479  
FXUS61 KPBZ 010023  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
823 PM EDT SAT MAY 31 2025  
   
SYNOPSIS
 
 
BEHIND A COLD FRONT, SCATTERED LIGHT RAIN SHOWERS AND COOLER  
TEMPERATURES CAN BE EXPECTED THIS AFTERNOON. PRECIPITATION ENDS  
THIS EVENING, AND WIND GUSTS ALSO SUBSIDE. DRY WEATHER AND  
RAPIDLY RISING TEMPERATURE WILL FOLLOW THROUGH EARLY NEXT WEEK,  
AS HIGH TEMPERATURE HITS ABOVE NORMAL READINGS BY TUESDAY.  
 

 
   
NEAR TERM /THROUGH SUNDAY/
 
 
KEY MESSAGES:  
 
- THUNDERSTORM CHANCES END AS THE COLD FRONT EXITS BY MID-  
AFTERNOON.  
- GUSTY NW WIND OF 25-35 MPH EASES THIS EVENING.  
- LOW TEMPERATURES 10 TO 15 DEGREES BELOW NORMAL, WITH FROST  
POTENTIAL IN EASTERN TUCKER COUNTY.  
-------------------------------------------------------------------  
 
THE COLD FRONT HAS SUNK SOUTH OF THE MASON-DIXON LINE, WITH ONLY  
A FEW SHOWERS AND THUNDERSTORMS REMAINING ALONG IT IN NORTHERN  
WEST VIRGINIA. THE ENVIRONMENT OVER THE NEXT HOUR DOES NOT  
APPEAR TOO CONDUCIVE FOR STRONG TO SEVERE STORMS, WITH  
DIMINISHING SURFACE-BASED CAPE AND INCREASING DRY AIR ALOFT,  
WHICH IS HELPING TO LIMIT UPDRAFT STRENGTH. BEHIND THE FRONT,  
COLD ADVECTION IN NORTHWEST FLOW AND UPPER TROUGHING ARE  
SUPPORTING SOME GENERALLY LIGHT RAIN SHOWERS/SPRINKLES  
UNDERNEATH A STRATOCUMULUS DECK. TEMPERATURES ARE STRUGGLING TO  
REMAIN IN THE 50S, AND HAVE EVEN FALLEN INTO THE 40S NORTHWEST  
OF PITTSBURGH, WHILE ZZV/MGW, WHERE COLD ADVECTION IS JUST  
STARTING TO KICK IN, REMAIN AROUND 60. WITH STEEPER LOW-LEVEL  
LAPSE RATES, NORTHWEST WIND GUSTS OF 25 TO 35 MPH CONTINUE THIS  
AFTERNOON.  
 
EXPECT A DRYING TREND TO TAKE HOLD BY THE LATE AFTERNOON/EVENING  
AS INCREASING DRY ADVECTION AND SUBSIDENCE WILL BRING AN END TO  
MOST PRECIPITATION BY SUNSET. CLOUDS WILL ALSO SHOW A DECREASING  
TREND, WITH A MOSTLY CLEAR SKY BY THE OVERNIGHT HOURS.  
STABILIZING LOW LEVELS WILL ALLOW WIND GUSTS TO TAPER THIS  
EVENING, WITH LIGHT WIND OVERNIGHT. THE COMBINATION OF LIGHT  
WIND AND DECREASING CLOUDS WILL LEAD TO OVERNIGHT LOWS SOME 10  
TO 15 DEGREES BELOW NORMAL. WITH EASTERN TUCKER COUNTY EXPECTED  
TO DROP INTO THE MID 30S, AND WITH WINDS BECOMING LIGHT ENOUGH  
AT LEAST IN SHELTERED LOCATIONS, A FROST ADVISORY WAS ISSUED FOR  
THE OVERNIGHT PERIOD.  
 

