669
AGUS76 KRSA 041440
HMDRSA
HYDROMETEOROLOGICAL DISCUSSION
NATIONAL WEATHER SERVICE / CALIFORNIA NEVADA RFC / SACRAMENTO CA
640 AM PST WED FEB 4 2026
..WARM AND DRY TODAY INTO THURSDAY
..WEAK SYSTEM ACROSS SOUTHERN AREAS WITH SCATTERED LIGHT PRECIP
..COLD FRONT TRAVERSES AREAS NORTH OF I-80 SUNDAY INTO MONDAY
METEOROLOGICAL CONDITIONS (WED AM - TUE AM)
STRONG HIGH PRESSURE ENCOMPASSES THE WESTERN US THIS
MORNING...CENTERED RIGHT OVER NORTHERN CA (5860-METERS AT 500-MB).
THIS WILL BRING DRY CONDITIONS AND WARM ABOVE SEASONAL AVERAGE
TEMPERATURES TO THE REGION WITH ANOMALIES RANGING FROM PLUS 5- TO
PLUS 25-DEGF TODAY AND TOMORROW AS THE PATTERN HOLDS IN PLACE. TWO
OTHER NOTABLE FEATURES IS A VERY WEAK AREA OF LOW PRESSURE JUST WEST
OF CENTRAL BAJA ALONG 120W...AND A S/WV TROF MOVING THROUGH THE BASE
OF THE EAST-CENTRAL PACIFIC TROF BEGINNING TO LIFT OFF TOWARD THE
NORTHEAST. LATER TOMORROW...LOOK FOR THIS S/WV TROF TO STRETCH AND
EVENTUALLY SPLIT WITH THE SOUTHERN PIECE MEANDERING ALONG THE
CENTRAL CA COAST AND EVENTUALLY THE SOUTHERN CA COAST ON FRIDAY.
ALSO...THAT WEAK UPR LOW WEST OF CENTRAL BAJA WILL DRIFT SLOWLY
NORTHWARD AND BECOME ENGULFED BY THIS FEATURE OFF THE
CENTRAL/SOUTHERN CA COAST. AS A RESULT...THERE WILL BE JUST ENOUGH
FORCING AND MOISTURE TO GENERATE SOME SCATTERED LIGHT SHOWERS AS
THIS S/WV TROF SLOWLY MOVES EASTWARD ACROSS SOUTHERN CA AND NORTHERN
BAJA ON FRIDAY. THEN ON SATURDAY...THIS S/WV TROF WILL FORM AN UPR
LOW OVER BAJA AND DRIFT FAR ENOUGH TO THE SOUTHEAST TO BRING AN END
TO ANY LIGHT PRECIP THAT DOES DEVELOP ACROSS THE SOUTHERN
SIERRA...SOUTHERN CA...AND SOUTHERN NV.
ATTENTION NEXT TURNS BACK TO THE NORTH AS THE UPR RIDGE BEGINS TO
LOSE ITS STRONG HOLD ON THE WEST COAST AS SEVERAL DISTURBANCES MAKE
THERE WAY ACROSS THE NORTHERN PACIFIC TOWARD THE WEST
COAST...PRIMARILY IMPACTING THE PACIFIC NORTHWEST AS A FETCH OF
MOISTURE FROM NEAR HAWAII ADVECTS NORTHEAST TO THE WA AND OR COAST.
EVENTUALLY...ONE S/WV TROF ARRIVING ALONG THE OR COAST ON SUNDAY
WILL SHUNT THE MOISTURE FAR ENOUGH SOUTH TO BRING PORTIONS OF
NORTHERN CA AND FAR NORTHERN NV SOME PRECIP AS A FRONTAL BOUNDARY
MOVES ACROSS THE REGION. HOWEVER...THE TREND IN THE
MODELS...ESPECIALLY THE EC AND GFS HAS BEEN WEAKER AND FARTHER NORTH
WITH THE PRECIP. THE CMC IS THE MOST BULLISH ACROSS THE REGION AT
THIS TIME...BUT WILL BE INTERESTING TO SEE HOW IT TRENDS OVER THE
NEXT SEVERAL MODEL CYCLES.
LOOK FOR PRECIP TO REACH THE FAR NORTHWEST CORNER OF CA AROUND
SUNDAY 12Z...AND THEN SPREAD ACROSS NORTHERN CA ON SUNDAY...DOWN TO
POINT ARENA ALONG COASTAL AREAS AND INLAND OVER THE SOUTHERN
CASCADE/NORTHERN SIERRA SOUTH TO THE FEATHER RIVER BASIN...BEFORE
SHIFTING INLAND ACROSS FAR NORTHERN NV NORTH OF I-80. TOTALS WILL BE
BEST OVER THE LOWER KLAMATH AND SMITH RIVER BASINS WITH 0.50- TO
1.00-INCH (LOCALLY TO 1.50-INCHES FOR DEL NORTE COUNTY)...TAPERING
OFF SOUTH AND EAST TO MAINLY 0.10- TO 0.33-INCH. FREEZING LEVELS
WILL START SUNDAY FROM 9000- TO 11000-FEET FOR AREAS NORTH OF I-80
AND THEN DROP TO 4500- TO 8000-FEET AFTER FRONTAL PASSAGE.
MONDAY IS A BIGGER QUESTION MARK AS THE EC WANTS TO REINVIGORATE THE
OLD FRONTAL BOUNDARY ACROSS CENTRAL CA NORTHEAST TO THE CENTRAL
SIERRA AND NORTHERN NV AS A S/WV TROF MAKES ITS WAY TO THE CA COAST.
THE GFS IS LESS EXCITED...KEEPING THE BEST FORCING WITH THE
DISTURBANCE FARTHER OFF THE COAST. THE CMC SWINGS IN ANOTHER S/WV
TROF FROM THE NORTHWEST. FOR NOW...USED A BLEND OF THE EC AND GFS TO
SHOW SOME PRECIP DEVELOPING ALONG THIS WEAKENED FRONTAL BOUNDARY.
PLEASE NOTE: THIS PRODUCT MAY NOT BE ROUTINELY UPDATED.
PLEASE REFER TO THE FOLLOWING PRODUCT ISSUED BY THE CNRFC
WWW.CNRFC.NOAA.GOV/DAILY-BRIEFING FOR A GRAPHICAL SUMMARY OF
WEATHER AND HYDROLOGIC CONDITIONS.
QPF GRAPHICS ARE AVAILABLE AT WWW.CNRFC.NOAA.GOV/QPF.PHP
DRK
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