333
FXUS01 KWBC 141927
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
326 PM EDT MON AUG 14 2023
VALID 00Z TUE AUG 15 2023 - 00Z THU AUG 17 2023
...FLASH FLOODING AND SEVERE THUNDERSTORMS POSSIBLE FOR THE GREAT
LAKES/OHIO VALLEY/MID-ATLANTIC THIS AFTERNOON, LINGERING ALONG THE
COAST INTO TUESDAY...
...PORTIONS OF THE SOUTH TO SEE A BRIEF REPRIEVE FROM THE HEAT
MID-WEEK AS A HEAT WAVE INTENSIFIES ACROSS THE PACIFIC NORTHWEST
INTO THE NORTHERN ROCKIES...
...MONSOONAL SHOWERS CONTINUE ACROSS THE FOUR CORNERS REGION WITH
SOME LOCALLY HEAVY DOWNPOURS POSSIBLE...
A CONSOLIDATING/ORGANIZING FRONTAL SYSTEM WILL PUSH EASTWARD FROM
THE MISSISSIPPI VALLEY TOWARDS THE EAST COAST TODAY AIDED IN PART
BY AN UNSEASONABLY STRONG UPPER-LEVEL DISTURBANCE DROPPING SOUTH
FROM CANADA. STRONG LIFT AS WELL AS VERY MOIST, SOUTHERLY FLOW
AHEAD OF AND AROUND THE SYSTEM WILL TRIGGER SCATTERED TO
WIDESPREAD SHOWERS AND THUNDERSTORMS THIS AFTERNOOON STRETCHING
FROM THE GREAT LAKES SOUTH INTO THE UPPER OHIO/TENNESSEE VALLEYS
EASTWARD THROUGH THE APPALACHIANS AND INTO THE MID-ATLANTIC. TWO
AREAS OF CONCERN HAVE ARISEN FOR FLASH FLOODING WITH SLIGHT RISKS
OF EXCESSIVE RAINFALL (LEVEL 2/4) IN PLACE. THE FIRST COVERS AREAS
AROUND THE LOWER GREAT LAKES WHERE SLOW MOVING, WIDESPREAD STORMS
MAY LEAD TO LONG DURATION, HEAVY RAINFALL TOTALS. THE SECOND
STRETCHES FROM THE UPPER TENNESSEE/OHIO VALLEYS EAST THROUGH THE
APPALACHIANS INTO THE NORTHERN MID-ATLANTIC WHERE SOME ORGANIZED
LINES AS WELL AS INDIVIDUAL STORMS WILL BOTH HAVE THE POTENTIAL TO
PRODUCE VERY HEAVY DOWNPOURS WITH ANOMALOUSLY HIGH MOISTURE IN THE
REGION. IN ADDITION TO FLASH FLOODING, THE STORM PREDICTION CENTER
HAS OUTLINED MUCH OF THIS REGION FOR A SLIGHT RISK (LEVEL 2/5) OF
SEVERE WEATHER AS STRENGTHENING UPPER-LEVEL FLOW WITH THE
APPROACHING WAVE WILL PROVIDE SUFFICIENT VERTICAL WIND SHEAR FOR
MORE ROBUST, ORGANIZED STORMS WHICH MAY PRODUCE SOME INSTANCES OF
DAMAGING WINDS AS WELL AS A FEW TORNADOES. THE COLD FRONT WILL
SLOW AS IT APPROACHES THE EAST COAST MONDAY NIGHT, ALLOWING FOR
RENEWED STORM DEVELOPMENT TUESDAY AHEAD OF THE FRONT FROM THE
DELMARVA SOUTH THROUGH THE EASTERN CAROLINAS, WHERE SLIGHT RISKS
FOR EXCESSIVE RAINFALL AND SEVERE WEATHER ARE IN PLACE. HIGHS
AHEAD OF THE FRONT IN THE MID-ATLANTIC WILL REMAIN SEASONABLY WARM
AND IN THE MID-80S TO MID-90S, WHILE LOCATIONS TO THE NORTH OF THE
SYSTEM INTO NEW ENGLAND AND BEHIND THE FRONT ACROSS THE GREAT
LAKES/MIDWEST WITNESS UNSEASONABLY COOLER AND MAINLY IN THE 70S.
