847  
FXUS61 KCTP 021500  
AFDCTP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE STATE COLLEGE PA  
1100 AM EDT MON JUN 2 2025  
   
SYNOPSIS  
 
* DRY WEATHER EXPECTED THROUGH MIDWEEK WITH HAZY SUNSHINE FROM  
CANADIAN WILDFIRES  
* TURNING INCREASINGLY WARMER AND MORE HUMID LATER THIS WEEK AS  
THE PATTERN SHIFTS INTO SUMMER MODE  
* SHOWERS AND THUNDERSTORMS RETURN TO THE FORECAST FROM THURSDAY  
INTO THE FIRST FULL WEEKEND OF JUNE  
 
 
   
NEAR TERM /THROUGH TONIGHT/  
 
CRAZY RISE IN TEMP AT BFD WHERE IT ROSE ALMOST 30 DEGREES IN  
JUST 3 HRS. MANY OTHER LOCATIONS ALSO POPPED UP VRY FAST WHEN  
THE JUNE SUN HIT THEM. SMOKE TO THE LEFT AND RIGHT OF US THIS  
MORNING. BUT THE PLUME THAT WAS TO THE WEST OF THE CWA IS  
DIVING SOUTHEASTWARD, AND SHOULD BE OVERHEAD/CENTERED ON US  
THIS AFTN. HAVE NOT ADJUSTED TEMPS FOR THE AFTN, BUT HAVE  
ADJUSTED DEWPOINTS DOWN A LITTLE, ESPECIALLY IN THE NORTH AND  
EAST WHERE THE DRY AIR ABOVE THIS MORNING'S INVERSION SHOULD MIX  
DOWN. THERE IS STILL SOME CHC FOR THE DEWPOINTS TO RISE THIS  
AFTN AS ALL GUIDANCE HAS A RISE OF 5-10F FOR MOST LOCATIONS.  
 
PREV...  
MAINLY CLEAR AND UNSEASONABLY CHILLY START TO WHAT IS LIKELY  
THE COLDEST MORNING UNTIL THE FALL SEASON. SEVERAL MESONET OBS  
IN MCKEAN, ELK, AND WARREN COUNTY (ALONG WITH A FEW ADDITIONAL  
WELL-KNOWN COLD SPOTS) HAVE PRINTED MIN TEMPS IN THE 29-32F  
RANGE.  
 
FOG IN THE RIVER AND STREAM VALLEYS ACROSS THE NORTHWEST  
ALLEGHENIES WILL DISSIPATE THIS MORNING AS TEMPERATURES WARMUP  
QUICKLY UNDER HAZY SUNSHINE; THIS HAS ALSO ENDED THE FROST  
THREAT AND THE ADVISORY WAS ALLOWED TO EXPIRE.  
 
HIGH PRESSURE WILL PROVIDE THE FIRST OF 3 DRY DAYS ACROSS CPA  
WITH HIGHS FROM THE MID 60S OVER THE NORTHERN AND WESTERN  
MOUNTAINS TO THE LOW 70S ELSEWHERE. HRRR VERTICALLY INTEGRATED  
SMOKE SUGGESTS HAZY SUNSHINE THROUGHOUT THE DAY WHICH SHOULD  
LEAD TO A VIVID AND VIBRANT SUNSET LATER THIS EVENING.  
 
MAINLY CLEAR TO PARTLY CLOUDY AND NOT AS COLD TONIGHT WITH MIN  
TEMPS RISING +10-20F NIGHT/NIGHT INTO THE 45-55F RANGE OR +/- 3  
DEGREES OF EARLY JUNE CLIMO.  
 
 
   
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/  
 
RIDGING AT THE SURFACE AND ALOFT MIGRATING OVER CPA SHOULD  
ENSURE TWO MORE DRY DAYS TO ROUND OUT THE SHORT TERM PERIOD  
THROUGH MIDWEEK. WE ADDED HAZE TO THE WX GRID ON TUESDAY BASED  
ON A BLEND OF THE HRRR NEAR-SFC SMOKE DENSITY/VERTICALLY  
INTEGRATED SMOKE AND COORDINATION WITH NEIGHBORING WFOS.  
 
THE PATTERN SHIFTS INTO SUMMER MODE BY WEDNESDAY WITH BROAD SW  
FLOW TRANSPORTING VERY WARM AIR AND HIGHER (60+) DEWPOINTS INTO  
CPA. WHILE IT'S NOT CLEAR HOW MUCH SMOKE MAY LINGER AND  
POTENTIALLY SHAVE OFF FROM DAYTIME MAX TEMPS, HIGHS ON  
WEDNESDAY ARE PROJECTED TO REACH THE 80-90F RANGE GOING FULL-  
SEND ON SUMMER. THE HEAT AND HUMIDITY MAY BE SOMEWHAT IMPACTFUL  
(DESPITE MAX HEAT INDEX VALUES ONLY IN THE LOW 90S) GIVEN THE  
EARLY SEASON RAMP UP FOLLOWING A VERY WET AND RELATIVELY COOL  
MAY; THE LACK OF HEAT ACCLIMATION WILL ALSO BE A KEY FACTOR. THE  
HEATRISK FORECAST PEAKS IN THE MODERATE LEVEL WHICH WOULD  
SUPPORT POSSIBLE IMPACTS IN SOME HEALTH SYSTEMS AND HEAT-  
SENSITIVE INDUSTRIES.  
 
