235
FXUS21 KWNC 131828
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EDT MARCH 13 2026
SYNOPSIS: VERY STRONG MID-LEVEL HIGH PRESSURE IS FORECAST OVER THE WESTERN AND
CENTRAL CONTIGUOUS UNITED STATES (CONUS), PROMOTING UNSEASONABLY WARM WEATHER
ACROSS MUCH OF THE REGION THROUGH THE FIRST HALF OF WEEK-2. SPRING EXTREME HEAT
CONDITIONS MAY BRIEFLY CONTINUE INTO WEEK-2 OVER PARTS OF THE DESERT SOUTHWEST
AND POTENTIALLY PORTIONS OF TEXAS. THE EARLY-SEASON WARMTH IS LIKELY TO
ACCELERATE SPRING SNOWMELT WHERE SEASONAL SNOWPACK HAS BEEN WELL BELOW NORMAL.
MEANWHILE, PERSISTENT MID-LEVEL HIGH PRESSURE CENTERED OVER THE WESTERN
ALEUTIANS IN CONCERT WITH DOWNSTREAM TROUGHING ACROSS EASTERN AND SOUTHERN
ALASKA SUPPORT ARCTIC SURFACE HIGH PRESSURE OVER MUCH OF THE STATE. THIS RAISES
THE POTENTIAL FOR MUCH BELOW NORMAL TEMPERATURES ACROSS CENTRAL AND SOUTHERN
ALASKA. AT THE SAME TIME, THE MID-LEVEL TROUGH IS EXPECTED TO INDUCE SURFACE
LOW PRESSURE NEAR THE GULF OF ALASKA, CREATING A PRESSURE GRADIENT THAT SETS UP
A SLIGHT RISK OF HIGH WINDS IN SOUTH-CENTRAL MAINLAND ALASKA AND SOUTHEAST
ALASKA FOR THE FIRST HALF OF WEEK-2.
HAZARDS
MODERATE RISK OF MUCH ABOVE-NORMAL TEMPERATURES FOR PORTIONS OF THE GREAT
BASIN, CALIFORNIA, DESERT SOUTHWEST, ROCKIES, AND PLAINS, SAT-SUN, MAR 21-22.
SLIGHT RISK OF MUCH ABOVE-NORMAL TEMPERATURES FROM MUCH OF THE WESTERN CONUS
INTO THE CENTRAL AND SOUTHERN PLAINS, SAT-TUE, MAR 21-24.
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES OVER MUCH OF CENTRAL AND SOUTHERN
ALASKA, SAT-TUE, MAR 21-24.
SLIGHT RISK OF HIGH WINDS OVER PORTIONS OF COASTAL SOUTHERN ALASKA AND
SOUTHEAST ALASKA, SAT-TUE, MAR 21-24.
DETAILED SUMMARY
FOR MONDAY MARCH 16 - FRIDAY MARCH 20:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR SATURDAY MARCH 21 - FRIDAY MARCH 27: THE LATEST 0Z GEFS, EUROPEAN ENSEMBLE
(ECENS), AND CANADIAN ENSEMBLE (CMCE) DAILY MEANS START WEEK-2 WITH A HIGHLY
AMPLIFIED RIDGE CENTERED OVER THE INTERIOR WEST, AND A 500-HPA TROUGH
DOWNSTREAM OVER THE NORTHEASTERN CONUS. ACCORDING TO THESE ENSEMBLES, THE PEAK
HEIGHTS ARE PREDICTED ON DAY 6 OR 7 (MAR 19 OR 20), WITH A GRADUAL DECLINE
THEREAFTER. TODAY, THE CMCE MEAN IS THE SLIGHTLY STRONGER MODEL, INDICATING 589
DM HEIGHTS JUST SOUTH OF THE FOUR CORNERS REGION ON MAR 21 AT THE START OF
WEEK-2. PEAK HEIGHTS AT THIS TIME ON THE GEFS AND ECENS MEANS ARE 1 TO 3 DM
LOWER. THE NORTHWARD-EXTENDING RIDGE AXIS IS ALSO SLIGHTLY FARTHER WEST IN THE
CMCE MEAN, CENTERED OVER THE ROCKIES, WHILE THE AXIS HAS MORE OF A POSITIVE
TILT ON THE ECENS AND GEFS MEANS, REACHING INTO THE NORTHERN GREAT PLAINS.
