278
FXUS01 KWBC 210751
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
350 AM EDT FRI JUL 21 2023
VALID 12Z FRI JUL 21 2023 - 12Z SUN JUL 23 2023
...FLASH FLOODING AND SEVERE WEATHER THREATS ACROSS PARTS OF THE
EAST COAST, LOWER MISSISSIPPI VALLEY AND SOUTHERN PLAINS TODAY...
...LENGTHY & DANGEROUS HEAT WAVE TO CONTINUE ACROSS THE SOUTHERN
TIER AND IN THE WEST...
...COOLER AND MORE COMFORTABLE TEMPERATURES SPREAD ACROSS GREAT
PLAINS AND MIDWEST...
A COLD FRONT SWEEPING THROUGH THE EAST COAST AND SOUTHEAST WILL BE
THE FOCUS FOR THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS. AN UPPER
TROUGH CENTERED OVER HUDSON BAY WILL SUPPORT A SURFACE LOW
PRESSURE SYSTEM MOVING THROUGH THE INTERIOR NORTHEAST TODAY.
THUNDERSTORMS (SOME POTENTIALLY SEVERE) AND HEAVY RAINFALL ARE
FORECAST FOR THE INTERIOR NORTHEAST. AN AXIS OF ESPECIALLY HEAVY
RAINFALL MAY DEVELOP OVER PORTIONS OF EASTERN NEW
YORK/PENNSYLVANIA, NEW JERSEY AND VERMONT WHERE A SLIGHT RISK OF
EXCESSIVE RAINFALL LEADING TO FLASH FLOODING IS IN EFFECT. RAIN
RATES OF OVER AN INCH COUPLED WITH UPSLOPE ENHANCEMENT ARE LIKELY
TO CAUSE RUNOFF ISSUES OVER THE ALREADY SATURATED ADIRONDACKS AND
GREEN MOUNTAINS. ELSEWHERE, SHORTWAVE ENERGY AND A COLD FRONT WILL
WORK IN TANDEM TO PROVIDE INSTABILITY, MOISTURE FLUX AND A FOCUS
FOR HEAVY RAINFALL ALONG A ZONAL AXIS EXTENDING FROM NORTHEASTERN
OKLAHOMA TO SOUTHERN GEORGIA. SLIGHT RISKS OF EXCESSIVE RAINFALL
LEADING TO FLASH FLOODING AS WELL AS SEVERE THUNDERSTORMS ARE IN
EFFECT FOR THE OKLAHOMA TO GEORGIA CORRIDOR WHERE POCKETS OF OVER
AN INCH OF RAINFALL, WIND DAMAGE AND HAIL ARE EXPECTED. MONSOONAL
MOISTURE WILL SUPPORT ADDITIONAL FLASH FLOODING CONCERNS OVER
ARIZONA AND ESPECIALLY NEW MEXICO TODAY, WHERE ANOTHER SLIGHT RISK
OF EXCESSIVE RAINFALL LEADING TO FLASH FLOODING IS IN EFFECT.
TEMPERATURES ARE EXPECTED TO DROP OFF SUBSTANTIALLY ON THE
BACKSIDE OF THE COLD FRONT. HIGH TEMPERATURES ARE LIKELY TO BE IN
THE 70S AND LOW 80S ACROSS THE GREAT PLAINS AND MIDWEST THROUGH
SATURDAY, WHICH WILL BE 10-25 DEGREES BELOW AVERAGE FOR THIS TIME
OF YEAR.
A DANGEROUS, LONG-LIVED, AND RECORD BREAKING HEAT WAVE WILL
CONTINUE OVER THE SOUTHWEST THROUGH THIS WEEKEND, PARTICULARLY IN
THE LOW DESERT AREAS, WITH TRIPLE DIGIT HIGH TEMPERATURES ALSO
EXTENDING NORTHWARD INTO THE CENTRAL GREAT BASIN THIS WEEKEND.
OPPRESSIVE HEAT AND HUMIDITY ARE FORECAST TO CREATE WIDESPREAD
105-110 DEGREE HEAT INDICES ACROSS THE MID-SOUTH, SOUTHEAST AND
GULF COAST THROUGH EARLY THIS WEEKEND. TAKE THE HEAT SERIOUSLY AND
AVOID EXTENDED TIME OUTDOORS. TEMPERATURES AND HEAT INDICES WILL
REACH LEVELS THAT WOULD POSE A HEALTH RISK, AND BE POTENTIALLY
DEADLY TO ANYONE WITHOUT EFFECTIVE COOLING AND/OR ADEQUATE
HYDRATION. NIGHTTIME TEMPERATURES WILL PROVIDE VERY LITTLE RELIEF.
HEAT IS THE LEADING WEATHER-RELATED KILLER IN THE U.S.
KEBEDE
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