textproduct: State College

WHAT HAS CHANGED

* Increased cloud coverage and introduced a few sprinkles for the Ncent Mtns of PA late this morning through mid afternoon.

KEY MESSAGES

1) Much drier air is moving in, and will result in a couple of fair and dry days.

2) Upper low over eastern Canada will spin a compact closed low through the northeast Friday-Saturday. Colder air and a dry spell will follow.

DISCUSSION

KEY MESSAGE 1: Much drier air is moving in, and will result in a fair and rain-free day.

850 mb thermal trough dropping south from New York state through this afternoon with about 3 deg C of additional cooling at that level through 22Z.

This feature will help to create an expanding area of stratocu south across the CWA. A glancing blow of cooler temps in the 700-500 mb layer will lead to some deeper clouds across the NE portion of our CWA with a few sprinkles expected there in the 17-22Z window.

Dewpoints have dipped into the mid-upper 40s over all of the CWA, except for the far SE. They should also visit the u40s shortly with continued dry/cool advection.

Max temps today will range from the low to mid 60s across the Northern Tier to the low-mid 70s in the Scent Valleys.

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KEY MESSAGE 2: Upper low over eastern Canada will spin a compact closed low through the northeast Friday-Saturday. Colder air and a dry spell will follow.

High pressure aloft and at the sfc will set up just to our west, and deflect a compact upper low off to our east, but not by much. The cold front associated with the upper feature will arrive late Friday. Other than kicking up the wind a little late Fri-Fri night, it should not generate measurable precip in the CWA due to the minimal moisture held by the system. The more- notable change will be the reduction in temps on Saturday as 8H temps dip close to 0C in the NE and low single digits elsewhere. NBM does not seem to reflect this possibility, so we went with a blend of MOS guidance and NBM for maxes. Sat night could get pretty chilly as the wind dies down overnight. Some places in the nrn tier could go below 40F, with all the CWA hitting the 40-45F range for mins. Temps should rebound into the 70s Sunday.

The chance of precip inches up into the 20-30pct range for the first half of the new week starting with another shot of lowered heights/pressure aloft around Monday. But, there really aren't any strong signals for a widespread rainfall for days 4-8 as the upper ridge to our west holds firm and makes it tough for Gulf and Pacific moisture to get into PA.

AVIATION /14Z THURSDAY THROUGH MONDAY/

VFR conditions are expected through the TAF period with mainly dry conditions. A few sprinkles possible this afternoon at KIPT.

Northwest winds will increase through the morning to 10 to 15 knots with gusts of 20 to 25 knots likely. Gusts could approach 30 knots during the afternoon at MDT and LNS as vertical mixing peaks at 6 kft AGL and mixes down winds in the mid-upper 20s (KTS) at the top of the layer.

Cool air aloft combined with diurnal heating will allow for scattered to broken clouds to develop with bases between 4000 and 7000 feet. Skies quickly clear out after sunset and winds will decrease to less than 5 knots.

Outlook...

Thu-Mon...VFR with no significant weather expected.

CTP WATCHES/WARNINGS/ADVISORIES

None.