881
FXUS01 KWBC 270751
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
350 AM EDT FRI SEP 27 2024
VALID 12Z FRI SEP 27 2024 - 12Z SUN SEP 29 2024
...HELENE IS FORECAST TO CONTINUE TO MOVE INLAND TO THE
NORTHWESTWARD TO THE OHIO VALLEY BY SATURDAY WHILE SLOWLY
WEAKENING...
...THERE IS A HIGH RISK OF EXCESSIVE RAINFALL OVER PARTS OF THE
SOUTHERN APPALACHIANS ON FRIDAY AND A SLIGHT RISK OVER PARTS OF
THE OHIO VALLEY ON SATURDAY...
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
THE SOUTHERN MID-ATLANTIC ON FRIDAY...
ā€THERE ARE EXCESSIVE HEAT WARNINGS OVER PARTS OF SOUTHEASTERN
CALIFORNIA AND THE SOUTHWESTā€
HELENE IS FORECAST TO MOVE INLAND, HEADING NORTHWESTWARD TO THE
OHIO VALLEY, AND SLOWLY WEAKEN BY SATURDAY. SHOWERS AND
THUNDERSTORMS WITH HEAVY RAIN WILL DEVELOP OVER PARTS OF THE
SOUTHERN APPALACHIANS AND SOUTHERN MID-ATLANTIC. THEREFORE, THE
WPC HAS ISSUED A HIGH RISK (LEVEL 4/4) OF EXCESSIVE RAINFALL OVER
THE SOUTHERN APPALACHIANS THROUGH SATURDAY MORNING. SEVERE,
WIDESPREAD FLASH FLOODING IS EXPECTED. IN ADDITION, AREAS THAT
NORMALLY DO NOT EXPERIENCE FLASH FLOODING WILL FLOOD. LIVES AND
PROPERTY ARE IN GREAT DANGER.
MOREOVER, SHOWERS AND SEVERE THUNDERSTORMS WILL DEVELOP OVER PARTS
OF THE SOUTHERN MID-ATLANTIC. THEREFORE, THE SPC HAS ISSUED AN
ENHANCED RISK (LEVEL 3/5) OF SEVERE THUNDERSTORMS OVER THE
SOUTHERN MID-ATLANTIC THROUGH SATURDAY MORNING. THE HAZARDS
ASSOCIATED WITH THESE THUNDERSTORMS ARE FREQUENT LIGHTNING, A FEW
TORNADOES, AND A MINIMAL THREAT OF SEVERE THUNDERSTORM WIND GUSTS
AND HAIL. ALSO, RAIN WILL DEVELOP OVER PARTS OF THE OHIO/TENNESSEE
VALLEYS ON FRIDAY.
ON SATURDAY, THE EXCESSIVE RAINFALL THREAT FROM HELENE LESSENS.
HOWEVER, HEAVY RAIN WILL DEVELOP OVER PARTS OF THE OHIO VALLEY.
THEREFORE, THE WPC HAS ISSUED A SLIGHT RISK (LEVEL 2/4) OF
EXCESSIVE RAINFALL OVER PARTS OF THE OHIO VALLEY FROM SATURDAY
THROUGH SUNDAY MORNING. THE ASSOCIATED HEAVY RAIN WILL CREATE
MAINLY LOCALIZED AREAS OF FLASH FLOODING, WITH URBAN AREAS, ROADS,
SMALL STREAMS, AND LOW-LYING AREAS THE MOST VULNERABLE.
FURTHER, THE THREAT OF SEVERE THUNDERSTORMS ENDS ON SATURDAY. YET
SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE FLORIDA PENINSULA.
ADDITIONALLY, RAIN WILL CONTINUE OVER THE OHIO/TENNESSEE VALLEYS
AND PARTS OF THE MID-ATLANTIC THROUGH SUNDAY MORNING.
MEANWHILE, A FRONT WILL MOVE ONSHORE OVER THE PACIFIC NORTHWEST
AND INLAND TO THE NORTHERN PLAINS. THE SYSTEM WILL PRODUCE RAIN
OVER PARTS OF THE NORTHWEST ENDING BY LATE FRIDAY AFTERNOON.
IN ADDITION, AN UPPER-LEVEL HIGH WILL REMAIN OVER THE SOUTHWEST
THROUGH SUNDAY. HIGH TEMPERATURES WILL RANGE FROM THE UPPER 90S TO
110S, AND LOW TEMPERATURES IN THE MID TO UPPER 80S WILL PROVIDE
LITTLE RELIEF FROM THE HEAT OVERNIGHT. THE TEMPERATURES HAVE
PROMPTED EXCESSIVE HEAT WARNINGS OVER PARTS OF SOUTHEASTERN
CALIFORNIA AND THE SOUTHWEST.
ZIEGENFELDER
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