057
FXUS21 KWNC 181903
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MARCH 18 2025
SYNOPSIS: AN ACTIVE AND PROGRESSIVE WEATHER PATTERN IS FAVORED TO BRING A
VARIETY OF POTENTIALLY HAZARDOUS WEATHER TO MANY PARTS OF THE CONTIGUOUS U.S.
(CONUS) DURING THE WEEK-2 PERIOD. AT THE BEGINNING OF WEEK-2 A LOW PRESSURE
SYSTEM IS PREDICTED TO MOVE OVER THE NORTHEAST, INCREASING THE LIKELIHOOD FOR
HIGH WINDS. ANOTHER LOW PRESSURE SYSTEM IS FORECAST TO COME ASHORE OVER THE
PACIFIC NORTHWEST AT THE OUTSET OF WEEK-2 AND MOVE INTO THE CENTRAL CONUS BY
THE MIDDLE OF THE PERIOD, BRINGING POTENTIALLY HEAVY SNOW, HIGH WINDS, AND
HEAVY PRECIPITATION TO PORTIONS OF THE WESTERN AND CENTRAL CONUS.
HAZARDS
SLIGHT RISK OF EPISODIC HIGH WINDS FOR THE NORTHEAST U.S. AND PORTIONS OF THE
MID-ATLANTIC, WED-THU, MAR 26-27.
SLIGHT RISK OF EPISODIC HIGH WINDS FOR COASTAL PORTIONS OF WASHINGTON, OREGON,
AND CALIFORNIA NORTH OF SAN FRANCISCO BAY, WED-TUE, MAR 26-APR 1.
SLIGHT RISK OF EPISODIC HIGH WINDS FOR MUCH OF THE CENTRAL CONUS, THU-SUN, MAR
27-30.
SLIGHT RISK OF PERIODS OF HEAVY PRECIPITATION FOR WESTERN WASHINGTON, OREGON,
AND NORTHERN CALIFORNIA, WED-TUE, MAR 26-APR 1.
SLIGHT RISK OF PERIODS OF HEAVY PRECIPITATION FOR PORTIONS OF THE OHIO,
TENNESSEE, AND LOWER AND MIDDLE MISSISSIPPI VALLEYS, SAT-MON, MAR 29-31.
SLIGHT RISK OF PERIODS OF HEAVY SNOW FOR THE CASCADE, KLAMATH, AND NORTHERN
SIERRA NEVADA MOUNTAINS, WED-TUE, MAR 26-APR 1.
SLIGHT RISK OF PERIODS OF HEAVY SNOW FOR THE NORTHERN ROCKIES, THU-SUN, MAR
27-30.
SLIGHT RISK OF PERIODS OF HEAVY SNOW FOR PORTIONS OF THE NORTHERN PLAINS AND
UPPER MISSISSIPPI VALLEY, SAT-TUE, MAR 29-APR 1.
RISK OF RAPID ONSET DROUGHT FOR PORTIONS OF THE SOUTHERN PLAINS.
DETAILED SUMMARY
FOR FRIDAY MARCH 21 - TUESDAY MARCH 25:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR WEDNESDAY MARCH 26 - TUESDAY APRIL 01: TODAY’S ENSEMBLE MODEL SOLUTIONS
CONTINUE TO SHOW GOOD AGREEMENT ON THE SYNOPTIC PATTERN AS DEPICTED IN 500-HPA
HEIGHT ANOMALIES, ALONG WITH CONVERGING SOLUTIONS WITH RESPECT TO YESTERDAY’S
MODEL SPREAD. HOWEVER, THERE REMAINS SOME UNCERTAINTY WITH REGARD TO THE
INTENSITY AND EVOLUTION OF SURFACE FEATURES, PARTICULARLY THE STRONG
CYCLOGENESIS EVENT FORECAST TO UNFOLD DURING THE MIDDLE OF WEEK-2. ENSEMBLE
SOLUTIONS DEPICT MID-LEVEL TROUGHING OVER THE NORTH PACIFIC AND NORTHEAST U.S.
AND RIDGING OVER THE BERING SEA, WESTERN CONUS, AND CANADIAN MARITIMES. THIS
HIGH WAVENUMBER TENDS TO RESULT IN EASTWARD PROPAGATION OF MULTIPLE SHORT-WAVE
TROUGHS EMBEDDED IN THE PREVAILING FLOW, WHICH IS DEPICTED IN MULTIPLE
ENSEMBLES.
