996
FXUS02 KWBC 131913
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
212 PM EST FRI JAN 13 2023
VALID 12Z MON JAN 16 2023 - 12Z FRI JAN 20 2023
...ACTIVE PATTERN CONTINUES FOR THE WEST AND OTHER PARTS OF THE
LOWER 48 BUT WITH CENTRAL/SOUTHERN CALIFORNIA TRENDING DRIER
MID-LATE WEEK...
..OVERVIEW AND GUIDANCE/PREDICTABILITY ASSESSMENT
LATEST GUIDANCE SHOWS A CONTINUED PROGRESSION OF PACIFIC SYSTEMS
THAT WILL BRING PRECIPITATION INTO THE WEST AND THEN TO AREAS EAST
OF THE ROCKIES AS LOW PRESSURE TRACKS NORTHEASTWARD FROM THE
PLAINS. A NOTABLE ASPECT OF NEXT WEEK'S EVOLUTION SHOULD BE
AMPLIFICATION OF AN EASTERN PACIFIC UPPER RIDGE THAT WOULD FOCUS
WEST COAST PRECIPITATION MORE OVER THE PACIFIC NORTHWEST WHILE AT
LEAST CENTRAL-SOUTHERN CALIFORNIA SEES DRIER CONDITIONS. THIS MAY
BE THE BEGINNING OF A LONGER TERM DRIER PERIOD OVER THE
SOUTHWESTERN STATES BASED ON THE CLIMATE PREDICATION CENTER'S 8-14
DAY OUTLOOK.
A GENERAL MODEL BLEND CONSISTING OF THE 00Z EC/CMC/UKMET AND 06Z
GFS WERE UTILIZED THROUGH DAY 5. AFTER DAY 5 THE BLEND WAS MORE
WEIGHTED TOWARD THE 00Z EC/ECE AND LESS SO TOWARD THE REST OF THE
DETERMINISTIC GUIDANCE. BY DAY 7 THE 00 CMCE IS INTRODUCED AND A
HEAVY ENSEMBLE MEAN BLEND IS USED. THERE WERE SOME DISCREPANCIES
REGARDING THE EVOLUTION OF THE NEW WEST COAST SYSTEM BEGINNING ON
DAY 4 WITH THE 06 GFS/GEFS BEING TOO PROGRESSIVE WITH THE UPPER
LEVEL TROUGH PROPAGATING THROUGH THE SOUTHWEST. THIS GFS/GEFS
CONTINUE WITH THIS FASTER MOVEMENT OF THE UPPER TROUGH AND
ASSOCIATED SURFACE WAVE THROUGHOUT ITS EVOLUTION OVER THE CONUS.
THIS MORNING'S 13Z NBM GUIDANCE HAS GENERALLY TRENDED DRIER IN THE
MISSISSIPPI VALLEY AND WETTER IN THE SOUTHWEST COMPARED TO ITS
OVERNIGHT ITERATION. SOME OF THE 00Z EC MEAN WAS BLENDED WITH THE
NBM OVER THE PACIFIC NORTHWEST TO ENHANCE AMOUNTS DUE TO THE
FASTER ARRIVAL OF THE DAY 3 PAC NW SYSTEM NOTED IN THE ENSEMBLE
GUIDANCE, ALSO BECAUSE PRECIP APPEARED TO BE UNDERDONE IN THE NBM
AND DETERMINISTIC GUIDANCE.
..WEATHER/HAZARD HIGHLIGHTS
WHAT SHOULD BE THE LAST IN THE SERIES OF SIGNIFICANT STORM SYSTEMS
TO AFFECT MOST OF CALIFORNIA WILL LIKELY REACH THE STATE ON MONDAY
WITH ADDITIONAL HEAVY RAINFALL AND MOUNTAIN SNOW, WITH HIGHEST
TOTALS OVER THE SIERRA NEVADA AND TO A LESSER DEGREE ALONG FAVORED
COASTAL AREAS. RAINFALL OVER ALREADY VERY OVER-SATURATED GROUND
MAY CONTINUE TO WORSEN FLOODING OR DELAY IMPROVEMENT OF ONGOING
ISSUES. EXPECT THIS MOISTURE TO BRING RAIN AND HIGHER ELEVATION
SNOW INTO THE SOUTHWEST/SOUTHERN ROCKIES EARLY IN THE WEEK AS
WELL, WITH HIGHEST TOTALS OVER FAVORED TERRAIN IN ARIZONA AND
SOUTHWESTERN UTAH. THE NEXT SYSTEM WILL FOCUS RAIN AND MOUNTAIN
SNOW MORE OVER THE PACIFIC NORTHWEST AND NORTHERN CALIFORNIA
AROUND TUESDAY-WEDNESDAY, WITH MUCH LIGHTER AMOUNTS REACHING
INLAND OVER THE WEST THEREAFTER. CENTRAL-SOUTHERN CALIFORNIA
SHOULD STAY FAIRLY DRY.
