Monday P.M. Disco- No Joke, Spring has Sprung! 4-1-2013

Synopsis

A cool start to the week will yield a warmer finish. Northwesterly wind s keeping the state cool today will taper off Tuesday night as high pressure starts to build in, and despite a threat for rain Thursday night into Friday, temperatures will slowly climb into the upper 50s, near 60s, by Friday and Saturday, leaving for a more spring like feeling across the state.

Short Term (Now through Thursday)

The cold front that crossed us this morning is still working its way through southeastern PA, and the radar implies added lifting behind the front, yet that is merely topographic lifting. Temperaturs across the state vary from 33 to 49 now, but once the front is through completely, the low temps tonight will sit in the 20s to low 30s. With the surface pressure gradient receding throughout Tuesday, expect winds in the teens during the day to die off by nightfall Tuesday. The net northwesterly flow will present a lake effect shower or two overnight tonight, along Erie, but the main focus for Tuesday will be the cloud cover induced my gravity waves and the contribution of upper level positive vorticity. Besides that, the surface gradient will be growing weaker Wednesday as high pressure begins to build in, yet an upper level shortwave will cut in over the state, limiting solar heating due to heavy cloud cover during the day

Long Term (Thursday into the weekend)

Thursday, high pressure will center itself over the state during the day, allowing for plenty of sun during the day to warm up the state well into the 50s, however, things will change overnight as a cutoff low system rushes in from the south, which will bring a threat for rain. Now, the 12z GFS and CMC agree on a solution that takes the rain upm the coast, yet the GFS brings the rain further inland earlier, giving Philly the most rain, whereas the CMC brings it more inland later, making Scranton the wet spot.  Looking at the NAO, it shows that we'll be in the negative phase, which favors the CMC a bit more than the gfs, yet the rain is so borderline that KAVP and KPHL could be hit hard equally, and it is all dependent on the progression of the cutoff low, so keep an eye opn this. Otherwise, beyond the rain lies a bulky ridge that will support the northward eddy heat flux, and the state will see a consistent warm weekend within the 60 regime continuing into next week.