEEK. SURFACE HIGH PRESSURE AND RIDGING ALOFT SHOULD KEEP
BLOCKING ANY DISTURBANCES FROM MOVING INTO THE AREA. LATE TUESDAY
CLOUDS WILL INCREASE OVER THE AREA A BIT AS A QUASI-STATIONARY FRONT
GETS SUPPRESSED INTO THE MID-ATLANTIC AREA. HOWEVER DYNAMICS WITH
THE UPPER DISTURBANCE AND JET...ASSOCIATED WITH THIS FRONT STAY
NORTH OF THIS CWA. LAPS RATES GET FAIRLY GOOD FOR THUNDERSTORM
DEVELOPMENT ALSO LATE TUESDAY...BUT NO LOW LEVEL CONVERGENCE IS
SHOWING UP SO FAR TO GET ANYTHING GOING.
EARLY WEDNESDAY THE FRONT TO OUR NORTH LIFTS BACK NORTHWARD AS
ANOTHER STORMS DIGS INTO THE SOUTHWEST PART OF THE COUNTRY AND OUR
UPPER RIDGING AMPLIFIES. I WILL BUMP TEMPS OVER GUIDANCE FOR
WEDNESDAY AND THURSDAY...UP TO LEVELS SIMILAR TO WHAT WE HAVE
NOW...AS WE SHOULD CONTINUE IN THE WARM SECTOR. THE MRF AND LATEST
ECMWF HAVE COME INTO AGREEMENT WITH BRINGING A FRONT ACROSS ON
FRIDAY. I WILL INTRODUCE A CHANCE OF AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS FOR FRIDAY TO GO ALONG WITH THE FRONTAL PASSAGE.
FCSTID = 69
GSP 62 88 59 87 / 0 0 0 10
AND 62 88 59 87 / 0 0 0 10
CLT 62 88 59 87 / 0 0 0 10
HKY 60 87 60 87 / 5 0 0 20
AVL 54 83 56 83 / 0 0 10 20
.GSP...
GA...NONE.
NC...NONE.
SC...NONE.
RBN
Let me point out the basics. You see that it's an area forecast discussion issued from the forecast office that made the discussion with the date and time under it. This is something we forecasters enjoy reading. I mean you can put out a forecast, but what does it mean? It's technical for most of the general public with the way it's explained but a good meteorologist can decipher the language and make their own discussion. Just want to point out that spelling isn't exactly pertinent (e.g. laps when it should be lapse) because you're just trying to get the point across. Also, there are no commas in discussions just ... that replaces the comma. And finally, you can get a feel for what will be in the upcoming forecast (e.g. I WILL INTRODUCE A CHANCE OF AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS FOR FRIDAY TO GO ALONG WITH THE FRONTAL PASSAGE.). These discussions are written before the public forecast is made and can clue you in on upcoming watches, warnings, or advisories as well. You can see that at the bottom of the discussion if needed. What you also see at the bottom is the forecaster ID that made the discussion, and a table of cities in the county warning forecast area that has high and low temperatures out 48 hours and then the probability of precipitation for those times. Here's more:
FXUS62 KFFC 081910
AFDATL
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
310 PM EDT SUN APR 8 2001
OVERVIEW: OLD 30/60 DAY OSCILLATION FROM MID FEB TO ABT APR 1 HAS
BROKEN! NEW 30/60 DAY PATTERN APPEARS TO HAVE SET IN WITH NEW RIDGE
AT 40N AND 20W. TELECONNECTIONS SUPPORTS WEAK RIDGE TO REMAIN IN
PLACE IN SE WITH TROUGH FROM GREAT LAKES TO SOUTHWEST. ECWMF/UKMET
SUPPORT TELECONNECTIONS MORE WITH HOLDING MORE RIDGING ON INTO NEXT
WEEKEND IN SE WHILE MRF DOES ITS CHARACTERISTIC RIDGE BREAKDOWN TOO
FAST. THIS PATTERNS MEANS WARMER THAN NORMAL TEMPS AND BELOW NORMAL
RAINFALL FOR NEXT 7 DAYS.
SHORT TERM: HIGH PRESSURE WILL RULE FROM SFC TO ALOFT NEXT 2 DAYS.
RECORD HIGHS ARE 85 TO 90 FROM NORTH TO SOUTH. EXPECT TEMPS WILL
REMAIN BLO RECORDS...BUT TEMPS ABT 12 TO 16 ABV NORMAL SO IT WILL BE
UNSEASONABLY WARM. ETA/NGM/AVN/CANADIAN/UKMET ARE IN EXCELLENT
AGREEMENT THRU TUE. 850 TEMPS SUPPORTS HIGHS A FEW DEGREES BLO
GUIDANCE. ETA GRIDS ALSO SUPPORT THIS AND WILL TRIM TEMPS ABT A
CATEGORY. WHAT THIS MEANS IS AVN MOS LOOKS MUCH BETTER THAN NGM MOS
NEXT 2 DAYS AND WILL LEAN TOWARD IT. WETTER SOIL CONDITIONS AND
EVAPOTRANSPIRATION ARE SHOWING TREND OF KEEPING HIGHS SLIGHTLY
COOLER THAN GUIDANCE TOO. EXPECT MOSTLY CLEAR NIGHTS AND PARTLY
CLOUDY DAYS PER CU MACRO. SOME HAZE CAN ALSO BE EXPECTED. PRECIP
EFFICIENCY IS AT OR BLO 0.6 INCHES THRU 00Z WED SO IT SHOULD REMAIN
DRY.