TO THE SOUTH, DANGEROUS HEAT WILL CONTINUE THIS AFTERNOON THANKS
TO A WELL ANCHORED UPPER-LEVEL RIDGE WITH WIDESPREAD HEAT-RELATED
ADVISORIES AND WARNINGS SPANNING FROM FLORIDA NORTH TO THE
CAROLINAS AND WEST TO TEXAS/OKLAHOMA. HIGH TEMPERATURES ONCE AGAIN
ARE FORECAST TO RANGE FROM THE MID-90S IN FLORIDA AND THE
CAROLINAS, THE UPPER 90S TO LOW 100S FOR THE SOUTHEAST INTO THE
LOWER MISSISSIPPI VALLEY, AND AS HIGH AS THE MID-100S INTO
PORTIONS OF TEXAS. THESE TEMPERATURES WHEN COMBINED WITH HIGH
HUMIDITY WILL ALLOW FOR SULTRY HEAT INDICES AS HIGH AS 110 TO 120F
FOR MANY LOCATIONS. NUMEROUS RECORD-TYING/BREAKING HIGHS ARE
FORECAST, WITH SIMILARLY RECORD-LEVEL WARM LOW TEMPERATURES IN THE
UPPER 70S TO LOW 80S PROVIDING LITTLE RELIEF FROM THE HEAT
OVERNIGHT. FORTUNATELY, THE NOTED STRONG UPPER-LEVEL WAVE/COLD
FRONT PUSHING SOUTHEASTWARD WILL BRING A BRIEF REPRIEVE TO
NORTHERN PORTIONS OF THE REGION BY TUESDAY. HIGHS FROM NORTHERN
GEORGIA WEST THROUGH NORTH TEXAS WILL DROP TO MUCH MORE SEASONABLE
VALUES IN THE MID-80S TO LOW 90S, AND EVEN UPPER 70S FOR PORTIONS
OF THE MID-SOUTH. THE HEAT WILL REMAIN OPPRESSIVE TUESDAY TO THE
SOUTH OF THE FRONT FROM SOUTH TEXAS EAST ALONG THE GULF COAST TO
FLORIDA AND NORTHEASTWARD INTO THE CAROLINAS, BUT EVEN SOME OF
THESE LOCATIONS MAY SEE A BIT OF RELIEF INTO MID-WEEK AS WELL.
ANOTHER MAJOR HEATWAVE TAKES HOLD OF THE PACIFIC
NORTHWEST/NORTHERN ROCKIES TODAY IN RELATION TO A STRENGTHENING
RIDGE OF HIGH PRESSURE ALOFT. HIGH TEMPERATURES WILL RANGE FROM
THE LOW 90S AROUND PUGET SOUND, THE UPPER 90S TO LOW 100S FOR THE
INTERIOR NORTHWEST AND NORTHERN ROCKIES, AND THE MID-100S TO
POTENTIALLY OVER 110 DEGREES FOR THE INTERIOR VALLEYS WEST OF THE
CASCADES IN OREGON. NUMEROUS NEAR RECORD-TYING/BREAKING HIGHS ARE
POSSIBLE HERE AS WELL. THESE TEMPERATURES COMBINED WITH THE
DURATION OF HEAT, EXPECTED TO CONTINUE THROUGH THIS WEEK, WILL
INCREASINGLY POSE A HEIGHTENED HEALTH RISK, ESPECIALLY FOR THOSE
WITHOUT ADEQUATE AIR CONDITIONING. EXCESSIVE HEAT WARNINGS HAVE
BEEN POSTED FROM THE IMMEDIATE PACIFIC NORTHWEST COASTLINE ON EAST
INTO THE COLUMBIA RIVER BASIN THROUGH MID-WEEK.
DAILY ROUNDS OF THUNDERSTORMS ARE FORECAST ACROSS THE FOUR CORNERS
REGION NORTHWESTWARD INTO THE GREAT BASIN AND PORTIONS OF THE
SIERRA THANKS IN PART TO MONSOONAL MOISTURE AND A LINGERING
FRONTAL BOUNDARY NEAR THE REGION. ANY OF THESE STORMS MAY HAVE THE
POTENTIAL TO PRODUCE HEAVY DOWNPOURS WITH AN ISOLATED THREAT FOR
FLASH FLOODING. DAILY HIGHS WILL BE NEAR SEASONAL AVERAGES WITH
70S IN PROXIMITY OF THE CALIFORNIA COAST, LOW TO MID-90S FOR THE
GREAT BASIN, AND 100S FOR THE DESERT SOUTHWEST. HIGHS IN THE
INTERIOR CALIFORNIA VALLEYS WILL TREND A BIT HOTTER WITH MID-100S
EXPECTED AND HEAT ADVISORIES IN PLACE. WITH COOLER, POST-FRONTAL
AIR FILTERING SOUTH INTO THE CENTRAL U.S., PORTIONS OF THE
CENTRAL/SOUTHERN HIGH PLAINS/ROCKIES WILL HAVE SOME COOLER HIGHS
THAN POINTS WEST ON MONDAY; MAINLY IN THE UPPER 70S TO LOW 80S.
TEMPERATURES WILL BEGIN TO RAPIDLY REBOUND TUESDAY AS CONDITIONS
MODERATE FOLLOWING THE FRONTAL PASSAGE, WITH HIGHS JUMPING BACK
INTO THE UPPER 80S TO LOW 90S.
PUTNAM/MULLINAX
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page