Special Weather Discussion

Latest Weather Discussion by Kyle Elliott

* frequent bouts of showers and storms through sunday *

2:00 p.m. Wednesday, April 2, 2025:

For the first time in 27 years, the mercury exceeded 81°F in the month of March at Millersville University on Saturday. With an official high of 84°F, it became the warmest March day since 03/31/1998. The mercury also exceeded 80°F on Monday, March 31, so this was also the first March since 1998 with at least two 80-degree days (see below).

Due in large part to the remarkably warm final three days of the month, March 2025 concluded as the 6th-warmest on record at Millersville since 1914. There has been no measurable snow at the 'Ville since February 15, and precipitation was below average for the 3rd-straight month (see below).

Fortunately, Monday's severe weather threat didn't materialize across northern MD and the Lower Susquehanna Valley. There were a handful of wind damage reports in southeastern PA, but most areas were spared from violent thunderstorms. For the most part, Monday's storms were highly beneficial due to the ongoing drought. A general 0.50-1.00" of rain fell south/east of the Route 15/I-81 corridors from Monday afternoon through Monday night with lower totals farther north/west. Most of southeastern PA actually received 1-2" of rain with locally higher amounts up to 2.50" (see below). The torrential downpours led to some poor-drainage and urban flooding, but streams and creeks remained well within their banks. 

Behind Monday night's cold frontal passage, northwesterly winds of 12-25 mph ushered much cooler and drier air into the Commonwealth on April Fool's Day. A Canadian high pressure system settled over the Northeast Monday night and promoted mainly clear and cold conditions across southern PA with lows near freezing (32°F). The high has since moved into the western Atlantic, and winds have turned southeasterly on its backside. The rest of this afternoon will turn out mostly cloudy, breezy and chilly with highs in the mid 50s for most. A warm front will traverse the region from southwest-to-northeast tonight, so clouds and patchy drizzle should prevent temperatures from dropping below the mid-to-upper 40s. Ahead of the front, showers and thunderstorms currently rumbling through eastern Ohio may graze areas north/west of Interstates 76 and 81 between 4-7 PM this evening. However, any showers would be brief and relatively light due to a complete absence of instability east of the Appalachians. 

Behind the warm front, southwesterly winds of 15-30 mph will usher unseasonably warm air back into south-central PA on Thursday with high temperatures around 15 degrees above normal, or in the mid-to-upper 70s, despite mostly cloudy skies. However, a cold front extending southward from a storm system over eastern Canada will press southeastward across the Commonwealth later Thursday afternoon into Thursday night. It will spark scattered showers and thunderstorms during this time, but I don't anticipate much if any severe weather. The boundary will weaken dramatically upon its southeastward journey through the state, and extensive cloud cover should limit instability ahead of it. By Friday morning, the boundary will likely sag south of the Mason-Dixon Line and remain there through Friday night. However, it will return northward as a warm front on Saturday and serve as the focal point for additional bouts of showers or batches of steadier, light rain. To the north of the front, the atmosphere will be even more stable from Friday through Saturday, so I don't expect any thunder during this time. There may be a "lull" in the wet weather Friday afternoon and evening, but trying to time any dry periods over the next 3-4 days will be quite difficult. Sunshine will be hard to come by through the end of the weekend, and you'll want to keep an umbrella handy at all times (see below). Be prepared for slowdowns on the roads, as well, and standing water in low-lying and poor-drainage areas. Rainfall amounts through Saturday night shouldn't be too high or noteworthy south/east of the Appalachian Front. To the south/east of I-76/81, most areas will likely receive 0.25-0.50" of rain with 0.50-1.00" more common farther north/west. These amounts are, however, subject to change depending on the exact location of the frontal boundary and where it stalls. High temperatures on Friday will peel back into the 60s, and low-level easterly flow off the Atlantic should prevent them from exceeding the mid-to-upper 50s on Saturday.

We may briefly break back into the "warm sector" on Sunday with highs back in the upper 60s to low 70s. If so, then the subsequent severe weather threat would by far be the highest of the next 4 days. Still, any severe storms would likely be of the "isolated" or "scattered" variety with locally damaging wind gusts the primary hazard. I'll be able to finesse these details on Friday, so check back then for an update! This weekend also marks the beginning of trout season in PA. The Pennsylvania Fish and Boat Commission will stock over 3 million adult trout in the state's waterways this year. Anglers will face cloudy, cool, damp and dreary conditions for the "opening bell" at 8 a.m. Saturday. As mentioned above, temperatures will hover in the 50s through most of the day with periods of light rain and drizzle. Fortunately, the steadiest and heaviest batch of rain should track across the northern half of the state, but stream conditions and water levels/clarity will depend on how much rain falls in the next 66 hours. Following our unseasonably mild March, water temperatures are above normal for early April. In fact, they may hover near 60°F in many streams over the weekend, so wading boots may actually be an "option" rather than a "necessity" for some. If you're wondering what type of bait might be most appealing to the trout this weekend, the "world is your oyster." With water temperatures so abnormally high, trout should be very active and strike anything from artificial lures to live bait and dry/wet flies. On Sunday morning, conditions may be even better (drier and warmer) for anglers, but they might deteriorate during the afternoon hours on account of more showers and thunderstorms. Regardless, I hope you're able to land "the big one" this weekend.. but keep an eye on the sky and have multiple ways to receive severe weather alerts!

The cold front responsible for Sunday's showers and storms should finally push off the mid-Atlantic coastline later Sunday night or Monday morning. Behind it, next week should start on a drier, cooler and more pleasant note with highs in the mid 50s to perhaps 60°F on Monday. Unfortunately, one last blast of unseasonably cold air appears poised to swing through the Northeast and mid-Atlantic States during the middle of next week. As a result, high temperatures may struggle to reach the 50-degree mark on Tuesday and/or Wednesday, and overnight lows could tumble below freezing for a night or two. I won't even rule out a few wet snowflakes or graupel pellets on Tuesday as a vigorous, upper-level disturbance moves through the Commonwealth. Thankfully, the pocket of cold air will exit the Northeast as quickly as it enters, and next week should end on a warmer, brighter and more seasonable note. Stay tuned! -- Elliott