EXTENDED: WE STAY IN WARM SECTOR WED SO WILL TREND FCST TOWARD A DRY
ONE. ANOTHER MAJOR STORM IN CENTRAL PLAINS TUE N AND WED WILL PUSH A
DYING FRONT TOWARD OUR AREA LATER THU INTO FRI WITH JUST A FEW
SHOWERS OR STORMS...20 OR 30 POP AT BEST. AFTER THIS FRONT
EXITS...EXPECT A MAINLY DRY AND MILD NEXT WEEKEND.
FCSTID = 14
ATL 61 83 63 84 / 0 10 0 10
AHN 60 86 60 86 / 0 10 0 10
GVL 60 83 61 84 / 0 10 0 10
RMG 57 84 57 84 / 0 10 0 10
CSG 61 86 62 87 / 0 10 0 10
MCN 59 86 59 87 / 0 10 0 10
.ATL...
GA...NONE.
NOEL
I love reading the Peachtree City discussion. They go into global processes, teleconnections in other words, that affects the weather not only there but through our country. Also, you see they go in order from short term to extended forecast discussions and end standard. Here's more:
FXUS62 KJAX 081809 AAA
AFDJAX
AREA FORECAST DISCUSSION...UPDATED FOR PRELIM NUMBERS
NATIONAL WEATHER SERVICE JACKSONVILLE FL
210 PM EDT SUN APR 08 2001
PUBLIC...LTST ETA BUFKIT SOUNDINGS SHOW DRY WX THRU 60 HRS WITH ONLY
.O1 SHOWING UP A JAX THIS EVE...WL WAIT UNTIL ISSUABCE TIME TO SEE
IF ANY PIN HEAD SHOWERS FORM AS SBRZS MEET OVR NRN FL. OTRW...MODELS
AGREE ON KICKING OUT CI TO THE E LATER TONIGHT WITH A RETURN TO SOME
CI ON TUE. WITH P TO M SUNNY SKIES ON MON SHUD SEE EVEN WARMER TEMPS
THAN TODAY. UPR 80S XPCTD ACRS INLD AREAS THRU SAT WITH A FEW 90 DEG
READING PSBL AS LLVL SW FLOW ACRS THE CWA DOMINATES. HV REMOVED 10%
POPS FM FCST ON MON AS NEW MESOETA SHOWS WEAKER CONV AND LESS PCPN
THAN TODAY. XTNDD...MANUAL PROGS STILL KEEP BACKDOOR COLD FRNT
STALLING TO THE N OF FA...MRF DRAGS BNDRY THRU SAT NGT WITH
"COOLER???" NW FLOW ON SUNDAY...MAYBE A FEW DEGS...BUT BNDRY LUKS
VERY WEAK AT THIS TIME AND TOO HARD TO PINPOINT WHICH DAY WILL HV
20% OF SHWRS AND AM LOATHE TO PUT A CHC IN FOR NXT SAT.
MARINE...MORE OF THE SAME SE TO SW FLUCTUATION XPCTD THRU THE WEEK
OF 10 TO 15 KNOTS AT THE MOST. AVN SEEMS A LTL TOO STRONG LATE
THU/FRI WITH THE APPCH OF FRNT FM THE NW AND THINK WE WL WAIT FOR
SOME MORE MODEL RUNS TO SEE IF SW FLOW MAY KICK UP CLOSE TO 20 KTS
FOR FRI.
FIRE WX...NO HEADLINES.
PRELIM
AMG 61/87/62/88 ----
SSI 63/83/64/83 0000
JAX 61/87/62/88 ----
GNV 60/87/61/88 ----
.JAX...
.GA...RIVER FLOOD WARNING FOR ALTAMAHA RIVER AT BAXLEY.
.FL...NONE.
PUBLIC/MARINE...HESS
AVIATION/FIRE WX...PETERSON
Now as you may see, some forecast areas have specific forecasts to make due to their location. I'm sure you know Jacksonville is on the Atlantic coast so they have to write a marine forecast for their coastal waters and since they've been in a severe drought, they have to write a fire weather forecast. As you see, the discussion was divided into the public and marine. Also, two different people wrote the discussion. What you also may see is that high use of abbreviations (e.g. LTST= latest, WX= weather, JAX= Jacksonville, WL= will, SBRZS= seabreeze, OVR= over, NRN= northern, OTRW= otherwise, CI= cirrus, E= east, P TO M= partly to mostly, SHUD= should, UPR= upper, XPCD= expected, ACRS= across, INLD= inland, DEG= degree, PSBL= possibly, LLVL= low level, HV= have, POPS= probability of precipitation, FM= from, FCST= forecast, CONV= convergence, PCPN= precipitation, XTNDD= extended, FRNT= front, FA= forecast area, BNDRY= boundary, LUKS= looks, NXT= next...etc) and that was just the first paragraph! Love the vernacular (e.g. "IF ANY PIN HEAD SHOWERS FORM") that are found in these discussions. Not like there's some official meteorological meaning for some of the stuff you may read, it's just added in there for entertainment value...for forecasters ya know. We're easily entertained. Here's more..
