Tropical Moisture Brings Slight Risk of Excessive Rainfall to the Southwest; Strong to Locally Severe Storms on the Plains

Heavy rain and flash flooding are possible across portions of the Southwest through Friday, where Flood Watches are in effect. Strong to locally severe thunderstorms are possible today across portions of the Plains. A tropical wave is causing heavy rainfall in Puerto Rico and the Virgin Islands, which may cause urban and small stream flooding and landslides today. Read More >

Hot Temperatures and/or High Heat Index Values

Heat Safety Information
The State College NWS Office will issue Advisories and Warnings under the header "PHLNPWCTP (WWUS71 KCTP)" for the following:
Extreme Heat Warning: Heat Index values will attain or exceed 105°F. Extreme Heat Watch: Possibility that Extreme Heat Warning Criteria may be met at longer ranges (12 to 48 hrs out).	Map of Extreme Heat Warning Criteria
Heat Advisory: Heat Index will be equal to or greater than 100°F, but less than 105°F.	Map of Heat Advisory Threshold
For an outlook beyond 3-4 days, see the extended heat index guidance we get from the NWS's Weather Prediction Center (WPC): Maximum Heat Index Outlooks

Cold Temperatures and/or Low Wind Chill Values

Cold Weather Safety Information
The State College NWS Office will issue Advisories and Warnings under the header "PHLNPWCTP (WWUS71 KCTP)" for the following:
Either wind chill or temperatures can meet these criteria (i.e. if there is light/no wind, temperatures alone can trigger these products)
Extreme Cold Warning Values of -20 F or colder along and south of I-80, and -25 F or colder for areas north of I-80	Extreme Cold Warning Map
Cold Weather Advisory Values of -10 F or colder along and south of I-80, and -15 F or colder for areas north of I-80	Cold Weather Advisory Map