textproduct: State College

WHAT HAS CHANGED

* THE FLOOD WATCH HAS BEEN EXPANDED IN AREA TO INCLUDE THE NORTHERN TIER OF CENTRAL PA AND EXTENDED IN TIME THROUGH 2 AM TONIGHT.

KEY MESSAGES

1) LOCALIZED FLASH AND URBAN FLOODING IMPACTS ARE POSSIBLE AGAIN THIS AFTERNOON AND EVENING

DISCUSSION

KEY MESSAGE 1: LOCALIZED FLASH AND URBAN FLOODING IMPACTS ARE POSSIBLE AGAIN THIS AFTERNOON AND EVENING

WAVES OF LOW PRESSURE MOVING ALONG A STATIONARY FRONTAL ZONE AND INTERACTING WITH A FAVORABLE THERMODYNAMIC ENVIRONMENT WILL CONTINUE TO PROMOTE INITIATION OF SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON THROUGH THE FIRST HALF OF TONIGHT. THUNDERSTORMS WILL BE CAPABLE OF HIGHLY EFFICIENT RAINFALL RATES WITH REPEAT/TRAINING POTENTIAL.

THE GREATEST RISK FOR FLASH FLOODING HAS SHIFTED FROM THE EASTERN INTO THE WEST/SOUTHWEST PORTION OF THE FORECAST AREA (BASED ON THE HREF AND REFS MODEL OUTPUT) WHERE FFGS ARE LOWER AND TERRAIN INFLUENCES ARE MORE IN-PLAY. HOWEVER, CONVECTION IS ALSO FIRING ALONG ZONES OF CONVERGENCE IN THE NORTHERN TIER, SO WE HAVE EXPANDED THE WATCH TO INCLUDE THAT AREA. WITH CAMS SHOWING THE POTENTIAL FOR HEAVY RAIN THROUGH MIDNIGHT, WE HAVE EXTENDED THE END TIME OF THE WATCH TO 06Z TUE.

THE SEVERE STORM THREAT ALSO DOES NOT APPEAR TO BE AS ROBUST AS IN PRIOR DAYS (54 SVR+TOR WARNINGS IN THE PAST 3 DAYS). THIS IS REFLECTED IN MOST OF THE AREA IN A GENERAL OR NON-SEVERE TSTM OUTLOOK AND ONLY LEVEL 1/5 MRGL RISK COVERING THE SOUTHWEST THIRD OF THE CWA WHERE HIGHER CAPE AND STEEPER LAPSE RATES WILL BE MAXIMIZED.

THE PATTERN FOR THE REST OF THE WEEK CAN BE SUMMARIZED MORE OR LESS BY TYPICAL EARLY JULY UNSETTLED/HUMID SUMMERTIME CONDITIONS WITH A LOW PROBABILITY OF SIGNIFICANT HAZARDOUS WEATHER.

AVIATION /01Z TUESDAY THROUGH SATURDAY/

Mid evening update.

Adjusted fcst for AOO, UNV, and JST. Showers and storms are moving and weakening, but at a slower rate. Thus added thunder to these 3 sites for the next few hours.

More information below.

Band of showers and storms to the west, should weaken as they move east.

Main issue later tonight into Tuesday morning will be low clouds and fog.

Some improvement later Tuesday.

Drier and better conditions Wednesday into Thursday.

Outlook...

Wed...Improving conditions. Still a chance of showers and storms near JST.

Thu...Mainly dry early. Chance of showers and storms late.

Fri...Showers and storms possible again late.

Sat...Chance of showers and storms.

CTP WATCHES/WARNINGS/ADVISORIES

Flood Watch until 2 AM EDT Tuesday for PAZ004>006-010>012- 017>019-024>028-033>037-041-042-045-046-049>053-056>059- 063>066.