 
   
SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/
 
 
KEY MESSAGES:  
 
- WARMING TREND WITH PREDOMINANTLY DRY WEATHER.  
- SHOWERS LATE MONDAY COULDN'T BE RULED OUT NORTHEAST OF  
PITTSBURGH.  
-------------------------------------------------------------------  
 
THE SHORT TERM FLOW PATTER REMAINS HIGH CONFIDENCE. A EASTERN  
TROUGH WILL BE REPLACED WITH RIDGING, CLEARING SKIES SUNDAY AND  
LEADING TO A TEMPERATURE REBOUND. HEATING UNDER SUBSIDENCE WILL  
LEAD TO WELL MIXED SURFACE PROFILES, WITH POTENTIALLY A WEAK  
SUBSIDENCE INVERSION OVERHEAD. WITH CLEAR SKIES AND TAPPING INTO  
THIS LAYER, OPTED TO RAISE TEMPERATURES A COUPLE DEGREES OVER  
GUIDANCE DURING THE DAY, AND LOWER DEW POINTS A HAIR. THIS MAY  
STILL RESULT IN BELOW NORMAL TEMPERATURES, BUT THE AIR MAY FEEL  
QUITE DRY.  
 
INTO SUNDAY NIGHT, CLEAR SKIES ARE EXPECTED TO PREVAIL WITH A  
RELAXATION IN WINDS WHICH MAY LEAD TO TEMPERATURES ENDING UP  
NEAR FROST CRITERIA NORTH OF PITTSBURGH WITH EFFICIENT  
RADIATIVE COOLING. NBM PROBS REMAIN <10%, BUT TEMPERATURES TEND  
TO UNDERPREFORM IN VALLEYS AND SHELTERED AREAS WHEN ALL FROST  
INDICATORS ARE FAVORABLE.  
 
MONDAY WILL SEE CONTINUED RIDGING AND A RETURN TO NEAR NORMAL  
TEMPERATURES, THOUGH THERE IS SOME INDICATION SMOKE ALOFT MAY  
RETURN WHICH COULD STAVE A COUPLE OF DEGREES OFF HIGHS. WITH  
LOWER DEW POINTS, MORE DRY SURFACE CONDITIONS ARE FORECAST. A  
SUBSET OF ENSEMBLE MEMBERS HAVE A FAST WEAK WAVE NORTHEAST OF  
PITTSBURGH WHICH MAY RESULT IN A LOW PROBABILITY OF CLOUD COVER  
AND PERHAPS A QUICK RAIN SHOWER, BUT WITH SURFACE PROFILES SO  
DRY, THERE IS ALSO THE CHANCE THAT EVEN WITH FORCING, THAT  
PRECIPITATION WILL NOT MAKE IT TO THE GROUND. STUCK WITH NBM  
POPS FOR NOW. FROST CONCERNS ARE NULL MONDAY NIGHT WITH DEW  
POINT RISES KEEPING LOWS WELL ABOVE THE 30S NECESSARY FOR  
FORMATION.  
 

 
   
LONG TERM /TUESDAY THROUGH SATURDAY/
 
 
KEY MESSAGES:  
 
- WARM TEMPERATURES THIS WEEK WITH MODERATE HEAT RISK BY  
WEDNESDAY AND THURSDAY.  
- RAIN AND SEVERE CHANCES AGAIN LATE-WEEK.  
-------------------------------------------------------------------  
 
CONTINUED RIDGING IS FORECAST WITH HIGH CONFIDENCE. ENSEMBLE  
CLUSTERS HAVE VERY LITTLE VARIABILITY AROUND THE PITTSBURGH  
AREA, WITH HEIGHT MAXES AROUND 588 DM LATE TUESDAY INTO  
WEDNESDAY. THIS WOULD GENERALLY TRANSLATE TO A FORECAST IN THE  
UPPER 80S FOR DAYTIME HIGHS. MODELING THESE RIDGING PATTERNS IN  
THE EAST TYPICALLY COME WITH SOME ISSUES MODELING THE EXTEND OF  
CLOUD COVER AND MAYBE DAYTIME CONVECTION; ADD ON THERE MAY THE  
THE INFLUENCE OF SMOKE ALOFT DURING THIS PERIOD. THIS WILL  
CREATE SOME LOWER PROBABILITY "COOLER SOLUTIONS" OF LOW 80S  
TUESDAY/THURSDAY WITH MID-80S WEDNESDAY.  
 
