839
FXUS21 KWNC 311928
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT OCTOBER 31 2024
SYNOPSIS: SURFACE HIGH PRESSURE OVER THE GREAT LAKES AND LOW PRESSURE IN THE
LEE OF THE ROCKIES SETS UP A TIGHT GRADIENT OVER THE GREAT PLAINS, RESULTING IN
THE POTENTIAL FOR HIGH WINDS DURING WEEK-2. A SERIES OF STRONG SURFACE LOW
PRESSURE SYSTEMS ARE FORECAST TO MOVE THROUGH THE GULF OF ALASKA, BRINGING THE
POTENTIAL FOR HIGH WINDS TO COASTAL PORTIONS OF SOUTHERN AND SOUTHEASTERN
ALASKA AS WELL AS THE PACIFIC NORTHWEST.
HAZARDS
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF THE GREAT PLAINS, FRI-TUE, NOV 8-12.
SLIGHT RISK OF HIGH WINDS FOR COASTAL PORTIONS OF THE PACIFIC NORTHWEST,
FRI-TUE, NOV 8-12.
SLIGHT RISK OF HIGH WINDS FOR MUCH OF THE SOUTHERN AND SOUTHEASTERN ALASKAN
COAST, FRI-TUE, NOV 8-12.
DETAILED SUMMARY
FOR SUNDAY NOVEMBER 03 - THURSDAY NOVEMBER 07:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR FRIDAY NOVEMBER 08 - THURSDAY NOVEMBER 14: THE SYNOPTIC PICTURE FOR THE
CONTIGUOUS U.S. (CONUS) DURING WEEK-2 IS CHARACTERIZED BY WEAK TROUGHING OVER
THE ROCKIES AND WEAK RIDGING OVER THE EASTERN SEABOARD, AS DEPICTED BY THE
ECENS, GEFS, AND CMCE 500-HPA HEIGHT AND ANOMALY SOLUTIONS. HEIGHT ANOMALIES
ARE GENERALLY POSITIVE OVER MUCH OF NORTH AMERICA, RESULTING IN ABOVE-AVERAGE
TEMPERATURES FAVORED FOR THE CONUS. THIS SETUP RESULTS IN A FAIRLY TRANQUIL
PERIOD FROM A HAZARDOUS WEATHER PERSPECTIVE, HOWEVER THERE ARE A FEW AREAS THAT
ARE AN EXCEPTION TO AN OTHERWISE QUIET WEEK-2.
DEEP UPPER-LEVEL TROUGHING OVER THE BERING SEA AND GULF OF ALASKA IS DEPICTED
AT THE OUTSET OF WEEK-2 AND PERSISTS THROUGHOUT THE FORECAST PERIOD, GRADUALLY
WEAKENING AS THE WEEK PROGRESSES. MODEL SOLUTIONS ALSO FAVOR A SERIES OF STRONG
SURFACE LOW PRESSURE SYSTEMS TO TRACK FROM THE BERING SEA ACROSS THE GULF OF
ALASKA. SOME DETERMINISTIC RUNS FEATURE SURFACE LOW PRESSURE CENTERS BELOW
950MB AND WIDESPREAD AREAS OF STRONG WINDS IN EXCESS OF 34 KTS. THESE ENHANCED
WINDS EXTEND SOUTHWARD ALONG THE PACIFIC NORTHWEST COAST AS WELL, WITH WIND
SPEED EXCEEDING 20 KTS AS FAR SOUTH AS CAPE MENDOCINO. MODEL SOLUTIONS INDICATE
THE POTENTIAL FOR THESE STORMY CONDITIONS TO LAST THROUGHOUT THE PERIOD,
ALTHOUGH CONFIDENCE DECREASES TOWARDS THE END OF WEEK-2. THEREFORE, A SLIGHT
RISK OF HIGH WINDS IS POSTED FOR THE ENTIRE SOUTHERN COAST OF ALASKA FROM THE
ALEUTIAN ISLANDS TO THE ALASKAN PANHANDLE, AS WELL AS FOR COASTAL PORTIONS OF
THE PACIFIC NORTHWEST FOR NOV 8-12. PERIODS OF HEAVY PRECIPITATION ARE LIKELY
TO IMPACT THESE REGIONS AS WELL, ALTHOUGH PRECIPITATION TOTALS ARE NOT FAVORED
TO BE SUFFICIENT TO WARRANT POSTING A HAZARD TO THE OUTLOOK AT THIS TIME.
OVER THE CONUS, A WEAK CUT-OFF UPPER-LEVEL LOW PRESSURE SYSTEM IS DEPICTED OVER
THE DESERT SOUTHWEST AT THE OUTSET OF WEEK-2. WEAK TROUGHING GENERALLY PERSISTS
IN THE WEST WHILE WEAK POSITIVE 500-HPA HEIGHT ANOMALIES OVERSPREAD MUCH OF THE
EASTERN CONUS. THESE FEATURES ARE REFLECTED AT THE SURFACE AS WELL, WITH HIGH
PRESSURE OVER THE GREAT LAKES AND WEAK TROUGHING IN THE LEE OF THE ROCKIES.
THIS SETS UP A STRONG PRESSURE GRADIENT AND THE POTENTIAL FOR HIGH WINDS OVER
MUCH OF THE GREAT PLAINS. SOLUTIONS FROM THE GEFS AND ECENS BOTH INDICATE AT
LEAST A 20% PROBABILITY OF WIND SPEEDS EXCEEDING 20 KTS FOR MUCH OF THE GREAT
PLAINS FROM THE TEXAS PANHANDLE NORTHWARD TO THE U.S.-CANADA BORDER. SIMILAR TO
THE ALASKA REGION, MODEL SOLUTIONS INDICATE THIS POTENTIAL FOR HIGH WIND
THROUGHOUT WEEK-2 ALTHOUGH CONFIDENCE DECREASES WITH TIME SO A SLIGHT RISK OF
HIGH WIND IS POSTED FOR MUCH OF THE GREAT PLAINS FOR NOV 8-12. ALSO, LIKE THE
ALASKA REGION, WHILE THERE IS THE POSSIBILITY OF HEAVY RAIN DUE TO BAROCLINIC
INSTABILITY ASSOCIATED WITH THE PRESSURE GRADIENT, PRECIPITATION TOTALS ARE
ONCE AGAIN NOT EXPECTED TO EXCEED HAZARDOUS THRESHOLDS.
FORECASTER: DANNY BARANDIARAN
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