FXUS61 KAKQ 090316
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1115 PM EDT SUN APR 8 2001
THUNDERSTORMS HAVE HELD TOGETHER CROSSING NRN VA AND ARE NOW
APPRCHG LWR MD ERN SHORE. HAVE ALRDY ISSUED UPDATE TO RELFECT
THE CONVECTIVE ACTIVITY.
RCRD HIGH TEMPS
MON TUE
RIC 90/1959 88/1922
ORF 87/1959 87/1922
SBY 85/1959 91/1922
FCSTID = 44
.AKQ...
MD...NONE.
NC...NONE.
VA...NONE.
Now when record temperatures are in the offing, the forecast discussion will note that like Wakefield did above. They put the airport abbreviations and then the day with the record temperature and year next to it.
FXUS61 KPHI 081339 AAA
AFDPHI
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
938 AM EDT SUN APR 8 2001
ADDITIONAL UPDATE TO PUT THUNDER IN RMNDR OF SRN ZNS AS RADAR SHOWING
AREA CNVCTN MOVG INTO AND THRU AREA.
REST SAME AS B4... -JWH-
********************************************************************
WL UPDATE YET AGAIN TO ADD THUNDER TO NRN CSTL ZONES WHERE I THOUGHT
IT WOULD BE A BIT MORE STABLE...AND ALSO TO ADD CHC SHWRS TO SRN
AREAS WHERE ONLY SPKLS WAS MENTIONED.
REST AS FROM PREVIOUS...
******************************************************************
WL UPDATE ZONES TO INCLUDE A CHC OF A MRNG THUNDERSTORM TO ZONES FM
PHL/ILG AND N...EXCEPT NOT FOR CSTL ZONES WHERE PBLY MORE STABLE.
SCT RW/TRW ACTIVITY OVR CNTRL AND NERN PA IS STARTING TO INITIATE
OVR SWRN PA...AND WUD XPCT THIS ACTIVITY TO DMSH DURG MRNG AS APRNT
UPPER S/WV MOVS PAST.
REST FM PREVIOUS...
*******************************************************************
NOT A HIGH CONFIDENCE FORECAST...SO WILL KEEP THE DISCUSSION SIMPLE.
AM HANGING THE TEMPERATURE FORECAST LARGELY ON THE SFC BASED LI
FIELDS FROM THE ETA AND TO A LESSER EXTENT THE AVN. THE INDICATION
THAT STABLE AIR WILL HOLD IN ALL BUT THE FAR SRN ZONES TODAY IS ALSO
SUPPORTED BY NO MORE THAN MODERATE FLOW ABOVE THE SFC MUCH OF THE
DAY AND THE BAGGINESS IN THE SFC PRESSURE FIELD THAT MOVES OFF THE
COAST AND E OF THE FA. THE FORMER INDICATES SCOURING OF THE STABLE
AIR WILL BE TOUGH...AND THE LATTER HINTS AT SOME BRIEF REINFORCEMENT
OF THE STABLE AIR.
******* UPDATED...MEANWHILE AT MID LEVEL THE RIDGE AXIS PASSED TO
OUR E TONIGHT...AND AN IMPULSE MOVING INTO IT IS TRIGGERING SHOWERS
AND EVEN THUNDERSTORMS IN THE VICINITY OF THE SFC FRONT TO OUR W.
SINCE EXPECT US TO STAY STABLE TODAY...DONT ANTICIPATE ANY NASTY
WEATHER. HOWEVER GIVEN ACTIVITY TO THE W HAVE DECIDED TO BRING
SHOWERS FURTHER S THAN PREV THOUGHT. DOWN FAR S...STILL THINKING
SOME ISENT LIFT OVER THE STABLE AIR THIS AM TO CAUSE SOME
SPRINKLES. *******
TONIGHT WILL FORECAST THE STABLE AIR TO FINALLY GIVE IT UP OVER FA.
IF IT HAPPENS...IT WILL ALLOW SKIES TO BREAK. UNFORTUNATELY...THE
BAROCLINIC ZONE DOESNT APPEAR TO MAKE IT VERY FAR N BEFORE ANOTHER
IMPULSE PERHAPS MOVES ALONG IT AND FORCES IT BACK DOWN INTO FA...
HENCE THE LATE DAY THIRD PD POPS CENTRAL AND N AND THE CHC ALL ZONES
FOURTH PD. WITH CAPES AND LIS INDICATING INSTABILITY ON THE WARM
SIDE OF THE FRONT...FELT IT WORTH MENTIONING THUNDER.
IF THE ABOVE SCENARIO IS CORRECT...THEN FCST MAX TEMPS TODAY IN THE
STABLE AIR ARE LIKELY TOO HIGH...BUT WITH A LACK OF CONFIDENCE FELT
SOME SEMBLANCE OF CONTINUITY WAS CALLED FOR. HAVE ALREADY CUT
GUIDANCE QUITE A BIT EXCEPT FAR S. TONIGHT TEMPS MAY ACTUALLY RISE
OVER PORTIONS OF FA. AGAIN...NOT CONFIDENT ENOUGH TO PUT IN SUCH
DETAIL. TMRW AND TMRW NITE HOPEFULLY THE STAT GUIDANCE HAS US IN THE
RIGHT AIR MASS AND IT WAS GENERALLY ACCEPTED.
