955  
FXUS61 KPBZ 191703  
AFDPBZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE PITTSBURGH PA  
103 PM EDT SUN JUL 19 2026  
   
WHAT HAS CHANGED  
 
AIR QUALITY ISSUES LINGER TODAY DUE TO FINE PARTICULATES FROM  
CANADIAN WILDFIRE SMOKE. SEVERE WEATHER AND FLASH FLOODING  
THREATS RETURN TUESDAY WITH ANOTHER LOW PRESSURE SYSTEM.  
 
 
   
KEY MESSAGES  
 
1) CODE ORANGE AIR QUALITY ALERTS ISSUED FOR PARTS OF WESTERN PA  
AND NORTHERN WV TODAY DUE TO LINGERING CANADIAN WILDFIRE SMOKE  
 
2) ENHANCED RISK FOR SEVERE WEATHER ON TUESDAY; SLIGHT RISK FOR  
EXCESSIVE RAINFALL  
 
 
   
DISCUSSION  
 
KEY MESSAGE 1...  
DESPITE THE RECENT THUNDERSTORM ACTIVITY AND COLD FRONT PASSAGE,  
CANADIAN WILDFIRE SMOKE LINGERS ACROSS THE REGION TODAY. AS A  
RESULT, AIR QUALITY LEVELS HAVE BEEN BOUNCING BETWEEN YELLOW  
AND ORANGE, SPURRING THE ISSUANCE OF AIR QUALITY ALERTS FOR  
PORTIONS OF WESTERN PENNSYLVANIA AND NORTHERN WEST VIRGINIA  
UNTIL MIDNIGHT TONIGHT.  
 
KEY MESSAGE 2...  
A POWERFUL STORM SYSTEM TRACKS FROM THE PACIFIC NORTHWEST  
TOWARD THE GREAT LAKES OVER THE NEXT 2 DAYS. BY TUESDAY, A  
COMBINATION OF HIGH ENERGY (1500J/KG TO 2500J/KG) AND STRONG  
WIND SHEAR (EFFECTIVE SHEAR 35KT-45KTS) IS EXPECTED TO CREATE A  
SIGNIFICANT RISK OF SEVERE STORMS ACROSS THE ENTIRE REGION,  
LEADING THE STORM PREDICTION CENTER TO ISSUE AN ENHANCED RISK  
(LEVEL 3 OUT OF 5) FOR OUR ENTIRE AREA. RESIDENTS SHOULD PREPARE  
FOR DAMAGING WIND GUSTS, THOUGH TORNADOES AND LARGE HAIL ARE  
ALSO POSSIBLE WITH ANY DISCRETE SUPERCELL STORMS THAT ARE ABLE  
TO DEVELOP. A SEVERE T-STORM OR TORNADO WATCH WILL LIKELY BE  
ISSUED DURING SOME PERIOD OF TIME ON TUESDAY.  
 
ANOMALOUSLY HIGH MOISTURE LEVELS WITH PWATS REACHING THE 80TH  
TO 90TH PERCENTILE RAISE THE RISK OF FLASH FLOODING TUESDAY  
EVENING. TRAINING STORMS COULD POTENTIALLY CREATE LOCALIZED  
SWATHS OF 2-4 INCHES OF RAINFALL IN A SHORT PERIOD OF TIME.  
LOCATIONS THAT SAW SIGNIFICANT RAINFALL FROM THIS PAST WEEKEND'S  
THUNDERSTORM ACTIVITY MAY BE ESPECIALLY VULNERABLE TO FLASH  
FLOODING DUE TO ALREADY SATURATED SOILS AND INCREASED RUNOFF.  
THE WEATHER PREDICTION CENTER (WPC) HAS ISSUED A SLIGHT RISK FOR  
PORTIONS OF REGION AND A FLASH FLOOD WATCH MAY BECOME NECESSARY  
PENDING FURTHER CLARITY FROM HIGH-RESOLUTION MODEL DATA OVER  
COMING DAYS.  
 
 
   
AVIATION /18Z SUNDAY THROUGH FRIDAY/  
 
CLOUDS HAVE LIFTED AND SCATTERED YIELDING VFR THIS AFTERNOON  
WHICH IS EXPECTED TO BE THE RULE THROUGH THE REMAINDER OF THE  
TAF PERIOD. THE EXCEPTION COULD BE FOG IMPACTS TOMORROW MORNING  
WITH LARGELY CLEAR SKIES AND LIGHT WINDS. MOST FAVORED AREAS  
WOULD BE OUR NORTHERN AND EASTERN PORTS, WHERE THE MOST RAIN WAS  
SEEN YESTERDAY. AT THIS TIME, CONFIDENCE IS TOO LOW TO INCLUDE  
IN TAFS. A LOWER END VFR SCT TO FEW STRATOCU DECK PREVAILS THIS  
AFTERNOON BEFORE ERODING NEAR SUNSET. LIGHT WINDS OUT OF THE  
NORTH/NORTHWEST PREVAIL TODAY BEFORE WINDS BECOME LIGHT AND  
VARIABLE TONIGHT.  
 
VFR CONDITIONS CONTINUE TOMORROW UNDER MOSTLY SUNNY SKIES WITH  
LIGHT WINDS.  
 
OUTLOOK... RESTRICTIONS RETURN IN SHOWERS AND THUNDERSTORMS ON  
TUESDAY WITH A COLD FRONT.  
 
 
   
PBZ WATCHES/WARNINGS/ADVISORIES  
 
PA...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR PAZ007-013-  
014-020>022-029-031-073>078.  
OH...NONE.  
WV...AIR QUALITY ALERT UNTIL MIDNIGHT EDT TONIGHT FOR WVZ001>004-  
012-021-509>514.  
 
 
 
 
 
DISCUSSION...CERMAK/HEFFERAN  
AVIATION...AK  
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