300
FXUS21 KWNC 141948
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST FEBRUARY 14 2024
SYNOPSIS: MID-LEVEL LOW PRESSURE IS FORECAST INITIALLY OVER THE BERING SEA AND
GULF OF ALASKA IS PREDICTED TO SHIFT SOUTHWARD THROUGHOUT WEEK-2, WHILE A
SECONDARY AREA OF MID-LEVEL LOW PRESSURE IS FORECAST TO FORM OVER THE
SOUTHWESTERN CONTIGUOUS U.S. (CONUS). THIS PATTERN IS ANTICIPATED TO BRING
HEAVY PRECIPITATION (HIGH ELEVATION SNOW) TO PARTS OF THE WEST COAST BY THE
MIDDLE OF THE PERIOD AND HEAVY SNOW TO HIGH ELEVATIONS OF THE NORTHERN AND
CENTRAL ROCKIES, AND EASTERN PORTIONS OF THE GREAT BASIN BY THE END OF THE
PERIOD. SURFACE LOW DEVELOPMENT IN THE LEE OF THE ROCKIES INCREASES CHANCES FOR
HIGH WINDS ACROSS PARTS OF THE CENTRAL AND EASTERN CONUS, WITH THE POTENTIAL
FOR HEAVY SNOW OVER THE NORTHEAST. . SURFACE LOW PRESSURE SYSTEMS OVER THE
BERING SEA AND GULF OF ALASKA INCREASES THE RISK FOR HIGH WINDS FOR MANY PARTS
OF THE SOUTHERN COAST OF ALASKA AT THE BEGINNING OF WEEK-2.
HAZARDS
SLIGHT RISK OF HEAVY PRECIPITATION ACROSS THE PACIFIC NORTHWEST AND CALIFORNIA,
SAT-WED, FEBRUARY 24-28.
SLIGHT RISK FOR HEAVY SNOW FOR THE SIERRA NEVADA, KLAMATH, AND CASCADE
MOUNTAINS, SAT-WED, FEBRUARY 24-28.
SLIGHT RISK OF HIGH WINDS FOR THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA,
SAT-MON, FEB 24-26.
SLIGHT RISK OF HEAVY SNOW FOR THE NORTHERN AND CENTRAL ROCKIES, AND EASTERN
PORTIONS OF THE GREAT BASIN, MON-WED, FEB 26-28.
SLIGHT RISK OF HIGH WINDS FOR PORTIONS OF THE HIGH PLAINS, THU-FRI, FEB 22-23.
SLIGHT RISK OF EPISODIC HIGH WINDS FOR PORTIONS OF THE EASTERN CONUS, THU-SAT,
FEB 22-24.
SLIGHT RISK OF PERIODS OF HEAVY SNOW FOR PARTS OF THE NORTHEASTERN CONUS,
THU-SAT, FEB 22-24.
SLIGHT RISK FOR PERIODS OF HIGH WINDS FOR THE SOUTHERN COAST OF ALASKA FROM THE
ALASKA PENINSULA TO SOUTHEASTERN ALASKA, THU-SAT, FEB 22-24.
POSSIBLE FLOODING FOR SOUTHWESTERN OREGON AND MUCH OF CALIFORNIA.