ON THE MARINE...SCA CONT ON OCEAN FNT FOR SEAS. ALSO CONTINUE THE
MENTION OF MINOR TIDAL FLOODING.
.PHI...
DE...SML CRFT ADVSRY ALNG ATLC CST. MINOR TIDAL FLOODING COAST AND
DE BAY.
MD...NONE.
NJ...SML CRFT ADVSRY ALNG ATLC CST. MINOR TIDAL FLOODING COAST AND
DE BAY.
PA...NONE.
MPD
Now this office, Mount Holly, does a lot of updating. I was reading one day where they didn't expect any kind of severe weather, and they updated an hour later saying the same, then the next hour they changed their tune. So as you see, updates are common from this office and sometimes you'll see the update followed by text from the previous discussion just to put some background on the update.
FXUS61 KBOX 090035
AFDBOX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
835 PM EDT SUN APR 8 2001
...LOOKS LIKE A ONE DAY SHOT OF SPRING WARMTH MONDAY...
HI LO LVL RH MAY CAUSE ST TO REFORM AFT CLRG ATTEMPT. REAL CLRG
MAY NOT TAKE PLACE UNTIL COMB SUN AND OFFSHORE FLOW MON MRNG. WILL
ADJUST WORDING A LTL IN ZFP TO REFLECT THIS. OCCLUSION XPCTD TO
PASS THRU CWA BTWN 09Z AND 12Z.
SLGT RISK OF ONSHORE FLOW DVLPG LATE IN DAY MA E CSTL ZNS.
EVEN SO...CONCUR WITH PREV FCST OF HI IN LO 60S WITH THINKING THAT
CAN GET THAT HI ON NW FLOW BFR PSBL SWITCH TO NE LATE IN DAY.
NE ONSHORE FLOW TUE LKLY TO RESULT IN RETURN OF VRY COOL AIR...
SPCLY E CSTL SXNS. INCLINED TO INDCT 45 TO 50 COAST AND NR 50
INLAND...AND EVEN THAT CUD BE OPTIMISTIC. ALTHO WED CUD FEATURE
PLENTY OF SUNSHINE...NE FLOW ABT 1033MB SFC HI DEPICTED ON AVN AND
H85 TEMPS ARND 0C SUG MIGHT BE A STRUGGLE TO GET ABV 50...SPCLY ALG
COAST.
HYDRO...CONCORD RVR REMAINS JUST ABV FLD STAGE AND EVER SO SLOWLY
RECEDING. WILL UPDATE FLS SHORTLY AFT RCV NERFC GUID. SNOMELT A
CONCERN FOR SMALL BASINS IN NRN MA AND SW NH...AND EVENTUALLY FOR
MAIN STEM CT AND MERR RVRS. MAY SEE MINOR TO MDT RISES WITH MILD
TEMPS MON...BUT MON NGT AND TUE COOL DOWN PRBLY ENUF TO SLOW DOWN
RUNOFF AND PREVENT STREAMS RCHG FLD STAGE. AVN AND ECMWF MODELS INDCT
POT WARM WET EVENT AT END OF WEEK WITH GLF OF MEX BEING TAPPED. SUCH
A PTRN CUD BE PROBLEMATIC FOR SOME TRIBS AND MAINSTEM CT/MERR RVRS
WITH BASE FLOWS HI FM SNOWMELT.
MARINE...WILL KEEP SCA FOR SEAS OUTER CSTL WATERS.
.BOX...FLOOD WRNG FOR CONCORD RVR IN ERN MA.
SCA FOR SEAS OUTER CSTL WATERS.
THOMPSON
Taunton was very high on the snowstorm that was suppose to rival the Blizzard of 78. Their discussions were very enjoyable to read and they gave a plethra of information. In this discussion, you notice a headline which many offices do just to show what the main weather event will be through the forecast period (e.g. ...LOOKS LIKE A ONE DAY SHOT OF SPRING WARMTH MONDAY...). Also, you scroll down and see the HYDRO, well they've had snowmelt at the time and rivers have been swollen in the area. So they highlight that discussion.
FXUS64 KEWX 090144
AFDSAT
SOUTH CENTRAL TEXAS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
844 PM CDT SUN APR 8 2001
SURFACE ANALYSIS AND VAD WINDS CONTINUES SOUTHEASTERLY LOWER LEVEL
FLOW. 00Z SOUNDINGS INDICATE MOISTURE DEPTH RANGING FROM 950 MB AT
CRP TO 850 MB AT DRT...DUE GOING AWAY FROM SUBSIDENCE UNDER UPPER
RIDGE OVER THE GULF OF MEXICO. SATELLITE IMAGERY SHOWS WEAK PLUME OF
UPPER LEVEL MOISTURE STREAMING FROM NEAR THE ITCZ IN THE TROPICAL
PACIFIC TO OVER THE SOUTHERN STATES BETWEEN UPPER TROUGH OFF THE
WEST COAST AND THE ABOVE MENTIONED UPPER RIDGE. NOT MUCH CHANGE
FROM 24 HOURS AGO. CURRENT FORECAST HAS GOOD HANDLE ON SITUATION...
