Monday PM Disco: Manic Monday of Snow and Sleet

Synopsis                                                                                     

With the winter storm pounding on us now, the questions  are "how much snow?' and "will there be much freezing rain or sleet?"  despite the snow falling across most of the central and eastern areas now, temperatures aloft will be on the rise, leaving room for more mixed precip later in the afternoon. the storm now is proving to be the biggest concern for us, as the rest of the week looks to be just cloudy and cool. A clipper system will threaten the south of the state by Thursday , so keep a watchful eye on this one, as it can bring a heavy burst of snowfall to our southern counties later this week.

Short Term (Now through Tuesday afternoon)

The storm is progressing through the state rather quickly, the 12z 4km NAM has the current radar signature happening at 2z, implying that it is about 7 hours too slow. If we compare that to how the 0z Euro and 12z GFS are doing now, they are also running slower than reality, showing that the storm could be out of the state before sunrise tomorrow. WAA aloft will be moderate throughout the evening, giving potential for more sleet and freezing rain as the evening hours come by, but the poor timing of this system in general implies that the advection is mishandled, but the updated 18z NAm shows colder 850 temps' than before, so sleet may only be in sporadic areas in the south central  counties. Surface WAA in the eastern counties will show that they will see mainly rain from this system, and in general, temperatures statewide will be omn the rise as the night rolls along, showing that freezing rain  will be more of an issue for us here in centre county, and in areas elsewhere in the centre region.  The dryslot with the system is pushing throught the western areas on a good quip, but the scattered light rain showers in ohio are puhing east with the system, which could show up in western PA, by tomorrow. Going into Tuesday, only a few snow showers will remain in northeastern PA,  

Longterm (Tuesday night into the Weekend)

The broad 500mg trough will help wrap around the blocking high that has been stretched along the north atlanitc last week, and this block will help keep that area in place for the entire week/. This will keep low clouds in the sky for most of the Northeast, and PA will be no exception. Dominant westerlies will take over with this trough, and any northerly component to those will help induce lake effect snow for Erie, moreso on Tuesday night going into Wednesday. Beyond this, a clipper looks to threaten the south by Wednesday overnight into Thursday, but the NA< resolves it as a weakening clipper from the 12z to 18z runs.   The clouds will keep state temps well below average for this time of year, and it will be one of the coldest ends to March in State College history.