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FXUS21 KWNC 101927
PMDTHR
US HAZARDS OUTLOOK
NWS CLIMATE PREDICTION CENTER COLLEGE PARK MD
300 PM EST FEBRUARY 10 2026
SYNOPSIS: A MAJOR PATTERN CHANGE IS FORECAST OVER THE WEST LATER THIS WEEK AS A
STRONG AREA OF MID-LEVEL LOW PRESSURE DEVELOPS ALONG THE WEST COAST. FOLLOWING
A DRIER-THAN-NORMAL JANUARY AND START TO FEBRUARY, A TRANSITION TO A MUCH
WETTER, COLDER PATTERN IS LIKELY FOR THE WEST BY THIS WEEKEND. THE STRONG AREA
OF MID-LEVEL LOW PRESSURE IS EXPECTED TO MAINTAIN AN INCREASED RISK OF HEAVY
PRECIPITATION, HIGH ELEVATION HEAVY SNOW, AND HIGH WINDS OVER THE PACIFIC
NORTHWEST, CALIFORNIA, AND INTERIOR WEST THROUGH THE EARLY PART OF WEEK-2.
ENHANCED ONSHORE FLOW IS EXPECTED TO SHIFT BACK TO THE NORTH TOWARDS NORTHERN
CALIFORNIA AND THE PACIFIC NORTHWEST LATER IN WEEK-2. THERE IS ALSO AN ELEVATED
WINTER STORM RISK FROM THE NORTHERN TO CENTRAL GREAT PLAINS NORTHEAST TO THE
UPPER MISSISSIPPI VALLEY FROM FEB 18 TO 20.
HAZARDS
HIGH RISK OF HEAVY SNOW FOR THE SIERRA NEVADA MOUNTAINS, WED, FEB 18.
MODERATE RISK OF HEAVY SNOW FOR THE SIERRA NEVADA, KLAMATH MOUNTAINS, AND
SOUTHERN CASCADES, WED-THU, FEB 18-19.
MODERATE RISK OF HEAVY SNOW FOR PARTS OF ARIZONA, UTAH, AND WYOMING, WED-THU,
FEB 18-19.
SLIGHT RISK OF HEAVY SNOW FOR THE CASCADES, KLAMATH MOUNTAINS, AND SIERRA
NEVADA MOUNTAINS, WED-TUE, FEB 18-24.
SLIGHT RISK OF HEAVY SNOW FOR THE INTERIOR WEST, WED-SAT, FEB 18-21.
SLIGHT RISK OF HEAVY SNOW FROM THE NORTHERN TO CENTRAL GREAT PLAINS TO THE
UPPER MISSISSIPPI VALLEY, WED-FRI, FEB 18-20.
MODERATE RISK OF HEAVY PRECIPITATION FOR COASTAL PARTS OF CALIFORNIA, WED, FEB
18.
SLIGHT RISK OF HEAVY PRECIPITATION FOR CENTRAL TO SOUTHERN CALIFORNIA AND THE
SOUTHWEST, WED-SAT, FEB 18-21.
SLIGHT RISK OF HEAVY PRECIPITATION FOR THE PACIFIC NORTHWEST AND NORTHERN
CALIFORNIA, WED-TUE, FEB 18-24.
MODERATE RISK OF HIGH WINDS FOR THE DESERT SOUTHWEST, FOUR CORNERS, AND CENTRAL
TO SOUTHERN HIGH PLAINS, WED-THU, FEB 18-19.
SLIGHT RISK OF HIGH WINDS FROM THE WEST COAST TO THE GREAT PLAINS, WED-THU, FEB
18-19.
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES FOR SOUTHEASTERN ALASKA, WED-FUE,
FEB 18-24.
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES FOR SOUTHWESTERN ALASKA, SAT-TUE,
FEB 21-24.
FLOODING POSSIBLE FROM THE BAY AREA TO SOUTHERN CALIFORNIA.
