The regional radar mosaic early today is revealing that there's a batch of light rain, which is in the process of pushing to the north and east and into New England...
This process is occurring because a warm front associated with a body of low pressure located in southeastern Canada is lifting to the north and east... Therefore, while we are expecting a couple of showers early today, there will probably be a 'prolonged break in the action' occurring after 7 or 8 a.m. — and it could last until sometime later this afternoon (perhaps until after 3 or 4 p.m.) before a couple of showers return...
And, with a cold front expected to bear down on the coastal plain early tonight, some of the showers that occur later today and early tonight will probably be accompanied by some thunder and lightning in at least parts of the area...
Most temperatures, even though clouds will break for sun on just a few occasions today, will manage to reach the mid and upper 70s... This "early and late" approach to forecasting today's shower activity is based on the idea that most of the day will be spent in a so-called warm sector...
And, with that next cool front expected to slow down quite a bit late tonight and tomorrow morning once it reaches the mid-Atlantic coast, there are going to be some places that will still get a shower or two tomorrow... The current thinking is that there should be enough dry air that will manage to filter down into New England, New York and northern New Jersey/northeastern Pennsylvania late tonight and tomorrow morning to prevent any showers from occurring... In these places, some early cloudiness tomorrow should be followed by a fair amount of sunshine (basically, from midmorning onward)...
But, for much of central and South Jersey, southeastern Pennsylvania and northern Delaware, we feel its still necessary to address a couple of showers for a while tomorrow morning before the sun ever manages to come out... Then, there'll obviously be a point even farther south where the prospects of the sun coming out are quite limited, and therefore — a shower could occur at virtually any time... These places should include southern Maryland and Delaware, as well as much of Virginia and the Greater Washington D.C. Metro Area...
As we discussed yesterday, the tendency for this cool front to stall over the mid-Atlantic states tomorrow afternoon, followed by the development of a wave of low pressure tomorrow night and Friday, will lead to a fairly cloudy, cooler and even wetter scenario on Friday in areas east of the Appalachians...
In fact, we'll have to be on the lookout for the rain to be getting underway as early as late tomorrow night, especially for areas close to Philadelphia and in South Jersey... Most temperatures on Friday afternoon will fail to get out of the 60s, and there should be a few periods of rain... Even though there may be some warmer air that will try to lift northward along the Eastern Seaboard, the odds at this point seem to favor that it will only manage to press as far north as the Greater D.C. and Baltimore Metro Areas, where it will probably reach the mid or upper 70s on Friday afternoon, because the bulk of the rain in these locations will be over with by mid or late-morning...
Not much has changed about our thinking for the upcoming weekend... Even though Saturday may not bring as much rain to the area as what we're expecting Friday, or the general flavor of the day will be "showery", the global models are still showing very strong signals that there will be another wave of low pressure emerging in the Eastern Region later this weekend...
The European model, for example, shows that a nearly stationary front draped over the mid-Atlantic state will be the focal point of a few showers on Saturday and early Saturday night, before this wave of low pressure begins to form later Saturday night near the coast...
And, depending upon which model you agree with, as this low pressure system "winds up" and continues to gain strength off the shores of Delaware, New Jersey and southeastern New York on Saturday night and early Sunday, there should be at least a few hours of steadier rain occurring in all of these areas before that body of low pressure begins to lift to the north and east on Sunday, pushing its plume of moisture into New England... In a "best-case scenario", we could see how rain for several hours later on Saturday or Saturday night wraps up early Sunday, or "tapers to a couple of showers" before ending...
But, if the models in the future show that this low pressure system is slowing down in any way, then there will need to be even more of a pessimistic outlook for Sunday... Temperatures over the weekend should be mostly in the 60s, because of the extensive cloud cover and some of that rain we're expecting.
Have a good day !!!