SO ONLY CHANGES WOULD BE REFLECT CURRENT TRENDS ALREADY MENTIONED IN
ZONES. OF NOTE IS THE TUTT LOW NEAR HONDURAS...THE ECMWF KEEPS IT
QUASI-STATIONARY THROUGH MUCH OF MEDIUM RANGE PERIOD SIMILAR TO ALL
OF THE OTHER MODELS...HOWEVER BY SUNDAY...IT DIFFERS BY ROTATING IT
AROUND THE UPPER RIDGE AND INTO THE SOUTHWESTERN GULF OF MEXICO.
COULD TROPICAL SEASON BE FAR BEHIND? 04/06
.EWX...NONE.
Ok, a couple of things. A Tutt low is a low pressure center that forms on the Intertropical convergence zone (ITCZ) from lower atmospheric pressure over the warm ocean waters. They cut off from the mid-latitude flow and become their own entity mainly from the mid and upper levels. They can start up tropical development or develop on their own. You don't see them normally until summer. But very interesting to note that in the Austin, TX discussion. I always learn some kind of new terminology when I read these discussions. Just when you think you know everything, you run across something else. Very cool for us forecasters.
FXUS64 KFWD 082308 AMD
AFDFTW
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE FORT WORTH TX
605 PM CDT SUN APR 8 2001
...AVIATION DISCUSSION...
BOTH THE ETA AND THE AVN DECREASE THE 925 MB TO 850 MB LAYER
RELATIVE HUMIDITIES A BIT TONIGHT AND EARLY MONDAY...OVER LAST
NIGHT. UPSTREAM SOUNDINGS SUGGESTS THAT THIS MAY VERIFY. THUS...WE
WILL CARRY MVFR CEILINGS...BUT WITH BROKEN TO SCATTERED CONDITIONS
...RATHER THAN OVERCAST. WILL ALSO DECREASE THE STRATUS A BIT AFTER
SUNRISE. CONDITIONS SHOULD REMAIN CAPPED THROUGH MONDAY...WITH NO
CHANCE FOR THUNDERSTORMS.
26
...WINDS INCREASING TO ADVISORY CRITERIA OVER CENTRAL AND WESTERN
ZONES. WILL ISSUE ADVISORY THROUGH THIS EVENING...AND CONTINUE WITH
CAUTION ON LAKES OVER EASTERN ZONES...
BRISK SOUTHERLY SURFACE FLOW CONTINUES ACROSS AREA. HEATING/MIXING
HAS SCATTERED OUT LOW CLOUDS OVER ALL BUT EXTREME EASTERN AND
NORTHWESTERN ZONES.
LARGE-SCALE EVOLUTION OVER NEXT 48 HOURS TAKES UPPER SYSTEM OVER
WASHINGTON SOUTHWARD THEN EASTWARD ACROSS CALIFORNIA AND ARIZONA.
NORTH TEXAS TO REMAIN IN BROAD SWLY FLOW ALOFT THROUGH MONDAY NIGHT.
IN THE SHORT TERM...PERSISTENCE LOOKS GOOD TONIGHT THROUGH MONDAY
NIGHT. WITH CONTINUED SOUTHERLY SURFACE FLOW...EXPECT LOW CLOUDS TO
RETURN IN THE LATE NIGHT HOURS AND ERODE DURING THE DAY. TEMPERATURE
RANGE SHOULD BE SIMILAR TO PAST FEW DAYS AND WINDS SHOULD REACH THE
15-25 MPH RANGE AGAIN MONDAY.
BY TUESDAY...UPPER SYSTEM BEGINS LIFTING OUT INTO CENTRAL PLAINS.
BEST UPPER SUPPORT SHOULD REMAIN NORTHWEST OF AREA. BUT...WE SHOULD
HAVE ENOUGH SUPPORT AND COOL ENOUGH 700MB TEMPS TO INTRODUCE SLIGHT
CHANCE POPS FOR WEST ZONES TUESDAY NIGHT AND CHANCE AREAWIDE ON
WEDNESDAY. IF AVN RUN PANS OUT...WEDNESDAY-FRIDAY COULD BE AN
ACTIVE TIME IN NORTH TX. DRYLINE SWEEPS ACROSS AREA WEDNESDAY THEN
RETREATS BACK WEST THURSDAY AND FRIDAY. WILL HANG ON TO CHANCE POPS
EAST ON THURSDAY...AND CENTRAL AND EAST ON FRIDAY. PATTERN BECOMES
MORE ZONAL BY SATURDAY SO WILL GO PARTLY CLOUDY FOR SATURDAY AND
SUNDAY.
06
PRELIM NUMBERS...
DFW 69/85/68/84 0011 ACT 69/85/69/85 0011
.FWD...WIND ADVISORY WEST OF A BONHAM-CENTERVILLE LINE THIS EVENING.
CAUTION ON AREA LAKES REMAINDER OF AREA THIS EVENING.
This type of discussion is especially important in areas where the airline industry is big, like Dallas. They have one of the biggest airports in the world, I think they have something like 10 runways. So they make the aviation discussion which I think should be standard in areas where aviation is big (ex. Chicago, Atlanta, New York).
