FXUS61 KCTP 190052 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 850 PM EDT SAT AUG 18 2001 GOING FCST LOOKS OK. I WAS THINKING AT FIRST THAT A DRY SLOT WOULD WORK ITS WAY INTO OUR AREA AND WE WOULD CLEAR FOR A WHILE OVNT. THAT DOES NOT APPR LIKELY AT THIS TIME. CLDS ARE BLOSSOMING N FROM VA AND WV AND WITH A LIGHT S FLOW DEVELOPING AHEAD OF THE MIDWEST SYSTEM... LO LVL MOISTURE WILL MOVE IN OVNT AS WELL. THIS WILL DEVELOP INTO A LO BKN-OVC AS THE NIGHT WEARS ON. SO THE CLOUD COVER FORECAST LOOKS OK. ACTUAL COVERAGE OF SHRAS MAY BE A BIT LESS THAN WHAT IS CURRENTLY ADVERTISED BUT THE CHC IS THERE AND WITH INCREASING MOISTURE AND 500 MB HGTS FALLING SLIGHTLY AGAIN AFTER 06Z...THE SHRA CHC SHD REMAIN EVEN AFTER MIDNT. I AM SOMEWHAT CONCERNED THAT THE SQUALL LINE MOVG INTO OH MAY REACH OUR WESTERN COUNTIES B4 DAYBREAK. PURE EXTRAPOLATION PUTS IT ONTO THE PA/OH BORDER AROUND 06Z AND TO THE ALLEGHENY FRONT BETWEEN 09 AND 10Z. THE TSRAS WILL PROBABLY WEAKEN B4 THE SQUALL LINE ENTERS PA. THERE ARE SLIGHTLY LOWER DEWPTS OVR WESTERN PA. USUALLY MOISTURE SURGES UP TO KPIT QUICKLY BUT THE FLOW IS DOWNSLOPE OFF THE WV MTNS AND THIS MAY BE CAUSING THE DRYING. I JUST TALKED TO JOHN AT SPC AND HE AGREES THAT THE STORMS WILL WEAKEN AND MAY ALREADY BE. THERE IS A SHARP INSTABILITY GRADIENT ACROSS OH. STABLE AIR OVER THE EAST...UNSTABLE AIR TO THE WEST. THE STORMS ARE JUST ENTERING THIS GRADIENT. SPC BELIEVES THAT OUR SHOW WILL COME FROM SOMETHING HOMEGROWN TOMORROW AND NOT LEFT OVERS FROM TONITE'S ACTIVITY. MY CONCERN IS HEATING FOR TOMORROW. THE CLD COVER COMING UP FROM THE S AND THE DYING CONVECTION TO OUR W WILL PROVIDE 2 SOURCES FOR MID AND HI LVL CLD THAT MAY INHIBIT CONVECTION. IF THE SUN DOES BREAK THROUGH WE COULD HAVE A VERY BUSY AFTN. I WROTE ALL THIS TO SAY NO UPDATE IS NECESSARY AND THERE WILL BE NONE FORTHCOMING UNLESS CONDITIONS CHANGE. .CTP...NONE. HEAD
FXUS61 KCTP 190658 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 255 AM EDT SUN AUG 19 2001 IR IMAGERY SHOWING UPPER LOW NEAR CHICAGO EARLY THIS MORNING AND SLOWLY TRACKING EASTWARD. ALTHOUGH MUCH OF THE CONVECTION HAS DIED OUT WITH THIS SYSTEM...EXPECT SHOWERS AND STORMS TO FILL IN THIS AFTN IN THTE TONGUE AHEAD OF UPPER LOW. LATEST MODEL GUIDANCE ONLY MOVES THIS SYSTEM ABOUT 200 MILES EASTWARD TODAY...THUS BULK OF SHOWERS/STORMS SHOULD REMAIN OVER WESTERN PA THIS AFTN...LEAVING MUCH OF EASTERN PA DRY. WILL CARRY ONLY CHC POPS ACROSS EASTERN ZONES AS PARTLY SUNNY SKIES SHOULD DESTABILIZE ATMOS ENOUGH FOR THE POSSIBILITY OF A FEW LATE DAY STORMS. STRONG SPEED AND DIRECTIONAL WIND SHEAR SUGGEST THAT ANY STORMS THAT DO FORM ACROSS CENTRAL PA COULD BECOME SEVERE (5H FLOW PROGGED AT 50KTS). 00Z ETA ALSO SHOWS A HIGH MICROBURST POTENTIAL THIS AFTN WITH A SFC-600MB THTE DIFF OF AROUND 20C. SHOWERS/STORMS SHOULD END FROM WEST TO EAST TONIGHT AS COLD FRONT/OCCLUDED FRONT MOVES THROUGH. MODELS NOW SUGGEST THAT A WAVE FORMS ON THE FRONT...SLOWING ITS PROGRESS OVER EASTERN PA. THUS WILL KEEP CHC POPS GOING INTO PART OF THE DAY ON MONDAY. DRY SLOT SHOULD EVENTUALLY WORK INTO THE REGION HOWEVER...BRINGING AT LEAST PARTLY SUNNY SKIES BY AFTN. SLOW MOVING UPPER LO PROGGED TO GRADUALLY WEAKEN AND LIFT NORTH OF THE AREA BY LATE TUESDAY. HOWEVER...MOSTLY CLOUDY SKIES AND SCT SHOWERS WILL REMAIN IN THE FCST FOR THE NORTHERN MTNS THROUGH TUES AFTN. .CTP...SPS FOR SLIGHT RISK SEVERE. FITZGERALD
