486
FXUS21 KWNC 162010
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 16 2024
SYNOPSIS: A GENERALLY QUIET PATTERN IS PREDICTED ACROSS THE CONTIGUOUS U.S.
(CONUS) DURING WEEK-2, WITH MID-LEVEL HIGH PRESSURE OVER THE EAST INTO PORTIONS
OF THE SOUTHWEST FAVORING ABOVE-NORMAL TEMPERATURES. ENHANCED ONSHORE FLOW MAY
BRING ROUNDS OF PRECIPITATION INTO THE PACIFIC NORTHWEST BUT THERE IS A LOT OF
UNCERTAINTY REGARDING THE STRENGTH AND DURATION OF ANY PRECIPITATION. FLOODING
IN THE WAKE OF HURRICANE MILTON REMAINS A CONCERN OVER PARTS OF FLORIDA.
CONVERSELY, RAPID ONSET DROUGHT REMAINS A RISK ACROSS PORTIONS OF THE SOUTHERN
PLAINS AND LOWER MISSISSIPPI VALLEY. IN ALASKA, AT LEAST ONE AREA OF
LOW-PRESSURE IS FORECAST THAT MAY BRING HIGH WINDS AND HEAVY PRECIPITATION TO
PORTIONS OF WESTERN MAINLAND ALASKA AND THE BERING AND CHUKCHI SEAS.
HAZARDS
A SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF WESTERN MAINLAND ALASKA, THU-MON,
OCT 24-28.
A SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF WESTERN MAINLAND ALASKA,
THU-SAT, OCT 24-26.
A SLIGHT RISK OF HEAVY SNOW FOR PORTIONS OF WESTERN INTERIOR ALASKA, THU-FRI,
OCT 24-25.
POSSIBLE FLOODING FOR THE NORTHERN AND CENTRAL FLORIDA PENINSULA.
RISK OF RAPID ONSET DROUGHT (ROD) ACROSS PORTIONS OF EASTERN TEXAS, NORTHERN
LOUISIANA, AND SOUTHERN ARKANSAS.
DETAILED SUMMARY
FOR SATURDAY OCTOBER 19 - WEDNESDAY OCTOBER 23:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY OCTOBER 24 - WEDNESDAY OCTOBER 30: ANOMALOUS RIDGING AND
UNSEASONABLY WARM TEMPERATURES ARE FORECAST TO BE WIDESPREAD ACROSS MUCH OF THE
CONUS AND ALASKA, EXCLUDING PORTIONS OF THE WEST COAST AND NORTHERN ROCKIES.
THE ANOMALOUS WARMTH MAY BE IN DECLINE BY THE END OF WEEK-2 BUT TEMPERATURES
ARE LIKELY TO REMAIN ABOVE-NORMAL THROUGHOUT THE PERIOD.
IN ALASKA, A PROGRESSIVE MID-LEVEL HEIGHT PATTERN IS FORECAST WITH MID-LEVEL
RIDGING FORECAST ACROSS THE ALEUTIAN ISLANDS AT THE START OF THE PERIOD TO
PROGRESS SOUTHEAST OVER TIME AND WEAKEN. MID-LEVEL TROUGHING IS THEN FORECAST
TO MOVE INTO WESTERN MAINLAND ALASKA FROM EASTERN SIBERIA AND PHASE WITH A
MID-LEVEL TROUGH OVER NORTHERN CANADA. AT LEAST ONE AREA OF SURFACE
LOW-PRESSURE IS FORECAST TO IMPACT WESTERN ALASKA DURING THE PERIOD. THIS MAY
POTENTIALLY SET UP A STRONG PRESSURE GRADIENT ACROSS WESTERN ALASKA BRINGING
HIGH WINDS TO THE REGION. THE PROBABILISTIC EXTREMES TOOLS (PETS) FROM THE GEFS
AND ECENS FORECASTS ELEVATED CHANCES OF HIGH WINDS ACROSS MUCH OF WESTERN
ALASKA AND IS SUPPORTED BY THE OVERALL FLOW PATTERN. THEREFORE, SLIGHT RISK OF
HIGH WINDS IS POSTED FOR WESTERN MAINLAND ALASKA FOR OCT 24-28.