THESE RELATIVELY MINOR DIFFERENCES ASIDE, THERE CONTINUES TO BE GOOD MODEL
AGREEMENT ON THE EVOLUTION OF THIS MID-LEVEL FEATURE GRADUALLY SLIDING EASTWARD
INTO THE CENTRAL CONUS AND DEAMPLIFYING. CONSEQUENTLY, HEIGHTS ARE FORECAST TO
RISE ACROSS THE CENTRAL AND SOUTHEASTERN CONUS IN WEEK-2, ACCOMPANIED BY
INCREASING COVERAGE OF ABOVE-NORMAL TEMPERATURES. IN THE WAKE OF THIS
EASTWARD-DRIFTING MID-LEVEL RIDGE, HEIGHTS ARE EXPECTED TO FALL ACROSS THE
NORTHWEST AS A WEAKENING 500-HPA TROUGH BROADENS AND DRIFTS TOWARD THE REGION
FROM THE GULF OF ALASKA. THIS IS EXPECTED TO LIMIT THE NORTHWARD EXTENT OF THE
UNSEASONABLE WARMTH, KEEPING IT OUT OF THE NORTHERN TIER OF THE WESTERN CONUS
FOR THE MOST PART.
THE PROBABILISTIC EXTREMES TOOLS (PETS) FROM ALL ENSEMBLES ARE VERY BULLISH ON
UNUSUAL WARMTH IN TERMS OF PERCENTILES FOR THIS TIME OF YEAR, BUT THE EXTENT OF
EXCESSIVE HEAT APPEARS TO BE VERY LIMITED. THE PETS FROM THE GEFS, ECENS, AND
CMCE ALL DEPICT GREATER THAN 90 PERCENT CHANCES THAT TEMPERATURES WILL END UP
IN THE TOP 15TH PERCENTILE HISTORICALLY AT THE START OF WEEK-2 ACROSS MOST OF
THE FOUR CORNERS REGION AND DESERT SOUTHWEST, BUT NON-TRIVIAL CHANCES FOR
TEMPERATURES ABOVE 90 DEG. F ARE RESTRICTED TO THE CLIMATOLOGICALLY-WARMEST
AREAS IN THE DESERT SOUTHWEST (WHERE ODDS ARE HIGH EARLY WEEK-2) AND IN A BAND
ACROSS SOUTHERN, WEST-CENTRAL, AND NORTH CENTRAL TEXAS, ALONG WITH ADJACENT
PARTS OF OKLAHOMA (20 TO 40 PERCENT). STILL, THE EXTREME CLIMATOLOGICAL NATURE
OF THE EARLY-SEASON WARMTH JUSTIFIES A MODERATE RISK OF MUCH ABOVE NORMAL
TEMPERATURES EARLY WEEK-2 THROUGH MUCH OF THE INTERIOR WESTERN CONUS, REACHING
AS FAR EAST AS THE CENTRAL AND SOUTH-CENTRAL GREAT PLAINS. THE PETS SHOW
CHANCES FOR UNUSUAL WARMTH DECLINING OVER THE COURSE OF WEEK-2, WITH CHANCES
FOR TEMPERATURES EXCEEDING 90 DEG. F DROPPING BELOW 50 PERCENT EVEN IN THE
DESERT SOUTHWEST IN ALL THREE PETS BY MID-WEEK. THE LIKELIHOOD OF TEMPERATURES
IN THE TOP 15 PERCENT HISTORICALLY DROP BELOW 50 PERCENT BY THE MIDDLE OF THE
PERIOD, AND ONLY MARGINALLY TOPS CLIMATOLOGY BY THE END OF WEEK-2. THIS
JUSTIFIES A SLIGHT RISK OF MUCH ABOVE NORMAL TEMPERATURES THROUGH THE MIDDLE OF
THE PERIOD ACROSS A LARGE PART OF THE WESTERN CONUS OUTSIDE THE NORTHERN TIER,
REACHING AS FAR EAST AS THE FRINGES OF THE LOWER MISSISSIPPI VALLEY.
THE PATTERN ACROSS THE CONUS FAVORS UNUSUALLY DRY CONDITIONS IN MOST LOCATIONS,
WITH POTENTIAL EXCEPTIONS IN THE NORTHEASTERN AND NORTHWESTERN CONUS AT TIMES.
AMOUNTS ARE FORECAST TO REMAIN BELOW HAZARDS THRESHOLDS, SO NO PRECIPITATION
HAZARDS ARE POSTED AT THIS TIME. SIMILARLY, PETS FOR STRONG WINDS ARE
UNREMARKABLE TODAY, AND DETERMINISTIC MODELS ARE INCONSISTENT IN DEPICTING WHEN
AND WHERE THERE MIGHT BE SHORT-LIVED HIGH WIND THREATS. GIVEN THIS GUIDANCE, NO
RISKS FOR HIGH WINDS ARE POSTED TODAY, BUT THE SITUATION WILL BE MONITORED FOR
INCREASED CONSISTENCY IN THE DETERMINISTIC MODELS, AND MORE BULLISH ODDS IN THE
PETS.
