For tonight: A cold front responsible for the showers and thunderstorms mainly across the southern sections, will pull out, allowing skies to clear. Temperatures will be well below normal for the time of year, with low temperatures generally in the 45 to 50 degree range. Some places along the far Southeast coast may be a degree or two warmer.
For tomorrow, sunshine and a beautiful afternoon. Temperatures will be a few degrees below normal, but who can complain about temperatures between 70 and 75 degrees, low humidity levels, and plenty of sun?
For tomorrow night and Friday, good radiational cooling conditions will set up tomorrow night. Therefore, there will be a wide range of temperatures. Low temperatures will range from the low 40s to the low 50s, with the usual suspects clocking in the coldest readings. It's not impossible for a few of the very coldest places to clock in a reading in the upper 30s! For Friday, high pressure overhead should allow for similar temperatures to those of Thursday, with readings once again in the 70 to 75 degree range.
In the longer term, looking at the weekend and beyond, a complicated situation will set up. The first reason it is complicated is because we'll have an Alberta Clipper system (yes, an Alberta Clipper system in JUNE) affecting the area! I have never forecasted an Alberta Clipper in June, but hope that my knowledge of synoptic meteorology will provide enough knowledge for how to forecast an Alberta Clipper in June. Anyway, the second reason it is a complicated forecast is because there are variations with the models' forecasted track of this system. Some models track the system so far to the north that the state can get very warm and we'd basically get a cold-frontal squall line of thunderstorms. Others track the system so far south that the state would remain in the cold sector, and we'd get stratiform rains. A low right near the region would actually create a good tornado threat. Without wanting to hype that too much, and knowing how much uncertainty there is in this forecast, the best course of action right now is to call for a chance of showers and thunderstorms any time from Saturday afternoon until Sunday morning. (It is not going to be raining that entire time!) Another issue would be timing. Cold frontal thunderstorms nearly always perform best (i.e. strongest) if they are timed around the heat of the day- mid to late afternoon. If we get a warm frontal passage, however, this could create spin-ups even at "odd hours", especially if it crosses paths with a sea breeze boundary near the south coast. Needless to say, there is a lot to watch for as this weekend system approaches. As for temperatures, again this is not set in stone, either, as the storm track could create large variations in temperatures. For now, a good compromise would be 70-75 Saturday, and near 80 Sunday, assuming we get clearing and a chance to warm up.
Early next week, another pleasant pattern is expected to set up, as more Canadian high pressure builds behind the weekend clipper system. With lots of sun, expect high temperatures in the 70 to 75 degree range Monday and Tuesday, and in the 75 to 80 degree range on Wednesday.
Looking beyond that, models are generally starting to show more of a typical summertime pattern developing, with high pressure in the more typical Bermuda pattern. That is, after a potential coastal low could affect the area Thursday! One word of caution, if we do get hot or even very hot for several days, it may not last all that long, as many of the long range models continue to show the -EPO pattern (Alaskan Ridge) continuing. If this happens, that favors high pressure in Eastern Canada, which does not favor sustained heat in the Eastern United States, at least not north of Washington, D.C., or so.
Now, let's take a look at the overall pattern in graphical format. First, here is a look at a prog of low temperatures for Friday morning. Keep in mind, this is a low-resolution model and does not account for local "microclimate" variations that happen on clear, calm nights. Also, keep in mind that the daily low temperature probably occurs 2 or 3 hours later than this, allowing for temperatures to easily be 2 or 3 degrees lower than what is being shown here.
Next, we'll look at a map showing the weekend clipper system.