 
   
LONG TERM /THURSDAY THROUGH SUNDAY/  
 
03Z UPDATE: NO SIGNIFICANT CHANGES TO THE EXTENDED FORECAST WITH  
THE EVENING UPDATE. SHOWERS AND THUNDERSTORMS RETURN TO THE  
FORECAST FOR THE SECOND HALF OF THE WEEK.  
 
PREVIOUS DISCUSSION...  
 
HIGH PRESSURE BEGINS TO SHIFT FURTHER EAST THURSDAY  
MORNING WITH MODEL GUIDANCE OUTLINING MODEST AGREEMENT IN A WEAK  
AREA OF LOW PRESSURE WEST OF THE AREA GRADUALLY MOVING CLOSER  
TO CENTRAL PENNSYLVANIA. SURGING PWATS AND LOWERING HEIGHTS  
AHEAD OF THIS AREA OF LOW-PRESSURE SUPPORT PRECIPITATION  
MENTIONS JUST AHEAD OF SUNRISE ON THURSDAY. AS LOW-PRESSURE  
APPROACHES AND BETTER MOISTURE SPREADS INTO THE AREA THURSDAY  
AFTERNOON, WIDESPREAD RAIN SHOWERS APPEAR INCREASINGLY LIKELY ON  
FRIDAY AS AN ASSOCIATED COLD FRONT APPROACHES THE AREA. COLD  
FRONT IS EXPECTED TO BE BEGINNING TO DECAY AT THIS JUNCTURE WITH  
LOWER SHEAR VALUES AND MARGINAL CAPE. GIVEN THESE PARAMETERS,  
LOW CONFIDENCE ON ANY SEVERE WEATHER CONCERNS ON THURSDAY.  
 
CONFIDENCE IN THE FORECAST BECOMES LOWER AFTER FRIDAY; HOWEVER,  
WITH ECMWF DETERMINISTIC GUIDANCE INDICATING DRIER CONDITIONS  
EARLY SATURDAY THROUGH THE END OF THE LONG-TERM FORECAST PERIOD.  
RECENT GFS DETERMINISTIC GUIDANCE DOES HOLD MOISTURE FURTHER  
INTO CENTRAL PENNSYLVANIA FOR THE FIRST HALF OF SATURDAY BEFORE  
TRENDING DRIER THROUGH THE END OF PERIOD. GIVEN THIS GUIDANCE,  
HAVE OPTED TO STICK CLOSE TO NBM GUIDANCE SATURDAY AND SUNDAY;  
HOWEVER, IN FUTURE CYCLES COULD REALISTICALLY SEE SUNDAY  
TRENDING DRIER OVERALL.  
 
 
   
AVIATION /15Z MONDAY THROUGH FRIDAY/  
 
HIGH PRESSURE WILL PROVIDE THE REGION WITH MAINLY CLEAR SKIES,  
DRY WEATHER, AND VFR CONDITIONS INTO TUESDAY AND WEDNESDAY. A  
FEW HIGH CLOUDS ARE AROUND TO START THE MORNING TODAY, AND WE  
COULD SEE SCATTERED HIGH CLOUDS MOVING ACROSS CENTRAL PA THIS  
AFTERNOON, OTHERWISE IT WILL BE MOSTLY CLEAR.  
 
A PLUME OF CANADIAN WILDFIRE SMOKE WILL BE INJECTED INTO THE  
UPPER ATMOSPHERE OVER THE PENNSYLVANIA AIRSPACE THIS EVENING AND  
INTO TUESDAY. SO FAR THERE HAS NOT BEEN ANY SURFACE LEVEL  
IMPACTS FROM THE SMOKE, MAINLY JUST HAZY SKIES. ADDITIONAL  
MIXING ON TUESDAY COULD BRING SMOKE LOWER INTO THE ATMOSPHERE,  
BUT SURFACE IMPACTS STILL REMAIN UNLIKELY.  
 
OUTLOOK...  
 
TUE-WED...VFR EXPECTED.  
 
THU...POTENTIAL BRIEF RESTRICTIONS IN SHRA/TSRA NW.  
 
FRI...NUMEROUS SHRA/TSRA, ESP NW. BRIEF REDUCTIONS TO MVFR AND  
IFR IN THE TSRA.  
 
 
   
CLIMATE  
 
MAY 2025 PRECIPITATION RANKINGS  
 
SITE 2025 | WETTEST MAY ON RECORD  
-----------------------------------------------------------  
HARRISBURG* 10.02" WETTEST | 9.71" IN 1989 (PREVIOUS)  
WILLIAMSPORT 7.18" 7TH WETTEST | 9.91" IN 1919  
ALTOONA* 7.34" WETTEST | 7.31" IN 1960 (PREVIOUS)  
STATE COLLEGE 7.56" T-7TH WETTEST | 9.45" IN 1894  
 
(* DENOTES THAT MAY 2025 SET A NEW RECORD IN PRECIPITATION IN  
THEIR RESPECTIVE LOCATIONS. THE PREVIOUS RECORD REMAINS LISTED  
UNDER THE "WETTEST MAY ON RECORD" COLUMN.)  
 
 
   
CTP WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
SYNOPSIS...STEINBUGL  
NEAR TERM...DANGELO/STEINBUGL  
SHORT TERM...STEINBUGL  
LONG TERM...BAUCO/NPB  
AVIATION...BOWEN  
CLIMATE...NPB  
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