Special Weather Discussion

Latest Weather Discussion by Kyle Elliott

* a dry and quiet weather pattern through labor day weekend *

11:45 a.m. Tuesday, August 26, 2025:

In the wake of Sunday night's cold frontal passage, west-northwesterly winds of 10-20 mph ushered a significantly drier air mass into the Commonwealth on Monday. Dewpoints tumbled into the upper 40s to low 50s by the afternoon hours, and high temperatures reached the seasonable low 80s under partly-to-mostly sunny skies. The lower humidity, sunshine and slightly cooler conditions on Monday were just the beginning of a prolonged stretch of dry and quiet weather across the mid-Atlantic States and a harbinger of things to come over the next 1-2 weeks. Quite frankly, there isn't much of anything to talk about.. at least locally.. in the wonderful world of meteorology in the foreseeable future, so this discussion will be rather short and sweet! A sprawling high pressure system currently centered over the Midwest will build into the mid-Atlantic States on Wednesday. As a result, partly-to-mostly sunny, dry and pleasantly cool conditions will grace northern MD and southeastern PA during the middle of the week. Temperatures will be 5-10°F below average with highs in the mid-to-upper 70s and overnight lows in the low-to-mid 50s. In addition, humidity will stay very low by late-August standards with dewpoints in the mid 40s to low 50s through Thursday (see below). A stray shower may impact areas north of the Turnpike between 3-7 PM this afternoon, but most areas won't receive a drop of rain.

The area of high pressure will shift into the western Atlantic on Thursday but remain in control of our weather. Thus, another partly sunny and pleasant day is expected with high temperatures around 80°F. A weak cold front will then sweep through the Commonwealth from northwest-to-southeast spanning Thursday evening to Friday morning, but it will be starved for moisture and pass through the Lower Susquehanna Valley at the coolest and most stable time of day. Therefore, I anticipate no more than an isolated shower or two later Thursday night and/or Friday morning with no measurable rain in most spots. Behind the front, winds will turn northwesterly again and knock dewpoints back down into the 40s Friday afternoon or evening. Clouds may thin out and dissipate Friday afternoon, as well, so the week should end on a nice note with highs in the mid 70s to perhaps 80°F. Due to more cloud cover Thursday night, overnight lows will be a bit higher than the next two nights and generally in the upper 50s to low 60s. In summary, this week's weather will be fantastic for outdoor activities and sleeping with the windows open at night! There won't be another 90-degree day through the end of August and perhaps the entire first week of September, and this last week of meteorological summer will feel more like late September than late August. How about that for a treat? I'll take it!

Looking ahead through Labor Day Weekend and the holiday itself, there will be nothing but "positive vibes" in terms of the weather! A deep trough, or dip in the Jet Stream, will remain in place across the eastern United States through most if not all of next week. A massive and persistent Jet Stream ridge over Alaska and western North America will be the culprit for the southward dip in the Jet Stream over the Eastern States. In the winter months, this type of Jet Stream configuration could spell trouble in the form of an Arctic outbreak, lake-effect snow squalls and/or clipper-type systems. However, it's great news in late August and September. Persistent, northwesterly flow out of Canada will keep high humidity, Gulf- and Atlantic moisture at bay, and the combination of mainly clear skies and low dewpoints will allow temperatures to tumble into the 50s on a night-to-night basis. In summary, abnormally dry and tranquil conditions will "rule the roost" through Labor Day and beyond (see below). Any early-morning chill will vanish quickly after sunrise, and high temperatures should be in the mid 70s on Saturday, upper 70s Sunday and upper 70s to low 80s on Labor Day.

In addition, a massive high pressure system will expand its reach from the Great Lakes region into the Northeast and mid-Atlantic States over Labor Day Weekend. The large-scale subsidence, or sinking motion, beneath the high will not only thwart shower and thunderstorm development but also promote a good deal of sunshine and low humidity from Saturday through the middle of next week. Overall, you couldn't ask for a nicer holiday weekend! The weather will be absolutely spectacular for outdoor gatherings with family or friends, as well as end-of-summer vacations to the Jersey, Delaware or Maryland Beaches (see below). Water temperatures at the Shore are generally in the low 70s and slightly below average for late August, so both the water and air may feel a bit chilly for surfers and beachgoers at times. However, you won't have to worry about any precipitation, and there will be plenty of sunshine to soak up. Just make sure to lather on the sunscreen!

I'll be out of the office and away on vacation from tomorrow afternoon through Labor Day, so check back next Tuesday for an update. In the meantime, "enjoy the calm!" Autumn is coming.. -- Elliott