DETAILED SUMMARY
FOR SATURDAY FEBRUARY 17 - WEDNESDAY FEBRUARY 21:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY FEBRUARY 22 - WEDNESDAY FEBRUARY 28: MID-LEVEL TROUGHING IS
PREDICTED OVER THE BERING SEA AND GULF OF ALASKA AT THE ONSET OF WEEK-2,
SHIFTING SOUTHWARD TO THE WEST COAST BY THE MIDDLE OF THE PERIOD AND INLAND
TOWARDS THE END OF WEEK-2, SUPPORTING THE CONTINUATION OF SLIGHT RISKS FOR
HEAVY PRECIPITATION AND HIGH WINDS ACROSS PORTIONS OF THE WEST. TODAY’S MODEL
ENSEMBLE SOLUTIONS CONTINUE TO SHOW RELATIVELY LOW PROBABILITIES OF ENHANCED
INTEGRATED VAPOR TRANSPORT (IVT) FOR THE WEST COAST DURING WEEK-2 AS THE
HEAVIEST ATMOSPHERIC RIVER (AR) ACTIVITY HAS MOSTLY SHIFTED INTO THE WEEK-1
PERIOD. BOTH THE GEFS AND ECMWF MEAN SOLUTIONS OF IVT DEPICT ENHANCED MOISTURE
SHIFTING FROM BRITISH COLUMBIA TO THE WEST COAST TOWARDS THE LATTER PORTION OF
WEEK-2, RESULTING IN DRIER CONDITIONS EARLY IN THE PERIOD. A SLIGHT RISK OF
HEAVY PRECIPITATION IS POSTED FOR NORTHERN AND CENTRAL CALIFORNIA AND THE
PACIFIC NORTHWEST, FEB 24-28, WHERE THE GEFS, ECENS, AND CANADIAN PROBABILISTIC
EXTREMES TOOLS (PETS) SHOW AT LEAST A 20% CHANCE OF 3-DAY LIQUID EQUIVALENT
TOTALS EXCEEDING THE 85TH PERCENTILE CLIMATOLOGICALLY AND ONE INCH. A SLIGHT
RISK OF HEAVY SNOW IS DESIGNATED FOR THE SIERRA NEVADA, KLAMATH, AND CASCADE
MOUNTAINS FOR THE SAME PERIOD. THIS IS ALSO SUPPORTED BY GEFS PET INDICATES AT
LEAST A 20% CHANCE OF 3-DAY SNOW WATER EQUIVALENT (SWE) TOTALS EXCEEDING THE
85TH PERCENTILE AND ONE INCH. THE HEAVIEST PRECIPITATION IS PREDICTED TO SHIFT
SOUTHWARD FROM THE PACIFIC NORTHWEST AT THE BEGINNING OF THE PERIOD TO
CALIFORNIA TOWARDS THE LATTER PORTION OF WEEK-2. A SLIGHT RISK OF HIGH WINDS IS
DESIGNATED FOR THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA, FEB 24-26, WHEN
THE PATTERN IS MOST FAVORABLE FOR A TIGHT PRESSURE GRADIENT SUPPORTING ENHANCED
WIND SPEEDS IN THIS AREA. PETS INDICATE AT LEAST A 20% CHANCE OF WIND SPEEDS
EXCEEDING THE 85TH PERCENTILE AND 25 MPH (>40 MPH LOCALLY ALONG THE COAST).
GIVEN THE LARGE PRECIPITATION TOTALS ANTICIPATED DURING THE WEEK-1 PERIOD AND A
WET PATTERN PERSISTING THROUGHOUT WEEK-2, INCREASED POSSIBLE RISK OF FLOODING
IS DESIGNATED FOR CALIFORNIA AND SOUTHWESTERN OREGON DURING THE FORECAST
PERIOD.AS THE MID-LEVEL TROUGH SHIFTS INLAND TOWARDS THE END OF WEEK-2,
ENHANCED MOISTURE IS PREDICTED FOR PORTIONS OF THE INTERIOR WEST. A SLIGHT RISK
OF HEAVY SNOW IS HIGHLIGHTED FOR THE NORTHERN AND CENTRAL ROCKIES, AND EASTERN
PORTIONS OF THE GREAT BASIN, FEB 26-28. THE GREATEST CHANCES FOR HEAVIER
AMOUNTS ARE INDICATED OVER THE NORTHERN ROCKIES AND ADJACENT HIGH ELEVATION
AREAS IN IDAHO.