AT THE OUTSET OF WEEK-2 A SURFACE LOW IS FAVORED TO TRACK OVER THE GREAT LAKES
REGION. MULTIPLE MODELS DEPICT SIGNIFICANT PRECIPITATION ASSOCIATED WITH THIS
SYSTEM WHICH COULD AFFECT THE EASTERN CONUS DURING WEEK-1, BUT BY DAY-8 (MARCH
26) THE HEAVIEST PRECIPITATION WILL LIKELY HAVE MOVED OFFSHORE. HOWEVER, TIGHT
SURFACE PRESSURE GRADIENTS ASSOCIATED WITH THE SURFACE LOW RESULT IN ENHANCED
PROBABILITIES OF HIGH WINDS FOR PARTS OF THE EAST COAST AS THIS SYSTEM SLOWLY
TRACKS TOWARDS THE CANADIAN MARITIMES. THE GEFS AND ECMWF PROBABILISTIC
EXTREMES TOOLS (PETS) BOTH INDICATE AT LEAST A 20% CHANCE OF MAXIMUM WIND
SPEEDS EXCEEDING THE 85TH PERCENTILE CLIMATOLOGICALLY FOR PORTIONS OF THE
MID-ATLANTIC EARLY IN WEEK-2, THEREFORE A SLIGHT RISK (20-40% PROBABILITY) OF
HIGH WINDS IS POSTED FOR MAR 26-27.
MULTIPLE MODEL SOLUTIONS DEPICT PERSISTENT TROUGHING AT THE SURFACE AND ALOFT
OVER THE NORTH PACIFIC RESULTING IN A STEADY MOIST ONSHORE FLOW PREVAILING OVER
THE PACIFIC NORTHWEST. THE INTEGRATED VAPOR TRANSPORT (IVT) TOOL INDICATES VERY
HIGH PROBABILITIES OF IVT TO EXCEED 150 KG/M S FROM BOTH THE ECMWF AND GEFS
THROUGHOUT WEEK-2. THE PRECIPITATION PETS FROM THE ECMWF AND GEFS SHOW A MORE
COHERENT SIGNAL THAN YESTERDAY WITH REGARD TO HEAVY PRECIPITATION POTENTIAL
OVER THE WEST COAST, INDICATING AT LEAST A 20% CHANCE OF 3-DAY PRECIPITATION
TOTALS TO EXCEED THE 85TH PERCENTILE AND AT LEAST 1 INCH AS FAR SOUTH AS SAN
FRANCISCO. THEREFORE A SLIGHT RISK OF PERIODS OF HEAVY PRECIPITATION IS POSTED
FOR PORTIONS OF THE WEST COAST NORTH OF THE BAY AREA FOR MARCH 26-APR 1. A
SLIGHT RISK OF HEAVY SNOW IS ALSO POSTED FOR THE CASCADE, KLAMATH, AND NORTHERN
SIERRA NEVADA MOUNTAINS FOR THE SAME PERIOD, AS WELL AS A SLIGHT RISK OF HIGH
WINDS ALONG THE COAST FROM THE CANADIAN BORDER TO SAN FRANCISCO BAY.