THE MORE HIGH PROBABILITY SCENARIO IS MOSTLY CLEAR AND DRY  
WEATHER UNDER RIDGING, PUSHING DAYTIME HIGHS INTO THE MID-TO-  
UPPER 80S FOR THIS PERIOD, WITH WEDNESDAY LIKELY THE WARMEST  
DAY. CHANCES OF >80F ALL THREE DAYS ARE 80% TO 100% APART FOR  
THE RIDGES, AND CHANCES OF >90F ARE ~50% FOR PITTSBURGH AND  
RIVER VALLEYS WEDNESDAY AND THURSDAY, AND AS HIGH AT 80% FOR THE  
OHIO RIVER VALLEY ALONG THE OHIO/WV BORDER. URBAN EFFECTS MAY  
INCREASE THESE PROBABILITIES LOCALLY. COMBINE THIS WITH  
OVERNIGHT LOWS ONLY GETTING TO THE UPPER 60S TO LOW 70S, HEAT  
RISK INCREASES TO MODERATE LEVELS WEDNESDAY AND THURSDAY.  
CONFIDENCE IN THE FORECAST IS HIGHER WEDNESDAY THAN THURSDAY  
WITH SOME CLOUD AND PRECIPITATION TIMING UNCERTAINTY WITH THE  
NEXT DISTURBANCE.  
 
PRECIPITATION SPREAD IS THE HIGHEST THURSDAY AND FRIDAY,  
INDICATING SOME SUBTLE DIFFERENCES IN TIMING THE NEXT RAIN  
CHANCES. SOME SEVERE CHANCES COME WITH THIS WAVE, AS EVIDENCED  
IN A 5% TO 15% CHANCE WITHIN 25MILES ON THE CSU-MLP PRODUCT.  
CHANCES OF RAIN >1" ARE LOW (AROUND 15%) FOR NOW, THOUGH LIKELY  
A TAD LOW DUE TO THE AFOREMENTIONED TIMING UNCERTAINTY. THIS  
SHOULD BRING SOME RELIEF, HEIGHT FALLS, AND A RETURN TO MORE  
QUASI-ZONAL FLOW, WITH MOST OF THE TEMPERATURE SPREAD NEXT  
WEEKEND ENCOMPASSED IN THE 70S FOR HIGHS.  
 

 
   
AVIATION /01Z SUNDAY THROUGH THURSDAY/
 
 
DRY ADVECTION AND  
INCREASING SUBSIDENCE WITH APPROACHING SURFACE HIGH PRESSURE WILL  
ALLOW FOR A DECREASING TREND IN CLOUD COVER. THIS WILL LEAD TO  
AREAWIDE VFR CONDITIONS OVERNIGHT. CANNOT TOTALLY RULE OUT PATCHY  
FOG IN AREAS THAT HAVE RECEIVED RAIN LATELY, BUT DRY ADVECTION MAY  
MITIGATE THIS OUTCOME.  
 
VFR WILL CONTINUE TOMORROW UNDER THE INFLUENCE OF HIGH PRESSURE  
AND DRY ADVECTION. TOMORROW AFTERNOON, GUSTY CONDITIONS (15-20  
KNOTS) ARE EXPECTED OVER WESTERN PENNSYLVANIA. WILDFIRE SMOKE  
IS EXPECTED TO REACH OUR REGION TOMORROW. CURRENTLY, THIS IS NOT  
EXPECTED TO IMPACT VISIBILITY AT THE SURFACE.  
 
OUTLOOK...  
SUBSIDENCE AND DRY CONDITIONS ARE LIKELY TO PERSIST UNDER  
RIDGE BUILDING TO START THE NEXT WEEK.  
 

 
   
PBZ WATCHES/WARNINGS/ADVISORIES
 
 
PA...NONE.  
OH...NONE.  
WV...FROST ADVISORY FROM 1 AM TO 8 AM EDT SUNDAY FOR WVZ514.  
 

 
 

 
 
SYNOPSIS...FRAZIER  
NEAR TERM...CL  
SHORT TERM...MILCAREK  
LONG TERM...MILCAREK  
AVIATION...CL/LUPO  
 
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