DETAILED SUMMARY
FOR FRIDAY FEBRUARY 13 - TUESDAY FEBRUARY 17:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
FOR WEDNESDAY FEBRUARY 18 - TUESDAY FEBRUARY 24: THE GEFS, ECENS, AND CMCE ARE
VERY CONSISTENT AND IN GOOD AGREEMENT THAT A 500-HPA TROUGH AMPLIFIES ALONG THE
WEST COAST THIS WEEKEND. THE PACIFIC NORTH AMERICAN (PNA) INDEX IS FORECAST TO
RAPIDLY BECOME NEGATIVE AND PERSIST IN THIS NEGATIVE PHASE THROUGH LATE
FEBRUARY. BY THE BEGINNING OF WEEK-2 (FEB 18), A HIGHLY AMPLIFIED 500-HPA
TROUGH (HEIGHT ANOMALIES OF -120 TO -180 METERS) IS FORECAST TO EXTEND SOUTH TO
CALIFORNIA. BASED ON 24-HOUR PRECIPITATION AMOUNTS FROM THE ECENS, GEFS, AND
CMCE ALONG WITH A CONSENSUS BETWEEN THE GEFS AND ECENS PROBABILISTIC EXTREMES
TOOLS (PETS), A MODERATE RISK OF HEAVY PRECIPITATION EXTENDS FROM THE BAY AREA
SOUTH TO SOUTHERN CALIFORNIA ON FEBRUARY 18. SINCE THE HEAVIEST PRECIPITATION
IS LIKELY TO OCCUR ON DAYS 6 AND 7 (FEB 16 AND 17), THE HIGH RISK OF HEAVY
PRECIPITATION WAS DISCONTINUED. DUE TO MULTIPLE DAYS OF HEAVY PRECIPITATION
THROUGH THE BEGINNING OF WEEK-2, A FLOODING HAZARD IS DESIGNATED FOR COASTAL
AREAS OF CENTRAL TO SOUTHERN CALIFORNIA WHERE FLASH FLOODING AND/OR SMALL
STREAM FLOODING MAY OCCUR. THE PETS SUPPORT A SLIGHT RISK OF HEAVY
PRECIPITATION (AT LEAST A 20 PERCENT CHANCE OF 3-DAY AMOUNTS EXCEEDING 1 INCH)
THROUGHOUT SOUTHERN CALIFORNIA AND THE SOUTHWEST THROUGH FEB 21. BEYOND THIS
DATE, THE 500-HPA TROUGH IS FORECAST TO RETRACT NORTHWARD TO THE GULF OF ALASKA
AND THE SLIGHT RISK OF HEAVY PRECIPITATION WAS DISCONTINUED SOUTH OF THE BAY
AREA LATER IN WEEK-2. THE PRECIPITATION TOOLS SUPPORT A CONTINUATION OF A
SLIGHT RISK OF HEAVY PRECIPITATION FOR NORTHERN CALIFORNIA AND THE PACIFIC
NORTHWEST THROUGH THE END OF WEEK-2, FEB 24. AS TEMPERATURES TREND COLDER
DURING LATE FEBRUARY, THERE COULD BE AN INCREASING CHANCE OF WINTER WEATHER
HAZARDS SUCH AS FREEZING RAIN AND/OR SNOW ACROSS THE LOWER ELEVATIONS OF THE
PACIFIC NORTHWEST. FORECAST CONFIDENCE IS TOO LOW TO SPECIFY ANY SNOW HAZARDS
AT TIME, BUT THIS WILL BE CLOSELY MONITORED IN THE NEXT FEW DAYS.
THE DEEP MID-LEVEL TROUGH IS LIKELY TO BRING MULTIPLE FEET OF SNOW TO THE
SIERRA NEVADA MOUNTAINS DURING THE NEXT TWO WEEKS. BASED ON 24-HOUR
PRECIPITATION AMOUNTS FROM THE GEFS AND ECENS, A HIGH RISK OF HEAVY SNOW IS
VALID ON FEB 18. THE MODERATE RISK OF HEAVY SNOW GOES THROUGH FEB 19 AND ALSO
INCLUDES THE KLAMATH MOUNTAINS AND SOUTHERN CASCADES. SINCE BOTH THE ECENS AND
GEFS FAVOR A 500-HPA TROUGH PERSISTING OVER THE NORTHEASTERN PACIFIC THROUGH
THE END OF WEEK-2, A SLIGHT RISK OF HEAVY SNOW IS VALID FROM FEB 18-24 AND
EXTENDS FROM THE CASCADES SOUTH TO THE SIERRA NEVADA MOUNTAINS. DUE TO THE
ANOMALOUS MID-LEVEL TROUGH ALONG WITH SUPPORT FROM THE ECENS SNOWFALL AMOUNTS,
A MODERATE RISK OF HEAVY SNOW IS POSTED FOR THE HIGHER ELEVATIONS OF UTAH AND
NORTHERN ARIZONA. A SLIGHT RISK OF HEAVY SNOW AT THE HIGHER ELEVATIONS OF THE
INTERIOR WEST WAS DISCONTINUED AFTER FEB 21 AS 500-HPA HEIGHTS ARE FORECAST TO
RISE SLIGHTLY. THE MUCH SNOWIER LATTER HALF OF FEBRUARY WILL BE WELCOMED ACROSS
THE WEST AS SNOW WATER EQUIVALENT (SWE) IS CURRENTLY BELOW 50% OF AVERAGE FOR
MUCH OF THE PACIFIC NORTHWEST, GREAT BASIN, AND CALIFORNIA.