A SHORTWAVE TROUGH IS ANTICIPATED TO MOVE OVER THE WEST COAST AND THE
INTERMOUNTAIN WEST AND INTO THE CENTRAL CONUS OVER THE COURSE OF WEEK-2. THIS
IS ANTICIPATED TO RESULT IN THE AFOREMENTIONED PACIFIC MOISTURE GETTING PUSHED
FURTHER INLAND, FAVORING ENHANCED SNOW FOR THE NORTHERN ROCKIES. THE
UNCALIBRATED ECMWF ENSEMBLE INDICATES ENHANCED PROBABILITIES OF 3-DAY SNOWFALL
EXCEEDING 6 INCHES FOR MAR 27-30, THUS A SLIGHT RISK OF HEAVY SNOW IS POSTED
THESE DATES FOR MUCH OF THE NORTHERN ROCKIES. AS THIS SYSTEM PUSHES FURTHER
EASTWARD, ENSEMBLES DEPICT ANOTHER ROUND OF STRONG LEE CYCLOGENESIS OVER THE
GREAT PLAINS DURING THE SECOND HALF OF THE WEEK-2 PERIOD. MODEL DEPICTIONS OF
MSLP ANOMALIES INDICATE A STRONG PRESSURE GRADIENT SETTING UP OVER THE GREAT
PLAINS BY MARCH 27, RESULTING IN STRONG SOUTHERLY FLOW AND THE ENHANCED
POTENTIAL FOR HIGH WINDS AT THE SURFACE. ONCE AGAIN, THE PETS FOR MAXIMUM WIND
SPEED ARE A LITTLE MIXED WITH REGARD TO THE POTENTIAL FOR EXTREMES IN WIND
SPEED, BUT THE SYNOPTIC SETUP, COUPLED WITH GOOD AGREEMENT FROM MODELS ON
SYSTEM INTENSITY AND EVOLUTION SUPPORTS A SLIGHT RISK OF HIGH WINDS POSTED FOR
MUCH OF THE CENTRAL CONUS FOR MAR 27-30. MULTIPLE ENSEMBLE SOLUTIONS ALSO
INDICATE THE POSSIBILITY OF HEAVY PRECIPITATION DEVELOPING AHEAD OF THIS SYSTEM
AS IT WINDS UP AND DRAWS IN GULF MOISTURE. THERE IS MODEST SUPPORT FROM THE
PETS INDICATING AT LEAST A 20% CHANCE OF 3-DAY PRECIPITATION TOTALS EXCEEDING
THE 85TH PERCENTILE FOR MAR 29-31, WITH THE ECMWF BEING MORE BULLISH THAN THE
GEFS. WHILE THERE IS SOME SPREAD AMONG MODEL SOLUTIONS REGARDING THE DETAILS,
ONCE AGAIN THE OVERALL GOOD AGREEMENT ON A FAVORABLE SYNOPTIC PATTERN WARRANTS
THE ISSUANCE OF A SLIGHT RISK OF HEAVY PRECIPITATION FOR PORTIONS OF THE OHIO,
TENNESSEE, AND LOWER AND MIDDLE MISSISSIPPI VALLEYS FOR MAR 29-31. HOWEVER, THE
GEFS PET FOR SNOW WATER EQUIVALENT (SWE) HAS A STRONGER SIGNAL, INDICATING AT
LEAST A 20% CHANCE OF 3-DAY SWE EXCEEDING THE 85TH PERCENTILE FOR PORTIONS OF
THE NORTHERN CONUS AS THIS SYSTEM STRENGTHENS, SO A SLIGHT RISK FOR HEAVY SNOW
IS POSTED FOR PORTIONS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY FOR
MARCH 29-APR 1.
MUCH OF THE SOUTHERN AND SOUTHWESTERN CONUS HAS BEEN EXPERIENCING BELOW-NORMAL
PRECIPITATION FOR SOME TIME NOW, A TREND THAT IS UNFORTUNATELY FAVORED TO
CONTINUE THROUGH THE WEEK-2 PERIOD. A RISK OF RAPID ONSET DROUGHT (ROD) REMAINS
POSTED FOR PORTIONS OF EASTERN NEW MEXICO AND NORTHERN TEXAS, DUE TO ANTECEDENT
DRY CONDITIONS AND ANTICIPATED PRECIPITATION DEFICITS. THERE ARE INSUFFICIENT
INDICATIONS AMONG THE FORECAST TOOLS TO WARRANT A RISK OF MUCH ABOVE-NORMAL
TEMPERATURES ON TODAY’S WEEK-2 HAZARDS OUTLOOK, BUT NONETHELESS VERY
ANOMALOUSLY WARM TEMPERATURES ARE LIKELY FOR PORTIONS OF THE RIO GRANDE VALLEY
AND BIG BEND REGIONS. ANTICIPATED ABOVE NORMAL TEMPERATURES COMBINED WITH
BELOW-NORMAL PRECIPITATION AND ENHANCED WIND SPEEDS INCREASES THE POTENTIAL FOR
WILDFIRES THROUGHOUT THE WEEK-2 PERIOD.
FORECASTER: DANNY BARANDIARAN
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