Currently: Cold front from last night is all the way down by VA Beach. High pressure is near KIAD, providing the area with a fair, sunny day.
Tonight: Generally clear. Clouds could increase later at night. Generally going close to the cooler guidance sets, as I do expect decent radiational cooling conditions. Lows should range from the mid 20s to the mid 30s.
Tomorrow: Clouds increase. Sfc low press stays way offshore. However, models are in fair agreemnt that a "Norlun trough" like feature will throw moisture back across a portion of CT. Right now, it seems like the highest chances of precip will be across SW CT, as the trough axis seems to favor CNJ to WCT. However, models generally don't have a good handle on these types of systems until the last minute. Pcpn type should be mainly snow, esp if it comes down hard enough, given cold upper levels. However, sfc temps should remain abv freezing. Therefore, any accumulations should be on grassy sfcs. And I will not use a standard 10:1 snow to water ratio. The snow to water ratio should be more like 5:1. Therefore, any accumulations would be an inch or less, and generally south of 84 and west of 91, or south and west of Waterbury. The best window for precip timing looks to be between mid afternoon and midnight. Temp guidance appears way too warm, given the setup aloft, so I'll go with highs in the low 40s, about 4-7 degrees cooler than guidance.
After the precip ends tomorrow night, skies should clear pretty quickly with high pressure building in. Any slushy snowcover will melt within an hour of sunrise on Saturday, as the combo of strong March sun and quickly warming temps goes to work. Temp guidance is in decent agreement. I'll go with the slightly cooler NAM temps, but there isn't all that much difference anyway. Look for highs generally between 40-45, though a few spots in the I 91 corridor could exceed 45.
Long Term (Sunday and beyond): Expect fair weather the first two days of the long term, with more unsettled weather thereafter.
For Sunday, i am going a couple degrees warmer than temp guidance, with a warm, downslope flow expected. Most places should soar into the mid 50s with plenty of sun, but it will be a bit cooler in the NW Hills.
Monday will be even warmer as high pressure books offshore, allowing for a return flow to establish itself. I could be too low on temps. I went a degree lower than guidance, only because guidance seems very aggressive. While it could be right, I like to be cautious at this range, because there could be a couple more clouds or a touch more onshore flow than anticipated. So for now, I am calling for highs in the upper 50s, although that could be adjusted upward in subsequent forecasts.
A cold front approaches Tuesday. For now, I prefer to keep most of the daytime dry and not bring precip in until around dark. The GFS is generating "0.01"s most of the day, but the GFS has a tendency to do that ahead of cold fronts, and in reality, there is no precip in that area. So I'll take the chance and assume it is showing that bias again. All in all, I feel guidance is a few degrees too warm on Tuesday. Even though I am keeping most of the day rain-free, it will still be mostly cloudy and for that reason, I think temps are too warm. Expect highs in the mid to upper 50s.
The next system to watch is a system developing along the cold front to our south and spreading overrunning moisture into our area Wed night. Since it comes at night and since the upper levels are cold, the favored precip type here is snow. However, once again, most of the precip at this time at least, looks to be on the light side, since the sfc low never really explodes. High temps on Wed should be near 50 and Thurs in the mid to upper 40s, but with the system sliding by at night, temps will slip into the low to mid 30s, so snow is possible then.
Yet another system could slide near or under the area by Friday, which would produce mainly rain, but also could start out as snow, if today's progs are close to being correct.
The long range looks to feature a warming trend, with generally warmer than normal temps expected. However, being that it is March, expect fairly frequent shifts in temps, even if the bias is toward warm. There could be a shot of cold air towards the last week of the month, but that's too far out to get excited about right now.
Now, let's take a look graphically at some systems that could affect the area in the coming week. First, I'll show tomorrow's NORLUN trough feature, then I'll show Wed night's frontal wave, since those are the two systems that could produce winter weather in our area. As you can see, most of the precip with the NORLUN trough is either over WNJ and EPA or over W LI. A spoke of moisture may extend into SW CT and they have the best chance of seeing decent precip rates.
-GP!