Special Weather Discussion

Latest Weather Discussion by Kyle Elliott

* a dry, pleasant and tranquil start to meteorological summer *

11:00 a.m. Friday, May 29, 2026, Update:

In the wake of Wednesday night's cold frontal passage, north-northwesterly winds of 12-25 mph directed slightly cooler and MUCH drier air into the Commonwealth on Thursday. In stark contrast to Wednesday's warm and muggy conditions, humidity was very low on Thursday with dewpoints around 50°F under partly-to-mostly sunny skies. Much like yesterday, today's weather will be absolutely spectacular to wrap up the last week of May. An area of high pressure over the Ohio Valley will promote sunny skies, light winds, low humidity and comfortable conditions this afternoon with high temperatures in the mid 70s to perhaps 80°F across northern MD, southeastern PA and the Lower Susquehanna Valley (see below). If possible, get outside and soak up the sunshine after work or school. You won't regret it! 😎

The last weekend of meteorological spring will kick off on a breezy and unseasonably cool note following another cold frontal passage later tonight. No precipitation and very few clouds will accompany the front, but northerly winds of 12-25 mph with gusts up to 30 mph will usher an even chillier air mass into the mid-Atlantic States behind it. As a result, high temperatures on Saturday will be around 10°F below normal, or in the mid 60s to perhaps 70°F, despite sunshine and only a few afternoon clouds. If you're anything like me, you may need to wear a sweater or light jacket outside tomorrow to feel comfortable, especially in the morning and evening hours. Low temperatures tonight will still be near normal by late-May standards and generally in mid 50s, but they'll bottom out in the relatively cold mid 40s Saturday night. Another Canadian high pressure system will settle into the Commonwealth during the second half of the weekend and cause winds to quickly subside Saturday evening. Under clear skies and with dewpoints in the low 40s, the stage will be set for efficient, radiational cooling Saturday night. In fact, minimum temperatures in the deepest valleys and most outlying areas of south-central PA may end up within a degree or two of 40°F early Sunday morning. Fortunately, the sun is nearly at its highest point in the sky across the Northern Hemisphere, so temperatures will rebound quickly Sunday morning and peak in the the low-to-mid 70s Sunday afternoon under sunny skies (see below). Winds be much lighter, as well, so it will be a perfect day for outdoor activities such as hiking, walking, biking, running, fishing and laying out in the sun. Just make sure to lather on the sunscreen!

Monday, June 1, marks the start of meteorological summer, and the season will kick off on a mostly sunny and gorgeous note with high pressure still in control of our weather. Winds will be light and humidity very low with highs in the mid-to-upper 70s Monday afternoon following a comfortably cool Sunday night with lows around 50°F (see below). There will be no heat, humidity, showers or thunderstorms in sight during the first few days of the season. My "hunch" from Tuesday regarding the forecast early next week appears to have been right. A weak disturbance over the Southeast will fail to link up, or join forces, with a much stronger disturbance dropping southward out of eastern Canada and through the mid-Atlantic States from Monday into Tuesday. Instead, the moisture-deprived, Canadian disturbance will fail to produce any precipitation, and Tuesday should simply turn out partly sunny and cool with high temperatures around 5-10°F below average (low-to-mid 70s).

A gradual warming trend is expected to then begin on Wednesday and continue through the end of next week. Another sprawling high pressure system will settle over the Eastern U.S. during the middle of the week and then shift into the western Atlantic by Thursday and Friday. After yet another comfortably cool night with lows around 50°F early Wednesday morning, high temperatures should be back in the upper 70s during the afternoon hours under mostly sunny skies. The large-scale subsidence, or sinking motion, associated with the high pressure system will promote plenty of sunshine and thwart any shower or thunderstorm chances through at least next Friday morning. In addition, the flow will turn southwesterly late next week, so temperatures will likely peak in the low 80s Thursday afternoon and then soar into the mid-to-upper 80s on Friday. Fortunately, humidity should remain relatively low with dewpoints no higher than the low 60s by Friday afternoon. Not until later Friday or Saturday do I expect the next chance for showers or thunderstorms. A weak cold front is expected to slide southeastward from the Great Lakes region during that time, but details about its strength and exact timing remain nebulous at this distance. Regardless of the outcome, another prolonged stretch of mostly sunny, dry and comfortable conditions appears likely in the wake of the front. As mentioned in my summer outlook, the first half of June should end up abnormally dry with no more drought relief in sight. However, most nights will be ideal for sleeping with the windows open, and you won't have to worry about dangerously hot weather anytime soon. I'll take it! -- Elliott

11:30 a.m. Tuesday, May 26, 2026:

As expected, Memorial Day Weekend turned out to be cloudy, chilly, damp and dreary across the mid-Atlantic States. Saturday was a total washout across the Lower Susquehanna Valley, and Sunday wasn't much nicer despite a dry afternoon. On a positive note, the rainfall was much needed due to the moderate-to-severe drought in place across northern MD and southeastern PA. Most areas received 1.25-2.50" of rain from Friday afternoon through Sunday morning with locally higher amounts up to 3.0" south of the Mason-Dixon Line (see below). Fortunately, the easterly flow was replaced by light, westerly flow on Memorial Day, and Monday afternoon turned out to be mostly cloudy, humid and much warmer with highs in the 70s following a few morning showers. 