THE HIGH AMPLITUDE 500-HPA TROUGH ALSO SUPPORTS A SLIGHT RISK OF HIGH WINDS
WITH A LARGE SPATIAL AREA FROM THE WEST COAST TO THE GREAT PLAINS FROM FEB 18
TO 19. A MODERATE RISK OF HIGH WINDS (ALSO VALID FEB 18 AND 19) IS POSTED FOR
THE DESERT SOUTHWEST, FOUR CORNERS REGION, AND CENTRAL TO SOUTHERN HIGH PLAINS
WHERE THE ECENS DEPICTS MORE THAN A 40% CHANCE THAT WINDS GUST ABOVE 40MPH.
MODEL SOLUTIONS FAVOR LEESIDE CYCLOGENESIS ACROSS EASTERN COLORADO ON FEB 18
WHICH WOULD BRING GUSTY WINDS AND ELEVATE WILDFIRE DANGER FOR THE CENTRAL AND
SOUTHERN HIGH PLAINS.
THE LONGWAVE PATTERN WOULD FAVOR MULTIPLE LOW PRESSURE SYSTEMS TO DEVELOP
ACROSS THE HIGH PLAINS WITH A SUBSEQUENT NORTHEASTWARD TRACK TO THE UPPER
MIDWEST DURING MID TO LATE FEBRUARY. ON FEB 19 AND 20, THE ECENS AND GEFS
DEPICT A LOW PRESSURE SYSTEM TRACKING FROM THE CENTRAL GREAT PLAINS TO THE
UPPER OR MIDDLE MISSISSIPPI VALLEY. TO THE NORTHWEST OF ANY LOW PRESSURE TRACK,
THERE IS AN ELEVATED RISK OF A WINTER STORM FROM THE NORTHERN TO CENTRAL PLAINS
INTO THE UPPER MISSISSIPPI VALLEY AND GREAT LAKES. BASED ON PATTERN RECOGNITION
AND THE GEFS SWE TOOL (20-40% CHANCE OF 3-DAY AMOUNTS TO EXCEED THE 85TH
PERCENTILE AND 0.5 INCH, LIQUID EQUIVALENT), A SLIGHT RISK OF HEAVY SNOW IS
POSTED FOR MUCH OF THE NORTH-CENTRAL U.S. FROM FEB 18 TO 20. INCREASING
ENSEMBLE SPREAD ON THE LOW TRACK ONCE IT APPROACHES THE UPPER MIDWEST PRECLUDES
A MODERATE RISK OF HEAVY SNOW.
DUE TO THE AMPLIFIED 500-HPA RIDGE TO THE WEST OF THE BERING STRAIT AND
ANOMALOUS NORTHERLY FLOW, BELOW-NORMAL TEMPERATURES ARE LIKELY THROUGHOUT
ALASKA FROM FEB 18-24. BASED ON THE GEFS AND ECENS PETS (> 20% CHANCE OF
MINIMUM TEMPERATURES IN THE LOWEST 15TH PERCENTILE), A SLIGHT RISK OF MUCH
BELOW-NORMAL TEMPERATURES IS POSTED FOR SOUTHEASTERN ALASKA DURING THE ENTIRETY
OF WEEK-2. GAP WINDS WOULD RESULT IN DANGEROUSLY COLD WIND CHILL VALUES.
ENSEMBLE MEANS VARY ON THE MAGNITUDE OF THE ANOMALOUS COLD OVERSPREADING
SOUTHWESTERN ALASKA, BUT THE PETS AND UNCALIBRATED MODEL OUTPUT SUPPORT A
SLIGHT RISK OF MUCH BELOW-NORMAL TEMPERATURES BEGINNING ON FEB 21.
OVER HAWAII, THE FORECAST PATTERN CONTINUES TO BE FAVORABLE FOR KONA LOW
DEVELOPMENT INTO THE LATTER HALF OF FEBRUARY. THE GEFS PET DEPICTS A 20 TO 50
PERCENT CHANCE THAT 3-DAY PRECIPITATION AMOUNTS EXCEED THE 85TH PERCENTILE FOR
THE ENTIRE ISLAND CHAIN FROM FEB 18-24.
FORECASTER: BRAD PUGH
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