FXUS63 KDVN 081930
AFDMLI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
230 PM CDT SUN APR 8 2001
JULY MCS ACTIVITY IN EARLY APRIL...WHAT WILL THE SUMMER BRING? ACTIVE
WEATHER PATTERN THIS WEEK WITH LONGWAVE TROF ON THE WEST COAST
GIVING SOUTHWEST FLOW ACROSS THE CWA. MODELS SHOW NUMEROUS WAVES
MOVING IN THE FLOW ALOFT TO ALLOW MCS ACTIVITY. FIRST EVENT TO BE
TONIGHT INTO WED AM. ATMOSPHERE DESTABILIZING AND INITIATION SHOULD
OCCUR VICINITY OF KSTJ WITHIN AN HOUR OR TWO. STRONG LLJ BRINGING
PLENTY OF MOISTURE NORTHWARD SO HEAVY RAIN A THREAT. MOST OF SEVERE
SHOULD BE BEFORE IT REACHES OUR CWA BUT 925 MB SHOWS 40 KNOTS ACROSS
THE SOUTHERN HALF AT 06Z...SO SEVERE POTENTIAL STILL POSSIBLE
TONIGHT. MCS TO DEPART AREA WED AM ALLOWING FOR A BRIEF RESPITE.
MODELS THEN UNCERTAIN ABOUT POTENTIAL ROUND 2 LATE MONDAY
AFTERNOON/NIGHT. ATMOSPHERE SHOULD BE PRIMED FOR DEVELOPMENT SO WILL
INCLUDE POPS.
MAIN EVENT TO BE TUESDAY NIGHT/WEDNESDAY WITH A SIGNIFICANT WAVE
PULLING OUT THE OF LONGWAVE TROF. AVN HAS STRONG LLJ BRINGING
PLENTY OF MOISTURE NORTHWARD. IF AVN IS CORRECT...HEAVIEST RAIN TO BE
ACROSS CENTRAL/SOUTHERN IOWA. EITHER WAY...HEAVY PRECIP IS VERY
POSSIBLE HEAR.
EXTENDED WISE...ACTIVE PATTERN TO CONTINUE WITH TIMING OF EVENTS
THE PROBLEM. AVN CONTINUES TO INDICATE A DRY PUNCH TO HIT US
THURSDAY WITH POTENTIAL FOR WINDY CONDITIONS. FRIDAY LOOKS LIKE THE
BEST DAY FOR DRY CONDITIONS BEFORE THE WEEKEND TURNS ACTIVE AGAIN.
GUIDANCE WISE...FWC/FAN/MAV SHOWING THEIR NORMAL SPREAD THROUGH THE
PERIOD.
COORDINATED WITH DSM..LSE...CHI...ILX...AND STL.
.DVN...
IA...NONE.
IL...NONE.
MO...NONE.
SCHULTZ
When there's a big weather event occuring over a region, the forecast offices coordinate with each other. The coordination is important for continuity in forecasts and any advisories as well as learning the philsophy of the forecasters for the given situation. These coordination calls can last awhile and as you see they've gotten such offices like Des Moines, Chicago, and St. Louis involved in that previous discussion.
FXUS66 KSGX 082122
AFDSAN
EXTREME SOUTHWESTERN CALIFORNIA AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN DIEGO CA
230 PM PDT SUN APR 8 2001
...SYNOPSIS...
PARTLY TO MOSTLY CLOUDY CONDITIONS WILL PREVAIL THIS EVENING. ANOTHER
COLD FRONT WILL MOVE SOUTH FROM THE GULF OF ALASKA INTO SOUTHERN
CALIFORNIA LATE TONIGHT AND CONTINUE INTO TUESDAY MORNING. SHOWERS AND
THUNDERSTORM...ALONG WITH HAIL...CAN BE EXPECTED ON MONDAY AND MONDAY
NIGHT. THE SHOWERS AND THUNDERSTORMS SHOULD LINGER INTO TUESDAY
MORNING...BEFORE GIVING WAY TO PARTLY CLOUDY SKIES BY TUESDAY AFTERNOON.
VARIABLE CLOUDS ARE EXPECTED WEDNESDAY THROUGH THURSDAY.
...DISCUSSION...
A DEEP MOIST LAYER IS STILL PRODUCING PUFFY CU OVER THE AREA...AND
SHOULD BE THE CASE TIL THE SUN GOES DOWN AND DIURNAL HEATING ENDS. THE
NEXT IN A SERIES OF GULF OF ALASKA SYSTEMS WILL MOVE IN LATE TONIGHT
INTO TUESDAY. NGM AND AVN MOS ARE GENERALLY IN THE CHANCE
CATEGORY...BUT WITH ALL THE MOISTURE AND DYNAMIC FEATURES COMING
TOGETHER...WE WILL GO AT LEAST LIKELY POPS WEST OF THE MOUNTAINS...AND
CHANCE POPS IN THE DESERTS. WITH THE FREEZING LEVEL SO LOW...AROUND 3000
FT...WE WILL POPULATE THE ZONE FORECASTS WITH HAIL. QUICKSCAT SATELLITE
WINDS SHOW WINDS BETWEEN 25 AND 30 KNOTS WITH THE FRONT...SO WE WILL GET
A BLUSTERY AND VIGOROUS EPISODE OF SHOWERS AND THUNDERSTORMS...WITH
MOUNTAIN SNOWS WITH THE FRONT. BEHIND THE FRONT THE LOW LEVEL
TRAJECTORY AND MOISTURE PROFILES SHOULD BE FAVORABLE FOR ISLAND EFFECT
SHOWERS AND THUNDERSTORMS IN THE CONVERGENCE ZONES DOWNWIND FROM THE
ISLANDS...ALONG WITH PLENTY OF OROGRAPHIC SHOWERS IN THE HIGHER TERRAIN.
