textproduct: State College

WHAT HAS CHANGED

* No significant changes

KEY MESSAGES

1) Short break in the muggy precip pattern today through Tuesday 2) Warmer/more humid with heavy downpours from mid to late week

DISCUSSION

KEY MESSAGE 1: Short break in the muggy precip pattern through Tuesday

More comfortable/less humid/lower dewpoint airmass will expand from NW->SE through Tuesday. Clearing skies, calm wind, recent rain/wet ground, and cooler min temps 45-60F overnight will favor fog formation and reduced visibility mainly across the western and central Alleghenies into early Tuesday morning. Tuesday looks really nice with plenty of sun, comfortable humidity and daytime highs near the historical average in the 75-85F range.

KEY MESSAGE 2: Warmer/more humid with heavy downpours from mid to late week

Mid to late week moisture surge with 70+F dewpoints and tropical PWAT plume spells an increasing risk for very heavy downpours and localized flash flooding Wednesday through Friday. Max heat indices are forecast to reach the mid to upper 90s across the Lower Susquehanna Valley during the afternoon.

AVIATION /01Z TUESDAY THROUGH SATURDAY/

VFR prevailing into this evening as drier air and high pressure move in. Fog remains possible at some of the TAF sites later tonight into Tuesday morning. Restrictions are most likely at KBFD, KIPT, and KUNV, where soils are still moist from recent rainfall. Confidence is greatest at BFD in particular with HREF guidance showing lower probabilities (~20% for less than 5SM) of restrictions at IPT and UNV, but these probs may be underdone. Regardless, the signal and setup for fog is still present and is worth monitoring. Calm winds and clear skies prevail Tuesday with lighter winds.

Outlook... Wed...Restrictions possible with SHRA/TSRA, especially in the south Thu...AM fog possible. Afternoon SHRA/TSRA. Fri-Sat... Daily chances for showers and isolated t-storms. Low VFR to MVFR conditions prevailing most of the time.

CLIMATE

With 5.28 inches of rain on Sunday August 2nd, Williamsport not only set the record daily rainfall for August, but also the 5th all time daily rainfall record since records began in 1895. What's especially remarkable is that yesterday's rain had no influence from a tropical system. Here are the top 8 daily rainfall amounts at Williamsport along with their associated tropical systems:

AMOUNT DATE TROPICAL SYSTEM 1 8.66" June 22, 1972 Agnes 2 6.76" Sept 7, 2011 Lee 3 6.29" Sept 7, 1999 Dennis 4 5.58" Sept 17, 2004 Ivan --> 5 5.28" Aug 2, 2026 N/A <--------- 6 5.22" Aug 24, 1933 Chesapeake - Potomac 7 4.38" Oct 14, 1955 Connie 8 4.32" Aug 29, 1988 Tropical Depression

CTP WATCHES/WARNINGS/ADVISORIES

None.