TO THE EAST OF THE ROCKIES, A SYSTEM TRACKING FROM THE WESTERN
ATLANTIC NORTHWARD INTO THE CANADIAN MARITIMES MAY BRING SOME
WINTRY WEATHER TO NORTHERN NEW ENGLAND EARLY IN THE WEEK. THE
FIRST OF TWO PLAINS-GREAT LAKES SYSTEMS SHOULD BRING MODERATE
AMOUNTS OF PRECIPITATION TO THE EASTERN HALF OF THE COUNTRY EARLY
IN THE WEEK, WITH ANY SNOW LIKELY LIMITED TO FAR NORTHERN AREAS.
THE SECOND SYSTEM SHOULD BRING A BROADER AREA OF HEAVIER
PRECIPITATION TO AREAS FROM THE PLAINS EASTWARD MID-LATE WEEK.
WITH TYPICAL SENSITIVITY TO EXACT TRACK, BEST SNOW POTENTIAL
CURRENTLY EXISTS FROM THE CENTRAL HIGH PLAINS THROUGH THE UPPER
MIDWEST, PARTS OF THE GREAT LAKES, AND NEW ENGLAND. MEANWHILE GULF
INFLOW MAY BE SUFFICIENT TO SUPPORT SOME AREAS OF HEAVY RAINFALL
OVER AND NEAR PORTIONS OF THE MISSISSIPPI VALLEY AND OHIO VALLEY.
WHILE SYSTEM PROGRESSION WILL PROVIDE SOME DAY-TO-DAY VARIABILITY
TO TEMPERATURES, THE OVERALL PATTERN SHOULD SUPPORT WELL ABOVE
NORMAL TEMPERATURES OVER MUCH OF THE EASTERN HALF OF THE COUNTRY
AND BELOW NORMAL TEMPERATURES OVER THE SOUTHERN TWO-THIRDS OF THE
WEST. THE WARMTH EAST OF THE ROCKIES WILL LIKELY ERODE SOMEWHAT
FROM WEST TO EAST WITH THE PASSAGE OF THE COLD FRONT ANCHORED BY
THE MID-LATE WEEK STORM. SOME AREAS MAY SEE ONE OR MORE DAYS WITH
MORNING LOWS 20-30F ABOVE NORMAL, AND POTENTIAL FOR WARM LOW DAILY
RECORDS MIGRATING FROM THE EASTERN PLAINS/MISSISSIPPI VALLEY INTO
THE EAST. HIGHS SHOULD BE A LITTLE LESS EXTREME WITH MERE POCKETS
OF PLUS 20-25F ANOMALIES, WHILE BEST POTENTIAL FOR ANY RECORD
HIGHS EXISTS OVER/NEAR SOUTHEASTERN TEXAS ON TUESDAY. THE SOUTHERN
TWO-THIRDS OR SO OF THE WEST WILL TEND TO SEE HIGHS 5-15F BELOW
NORMAL.
KEBEDE/RAUSCH
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,
QUANTITATIVE PRECIPITATION, EXPERIMENTAL EXCESSIVE RAINFALL
OUTLOOK, WINTER WEATHER OUTLOOK PROBABILITIES AND HEAT INDICES ARE
AT:
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST500_WBG.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/MEDR/5DAYFCST_WBG_CONUS.GIF
HTTPS://WWW.WPC.NCEP.NOAA.GOV/5KM_GRIDS/5KM_GRIDSBODY.HTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/QPF/DAY4-7.SHTML
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=ERO
HTTPS://WWW.WPC.NCEP.NOAA.GOV/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page