January 23, 2004
No major changes for our thinking in regards to the late weekend storm system, minor changes to the forecast for late tonight into Saturday morning. The remainder of today will be partly sunny, breezy, and quite cold with high temperatures topping out around 23F. Clouds will increase later tonight as an Alberta Clipper makes it's way towards the region during the overnight hours. Looking at the current Radar Loop this morning, the system does indeed look fairly impressive over the midwest. However, as is often the case with these systems, as it makes it's way Eastward and over the mountainous terrain, precipitation associated with this system will become ragged and much less impressive. For our area, expect a period of light snow and / or flurries after midnight with accumulations from a dusting to no greater than an inch. Low temperature tonight around 15F with winds becoming light.
Saturday will feature flurries in the morning and increasing sunshine throughout the afternoon. It will continue to be cold with the high temperature in the upper 20s. Clouds start to increase Saturday night, it will be breezy with the low temperature around 13F.
The next disturbance slated to affect our area can be seen quite clearly in our Water Vapor Imagery over the Baja Peninsula and Southern California. This upper level low will eject minor disturbances and send them on a ride Eastward across the lower 48 throughout the next few days. The first will affect our area on Sunday. Guidance is slowly coming together on a solution and we have not changed our outlook much since yesterday, only a minor fine-tuning of potential accumulation spreads.
While the system responsible is not very dynamic in nature, it's trajectory in latitude and mid level flow will allow a decent amount of Gulf moisture to be picked up on it's ride Eastward. With a nose of cold high pressure to our North on Sunday, this moisture will be forced up and over the cold air at the surface, a scenario which is referred to as overrunning. Aside from a true coastal Nor'easter, for our area, this is generally the second most common source of heavy snowfall. In any event, snow looks to overspread the region from the South and West at some point late Sunday afternoon. High temperature will be in the upper 20s. Snow looks to become moderate to heavy for a few hours Sunday evening and night with snowfall accumulations exceeding 3". While some guidance still hints at the idea of snowfall in excess of 10", we feel it is a safe bet at this time to side with the lower totals (3-6") until more model support becomes evident. Keep in mind that this system is still 60 hours away and our forecasted totals could be fine-tuned once again in the next day or so.
Snow will taper to snow showers Monday morning. At this tine, it appears a surge of warmer air could advect westward from the coast and cause a change to sleet or freezing rain / drizzle during the morning on Monday. These details will need to be hammered out over the next few days and will depend entirely on what this storm system decides to do on Sunday. There may also be some minor development near the coast on Monday which could throw more moisture our way during the afternoon while dragging colder air back Southward yielding another period of snow Monday PM.
We will be busy over the next few days hammering out this difficult forecast. For now, we feel confident regarding Sunday and into Sunday night. May fine-tune things just a bit over the next day or so in regards to snowfall amounts. Monday may or may not spell more of a mess, we will need to see what our Sunday storm does before seeing what implications it will have with another disturbance being ejected out of the Soutwest. More later . . .
S.B.
