textproduct: State College

WHAT HAS CHANGED

* Allowed the Winter Weather Advisories across Central and Southern PA to expire at 18Z today as the first round of precip is ending and sfc temps are inching just above freezing across that region.

KEY MESSAGES

1) Light freezing rain brings additional minor ice accumulation and the potential for slippery road conditions into late this afternoon across the area north and east of KIPT.

2) Periods of much-needed rain expected from Wednesday through the first weekend of March; wet pattern favored into next week with above-normal rainfall likely.

3) Significant springtime warming pattern ramps up from late week into the second week of March.

DISCUSSION

KEY MESSAGE 1: Light freezing rain brings additional minor ice accumulation and the potential for slippery road conditions into late this afternoon across the area north and east of KIPT.

A low-level warm advection regime (via a 30-40 kt swrly speed max AOA 2 kft AGL) will glide up and over the near to slightly sub-freezing cold dome of air entrenched across CPA and the Susq valley to sustain a few periods of light freezing rain changing to rain across Ncent PA with plain rain elsewhere.

Additional minor ice accumulation 0.01-0.05" expected this afternoon across the region to the north and east of KIPT.

Temperatures slowly warm above the freezing mark from southwest to northeast through the rest of this afternoon into tonight effectively transitioning ptype to plain rain. Fog and low stratus may be expansive overnight with lingering areas of light rain and drizzle.

KEY MESSAGE 2: Periods of much-needed rain expected from Wednesday through the first weekend of March; wet pattern favored into next week with above-normal rainfall likely.

On the heels of one of the driest winter seasons on record (see climate section), periods of much needed rainfall are expected from Wednesday through the first weekend of March. The wet pattern is favored to last into the second week of March based on the latest CPC 6-10/8-14 day precip outlooks. Surges of Pacific and Gulf moisture interacting with wavy or slow moving frontal zones is projected to deliver total rainfall amounts between 1 and 3 inches across CPA through next Monday.

KEY MESSAGE 3: Significant springtime warming pattern ramps up from late week into the second week of March.

Persistent and amplified Southeast U.S./Atlantic centered upper ridging will promote a significant springtime warming trend from late week into the second week of March. Fcst max and min temperatures will be 15-30 degrees above the historical average Fri-Tue and may challenge daily records.

AVIATION /19Z TUESDAY THROUGH SUNDAY/

Periods of light to briefly moderate rain will continue fall across Central and SW PA airfields into tonight, while KIPT and points North and East could hang onto the light freezing precipitation through about 22Z today before following the same course of precip as elsewhere.

High confidence in a prolonged period of IFR/LIFR conditions for all Central PA TAF sites from late today through Wednesday morning, though JST will see a few hours where ceilings briefly rise to MVFR or even VFR during the mid to late afternoon today.

A 40 to 50 knot southwesterly low-level jet moves over the region late today and tonight. While the strongest winds are expected to remain above 2000 feet for much of the day, LLWS concerns will develop at Central and Western PA TAF sites (likely excluding KIPT, KMDT and KLNS) with the strongest wind shear expected at JST early this evening.

Outlook...

Wed-Sat...Restrictions at times in periods of rain.

CLIMATE

It was a very dry meteorological winter (Dec-Jan-Feb). Some of our long-term climate stations cracked the top-ten of their driest winter seasons (Dec 1st-Feb 28/29th).

Station Total Precip Rank Period of (inches) (Driest) Record (since) ------------ ------------ -------- -------------- Altoona 4.15 5th 1948 Bradford 4.25 2nd 1957 Harrisburg 6.05 17th 1888 Johnstown 4.93 3rd 1892 Williamsport 5.24 15th 1895 State College 4.52 8th 1893

CTP WATCHES/WARNINGS/ADVISORIES

Winter Weather Advisory until 4 PM EST this afternoon for PAZ006-037-041-042.