WOULD NOT BE TOO SURPRISED TO SEE FUNNEL CLOUD...WATERSPOUT... OR BRIEF
TORDADO WITH THIS PATTERN. ALTHOUGH PATTERN IS NOT PERFECT...IT IS STILL
POSSIBLE.
FIRST STAB ESTIMATES FOR RAINFALL TOTALS THROUGH TUESDAY ARE 0.10 TO
0.25 COASTAL AREAS...AND 0.25 TO 0.50 MOUNTAINS...BUT AMOUNTS WILL BE
HIGHLY VARIABLE SINCE IT WILL BE VERY CONVECTIVELY UNSTABLE. AS FOR
SNOW...UP TO ABOUT 4 INCHES FOR THE ENTIRE STORM IN THE SNOWIEST
LOCATIONS LOOKS REASONABLE.
THE STORM LIFTS RAPIDLY OUT BY TUESDAY MIDDAY TO GIVE US SOME WARMING
AND CLEARING. THE NEXT IN A SERIES OF WEAK WAVES CAN BE SEEN ON THE MRF
AND ECMWF FOR LATE WEDNESDAY OR THURSDAY. WILL GO PARTLY CLOUDY FOR
NOW...BUT LATER SHIFTS MAY HAVE TO INTRODUCE PRECIPITATION AS THE
COASTAL MARINE LAYER SHOULD BE RATHER DEEP WITH THIS WAVE.
BY FRIDAY I AM STILL THINKING THAT WE SHOULD BE SETTLING INTO A NIGHT
AND MORNING LOW CLOUDS AND FOG WITH AFTERNOON SUN TYPE OF PATTERN...
WHICH SHOULD CONTINUE INTO THE WEEKEND.
SAN 2752
.SAN...NONE.
SMALL
They start with what's going on now, what has been going on with their synopsis and then go into the formal discussion. Forecast discussions start with that usually but they aren't highlighted like San Diego's.
My Forecast Discussions Over The Years
"PARTIAL THICKNESSES AND MODEL SOUNDINGS GENERALLY SUPPORT ALL SNOW OVER THE NC MTNS."
VARYING AMOUNTS OF CLOUDINESS TODAY WITH TEMPERATURES
COOLER THAN THEY HAVE BEEN WITH
HIGHS ONLY IN THE UPPER 40S. A NICE WEEKEND IS ON TAP
WITH A WARMING TREND NOTED AS WE
GO INTO THE FIRST PART OF NEXT WEEK AS HIGH PRESSURE
BUILDS IN. LOW OFF THE SOUTH
ATLANTIC COAST THAT WILL DEVELOP WON'T BOTHER US THIS
FAR NORTH AND WEST. CHANGES ARE
COMING TO OUR WEATHER. WE'VE SKATED BY WITH ABOVE
NORMAL TEMPERATURES ALL WINTER LONG
IT SEEMS THAT BY THE TIME WE GET INTO MET. SPRING WE
SHOULD BE IN THE DEEP FREEZE. IN
FACT THE NEXT 14 DAYS HAS TEMPERATURES MUCH BELOW
NORMAL AND PRECIPITATION MUCH ABOVE
NORMAL AND THE COMBINATION OF THE TWO EVEN IN MARCH
CAN PROVIDE SOME FREEZING AND
FROZEN PRECIPITATION. SO WITH THAT IN MIND THE
SIBERIAN EXPRESS SHOULD START ROLLING IN
LONG ABOUT TUESDAY WITH A POWERFUL COLD FRONT THAT
WILL KEEP US EXTREMELY COLD FOR ALL
OF NEXT WEEK. SHOWERS ASSOCIATED WITH IT MOVE IN EARLY
TUESDAY THEN CHANGES TO SNOW
BEFORE ENDING DURING THE DAY. IT WILL ALSO BE WINDY
AND COLD SO BUNDLE UP. WE'LL KEEP
THE CHANCE FOR SNOW SHOWERS GOING INTO WEDNESDAY BUT
THAT'S BEYOND MY FORECAST SCOPE.
AND A WEEK FROM NOW WE COULD BE DEALING WITH A
SIGNIFICANT EAST COAST WINTER STORM WITH
THE VERY COLD AIR ALREADY IN PLACE. STAY TUNED ALL
NEXT WEEK AS WINTER STRIKES BACK.
ENJOY THIS WEEKEND ITS GOING TO BE A NICE ONE.