ANY LOW PRESSURE SYSTEM THAT DOES DEVELOP MAY BRING CHANCES FOR HEAVY RAIN AND
SNOW TO PORTIONS OF WESTERN ALASKA. THE GEFS AND ECENS PETS FORECAST 20-40%
CHANCES OF 3-DAY PRECIPITATION AMOUNTS TO EXCEED THE 85TH PERCENTILE FOR DAYS
8-10. THEREFORE, A SLIGHT RISK OF HEAVY PRECIPITATION IS POSTED FOR PORTIONS OF
WESTERN ALASKA FOR OCT 24-26. IN PORTIONS OF THE CENTRAL INTERIOR MUCH OF THIS
PRECIPITATION WOULD LIKELY FALL AS SNOW AND A SLIGHT RISK OF HEAVY SNOW IS
POSTED FOR OCT 24-25. NEAR THE WESTERN COAST THE HEAVY SNOW IS FAVORED ACROSS
HIGHER ELEVATIONS WITH MORE MIXED PRECIPITATION CHANCES AT LOWER ALTITUDES AND
SO THERE IS SOME OVERLAP OF THE HEAVY SNOW AND HEAVY PRECIPITATION SLIGHT RISKS
IN THIS AREA.
ALONG THE WEST COAST OF THE CONUS, A MID-LEVEL TROUGH IS FORECAST TO BE DIGGING
SOUTH ALONG THE COAST AT THE START OF WEEK-2. THE TROUGH MAY BRING A PERIOD OF
UNSETTLED WEATHER TO PORTIONS OF THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA.
THE PETS FROM THE ECENS AND GEFS FORECAST 20-40% CHANCES FOR 3-DAY
PRECIPITATION AMOUNTS TO EXCEED THE 85TH PERCENTILE ACROSS NORTHERN CALIFORNIA
AND OREGON. HOWEVER, THERE ARE DIFFERENCES AMONG THE TOOLS REGARDING ACTUAL
PRECIPITATION AMOUNTS WITH THE GEFS HAVING LOW CHANCES OF PRECIPITATION
EXCEEDING 1 INCH OVER THE 3-DAY PERIOD TO START WEEK-2, WHILE THE ECENS HAS
INCREASED CHANCES OF 1.5 INCHES ACROSS PORTIONS OF NORTHERN CALIFORNIA AND
OREGON. GIVEN THAT THE UNCALIBRATED ENSEMBLE MEANS SHOW VERY LITTLE
PRECIPITATION IN THESE REGIONS, WITH THE 0Z ECENS AND 6Z GEFS ENSEMBLE MEANS
FORECASTING BELOW-NORMAL PRECIPITATION CHANCES DURING WEEK-2, NO HAZARD IS
POSTED BUT THIS AREA WILL CONTINUE TO BE MONITORED.
ANY MOISTURE THAT REACHES THE NORTHERN ROCKY MOUNTAINS OR HIGH PLAINS MAY
INTERACT WITH AN EARLY ALBERTA CLIPPER LIKE SYSTEM AND BRING AN EARLY SEASON
SNOWFALL TO THE REGION. AT THIS TIME, ANY SNOWFALL DOES NOT APPEAR TO BE
PARTICULARLY HEAVY OR HAZARDOUS AND NO ASSOCIATED HAZARD IS POSTED.
HURRICANE MILTON MADE LANDFALL ON OCT 9 NEAR SIESTA KEY, FLORIDA LEAVING BEHIND
EXTENSIVE ONGOING FLOODING AND IS FORECAST TO CONTINUE THROUGH WEEK-1 AND
POSSIBLY INTO WEEK-2. THEREFORE, THE FLOODING POSSIBLE AREA REMAINS POSTED
ACROSS PORTIONS OF THE NORTHERN AND CENTRAL FLORIDA PENINSULA.
THE RAPID ONSET DROUGHT (ROD) RISK REMAINS CONFINED TO PORTIONS OF EASTERN
TEXAS, NORTHERN LOUISIANA, AND SOUTHERN ARKANSAS. THESE AREAS REMAIN FAVORED TO
HAVE NEAR- TO BELOW-NORMAL PRECIPITATION DURING WEEK-2, ALONG WITH THE
POTENTIAL FOR TEMPERATURES IN THE 80S DEG F SUPPORTING HIGHER
EVAPOTRANSPIRATION RATES.
FORECASTER: RYAN BOLT
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