Technical Discussion

Synopsis...

Complex winter storm/two disturbances to effect state tonight-Tuesday morning.  Clearing and chilly on Tuesday before moderating temps and sunny skies on Wed.  Next weather maker will move towards the area by Thursday.

Short Term (Sun Night-Mon Night)...

Radar shows echoes in W PA at this hour buy sfc obs show that it is all virga.  With Td in the teens and resultant DP depressions ~20F, it will take a bit to fully saturate the column as the first disturbance moves in from the west.  Precip should get going just after sunset across western zones with rain far SW and snow farther north.  All of the state gets in on the action by midnight with ALL snow generally N of I-80 and mixed precip/plain rain farther S.  Looks like a general 4-8" northern third, 2-4" central third with an icy glaze on top, and a coating to an isolated inch southern tier with mostly rain in those zones.  Precip will let up tomorrow morning with mostly cloudy skies throughout the rest of the day.  Winds shift from SE to NE/N tomorrow afternoon, allowing the 1037mb high to the north to start draining cold air southward.  This will set the stage for the next disturbance on Monday night.  The precip with this system looks to remain mainly across the southern two-thirds of the state and almost all snow.  A general 2-4" is expected with isolated higher amounts.  Models seem to have been trending wetter and this will need to be monitored.  Snow tapers off by daybreak Tuesday.

Long Term (Tues-Thurs)...

Lingering snow showers will effect the state early on Tuesday as the bdry layer remains saturated.  However, strong high pressure to the north will create drying and cooling influence throughout the day, leading to clearing skies.  Temperatures will be much chillier with northern zones struggling to reach 20.  Went slightly below MOS on Tuesday night lows due to fresh snow pack and light winds.  Could be VERY chilly N and W early Wed morning but lack of wind will not create the need for any Wind Chill advisories from the NWS.  Wed will be sunny as high pressure slides just north of the state.  The next system looks to affect our region on Thursday with the parent low going northward into Canada.  This track would be more conducive of rain rather than snow and disorganized nature of system has led us to just mention rain showers (snow farther north) for Thursday afternoon.

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