848
FXUS01 KWBC 110742
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
341 AM EDT FRI AUG 11 2023
VALID 12Z FRI AUG 11 2023 - 12Z SUN AUG 13 2023
...DANGEROUS HEAT WILL PERSIST ACROSS MUCH OF THE SOUTHERN TIER OF
THE U.S...
...SEVERE THUNDERSTORMS POSSIBLE TODAY FOR THE MIDWEST AND
SATURDAY FOR THE OHIO VALLEY/NORTHEAST...
...MONSOONAL SHOWERS FOR THE FOUR CORNERS REGION WITH GENERALLY
BELOW TO NEAR AVERAGE TEMPERATURES IN THE WEST...
DANGEROUS HEAT WILL CONTINUE FOR MUCH OF THE SOUTHERN TIER OF THE
U.S. INTO THE WEEKEND AS A STAGNANT UPPER-LEVEL HIGH REMAINS IN
PLACE. WIDESPREAD HEAT-RELATED ADVISORIES AND WARNINGS ARE IN
EFFECT FROM FLORIDA WEST THROUGH THE GULF COAST AND INTO THE LOWER
MISSISSIPPI VALLEY AND CENTRAL/SOUTHERN PLAINS, WITH THE MOST
EXCESSIVE HEAT EXPECTED OVER PORTIONS OF TEXAS AND THE LOWER
MISSISSIPPI VALLEY. FORECAST HIGHS FRIDAY AND SATURDAY RANGE FROM
THE MID-90S IN FLORIDA AND THE CENTRAL PLAINS TO THE LOW 100S IN
OKLAHOMA AND THE LOWER MISSISSIPPI VALLEY AND THE MID- TO UPPER
100S INTO TEXAS. WHEN COMBINED WITH HIGH HUMIDITY VALUES, HEAT
INDICES WILL RANGE BETWEEN 110-120 DEGREES FOR MANY LOCATIONS.
NUMEROUS RECORD-TYING/BREAKING HIGHS ARE FORECAST BOTH DAYS, WITH
SIMILARLY RECORD-LEVEL WARM LOW TEMPERATURES IN THE UPPER 70S TO
LOW 80S PROVIDING LITTLE RELIEF FROM THE HEAT OVERNIGHT.
UNFORTUNATELY, THE HEAT LOOKS TO CONTINUE BEYOND THE CURRENT
FORECAST PERIOD, WITH SOME MODERATION POTENTIALLY BY THE MIDDLE OF
NEXT WEEK. AREAS NORTH OF THE GULF COAST IN THE SOUTHEAST AND
INTO THE CAROLINAS LOOK TO BE SPARED SOME OF THE MOST OPPRESSIVE
HEAT AS A LINGERING FRONTAL BOUNDARY HELPS TO TRIGGER SHOWER AND
THUNDERSTORMS.
MEANWHILE, TO THE NORTH, ENERGETIC UPPER-LEVEL FLOW ABOVE A
CONSOLIDATING LOWER PRESSURE SYSTEM ACROSS THE MIDWEST/PLAINS WILL
PROVIDE THE FOCUS FOR SHOWER AND THUNDERSTORM CHANCES FRIDAY. THE
STORM PREDICTION CENTER HAS ISSUED A SLIGHT RISK (LEVEL 2/5) OF
SEVERE WEATHER FOR THE MID- TO UPPER MISSISSIPPI VALLEY AND LOWER
MISSOURI VALLEY WHERE SOME OF THE STRONGER STORMS MAY PRODUCE SOME
INSTANCES OF DAMAGING WINDS AND LARGE HAIL. THE SYSTEM AND
SUBSEQUENT STORM CHANCES WILL SHIFT EASTWARD INTO THE NORTHEAST
AND OHIO VALLEY ON SATURDAY, WITH ANOTHER SLIGHT RISK OF SEVERE
WEATHER IN PLACE FOR THE CONTINUED RISK OF SOME DAMAGING WINDS AND
LARGE HAIL. ADDITIONAL STORMS ARE EXPECTED TO THE SOUTHWEST OVER
PORTIONS OF THE CENTRAL/SOUTHERN HIGH PLAINS AS A COLD FRONT SAGS
SOUTHWARD ACROSS THE REGION. ANOTHER STORM SYSTEM WILL BRING STORM
CHANCES BACK TO THE CENTRAL/NORTHERN PLAINS INTO THE MIDWEST
SATURDAY AFTERNOON INTO EARLY SUNDAY. FORECAST HIGHS RANGE FROM
THE UPPER 70S TO THE MID-80S FOR THE NORTHEAST, THE UPPER 80S TO
MID-90S FOR THE MID-ATLANTIC, THE MID 80S TO LOW 90S FOR THE
MIDWEST, AND THE LOW 90S FOR MUCH OF THE PLAINS. THE FAR NORTHERN
TIER WILL SEE COOLER TEMPERATURES BEHIND A COLD FRONT, WITH 60S IN
THE UPPER GREAT LAKES AND 70S TO LOW 80S IN THE NORTHERN PLAINS.
TO THE WEST, MONSOONAL MOISTURE IN THE FOUR CORNERS REGION WILL
LEAD TO DAILY ROUNDS OF AFTERNOON THUNDERSTORMS WITH A FEW LOCALLY
HEAVY DOWNPOURS POSSIBLE. THIS WILL ALSO HELP TO KEEP TEMPERATURES
A BIT BELOW AVERAGE, WITH HIGHS ONLY INTO THE UPPER 70S FOR SOME
LOCATIONS. AREAS OF THE CENTRAL/SOUTHERN ROCKIES AND GREAT BASIN
WILL BE A BIT CLOSER TO AVERAGE, SEEING HIGHS IN THE MID-80S TO
LOW 90S, AND UPPER-90S TO MID-100S FOR THE DESERT SOUTHWEST. A
LINGERING UPPER-LEVEL LOW WILL KEEP TEMPERATURES UNSEASONABLY COOL
OVER PORTIONS OF CALIFORNIA, AS HIGHS ARE EXPECTED TO BE IN THE
UPPER 60S TO MID-70S FOR THE COAST AND MOSTLY 80S FOR THE INTERIOR
VALLEYS OUTSIDE OF THE DESERTS. CONDITIONS WILL BE TRANQUIL WITH
NEAR AVERAGE TEMPERATURES IN THE PACIFIC NORTHWEST. HIGHS WILL
GENERALLY RANGE FROM THE MID-80S TO LOW 90S. HOWEVER, AN
UPPER-LEVEL RIDGE BUILDING IN OVER THE REGION LOOKS TO BRING A
HEAT WAVE JUST BEYOND THE CURRENT FORECAST PERIOD.
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