409
FXUS01 KWBC 252015
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
414 PM EDT TUE AUG 25 2026
VALID 00Z WED AUG 26 2026 - 00Z FRI AUG 28 2026
...DANGEROUS RECORD-BREAKING HEAT CONTINUES ACROSS THE
SOUTH-CENTRAL U.S. INTO THE SOUTHWEST THIS WEEK...
...SCATTERED INSTANCES OF FLASH FLOODING (LEVEL 2/5) WILL BE
POSSIBLE WEDNESDAY AND THURSDAY ACROSS THE LOWER MISSISSIPPI
VALLEY...
STRONG TO SEVERE STORMS WILL BE POSSIBLE AHEAD OF A COLD FRONT IN
THE MID-SOUTH TO THE OHIO VALLEY TOMORROW AND INTO THE NORTHEAST
ON THURSDAY...
A STRONG UPPER-LEVEL RIDGE WILL REMAIN ANCHORED ACROSS THE
SOUTHWEST INTO THE SOUTH-CENTRAL U.S. INTO LATE WEEK. THIS WILL
MAINTAIN AN ABNORMAL HAZARDOUS HEAT ACROSS THE REGION. DAYTIME
HIGHS OF 100-110 DEGREES F ARE FORECAST ACROSS THE SOUTHERN PLAINS
FOR WEDNESDAY AND THURSDAY, WHILE PORTIONS OF THE SOUTHWEST WILL
REACH UPWARDS TO THE UPPER 90S AND LOW 100S F IN THE VALLEYS AND
110S IN THE DESERTS. THE URBAN AREAS OF SAN DIEGO AND LOS ANGELES
ARE UNDER HEAT ADVISORIES AND EXTREME HEAT WARNINGS THROUGH THE
END OF THE WEEK. WITH OVERNIGHT TEMPERATURES PROVIDING LIMITED
RELIEF, HEAT-RELATED ILLNESS MAY INCREASE, ESPECIALLY FOR THOSE
WITHOUT PROPER HYDRATION AND ADEQUATE COOLING. ACCORDINGLY,
WIDESPREAD MAJOR TO EXTREME HEATRISK IS FORECAST FOR MUCH OF THE
SOUTHWEST INTO TEXAS THROUGH LATE WEEK. SEE THE LATEST KEY
MESSAGES LINKED AT THE BOTTOM OF THE DISCUSSION FOR MORE
INFORMATION.
AN UPPER-LEVEL TROUGH AND SURFACE COLD FRONT WILL BEGIN TO SWEEP
EASTWARD ACROSS THE MID-MISSISSIPPI VALLEY TO THE GREAT LAKES
TOMORROW, SPARKING CHANCES FOR STRONG TO SEVERE THUNDERSTORMS
CAPABLE OF DAMAGING WINDS AND HAIL. A TORNADO OR TWO MAY ALSO BE
POSSIBLE ON WEDNESDAY IN THE GREAT LAKES REGION, ACCORDING TO THE
STORM PREDICTION CENTER. ON THURSDAY, THE SEVERE WEATHER THREAT
(LEVEL 2/5) WILL SHIFT TO THE NORTHEAST FOR THREATS OF DAMAGING
WINDS, HAIL, AND A TORNADO OR TWO POSSIBLE. ADDITIONALLY, THE HIGH
/ CENTRAL PLAINS INTO THE EASTERN ROCKIES WILL SEE A CHANCE FOR
STRONG TO SEVERE STORMS WEDNESDAY AND THURSDAY FOR MAINLY HAZARDS
OF LARGE HAIL.
ACROSS THE SOUTHWEST AND PORTIONS OF THE ROCKIES, MONSOONAL
MOISTURE WILL CONTINUE TO MOVE NORTHWARD ALONG THE WESTERN
PERIPHERY OF THE RIDGE AND INTERACT WITH EMBEDDED SHORTWAVE
ENERGY. THIS WILL LEAD TO DAILY SCATTERED SHOWERS AND
THUNDERSTORMS WEDNESDAY AND THURSDAY. 1-2 INCH AN HOUR RAINFALL
RATES WITH STORMS WILL CONTINUE TO POSE ISOLATED FLASH-FLOODING
CONCERNS, PARTICULARLY OVER SENSITIVE TERRAIN SUCH AS BURN SCARS,
SLOT CANYONS, ETC... FATHER EAST, INCREASING INSTABILITY AND
PERSISTENT GULF MOISTURE ALONG A SLOW-MOVING FRONTAL BOUNDARY WILL
SUPPORT REPEATED SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHEAST
INTO LOWER MISSISSIPPI VALLEY. THE EXCESSIVE RAINFALL OUTLOOK WAS
BUMPED UP TO A SLIGHT RISK ON WEDNESDAY FOR PORTIONS OF ARKANSAS,
MISSISSIPPI, AND TENNESSEE DUE TO A FRONTAL WAVE ENHANCING THE
ORGANIZATION AND COVERAGE OF STORMS. A SLIGHT RISK IS ALSO
FORECAST ON THURSDAY FROM LOUISIANA TO SOUTH CAROLINA AS A STALLED
FRONTAL BOUNDARY AND SHORTWAVE ENERGY INTERACTS WITH SUMMER
INSTABILITY TO PRODUCE THE LIKELIHOOD OF LOCALLY HEAVY RAINFALL.
LASTLY, THE NORTHERN ROCKIES INTO THE MOUNTAIN RANGES OF THE
PACIFIC NORTHWEST WILL CONTINUE TO SEE ELEVATED FIRE WEATHER
CONCERNS WITH ABOVE AVERAGE TEMPERATURES OVERLAPPING WITH LOW
RELATIVE HUMIDITIES AND GUSTY WINDS (10-30 MPH). FOLLOW LOCAL
OFFICIALS ON FIRE WEATHER ORDERS.
WILDER/OUDIT
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
EXTREME HEAT KEY MESSAGES AVAILABLE AT:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/KEY_MESSAGES/LATESTKEYMESSAGE_1.PNG
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