Area Forecast Discussion
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FXUS61 KCTP 250959
Area Forecast Discussion
National Weather Service State College PA
559 AM EDT Tue Apr 25 2017
Low pressure will track north-northeast from the Carolinas today
and reach the southern New England coast by Thursday morning.
This system will bring periods of rain today followed by
improving conditions through midweek as the storm lifts away
from the area. A summerlike pattern is forecast later this week
with temperatures likely remaining well-above normal through the
end of April.
.NEAR TERM /THROUGH TONIGHT/...
A complex/consolidating low pressure system over the Carolinas
this morning will lift slowly north-northeast today and reach
the Delmarva/NJ coast by the end of the period. S-SE 850mb flow
increases to 40-50kts by 18-21z supporting strong low/mid level
MFLUX surge with PWATs peaking around 1.50 inches. Despite the
placement/magnitude of MFLUX and S-SE 850mb wind anomalies, a
high res model mean keeps the heaviest rain focused into NJ.
However will need to watch for locally heavy rain bands tapping
into some elevated instability that may try to wrap NWWD into
southeast PA. The high res models also suggest rainfall amounts
may be enhanced along eastern slopes of higher terrain due to
strong S-SE upslope flow. Max 12hr POPs ending 26/00z are near
100% are over the far southeast portion of the CWA tapering to
relative minimum around 50% along the Allegheny spine.
Precipitation potential drops off from west to east later
tonight into Wednesday morning. The cool/moist easterly flow
will hold max temps in the mid 50s to low 60s.
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A very low chance for rain will linger early Wednesday over the
far eastern part of the CWA. However, the main story for Wed.
should be improving conditions/increasing sunshine (west-to-
east) and the start of a significant warming trend that should
last well beyond the short term period. A mild southerly flow
in advance of an approaching cold front will help boost temps
+10 to +20 degrees above late April climo by Thursday. Models
shows the front moving through the area Thursday night
accompanied by scattered showers. Final NDFD POPs incorporated
blend of 25/00z NBM and ECENS MOS which increased precip
probs to around 60% over north-central PA.
.LONG TERM /FRIDAY THROUGH MONDAY/...
The Fri-Sun period looks mild and somewhat unsettled with the
medium range model guidance generating periods of showers mainly
across the NW portion of the CWA. The placement and especially
timing of these showers is difficult to resolve at this stage
and therefore stayed close to NBM/ECENS/WPC blend for POPS.
While confidence is high in above normal temperatures, the
question is how warm with frontal boundaries, cloud cover and
risk for pcpn all contributing to potential bust scenario on
the high side. There is a pretty strong consensus this cycle
for the greatest risk for widespread showers/storms on Monday
May 1st associated with a rather strong cold front crossing the
Appalachians. Temperatures should trend closer to seasonal
averages behind the front by next Tuesday May 2nd.
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
Low pressure lifting up the east coast will spread lowering
clouds and spotty light rain into central Pa overnight. Model
soundings and SREF prob charts suggest MVFR conditions will
become likely by 04Z-06Z across southern Pa and after midnight
over the northern half of the state. As the storm system moves
closer, expect a steadier rain to develop Tuesday. With the
exception of BFD/IPT, model soundings support IFR CIGs across
central Pa Tuesday.
Wed...AM drizzle/low CIGs possible.
Thu...AM fog possible. Isolated PM tsra impacts possible west.
Fri...Isolated PM tsra impacts possible east.
Sat...Isolated PM tsra impacts possible.