FXUS61 KCTP 191352 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 950 AM EDT SUN AUG 19 2001 FOG HANGING TOUGH IN WEST BRANCH...BUT FINALLY GIVING UP THE GHOST ATTM. WL THEREFORE NEED TO UPD IN A FEW ZNS AND WL ALSO TWEAK CLD CVR WORDING MOST ZNS. ONTO BIGGER AND MORE IMPORTANT THINGS... LOOKING MIGHTY UNSTABLE AND THEREFORE INTERESTING FOR THIS AFTN AND EVENING...AS SPC INCREASING RHETORIC FOR WRN PA. ALL SVR INDICATORS MAKE IT SEEM LIKE IT WL BE A VERY ACTIVE DAY ACRS REGION. WL ADD SOME HEIGHTENED WORDING FOR WIND GUSTS AND LG HAIL TO WRN AND CENTRAL ZNS AND INTO THE SPS. NEWEST MESOETA AND MM5 BOTH MAKE IT SEEM PLAUSIBLE FOR MUTIPLE N-S LINES OF SUPERCELLS TO FORM AS DAYLIGHT GOES INTO EVENING. AT A MINIMUM...PER LOCAL STUDIES...THIS SYNOPTIC SCENARIO IS PROBABLY THE MOST EASILY IDENTIFIED PATTERN FOR THE OCCURRANCE OF SEVERE WX IN CENTRAL PENNA. (UPR LOW LIFTING NE UP ST LAWRENCE W/ASSOCD N-S COLD FRONT). AVG STORM MOTIONS OF 30 KTS AND RELATIVELY LOW (1.5") PWATS SHUD KEEP WORRIES AWAY FROM TOO MUCH WATER...EXCEPT WHERE REPEATERS MAY OCCUR. .CTP...SPS FOR SLIGHT RISK SEVERE. DANGELO
FXUS61 KCTP 191822 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 220 PM EDT SUN AUG 19 2001 THINGS ARE A-POPPIN IN THE WEST. NOTHING BEASTLY YET...BUT POTENTIAL IS STILL THERE. MANY PSU STUDENTS RETURNED THIS WEEKEND...AND THE METEO TYPES ARE ALL EXCITED ABT SVR POTENTIAL AND STORM CHASING. ALL I CAN SAY IS...BE CAREFUL! TEMPS NOT QUITE AS HOT AS I HAD THOUGHT IN THE SOUTH/CENTRAL...THIS SEEMS TO BE TEMPERING ACTIVITY OVER THE SC MTNS ATTM...BUT PROBABLY NOT FOR LONG. AS UPR LOW NOW PROGGD TO DEEPEN SLIGHTLY MORE THAN PREV...BELIEVE THAT FROPA WL BE SLOWER ON THE WHOLE...BUT TIMING ON SAT LOOP PUSHES THE FRONT TO FAR WRN ZNS BEFORE 00Z. NEWEST MESOETA NOW HEAVES THE FRONT THRU THE ERN PT OF THE STATE WITH A DECENT DRY SLOT BEHIND...WHERE IT HUNG IT UP DURING THE MORNING HOURS IN PREV RUNS. A FEW SHRA MAY LINGER DURING THE DAY ON MON...AND WL LEAVE IN LOW CHC POPS MOST PLACES...XCPT FOR THE NW WHERE 40 POPS WL SHOW UP DUE TO PROXIMITY TO COLDER MID LVL AIR. THINGS QUIET DOWN FOR TUE...BUT CHCS RETURN BY LATE WED/THUR. ALTHO WITH FRONT NOW PROGGD BY NEW AVN TO PUSH TO THE SOUTH WISHING TO MAKE A RETURN APPEARANCE...THE CHCS WON/T BE ALL THAT GREAT. TEMPS TO HANG CLOSE TO CLIMO THRU THE PD...PERHAPS A BIT BETTER. .CTP...SPS FOR SLIGHT RISK SEVERE. DANGELO
FXUS61 KCTP 200153 AFDCTP AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 945 PM EDT SUN AUG 19 2001 BUSY EVE HERE IN CTP. ALL BUT 5 OF OUR WARNINGS ISSUED HAVE VERIFIED AND SOME DIGGING WITH POST OFFICES AND SPOTTERS AFTER THE SUN COMES UP SHOULD REVEAL MORE DAMAGE. ALSO WE STILL HAVE ONE WARNING STILL GOING WHICH MAY YET VERIFY IN FRANKLIN COUNTY. THAT STORM IS PUTTING DOWN SOME RAIN AS WELL. WE ARE ISSUING FFW DUE TO SLO MOVG NATURE OF STORM AND SOME HINT OF TRAINING BACK INTO MD. WE HAVE A HAM JUST N OF ST THOMAS GATHERING REPORTS FOR US BUT SO FAR HE HAS NOTHING SEVERE TO REPORT. JUST VERY HEAVY RAIN! AS BUSY AS IT HAS BEEN THIS EVE WE JUST HAVE NOT HAD THE TIME TO LOOK PAST TONIGHT. A BRIEF GLANCE SHOWS UPPER LOW DRIFTING N OF US MON BUT WITH DRIER AIR IN PLACE IN LOW LEVELS. THEREFORE THERE IS STILL THE CHC OF SOME SHRA/TSRA DURG THE AFTN HEATING MON BUT COVERAGE...RAIN AMTS AND SEVERITY SHOULD BE MUCH REDUCED FROM TODAY'S EVENT. WE WILL ISSUE AN UPDATE WHEN SEVERE TSTM WATCH EXPIRES. .CTP...FFW TIL 1230 AM EDT FOR FRANKLIN COUNTY. HEAD
