741
FXUS01 KWBC 241941
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
341 PM EDT THU AUG 24 2023
VALID 00Z FRI AUG 25 2023 - 00Z SUN AUG 27 2023
...DANGEROUS HEAT CONTINUES FROM THE MIDWEST TO GULF COAST, WITH
RELIEF FINALLY ON THE WAY FOR SOME BY THIS WEEKEND...
...SEVERE THUNDERSTORMS AND FLASH FLOODING POSSIBLE ACROSS THE
LOWER GREAT LAKES AND PARTS OF THE CENTRAL APPALACHIANS INTO
TONIGHT...
...SCATTERED FLASH FLOODING CONCERNS FORECAST FROM THE CENTRAL
GREAT BASIN TO THE CENTRAL HIGH PLAINS THROUGH FRIDAY...
DANGEROUS AND OPPRESSIVE HEAT WILL CONTINUE THROUGHOUT A LARGE
PORTION OF THE NATION SITUATED UNDERNEATH A POTENT UPPER LEVEL
RIDGE. RECORD-BREAKING HEAT WITH FORECAST HIGHS INTO THE UPPER 90S
AND LOW 100S WILL IMPACT A BROAD REGION BETWEEN THE MIDWEST AND
CENTRAL GULF COAST THROUGH FRIDAY. WHEN FACTORING IN SULTRY
HUMIDITY LEVELS, HEAT INDICES COULD APPROACH 120 DEGREES. THIS
HEAT WAVE WILL POSE A GREATER HEALTH RISK THAN USUAL, AND BE
POTENTIALLY DEADLY, DUE TO THE MULTIPLE CONSECUTIVE DAYS OF
EXTREME HEAT, THE INTENSITY OF THE HEAT, AND LACK OF OVERNIGHT
COOLING ASSOCIATED WITH RECORD WARM OVERNIGHT LOWS. HEAT ALERTS
(EXCESSIVE HEAT WARNINGS/WATCHES AND ADVISORIES) CURRENTLY SPAN A
LARGE PORTION OF THE COUNTRY. BY THIS WEEKEND, A COLD FRONT MOVING
SOUTHWARD SHOULD BRING AN END TO THE EXCESSIVE HEAT AND SOME
WELCOMED MORE COMFORTABLE TEMPERATURES TO MUCH OF THE MIDWEST.
UNFORTUNATELY THOUGH, EXCESSIVE HEAT LOOKS TO CONTINUE ACROSS
PORTIONS OF THE SOUTHERN PLAINS TO THE GULF COAST WELL INTO NEXT
WEEK. SEE KEY MESSAGES FROM WPC FOR ADDITIONAL INFORMATION ABOUT
THE ONGOING HEAT.
ON THE NORTHERN SIDE OF THE AFOREMENTIONED UPPER RIDGE, SHOWERS
AND THUNDERSTORMS WILL FOCUS ALONG A FRONTAL BOUNDARY FROM PARTS
OF THE LOWER GREAT LAKES TO THE UPPER OHIO VALLEY AND NORTHEAST
THIS EVENING/TONIGHT. WITH AMPLE MOISTURE AND INSTABILITY PRESENT,
FLASH FLOODING WILL BE POSSIBLE FROM NORTHEAST OHIO TO WESTERN
PENNSYLVANIA WHERE WPC HIGHLIGHTS A SLIGHT RISK (LEVEL 2/4) ON THE
EXCESSIVE RAINFALL OUTLOOK FOR THIS AFTERNOON/TONIGHT. SEVERE
THUNDERSTORMS ARE ALSO POSSIBLE WITH THE THREAT FOR DAMAGING
WINDS, LARGE HAIL, AND PERHAPS A TORNADO. THE STORM PREDICTION
CENTER HAS AN ENHANCED RISK (LEVEL 3/5) FROM SOUTHERN MICHIGAN TO
FAR WESTERN PENNSYLVANIA. ON FRIDAY, THE FRONTAL SYSTEM IS
EXPECTED TO PUSH FARTHER SOUTH AND EAST, SPREADING
RAIN/THUNDERSTORM CHANCES TO NEW ENGLAND AND THE MID-ATLANTIC.
FARTHER WEST, MONSOONAL MOISTURE ROUNDING THE WESTERN EDGE OF THE
CENTRAL U.S. UPPER RIDGE WILL CONTINUE TO LEAD TO SCATTERED FLASH
FLOODING POTENTIAL OVER THE CENTRAL GREAT BASIN TODAY. IN
PARTICULAR, SOUTHERN UTAH AND WESTERN COLORADO ARE LOCATED WITHIN
A SLIGHT RISK (LEVEL 2/4) OF EXCESSIVE RAINFALL. THESE AREAS ARE
SITUATED WITHIN OVERLAPPING VULNERABLE TERRAIN AND BEST
ATMOSPHERIC CONDITIONS CONDUCIVE FOR HEAVY RAINFALL. THE FLASH
FLOODING RISK IS EXPECTED TO SHIFT INTO THE CENTRAL ROCKIES AND
CENTRAL HIGH PLAINS BY FRIDAY AS THE AFOREMENTIONED LINGERING
MOISTURE INTERACTS WITH AN APPROACHING COLD FRONT. A FEW INCHES OF
RAIN WITHIN A SHORT PERIOD OF TIME COULD LEAD TO RAPID RUNOFF AND
FLOODING CONCERNS. SHOWERS AND STORMS SHOULD FOCUS ALONG THE COLD
FRONT AS IT DROPS FARTHER INTO THE CENTRAL PLAINS/MIDWEST ON
SATURDAY.
SANTORELLI/SNELL
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page