613
FXUS21 KWNC 171952
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST JANUARY 17 2024
SYNOPSIS: MOIST AIR OFF THE GULF OF MEXICO IS FORECAST TO INTERACT WITH A STORM
SYSTEM OVER THE GREAT PLAINS BEGINNING LATE IN WEEK-1, FAVORING POTENTIALLY
HEAVY PRECIPITATION INTO EARLY WEEK-2 FOR PORTIONS OF EASTERN TEXAS AS WELL AS
THE OHIO, TENNESSEE, LOWER MISSISSIPPI VALLEYS, AND THE SOUTHEAST U.S. STORMY
PACIFIC ONSHORE FLOW IS FORECAST TO CONTINUE FOR NORTHERN PORTIONS OF THE WEST
COAST EARLY IN THE FORECAST PERIOD, BRINGING THE POTENTIAL FOR HEAVY
PRECIPITATION AND HEAVY SNOW FOR THE HIGHER ELEVATIONS.
HAZARDS
MODERATE RISK FOR HEAVY PRECIPITATION FOR PORTIONS OF EASTERN TEXAS AS WELL AS
MOST OF LOUISIANA, MISSISSIPPI, AND ALABAMA, THU-FRI, JAN 25-26.
SLIGHT RISK FOR HEAVY PRECIPITATION FOR PORTIONS OF EASTERN TEXAS, LOWER AND
MIDDLE MISSISSIPPI, OHIO, AND TENNESSEE VALLEYS, AND SOUTHEAST U.S., THU-SAT,
JAN 25-27.
SLIGHT RISK FOR HEAVY PRECIPITATION FOR WESTERN PORTIONS OF WASHINGTON AND
OREGON, THU-SAT, JAN 25-27.
SLIGHT RISK FOR HEAVY SNOW FOR THE CASCADE MOUNTAINS, THU-SAT, JAN 25-27.
SLIGHT RISK FOR HEAVY SNOW FOR THE NORTHERN ROCKIES, THU-FRI, JAN 25-26.
SLIGHT RISK FOR HEAVY SNOW FOR HIGHER ELEVATIONS OF COLORADO AND NEW MEXICO,
THU-FRI, JAN 25-26.
SLIGHT RISK FOR HIGH WINDS FOR THE WASHINGTON AND OREGON COAST, THU-SAT, JAN
25-27.
FLOODING POSSIBLE FOR THE WESTERN FOOTHILLS OF THE CASCADE MOUNTAINS.
DETAILED SUMMARY
FOR SATURDAY JANUARY 20 - WEDNESDAY JANUARY 24:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR THURSDAY JANUARY 25 - WEDNESDAY JANUARY 31: AS SURFACE HIGH PRESSURE
ASSOCIATED WITH THE ONGOING COLD SNAP OVER THE CONTIGUOUS U.S. (CONUS) SHIFTS
EASTWARD, MOIST RETURN FLOW IS FAVORED TO DEVELOP OVER THE GREAT PLAINS. MODELS
DEPICT A SHORTWAVE TROUGH MOVING OFF THE ROCKIES DURING WEEK-1 AND DEVELOPING
HEAVY PRECIPITATION AS IT MOVES EASTWARD. WHILE THE EFFECTS OF THIS SYSTEM ARE
NOW MOSTLY WITHIN THE WEEK-1 PERIOD, THE POTENTIAL FOR HEAVY PRECIPITATION
CONTINUES INTO WEEK-2. THE ECMWF AND GEFS PROBABILISTIC EXTREMES TOOLS (PETS)
BOTH INDICATE AT LEAST A 20% PROBABILITY OF 3-DAY PRECIPITATION EXCEEDING THE
85TH PERCENTILE AND AT LEAST 1 INCH FOR MUCH OF THE SOUTHEASTERN CONUS. THE
ECMWF IS ESPECIALLY BULLISH WITH PROBABILITIES EXCEEDING 60% FOR PORTIONS OF
THE TENNESSEE AND LOWER MISSISSIPPI VALLEYS, WITH THE GEFS SHOWING MORE MODEST
BUT STILL ENHANCED PROBABILITIES FOR THE SAME REGIONS. DAILY ANALYSIS SUGGESTS
THAT THE HIGHEST POTENTIAL FOR HEAVY PRECIPITATION ENDS AFTER THE 26TH, WITH
SOME LINGERING POTENTIAL FOR HEAVY PRECIPITATION FURTHER EAST ON THE 27TH.