OVER ALASKA, ANOMALOUS 500-HPA RIDGING FROM THE WESTERN ALEUTIANS INTO EASTERN
SIBERIA IS FORECAST IN CONCERT WITH DOWNSTREAM TROUGHING OVER SOUTH-CENTRAL
THROUGH EASTERN ALASKA, ALONG WITH THE ADJACENT GULF OF ALASKA, WHERE THE
GREATEST NEGATIVE HEIGHT ANOMALIES ARE EXPECTED EARLY WEEK-2. THIS PATTERN
FAVORS ARCTIC HIGH PRESSURE DOMINATING MOST OF THE STATE. AS A RESULT, A SLIGHT
RISK OF MUCH BELOW NORMAL TEMPERATURES IS POSTED FOR A LARGE PORTION OF CENTRAL
AND SOUTHERN ALASKA OVER THE FIRST HALF OF WEEK-2. THE PETS ALL SHOW LARGE
PARTS OF ALASKA WITH A BETTER THAN 50 PERCENT CHANCE FOR TEMPERATURES TO DROP
INTO THE LOWEST 15 PERCENT OF THE CLIMATOLOGICAL ENVELOPE AT THE START OF THE
PERIOD, WITH THE GEFS SHOWING SUCH CONDITIONS ACROSS ROUGHLY THE SOUTHERN HALF
OF THE MAINLAND AND ADJACENT PARTS OF THE ALEUTIANS AND PANHANDLE. PETS FROM
THE ECENS COVER A LARGER AREA (SOUTHERN TWO-THIRDS) WITH SIMILAR ODDS FOR MUCH
BELOW NORMAL TEMPERATURES, WHILE THE CNENS DEPICTS THIS ACROSS THE ENTIRE
MAINLAND, ALONG WITH ADJACENT PARTS OF THE ALEUTIANS AND THE PANHANDLE. THIS
PROMPTED AN EXPANSION OF THE SLIGHT RISK AREA FOR MUCH BELOW NORMAL
TEMPERATURES ACROSS THE ENTIRETY OF THE SOUTHERN TWO-THIRDS OF THE STATE. THERE
IS INCREASING UNCERTAINTY ON THE EVOLUTION OF THE TEMPERATURE PATTERN AS WEEK-2
PROGRESSES, BUT ALL GUIDANCE FAVORS MODERATING TEMPERATURES AROUND THE MIDDLE
OF WEEK-2, AS BOTH THE MID-LEVEL RIDGE AND DOWNSTREAM TROUGH WEAKEN AND DRIFT
SOUTHWARD, REDUCING THEIR IMPACTS ON THE STATE. WITH SUPPORT WANING, THE SLIGHT
RISK FOR MUCH BELOW NORMAL TEMPERATURES IS DISCONTINUED AFTER THE MIDDLE OF
WEEK-2.
ACROSS SOUTHERN MAINLAND ALASKA AND SOUTHEAST ALASKA, SURFACE LOW PRESSURE IS
EXPECTED IN OR NEAR THE GULF OF ALASKA IN RESPONSE TO THE AFOREMENTIONED
MID-LEVEL TROUGH. THE PRESSURE GRADIENT BETWEEN THIS SYSTEM AND THE ARCTIC HIGH
DOMINATING MOST OF ALASKA RAISES THE CHANCES FOR HIGH WINDS ALONG THE SOUTHERN
TIER OF THE MAINLAND AND SOUTHEAST ALASKA THROUGH THE MIDDLE OF WEEK-2. THIS IS
EXPECTED TO BRING SUBSTANTIAL PRECIPITATION TO PARTS OF SOUTHEAST ALASKA AS
WELL, BUT AMOUNTS ARE EXPECTED TO REMAIN BELOW HAZARDOUS THRESHOLDS.
FOLLOWING A KONA LOW EVENT ONGOING OVER THE CENTRAL PACIFIC THAT LOOKS TO BRING
HEAVY RAINS, HIGH WINDS AND FLOODING TO HAWAII, ENSEMBLES DEPICT SOME POTENTIAL
FOR THE MID-LEVEL TROUGH TO RELOAD TEMPORARILY TO THE WEST OF THE STATE BY
EARLY WEEK-2, WHICH MAY INDUCE ADDITIONAL HEAVY PRECIPITATION. THE ECENS AND
GEFS PETS CONTINUE TO HIGHLIGHT 20% TO 50% CHANCES FOR 3-DAY PRECIPITATION
AMOUNTS EXCEEDING THE 85TH PERCENTILE OVER MUCH OF THE ISLAND CHAIN DURING THE
FIRST HALF OF WEEK-2. IF IT MATERIALIZES AS EXPECTED, THE ADDITIONAL RAINFALL
WILL EXACERBATE ANY FLOODING ONGOING AT THE START OF THE PERIOD.
FORECASTER: RICH TINKER
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