Today's NWS forecast discussion , and spc discussion on th
Area Forecast Discussion
National Weather Service State College PA
509 AM EDT Tue May 6 2025
.SYNOPSIS...
* Multi-day stretch of wet weather continues into late week
* A few strong to marginally severe storms are possible this
afternoon across east-central PA with localized downpours
* Eventual breakdown of the stagnant/repeat wet pattern signals
improving conditions for Mother`s Day Weekend
&&
.NEAR TERM /THROUGH TONIGHT/...
Training rain bands continue to track north-south across the
Susquehanna Valley near the occluded frontal zone early this
morning. MRMS data indicates hourly rain rates have leveled off
quite a bit from last night at <0.50 inch/hr. Noticeably cooler
and drier air has arrived in clear slot behind the front with
areas of locally dense fog across the Laurel Highlands and south
central ridges.
The closed upper low responsible for the recent multi-day
stretch of wet weather throughout most of CPA will begin to
unravel and lift to the northeast into New England by 12Z Wed.
Despite its pending departure, it will help to trigger another
round of rain/showers and a few thunderstorms ramping up through
peak heating. Hires guidance focuses isolated to scattered
convection along the occluded front over east central PA this
afternoon and early evening.
Low-level convergence along the front and large-scale ascent
associated with the 500mb low will combine with 500-1,000 J/kg
of MUCAPE, robust deep layer shear, and steep lapse rates to
support a marginal wind damage/hail threat. Although PWs are on
the decline, locally heavy north-south training downpours on low
FFGs will also support the potential for isolated instances of
flooding especially in areas where soils have been substantially
saturated.
Trailing shortwave energy on the backside of the departing
upper low should maintain showers into tonight particularly
over the southern tier of CPA before POPs gradually decrease
into early Wednesday morning.
Highs will be +/- 5 degrees either side of early May climo with
cooler conditions (60-65F maxT) in the western Alleghenies and
milder temps (65-75F) throughout the Susquehanna Valley or
ahead of the occluded front.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A brief respite or lull in the frequent rain showers is expected
into midweek as the upper low continues to pull away from the
region. We still can`t rule out a few showers especially across
the northern mtns Wednesday PM - but on the margin it should be
drier vs. recent days. Highs trend a bit warmer on balance with
daytime maxes in the 65-75F range.
The lull in the precip will be short-lived with yet another
upper trough fcst to close off over PA by Thursday night. Rain
showers and a few t-storms are likely Thursday afternoon into
Thursday night with ensemble data placing max POPs across the
southern and eastern portions of the forecast area. Temp trends
for Thursday should be flat to down day over day with the most
noticeable change in the northern tier with highs falling back
into the 50s followed by mins in the 35-40F range Thursday
night.
The full discussion is in the link.
https://forecast.weather.gov/product.php?site=CTP&issuedby=CTP&product=AFD&format=CI&version=1&glossary=1&highlight=off