Currently: The backdoor cold front has receded south again, contrary to model predictions, and now runs along the Mason-Dixon line. Waves of low pressure were moving along that boundary. Another cold front, this one which will bring in drier air, is along the Allegheny Mountains in PA.
Tonight: Rain and showers will be more numerous in the first part of the night, and tend to slowly diminish after midnight. Low temperatures will generally be 35-40, but as skies clear, some areas in the NW Hills could get near 30.
Tomorrow: Finally a nice day. Clearing skies, breezy, with wind gusts to 25 MPH, and near normal temperatures in the 50-55 degree range for highs.
Tomorrow Night/Thursday: Continued nice. As cool high pressure centers overhead, winds diminish, but overall temperatures will be a few degrees cooler, with highs around 50. Some areas in the NW Hills may not make it out of the 40s.
Long Term: The long term period will be highlighted by two significant precipitation makers, the first at the beginning of the long term period, and the second at the end, with nice weather in between.
Models are coming into pretty good agreement that a fairly powerful coastal storm will affect the state Friday and perhaps at least part of Saturday. The main questions that remain are: How long will the storm last, how heavy the precipitation will be, how strong the low will be, how far north the precipitation shield will make it, and if there will be enough cold air around to support wintry precipitation.
To answer some of those questions, the storm has sped up a bit on recent model runs, which would confine most of the precipitation to Friday. However, since the pattern has become more of a slow-moving pattern, I would not completely rule out that the storm slows into Saturday. Most models are trending wetter, so heavy precipitation, as well as the storm spreading far enough north, are becoming resolved now. Most models have also trended a bit colder, so it is becoming more likely for accumulating snow in the northern part of the state. At this time, it looks like the potential is there for several inches of snow, mostly on colder surfaces, with localized higher amounts in the NW hills. Also, in the NW Hills, it is possible that snow sticks to all surfaces, since surface temperatures will be a degree or two lower. As far as temperatures Friday, expect high temperatures to range from the mid 30s in the NW hills to low 40s along the SW Coast. As slightly warmer air advects in, temperatures could rise a degree or two Friday night.
After the storm clears out, Saturday should still be quite chilly, with high temperatures only in the 40-45 degree range. Sunday and Monday should see nicer weather, with temperatures closer to normal- 50-55 degrees.
Yet another slow-moving storm is on track to affect the state centered around Tuesday. The track actually looks very similar to Friday's storm, but this time, there will be less of a cold air source to the north, so that one should be all rain, at least for now.
Looking into the longer range, a parade of slow-moving, juicy systems looks to continue into the foreseeable future. In fact, when it all comes down to the statistics, it could very well end up that we see more days WITH measurable rain than without.
Hydrology: For now, other than nuisance flooding, not expecting a lot of problems. However, the longer this pattern continues, and if anyone gets a decent snowfall Friday before any changeover to rain, the chance for flooding will increase.
Now, let's look at some of the systems affecting our state in graphical format. First, let's take a look at the system slated to move in on Friday.
Next, we'll take a look at the next system on the pipeline for Tuesday. You can see this storm riding the Mason-Dixon line, not much of a change from the track of Friday's low. However, with Friday's system, the cold high pressure is located over New Brunswick, Canada, but on Tuesday, the cold air source is way up over Labrador, so unless that is vastly incorrect, Tuesday's storm will be all rain.