225
FXUS01 KWBC 210734
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
333 AM EDT MON JUL 21 2025
VALID 12Z MON JUL 21 2025 - 12Z WED JUL 23 2025
...DANGEROUS HEAT WAVE TO EXPAND ACROSS THE CENTRAL PLAINS,
MISSISSIPPI VALLEY, AND SOUTHEAST THROUGH MID-WEEK...
...THUNDERSTORMS TO POSE A FLASH FLOOD THREAT IN PORTIONS OF THE
SOUTHWEST, NORTHWEST, MIDWEST, MID-SOUTH, AND SOUTHEAST...
...SEVERE STORMS ARE LIKELY IN PARTS OF THE MIDWEST; UNSEASONABLY
COOLER & COMFORTABLE CONDITIONS IN THE NORTHEAST...
THE "DOG DAYS OF SUMMER" ARE IN FULL SWING FOR MOST OF THE EASTERN
TWO-THIRDS OF THE LOWER 48. THIS IS BROUGHT ABOUT BY A
STRENGTHENING HEAT DOME ORIGINATING OVER THE DEEP SOUTH THAT
BUILDS IN OVER THE MISSISSIPPI AND OHIO VALLEYS BY MID-WEEK.
EXPECT SOME LOCALIZED DAILY RECORD HIGHS TO BE BROKEN IN THE
SOUTHEAST, WITH AN EVEN LARGER SWATH OF DAILY RECORD WARM MINIMUM
TEMPERATURES. HEAT INDICES FROM THE CENTRAL PLAINS TO THE
SOUTHEAST WILL RANGE BETWEEN 100-110F EACH DAY, WITH SOME
LOCATIONS REACHING AS HIGH AS 115F. FOR MONDAY, HEATRISK SHOWS AN
EXPANSIVE AREA OF MAJOR IMPACTS THAT ARE MOST COMMON IN THE
SOUTHEAST AND LOWER MISSISSIPPI VALLEY. BY TUESDAY, MUCH OF THE
DEEP SOUTH ON NORTH THROUGH THE MIDDLE MISSISSIPPI VALLEY AND INTO
THE LOWER MISSOURI RIVER VALLEY SEE MAJOR IMPACTS ACCORDING TO
HEATRISK. EXTREME HEAT WARNINGS ARE IN PLACE FOR PARTS OF THE
CENTRAL PLAINS AND LOWER-TO-MIDDLE MISSISSIPPI VALLEY, WHILE AN
EXPANSIVE LIST OF HEAT ADVISORIES SPANS FROM SOUTH DAKOTA ON SOUTH
AND EAST TO THE FLORIDA PENINSULA. LOOK FOR THE HEAT DOME TO
EXPAND EAST INTO THE GREAT LAKES BY WEDNESDAY AND THURSDAY. WPC
CONTINUES TO CARRY KEY MESSAGES FOR THIS IMPENDING HEAT WAVE.
PLEASE VISIT WWW.WEATHER.GOV/SAFETY/HEAT FOR MORE INFORMATION ON
TIPS FOR HOW TO STAY COOL AND SAFE WHEN DEALING WITH OPPRESSIVE
HEAT.
PRECIPITATION ACROSS THE CONTINENTAL U.S. WILL BE LARGELY DRIVEN
DUE TO A "RING OF FIRE" UPPER-LEVEL RIDGE PATTERN OVER THE
SOUTHERN U.S. AND A SERIES OF DISTURBANCES TRAVERSING THE NORTHERN
TIER OF THE U.S.. THIS RIDGE OF HIGH PRESSURE IS CHANNELING RICH
GULF MOISTURE NORTH INTO THE UPPER MIDWEST AND AHEAD OF AN
APPROACHING COLD FRONT. THERE IS ALSO A POOL OF ANOMALOUS MOISTURE
AND A STALLED FRONT OVER THE TENNESSEE AND OHIO VALLEYS TODAY. WPC
ISSUED A SLIGHT RISK (THREAT LEVEL 2/4) FOR FLASH FLOODING IN
PORTIONS OF THE OHIO AND TENNESSEE VALLEYS TODAY, WITH A SLIGHT
RISK IN PLACE FOR PARTS OF THE UPPER MIDWEST ON TUESDAY. THERE ARE
FLOOD WATCHES IN EFFECT FOR PARTS OF THE MIDDLE MISSISSIPPI AND
OHIO VALLEYS THROUGH THIS AFTERNOON. MEANWHILE, THERE IS ALSO
ANOMALOUS MOISTURE OVER THE NORTHWEST AND NORTHERN ROCKIES TODAY.
THUNDERSTORMS COULD PRODUCE LOCALLY HEAVY RAINFALL AMOUNTS IN
PARTS OF WASHINGTON AND OREGON (EAST OF THE CASCADES) AND INTO THE
HEART OF MONTANA, PROMPTING THE ISSUANCE OF A MARGINAL RISK
(THREAT LEVEL 1/4) FOR FLASH FLOODING. THE SOUTHWEST AND SOUTHEAST
ALSO SPORT MARGINAL RISKS FOR FLASH FLOODING TODAY AND TUESDAY
GIVEN THE MODEST MOISTURE AND INSTABILITY PRESENT.
SPEAKING OF INSTABILITY, MANY OF THE AFOREMENTIONED STORMS IN THE
NORTHERN PLAINS AND MIDWEST HAVE THE POTENTIAL TO BE SEVERE TODAY
AND TUESDAY. THE STORM PREDICTION CENTER (SPC) HAS A SLIGHT RISK
(THREAT LEVEL 2/4) IN PLACE OVER EASTERN MONTANA TODAY, THEN OVER
PARTS OF THE EASTERN DAKOTAS AND CENTRAL MINNESOTA ON TUESDAY.
ISOLATED SEVERE STORMS ARE ALSO POSSIBLE IN THE CENTRAL PLAINS AND
SOUTHEAST EACH DAY. DAMAGING WINDS AND LARGE HAIL ARE THE PRIMARY
MODES OF SEVERE WEATHER, ALTHOUGH THE NORTHERN PLAINS COULD ALSO
CONTEND WITH SOME TORNADOES.
ELSEWHERE, REGIONS EXPECTING COOLER THAN NORMAL TEMPERATURES AND A
MORE TRANQUIL WEATHER PATTERN TO START THE WEEK ARE THE DESERT
SOUTHWEST AND NORTHEAST. THE NORTHEAST WILL WITNESS UNUSUALLY COOL
AND COMFORTABLE TEMPERATURES FOR LATE JULY WITH SOME COMMUNITIES
IN NORTHERN NEW ENGLAND STRUGGLING TO GET ABOVE 70 DEGREES. THIS
PERIOD OF COOL/COMFORTABLE CONDITIONS IN THE NORTHEAST WILL BE
SHORT LIVED AS SULTRY CONDITIONS RETURN BY THE SECOND HALF OF THE
WORK-WEEK.
MULLINAX
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
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