textproduct: State College

WHAT HAS CHANGED

* No significant changes.

KEY MESSAGES

1) Hottest temperatures of the year so far forecast early next week

DISCUSSION

KEY MESSAGE 1: Hottest temperatures of the year so far forecast early next week

Daytime high temperatures will be steadily rising today through early in the upcoming week.

An anomalous upper ridge building over the east-central U.S. will deliver summerlike conditions this weekend through the first part of the new week.

High temperatures will peak in the mid 80s to lower 90s Monday and Tuesday and could challenge daily records in some locations.

Manual adjustments were made to lower NBM maxT by a few degrees due to a known systematic bias correction issue identified during the shoulder seasons.

This should also keep max heat indices under 100F for the most part. However, heat risk impacts will continue to be monitored given the quick ramp- up in heat and limited acclimation time.

There will be a chance for some stray afternoon and early evening showers or thunderstorms Monday and Tuesday.

A cold front (accompanied by more widespread and frequent showers/t-storms) brings relief next Wednesday into Thursday. Temperatures are forecast to cool down back to historical/climo averages for late May for the end of next week.

AVIATION /07Z SATURDAY THROUGH WEDNESDAY/

Mainly clear skies will prevail through Saturday morning as high pressure sets up off the Mid-Atlantic coast. VFR clouds will increase west to east as a shortwave tracks across the northern periphery of this high pressure & its concurrent ridge Saturday afternoon/evening, bringing scattered showers with any flight restrictions looking to be brief and unlikely outside of any locally heavier showers. A few thunderstorms may develop across the Allegheny Plateau (KBFD/KJST) where the HREF mean MUCAPE values are around 100 J/kg. As precipitation progresses eastward, height rises and increasingly stable conditions will result in a downtrend in activity.

As the shortwave exits our area during the evening, ridging will continue to build across the region, resulting in residual low-level moisture becoming trapped beneath a subsidence inversion. As a result, MVFR/IFR restrictions are expected to develop after 22Z-23Z Saturday across the Allegheny Plateau (KBFD/KJST), with lesser confidence in evening/overnight flight restrictions east of the Alleghenies due to downsloping flow and less antecedent moisture.

Outlook...

Sun-Tue...Mainly VFR. Patchy A.M. fog. Isolated P.M. shower or t-storm possible.

Wed...Restrictions probable through Wednesday night with showers/storms along CFROPA.

CLIMATE

Daily record max temperature for May 18-19:

5/18 5/19 Harrisburg 94 in 1962 95 in 1962 Williamsport 95 in 1962 96 in 1996 Altoona 91 in 1962/1996/2017 92 in 1996 Bradford 85 in 1962 85 in 1962 State College 92 in 1962 92 in 1934/1996

Please note: State College Co-operative observations are a 24-hour summary taken once per day around 7 AM (7AM-7AM). Therefore, a max temp occurring in the daylight or late in the day is usually reported in the _next_ day's observation. Also, the same min temp may be reported on two consecutive days if the min occurs at observation time.

CTP WATCHES/WARNINGS/ADVISORIES

None.