895
FXUS01 KWBC 110810
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 AM EST WED DEC 11 2024
VALID 12Z WED DEC 11 2024 - 12Z FRI DEC 13 2024
...WIDESPREAD HEAVY RAIN AND SEVERE THUNDERSTORM TREATS SPREADING
UP THE EAST COAST TODAY AND THROUGH NEW ENGLAND INTO TONIGHT...
...A SURGE OF COLD AIR INTO THE EASTERN U.S. TODAY WILL BE
FOLLOWED BY A REINFORCING SURGE OF ARCTIC AIR INTO THE NORTHERN
U.S. THROUGH THE NEXT COUPLE OF DAYS...
...ANOTHER ROUND OF SIGNIFICANT LAKE EFFECT SNOW EXPECTED THROUGH
THE NEXT COUPLE OF DAYS DOWNWIND OF THE LAKES...
THE STAGE IS SET FOR A RAPIDLY INTENSIFYING LOW PRESSURE SYSTEM TO
TRACK UP THE EAST COAST TODAY. A POTENT COLD FRONT TRAILING
SOUTHWEST FROM THE CENTER OF THIS ELONGATED LOW PRESSURE SYSTEM
WILL BE THE FOCUS FOR HEAVY RAIN, BLUSTERY WINDS, AND STRONG TO
SEVERE THUNDERSTORMS. AHEAD OF THE FRONT, WARM AND MOIST AIR
STREAMING IN FROM THE NEARBY ATLANTIC AND GULF OF MEXICO WILL
INTERACT MORE VIGOROUSLY WITH A JET STREAM ALOFT TO DEVELOP AND
EXPAND THE COVERAGE OF SHOWERS AND THUNDERSTORMS, FIRST ACROSS THE
SOUTHEAST AND THE CAROLINAS THIS MORNING, FOLLOWED BY THE
MID-ATLANTIC STATES DURING THE DAY, AND INTO NEW ENGLAND THIS
EVENING. THE HIGHLY DYNAMIC NATURE OF THIS FRONT WILL LIKELY
TRIGGER FORMATION OF STRONG TO SEVERE THUNDERSTORMS. THIS IS
ESPECIALLY THE CASE ACROSS EASTERN NORTH CAROLINA THIS AFTERNOON,
AND INTO SOUTHERN NEW ENGLAND THIS EVENING, WHERE THE STORM
PREDICTION CENTER HAS ISSUED A SLIGHT RISK (LEVEL 2 OF 5) FOR
SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING WIND GUSTS.
ELSEWHERE ALONG THE EASTERN SEABOARD, THE MAIN CONCERN WILL BE A
PERIOD OF HEAVY RAIN WITH EMBEDDED STRONG THUNDERSTORMS AND
INTENSE DOWNPOURS. DESPITE MUCH OF THE REGION CURRENTLY
EXPERIENCING MODERATE TO EXTREME DROUGHT CONDITIONS, THE RAIN,
WHILE MOSTLY BENEFICIAL, COULD LEAD TO SOME LOCALIZED INSTANCES OF
FLASH FLOODING. THE MORE URBANIZED LOCATIONS AND POOR DRAINAGE
AREAS WOULD HAVE THE GREATER RISK OF FLOODING ISSUES.
BEHIND THE POTENT COLD FRONT SHARPLY COLDER AIR WILL SURGE INTO
THE EAST COAST FROM THE NORTH AND NORTHWEST. A PERIOD OF
ACCUMULATING WET SNOW CAN BE EXPECTED TO SPREAD UP THE WESTERN
SLOPE OF THE ENTIRE SPINE OF THE APPALACHIANS FROM SOUTH TO NORTH
TODAY THROUGH TONIGHT. MEANWHILE, A REINFORCING SHOT OF ARCTIC
AIR IS PLUNGING INTO THE NORTHERN PLAINS AND WILL OVERSPREAD MUCH
OF THE NORTHERN TIER STATES THROUGH THE NEXT COUPLE OF DAYS. HIGH
TEMPERATURES THE NEXT COUPLE OF DAYS WILL BE ROUGHLY 10 TO AS MUCH
AS 30 DEGREES BELOW NORMAL.
ATTENTION THEN TURNS TO YET ANOTHER ROUND OF SIGNIFICANT LAKE
EFFECT SNOW DOWNWIND OF THE GREAT LAKES THROUGH THE NEXT COUPLE OF
DAYS. THE AFOREMENTIONED SURGE OF ARCTIC AIR WILL STREAM ACROSS
THE STILL RELATIVELY WARM GREAT LAKES AND IGNITE INTENSE BANDS OF
LAKE EFFECT SNOW, INITIALLY DOWNWIND OF LAKES SUPERIOR AND
MICHIGAN ON TODAY AND THEN DOWNWIND OF LAKES ERIE AND ONTARIO
TONIGHT INTO EARLY THURSDAY. BY THE TIME THE SNOW STARTS TO TAPER
OFF ON FRIDAY, SNOWFALL TOTALS OF 1 TO 2 FEET ARE LIKELY IN THE
FAVORED SNOW BELT ACROSS PORTIONS OF NORTHWEST AND WESTERN NEW
YORK STATE, FAR NORTHWEST PENNSYLVANIA, FAR NORTHEASTERN OHIO, THE
UPPER PENINSULA OF MICHIGAN AND THE WESTERN PORTIONS OF THE LOWER
PENINSULA OF MICHIGAN.
ALONG THE WEST COAST, MOISTURE AHEAD OF THE NEXT CYCLONE FROM THE
PACIFIC IS POISED TO OVERSPREAD MUCH OF THE REGION THROUGH THE
NEXT COUPLE OF DAYS. NORTHERN CALIFORNIA WILL SEE HEAVY COASTAL
RAIN BY THIS EVENING, FOLLOWED BY HEAVY MOUNTAIN SNOW FARTHER
INLAND AND DOWN THE SIERRA NEVADA WHERE A FOOT OR MORE OF NEW SNOW
IS FORECAST THROUGH THURSDAY. IT APPEARS THAT THIS ROUND OF
PRECIPITATION WILL MOSTLY TAPER OFF THURSDAY NIGHT PRIOR TO THE
ARRIVAL OF THE NEXT PACIFIC SYSTEM.
KONG/MILLER
GRAPHICS AVAILABLE AT
HTTPS://WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page