EARLIER IN THE PERIOD, SURFACE LOW DEVELOPMENT AND ASSOCIATED FRONTAL
ACTIVITY OVER THE CENTRAL CONUS IS FAVORED TO SHIFT EASTWARD. A SLIGHT RISK OF
HIGH WINDS IS HIGHLIGHTED FOR PORTIONS OF THE HIGH PLAINS, FEB 22-23. THE ECENS
PETS HAS A STRONGER SIGNAL SUPPORTING HIGH WINDS SHOWING AT LEAST A 20% CHANCE
OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 25 MPH ACROSS THE LOCALIZED
PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS, WHEREAS THE GEFS COUNTERPART
LIMITS THESE SIGNALS TO THE NORTHERN HIGH PLAINS AND LOWER WIND SPEEDS (LESS
THAN 25 MPH).
AS THE ASSOCIATED FRONTAL SYSTEM SHIFTS DOWNSTREAM OVER THE EASTERN U.S., THERE
ARE INCREASED CHANCES FOR EPISODIC HIGH WINDS AND HEAVY PRECIPITATION ACROSS
PARTS OF THE EASTERN HALF OF THE CONUS. A BROAD SWATCH AREA IS HIGHLIGHTED WITH
A SLIGHT RISK OF HIGH WINDS EXTENDING FROM THE MIDDLE MISSISSIPPI VALLEY TO THE
NORTHEAST AND MID-ATLANTIC, FEB 22-24. THE ECENS PET SHOWS AT LEAST A 20%
CHANCE OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 20 MPH IN THE
DESIGNATED AREA. A SLIGHT RISK OF PERIODS OF HEAVY SNOW IS POSTED FOR THE
NORTHEASTERN CONUS, FEB 22-24 BASED ON BETTER AGREEMENT AMONG MODELS SHOWING A
TRACKING SURFACE LOW ACROSS THE NORTHEAST COMPARED TO YESTERDAY. THE GEFS 3-DAY
SWE PET TOTALS SHOW SIGNALS FOR ABOVE NORMAL SNOW IN THE AREA BUT DO NOT
INDICATE AREAS REACHING AT LEAST 20% OF EXCEEDING THE 85TH PERCENTILE AND
UNCALIBRATED ECENS ENSEMBLE MEANS SHOW 3-DAY TOTALS REACHING 4 TO 6 INCHES.
HEAVY SNOW AND HIGH WINDS COULD BE IMPACTFUL SINCE BLOWING SNOW COULD LEAD TO
LOW VISIBILITY AND NEW ENGLAND HAS NOT HAD MUCH SIGNIFICANT SNOW THUS FAR THIS
WINTER. FURTHER SOUTH, TRACKING SURFACE LOWS AND ENHANCED MOISTURE FLOW FROM
THE GULF OF MEXICO COULD SUPPORT ENHANCED PRECIPITATION ACROSS PARTS OF THE
SOUTHEAST AT THE END OF WEEK-2. THE GEFS AND ECENS PETS SHOW AT LEAST A 20%
CHANCE OF 3-DAY RAINFALL EXCEEDING THE 85TH PERCENTILE AND ONE INCH, FEB 26-28.
DUE TO SIGNIFICANT UNCERTAINTY AT THIS TIME LEAD FOR THIS FEATURE, AN
ASSOCIATED HAZARD IS NOT SPECIFIED AT THIS TIME BUT WILL BE MONITORED IN THE
UPCOMING DAYS.
A SERIES OF STRONG LOW PRESSURE SYSTEMS ARE DEPICTED TRACKING FROM THE BERING
SEA INTO THE GULF OF ALASKA, BRINGING PERIODS OF STORMY WEATHER INTO THE
SOUTHERN COASTAL PORTIONS OF THE STATE. A SLIGHT RISK OF HIGH WINDS IS
HIGHLIGHTED FOR SOUTHERN COASTAL ALASKA EXTENDING FROM THE ALASKA PENINSULA TO
THE SOUTHEAST, FEB 22 TO 24, WHERE PETS SHOW AT LEAST A 20% CHANCE OF WIND
SPEEDS EXCEEDING THE 85TH PERCENTILE AND 40 MPH.
FORECASTER: MELISSA OU
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