THEREFORE, A MODERATE RISK FOR HEAVY PRECIPITATION IS POSTED FOR EASTERNMOST
TEXAS AS WELL AS PORTIONS OF THE LOWER AND MIDDLE MISSISSIPPI AND TENNESSEE
VALLEYS AND THE SOUTHEAST U.S., AND A SLIGHT RISK FOR HEAVY PRECIPITATION IS
POSTED FOR ADJOINING EASTERN TEXAS AND PORTIONS OF THE OHIO, AND TENNESSEE
VALLEYS AND SOUTHEAST U.S. FOR JAN 25-27.
THERE IS CONTINUED CONFIDENCE REGARDING ENHANCED CHANCES FOR PERIODS OF HIGH
WINDS AND HEAVY PRECIPITATION FOR WESTERN WASHINGTON AND OREGON EARLY IN THE
FORECAST PERIOD, WITH ENSEMBLE SOLUTIONS DEPICTING A SHORTWAVE TROUGH COMING
NEAR THE COAST EARLY IN WEEK-2. AS IS THE CASE FOR THE SOUTHEASTERN U.S., THE
ECMWF IS MORE BULLISH THAN THE GEFS WITH THE CHANCES FOR HEAVY PRECIPITATION,
BUT BOTH PETS INDICATE AT LEAST A 20% PROBABILITY OF 3-DAY PRECIPITATION
EXCEEDING THE 85TH PERCENTILE AND 2 INCHES FOR JAN 25-27. THE CASCADE MOUNTAINS
HAVE A SLIGHT RISK OF HEAVY SNOW POSTED FOR JAN 25-27 FOLLOWING THE FORECAST
REASONING OUTLINED ABOVE FOR HEAVY PRECIPITATION. THE PETS FROM THE GEFS AND
ECMWF ALSO INDICATE THE POTENTIAL FOR HIGH WINDS ALONG THE WEST COAST SIMILAR
TO WHAT IS SEEN WITH HEAVY PRECIPITATION. BOTH MODELS INDICATE AT LEAST A 20%
PROBABILITY OF WIND SPEEDS EXCEEDING THE 85TH PERCENTILE AND 25 MPH FOR THE
NORTHERN WEST COAST. THEREFORE A SLIGHT RISK FOR HIGH WINDS IS POSTED FOR
COASTAL PORTIONS OF OREGON AND WASHINGTON FOR JAN 25-27. MODELS DEPICT THE
MOISTURE FROM THIS SHORTWAVE MOVING INTO THE INTERIOR WEST AS WELL, WHICH
ENHANCES THE CHANCES FOR HEAVY SNOWFALL INLAND, ALTHOUGH MODEL SOLUTIONS LIMIT
THIS TO JUST DAYS 8-9. THIS IS HIGHLIGHTED BY A PAIR OF SLIGHT RISKS FOR HEAVY
SNOW, OVER THE NORTHERN ROCKIES, AND FOR HIGHER ELEVATIONS OF COLORADO AND NEW
MEXICO, FOR JAN 25-26. FINALLY, FLOODING IS POSSIBLE FOR THE WESTERN FOOTHILLS
OF THE CASCADES AS HEAVY PRECIPITATION AND SNOW CONTINUE TO AFFECT THE REGION
AND TEMPERATURES EXPECTED TO RISE QUICKLY DURING THE FORECAST PERIOD.
ENSEMBLE SOLUTIONS FROM THE GEFS, ECMWF, AND CMCE ALL INDICATE SURFACE LOW
PRESSURE SYSTEMS IN THE GULF OF ALASKA THROUGHOUT THE WEEK-2 PERIOD, RESULTING
IN ELEVATED CHANCES FOR HIGH WIND AND HEAVY PRECIPITATION FOR THE SOUTHERN AND
SOUTHEASTERN COASTS OF ALASKA, INCLUDING THE POTENTIAL FOR GAP WINDS. A STRONG
YUKON SURFACE HIGH IS FAVORED IN SOME MODEL SOLUTIONS WHICH ENHANCES THE
CHANCES FOR GAP WINDS, BUT THERE IS STILL INSUFFICIENT CONSENSUS AT THIS TIME
REGARDING VALUES REACHING HAZARDOUS THRESHOLDS THUS NO CORRESPONDING HAZARDS
ARE POSTED AT THIS TIME, BUT WILL BE MONITORED CLOSELY IN THE COMING DAYS.
FORECASTER: DANNY BARANDIARAN
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