Current sfc analysis shows a warm front along the Delmarva Peninsula. Low pressure was located along the Wrn Appalachians. This whole system moves NE during the later day and evening tonight, thru tomorrow. Temps have pretty much risen above freezing everywhere, except a few sheltered valleys, and they will do so very soon. BOX and ALY have WXA (Advisory for Freezing Rain) up for the far Nrn counties for another hr or so. I expect this will be allowed to expire and not be extended. But still use caution driving for the next few hrs along and N of I 84, esp on back roads.
Tonight: A shower is possible at any time, esp right around sunset. Otherwise, expect rain to really begin to ramp up again between midnight and 3 AM. Temperatures are a bit tricky tonight. I don't expect temps to fall, with warmer air moving in, but the question du jour is: How far N can the warm front get? Nam guidance for tonight has been completely discounted, as it actually has the warm front SOUTH of its current location around midnight tonight, which isn't going to happen. That said, the GFS has also cooled, but nowhere near the extent of the NAM. I'll trend the forecast cooler tonight, but I won't go as cool as the new models. This is a fairly strong system and I still think the warm front moves quite a bit N tonight. Will word the fcst as steady or slowly rising temps. Temps by morn should be in the low 40s most places.
Tomorrow: It's going to be a race between warm air and the incoming cold shot with the fropa later in the day. The one biggest certainty for tomorrow will be strong winds. Winds should gust from 40 to 50 MPH after the frontal passage. I'll go a touch under temp guidance for tomorrow, but all in all, very close to what the lower end of guidance has. Another question for tomorrow is if we can actually get thunderstorms tomorrow midday to early afternoon, with the frontal passage. So first off, for temperatures, I would call for highs to generally be in the upper 40s. I will word the fcst as early highs. High temps should generally occur around midday or so, before they begin to drop sharply. As for t-storms, I have decided to include a chc of t-storms in the fcst. Oddly enough, the chances for thunderstorms could be higher in Ern CT (E of 91) than W. The reasoning here is that the front will take longer to get there and allow for more heating. At any rate, the early afternoon period tomorrow should be quite interesting, as a line of convection moves thru the state, followed by a sharp temp drop, gusty winds, and maybe even a few snow showers on the back side of the storm.
Tomorrow Night/Sat: Cold air rushes in. Temps tomorrow night plunge into the mid teens to low 20s across the state. Realistically, this is not all that cold for the time of year, albeit a bit below normal. But it will feel very cold, given how warm it has been lately. Sat should be a chilly day, again, realistically, only a bit below normal, but it will feel cold. Remember, everything is relative! I'll go just a touch below the coolest guidance, but not too far off, as the combo of arriving clouds and cold air advection should keep temps at bay. Most places will see highs not reach freezing, although a few places along I 91 could reach 35.
Long Term (Sunday and beyond): A weak clipper system will see most of its pcpn die off as it travels east of the Appalachian mtns. However, it will get a bit of Atlantic enhancement as it heads toward our state. Snow showers and flurries will be common across the state Sunday afternoon. Due to the combo of marginal temps and not that much precipitation, accums will be very limited. The area with the best chance of seeing any accumulations at all would be the NW hills- both due to orographic lifting processes and lower sfc temps. Even there, any accumulations would be an inch or less. As far as temps on Sunday, guidance looks pretty good. I'll just make a tweak here or there to better suit my ideas. Look for highs in the mid to upper 30s on Sunday.
Unfortunately, there will not be many totally dry days in the long term period. On Monday, a warm frontal system will approach. Timing is terrible for those who wanted to do anything outside, as rain should fall most of the day with the most soaking of the rainfall around midday. I have chopped 3 to 5 degs off temp guidance for Monday, because models like to rush warm fronts further N than reality at that range. Even so, none of the state is even close to frozen precipitation. High temperatures should be in the mid 40s.
For Tuesday, we may be able to salvage a mostly dry day, between any lingering early AM rain and pcpn that arrives later Tuesday night. However, even if we do get a dry day, it will likely be dank and dreary. Since I never really think the warm front goes thru, I'll chop off a couple degrees of temp guidance. So expect highs to range in the low 40s, although some places along I 91 could get into the mid 40s.
The weather could turn more interesting later Tuesday night into Wednesday. Some models are now hinting at a low redeveloping off the coast. This would mean a threat for an accumulating snowstorm for much of the state. It should be noted, however, that even the models showing potential accumulating snow are quite warm at the sfc. In a normal year, I'd dismiss these models as not handling the thermal profiles correctly. However, this is not a normal year. It's quite possible that some areas could be too warm at the sfc to see accumulations. Therefore, the most favored areas for accumulating snow would be the NW Hills. But we will continue to watch this system, since it could be a legitimate concern for our area. As for temps on Wednesday, with the potential storm, I'll go a few degrees under guidance. This still yields highs near 40, and perhaps a bit warmer than that in the I 91 corridor. Like I said, if it's going to snow and amount to anything, it's going to have to be well-timed, perhaps even nocturnal, at least for now.
If this storm materializes, much cooler air could move in for Thursday, on gusty NW winds. I say if because the caviat is that the storm does not follow this course of action. If it ends up cutting into the Great Lakes or passing harmlessly out to sea, it won't have nearly as much of an impact on the pattern beyond. For now, I'll compromise between the guidance that shows this being a coastal, and guidance that does not. This implies an Arctic shot for the end of next week, but also implies it will be temporary, unlike what some of today's guidance is showing. For now, will assume strong cold air advection for Thursday, with gusty winds. Based on all of this, I'll go a couple degrees below guidance for Thursday assuming the basic ideas of the fcst are correct.
The long range has become a bit more muddled today. Previous versions of the long range basically continued the pattern we've been in. Today's new long range guidance is much colder. I'd like to see a few more runs show this before biting on it, especially given this season's tendencies. We've had "all but certain" pattern changes fail this winter. So until I fall for it again, I'd like to see this show up more consistently in guidance.
Now let's take a look at some systems that will be affecting our area in the coming week. We'll look at tomorrow's line of t-storms, then we'll look at Monday's rain. I'll keep Wednesday's potential out of it for now, since it is much lower confidence, and let later crews assess the situation.
Anyway, that's all for now! See you again next week!