Much like yesterday, today will turn out partly-to-mostly cloudy and seasonable with highs in the mid 70s to low 80s from south-to-north across the region. An area of high pressure centered over the Poconos will suppress thicker cloud cover and any showers south of the Mason-Dixon Line this afternoon (see below). It won't be quite as humid as yesterday, though, with dewpoints ranging from the low-to-mid 50s north of the Turnpike to low-to-mid 60s across northern MD. 

A quasi-stationary frontal boundary is currently draped across the southern mid-Atlantic States, and a disturbance will move eastward along it through the Delmarva Region later tonight into Wednesday. A few showers may graze the southern-tier counties of PA between 1 AM and 1 PM Wednesday, but heavier downpours and thunderstorms will likely remain south of the Mason-Dixon Line and perhaps even I-70 tomorrow. Most of the afternoon should be mostly cloudy and dry, but humid, with dewpoints in the mid-to-upper 60s and a temperature distribution similar to today. Due to the clouds, showers and high humidity, tonight will be unseasonably warm with lows in the 60s. Rainfall amounts through Wednesday afternoon are uncertain at this time, but the most likely outcome is for very little rain north of I-76, 0.25" or less between I-76 and the Mason-Dixon Line, and up to 0.50-0.75" near I-70 (see below). Grab an umbrella and rain gear before heading out the door to work or school tomorrow, but you shouldn't need them by the PM commute. Overall, the weather during the middle of this week will be quite "normal" by late-May standards.

In the wake of Wednesday's disturbance, a Canadian high pressure system will settle into the northern Great Lakes region on Thursday. At the same time, a weak cold front will sag southward through the Commonwealth later Wednesday night into Thursday morning. Behind it, north-northwesterly winds of 10-20 mph will usher slightly cooler and much drier air into the Lower Susquehanna Valley. As a result, skies will gradually clear late Wednesday night, and Thursday is expected to be mostly sunny and beautiful with highs in the mid-to-upper 70s and dewpoints in the 50s. Wednesday night will still be rather warm and humid with lows and dewpoints in the upper 50s to mid 60s, but that humidity will go out of the air Thursday morning. The aforementioned high pressure system will then shift into the Ohio Valley and eastern Great Lakes region by the end of the week and promote a beautiful Friday with low humidity. After a mainly clear and crisp Thursday night with lows around 50°F, high temperatures should reach the mid 70s Friday afternoon under sunny skies. Winds will be light, as well, making it the perfect day for outdoor activities in shorts and t-shirts.

Looking ahead into the upcoming weekend and start of June, there are no more 90-degree days on the horizon. An "Omega Block".. or weather pattern featuring a massive, Jet Stream ridge sandwiched between two Jet Stream troughs.. will develop across North America late this week and persist into early June. In this case, the Jet Stream ridge will extend from Central Canada through the Northern Plains and Upper Midwest with the two troughs centered over New England and the Four Corners Region. On the southeastern side of the ridge and backside of the New England trough, persistent, northwesterly flow out of Canada will keep heat at bay and relatively cool conditions locked in place across the Eastern United States through at least the first week of June (see below).

A potent disturbance will move through northern New England from Friday night into Saturday, and a weak cold front extending to its southwest will likely move through the Commonwealth sometime on Saturday. Large-scale subsidence, or sinking motion, on the southwestern periphery of the disturbance and upper-level low should prevent all but a stray shower or two from accompanying the cold frontal passage. Instead, skies will likely be partly-to-mostly sunny on Saturday, and high temperatures will depend on the front's timing. In the event of a Saturday morning frontal passage, highs would only be in the upper 60s to low 70s. However, they'd be in the upper 70s or even low 80s with a late-afternoon or evening frontal passage. At this point, a "middle ground solution" is the most likely outcome.. i.e. an early-to-mid afternoon frontal passage with highs in the mid 70s and increasingly breezy conditions throughout the day. Behind the front, an even cooler and drier air mass will settle into the mid-Atlantic States during the second half of the weekend, and low temperatures could bottom out in the upper 40s early Sunday morning. That being said, the sun is nearly at its highest point in the sky across the Northern Hemisphere, so temperatures should still rebound quickly Sunday morning and peak in the the low 70s Sunday afternoon under mostly sunny skies. Overall, the weekend looks spectacular for outdoor activities and sleeping with the windows wide open at night. Humidity will be about as low as it can be in late May, and winds should be light again on Sunday. If only that had been the case over Memorial Day Weekend..

The forecast then becomes rife with uncertainty early next week. Some numerical computer models show two disturbances joining forces along the mid-Atlantic coastline and creating another wind-driven rain for the first day or two of Meteorological Summer. If so, then June 1st would feel nothing like the season with highs in the 50s or 60s. However, other models simply show a continuation of northwesterly flow and the two disturbances remaining separate from one another. Given early-June climatology, I favor the latter solution and expect a partly sunny, dry and pleasantly cool start to next week with highs in the upper 60s to mid 70s and lows in the upper 40s to mid 50s on Monday and Tuesday. However, it would be foolish to discount the first solution at this distance, so I'll keep an eye on trends this week. Check back Friday for a more confident forecast! -- Elliott