695
FXUS01 KWBC 112001
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 PM EDT FRI AUG 11 2023
VALID 00Z SAT AUG 12 2023 - 00Z MON AUG 14 2023
...DANGEROUS HEAT WILL PERSIST ACROSS MUCH OF THE SOUTH THROUGH
THIS WEEKEND, WITH A NEW HEAT WAVE EXPECTED TO BEGIN DEVELOPING
ACROSS THE PACIFIC NORTHWEST BY SUNDAY...
...SEVERE THUNDERSTORMS POSSIBLE THIS EVENING ACROSS THE MIDWEST
AND ON SATURDAY FOR PARTS OF THE OHIO VALLEY AND NORTHEAST...
...MONSOONAL SHOWERS ARE EXPECTED ACROSS THE FOUR CORNERS REGION
WITH GENERALLY BELOW TO NEAR AVERAGE TEMPERATURES IN THE WEST...
...NEW ROUNDS OF HEAVY SHOWERS AND THUNDERSTORMS TO ARRIVE ACROSS
THE MIDWEST BY SUNDAY...
DANGEROUS HEAT WILL CONTINUE FOR MUCH OF THE SOUTHERN U.S. THROUGH
THE WEEKEND AS A WEST TO EAST ORIENTED UPPER-LEVEL RIDGE OF HIGH
PRESSURE 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 SOUTHERN PLAINS, WITH
THE MOST EXCESSIVE HEAT EXPECTED OVER PORTIONS OF TEXAS AND THE
LOWER MISSISSIPPI VALLEY. FORECAST HIGHS FRIDAY AND SATURDAY WILL
RANGE FROM THE MID-90S IN FLORIDA TO THE LOW 100S IN OKLAHOMA AND
THE LOWER MISSISSIPPI VALLEY WITH HIGHS ACROSS TEXAS REACHING AS
HIGH AS 105 TO 110F. WHEN COMBINED WITH HIGH HUMIDITY VALUES, HEAT
INDICES WILL REACH AS HIGH AS 110 TO 120F 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.
A NEW HEAT WAVE IS ALSO FORECAST TO BEGIN BUILDING ACROSS THE
PACIFIC NORTHWEST BY SUNDAY AS A STRONG RIDGE OF HIGH PRESSURE
BUILDS OVERHEAD. THIS WILL ALLOW FOR TEMPERATURES TO REACH WELL
THROUGH THE 90S AND INTO THE LOW 100S. THE HOTTEST TEMPERATURES
WILL BE OVER THE INTERIOR VALLEYS AND LOWER ELEVATIONS AWAY FROM
THE CASCADES. THE HEAT WILL EXPAND IN COVERAGE HEADING INTO EARLY
NEXT WEEK AND NEAR-RECORD TO RECORD-SETTING HIGH TEMPERATURES WILL
BE POSSIBLE AS THIS RIDGE OF HIGH PRESSURE PERSISTS OVER THE
REGION.
MEANWHILE, FOR THE MIDWEST AND GREAT LAKES, A CONSOLIDATING AREA
OF LOW PRESSURE WILL ADVANCE FROM THE UPPER MIDWEST THIS EVENING
EASTWARD THROUGH THE GREAT LAKES REGION AND INTO SOUTHEAST CANADA
BY LATE SATURDAY. A TRAILING COLD FRONT WILL SETTLE DOWN INTO THE
OHIO VALLEY AND ALSO MOVE INTO THE NORTHEAST BY SATURDAY NIGHT,
AND A COMBINATION OF THE LOW CENTER AND FRONT WILL PRODUCE
SCATTERED TO BROKEN AREAS OF SHOWERS AND THUNDERSTORMS AND SOME OF
THESE STORMS MAY BE SEVERE WITH DAMAGING WINDS. THE STORM
PREDICTION CENTER HAS HIGHLIGHTED A SLIGHT RISK OF SEVERE WEATHER
ACROSS PORTIONS OF THESE AREAS. HOWEVER, IN THE NEAR-TERM, THE
GREATEST RISK OF SEVERE WEATHER WILL BE FOR THIS EVENING ACROSS
AREAS OF NORTHEAST KANSAS AND NORTHWEST MISSOURI WHERE THE STORM
PREDICTION CENTER HAS HIGHLIGHTED AN ENHANCED RISK OF SEVERE
WEATHER. SOME SUPERCELL THUNDERSTORMS HERE WILL BE CAPABLE OF
PRODUCING DAMAGING WINDS, LARGE HAIL AND POSSIBLY A TORNADO.
AREAS OF SHOWERS AND THUNDERSTORMS ARE ALSO EXPECTED TO THE
SOUTHWEST OVER PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS AS
A COLD FRONT SAGS SOUTHWARD ACROSS THE REGION. ANOTHER STORM
SYSTEM WILL BRING STORM CHANCES TO AREAS OF THE NORTHERN PLAINS BY
LATE SATURDAY AND THEN ACROSS THE MIDWEST ON SUNDAY. COOLER
TEMPERATURES WILL BE NOTED BEHIND THIS NEXT STORM SYSTEM, AND
TEMPERATURES WILL BE DROPPING BELOW NORMAL ACROSS AREAS OF THE
NORTHERN HIGH PLAINS BY THE END OF THE WEEKEND.
OVER THE WEST, MONSOONAL MOISTURE IN THE FOUR CORNERS REGION WILL
LEAD TO DAILY ROUNDS OF AFTERNOON THUNDERSTORMS WITH A FEW LOCALLY
HEAVY DOWNPOURS POSSIBLE. SOME ISOLATED CONCERNS FOR FLASH
FLOODING WILL BE 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.
ORRISON/PUTNAM
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page