Forecasting With MOS
KAVL AVN MOS GUIDANCE 5/08/2002 1200 UTC
DT /MAY 8/MAY 9 /MAY 10 /MAY 11
HR 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00 06 12
N/X 60 84 60 76 54
TMP 82 83 76 69 65 63 63 75 81 79 74 66 63 62 61 67 73 74 68 58 56
DPT 62 61 63 62 61 60 60 61 60 60 60 60 60 59 58 55 52 52 54 55 54
CLD BK SC SC SC SC SC BK SC BK OV OV OV OV OV OV BK SC BK SC SC BK
WDR 20 20 19 18 18 17 27 19 22 27 30 32 34 34 35 36 35 35 34 30 14
WSP 07 09 06 01 01 02 03 09 15 12 09 07 05 06 08 08 07 10 09 01 01
P06 8 9 3 4 24 33 27 15 15 14 9
P12 13 24 45 24 15
Q06 0 0 0 0 0 0 0 0 0 0 0
Q12 0 0 1 0 0
T06 11/ 5 4/ 3 12/ 1 9/ 6 19/11 16/ 3 17/ 0 12/ 4 19/ 6 8/ 0
T12 11/ 7 14/ 6 29/11 18/ 4 23/ 8
POZ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
POS 3 4 4 4 4 4 3 3 3 3 3 1 4 0 1 1 3 2 1 1 1
TYP R R R R R R R R R R R R R R R R R R R R R
CIG 7 7 7 7 7 7 7 7 7 7 6 6 5 5 5 7 7 7 7 7 7
VIS 7 7 7 7 7 7 7 7 7 7 7 7 7 6 6 7 7 7 7 7 7
OBV N N N N N N N N N N N N HZ BR BR N N N N N N
KAVL ETA MOS GUIDANCE 5/08/2002 1200 UTC
DT /MAY 8/MAY 9 /MAY 10 /
HR 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00
N/X 59 81 60 75
TMP 82 82 77 68 64 61 62 74 78 78 74 67 64 62 62 69 72 72 67
DPT 63 62 62 62 61 59 59 60 58 59 59 61 60 59 59 58 56 55 55
CLD BK BK BK CL CL SC BK BK BK BK OV OV BK BK BK BK BK BK BK
WDR 19 20 20 25 00 00 18 22 21 25 31 32 33 34 34 35 36 35 32
WSP 08 11 07 03 00 00 01 07 10 10 10 05 04 05 05 08 11 11 09
P06 3 7 11 17 31 13 14 21 41
P12 16 33 19 44
Q06 0 0 0 0 0 0 0 0 1
Q12 0 0 0 1
AVL ES NGM MOS GUIDANCE 5/08/02 1200 UTC
DAY /MAY 8 /MAY 9 /MAY 10 /
HOUR 18 21 00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00
MN/MX 59 83 58 76
TEMP 73 75 71 66 63 61 62 72 79 79 73 65 62 60 60 68 73 72 66
DEWPT 64 64 63 62 60 59 59 60 58 57 57 57 56 55 55 55 51 51 51
CLDS BK BK BK SC SC SC BK BK BK OV OV OV OV OV OV BK BK SC SC
WDIR 19 19 20 17 17 18 18 23 27 28 32 33 33 34 34 34 35 33 34
WSPD 07 09 09 05 05 04 05 11 13 13 11 08 06 07 06 08 10 13 13
POP06 20 13 11 20 28 38 29 16 29
POP12 18 37 47 37
QPF 0/ 0/ 0/0 0/ 0/0 1/ 1/2 0/ 0/1
TSV06 60/28 37/10 24/ 8 30/ 6 37/38 33/ 6 29/ 0 19/ 0 32/19
TSV12 63/31 44/12 52/41 40/ 0
PTYPE R R R R R R R R R R R R R R R
POZP 1 0 1 0 0 0 0 0 0 0 0 0 0 1 0
POSN 2 1 0 0 0 0 2 0 0 0 0 0 0 0 0
SNOW 0/ 0/ 0/0 0/ 0/0 0/ 0/0 0/ 0/0
CIG 7 7 7 7 7 7 5 5 7 6 6 5 5
VIS 5 5 5 5 3 3 4 5 5 5 5 3 2
OBVIS N N N N F F F N N N N F F
KAVL MRF MOS GUIDANCE 5/08/2002 0000 UTC
FHR 24| 36 48| 60 72| 84 96|108 120|132 144|156 168|180 192
WED 08| THU 09| FRI 10| SAT 11| SUN 12| MON 13| TUE 14| WED 15 CLIMO
X/N 84| 60 83| 57 76| 53 73| 57 80| 58 76| 52 71| 46 72
TMP 75| 63 75| 60 68| 56 67| 60 72| 61 68| 56 65| 50 65
DPT 63| 61 60| 57 58| 53 56| 57 58| 58 57| 52 49| 46 48
CLD PC| PC PC| OV OV| OV OV| OV OV| OV OV| OV PC| CL OV
P12 23| 11 22| 38 48| 34 44| 37 41| 32 33| 23 16| 12 21
P24 | 24| 62| 54| 65| 51| 34| 32
Q12 0| 0 0| 1 1| 0 2| 1 2| 0 1| 0 |
Q24 | 0| 3| 2| 3| 3| |
T12 19| 4 26| 21 32| 13 33| 21 33| 15 28| 14 8| 6 12
T24 | 20 | 49 | 34 | 48 | 39 | 39 | 13
PZP 0| 0 0| 0 0| 0 0| 0 0| 0 0| 0 0| 0 0
PSN 0| 0 0| 0 0| 0 0| 0 0| 0 0| 1 0| 0 0
PRS 0| 0 0| 0 0| 0 0| 0 0| 0 0| 1 0| 0 1
TYP R| R R| R R| R R| R R| R R| R R| R R
MESO ETA Model
NGM Model
AVN Model
RUC Model
ECMWF Model
MRF Model
MOS Guidance
ARPS Model
WRF Model
LAMPS Model
Marcus Smith
