textproduct: State College

WHAT HAS CHANGED

* Lowered dewpoints & minimum relative humidity this afternoon

KEY MESSAGES

1) Noticeable warmup into Thursday precedes rain and thunderstorms through Thursday night followed by chilly cooldown for the last weekend of March

DISCUSSION

KEY MESSAGE 1: Noticeable warmup into Thursday precedes rain and thunderstorms Thursday night followed by chilly cooldown into the last weekend of March

High pressure centered over western PA this morning will shift eastward and bring dry weather through midweek. We cut dewpoints (and computed minRH in-kind) as sounding profiles show steep 0-3km lapse rates and wedge of very dry air atop weak inversion. The Spring fire weather/prescribed burn season is ramping up across CPA.

More sunshine and increasing south to southwest flow will allow temperatures to climb back to/slightly above seasonal levels for late March by Wednesday. The main surge of warmth arrives Thursday: fcst max temps +10-20 degrees above the historical average with potentially more room to the upside. Daily record highs seem out of reach, but could get close within a few to several degrees (see climate section). The late March temperature roller coaster continues to end the week with a gusty NNW wind helping to deliver a 24hr maxT change of -10 to -25 degrees Friday followed by a rather chilly cool down below climo to start the last weekend of March.

The best signal for rain continues to flash between 00-12Z Friday as a strong cold front moves southeastward across CPA. Heavy rain and severe storm risks are primarily focused to the west of PA over the Ohio Valley into the Midwest. The D3 MRGL SWO does clip the western periphery of the forecast area as a late night threat could extend from the Ohio Valley into western PA; but odds are that increasing stability with eastern extent greatly reduces the severe risk to the east of the Alleghenies.

AVIATION /07Z TUESDAY THROUGH SATURDAY/

A few streamers of lake effect/upslope flow, strato cumulus clouds producing MVFR to low end VFR Cigs will persist across the Northern Mtns (KBFD), Laurel Highlands (KJST) and the Susquehanna Valley (KIPT, KMDT and KLNS) through the mid morning hours before a ridge of surface high pressure moves across the Commonwealth and brings widespread VFR with relatively light wind this afternoon and tonight.

Outlook...

Wed...A thick BKN-OVC mid-level cloud deck (generally based between 7000-9000 ft AGL) moves ESE across the region. Light rain may brush the northern tier.

Thu-Friday...Showers becoming more widespread with perhaps a thunderstorm. Restrictions likely.

Fri PM...Breezy with light rain exiting the southern tier.

Sat...VFR.

CLIMATE

Record high temperatures for March 26th:

Harrisburg 80 in 1921 Williamsport 78 in 1939 Altoona 79 in 1998 Bradford 73 in 2007 State College 76 in 1949

CTP WATCHES/WARNINGS/ADVISORIES

None.