706
FXUS02 KWBC 211846
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
145 PM EST WED FEB 21 2024
VALID 12Z SAT FEB 24 2024 - 12Z WED FEB 28 2024
..OVERVIEW
AN UPPER RIDGE TRAVERSING THE COUNTRY THIS WEEKEND INTO EARLY NEXT
WEEK WILL SPREAD MUCH ABOVE NORMAL TEMPERATURES TO THE PLAINS AND
MIDWEST AND EVENTUALLY THE EAST BY THE MIDDLE OF NEXT WEEK.
MEANWHILE AN EASTERN PACIFIC UPPER LOW SHOULD SPREAD SOME
INCREASING PRECIPITATION CHANCES TO THE WEST COAST ONCE AGAIN,
POSSIBLY BY THE WEEKEND BUT MORE CONFIDENTLY BY EARLY NEXT WEEK AS
NORTHERN AND SOUTHERN STREAM TROUGHING PHASE AND TRACK INTO THE
WEST. COOLER TEMPERATURES, LOWER ELEVATION RAIN AND HIGHER
ELEVATION SNOW, AND WINDY CONDITIONS ARE ALL EXPECTED FOR THE WEST
COAST TO THE ROCKIES EARLY NEXT WEEK. INCREASED PRECIPITATION IS
ALSO LIKELY FOR THE OHIO VALLEY/GREAT LAKES BY MONDAY-TUESDAY WITH
A FRONTAL SYSTEM OR TWO AHEAD OF THIS TROUGH.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST MODEL GUIDANCE TODAY CONTINUES TO BE FAIRLY CONSISTENT
WITH PREVIOUS GUIDANCE REQUIRING NO MAJOR CHANGES NEEDED FOR THE
UPDATED PROGS COMPARED TO PREVIOUS WPC CONTINUITY. THERE WERE SOME
MAINLY MINOR TIMING DIFFERENCES IN THE GUIDANCE WITH AN INITIAL
SHORTWAVE OUT OF THE NORTHEAST AND ANOTHER BEHIND ACROSS THE GREAT
LAKES THIS WEEKEND/MONDAY BUT A GENERAL MODEL COMPROMISE SEEMED TO
SERVE AS A GOOD STARTING POINT. OTHERWISE, THE GREATEST
UNCERTAINTIES SEEM TO BE LATE PERIOD REGARDING THE DETAILS OF
PHASING BETWEEN A NORTHERN STREAM SHORTWAVE INTO THE NORTHWEST AND
AN OPENING LOW OFF THE SOUTHERN CALIFORNIA COAST. GUIDANCE AGREES
THE TWO FEATURES SHOULD PHASE RESULTING IN ONE ELONGATED TROUGH
THROUGH THE WEST BY NEXT TUESDAY-WEDNESDAY BUT THERE ARE SOME
TIMING INCONSISTENCIES. THE GFS IS SLOWEST TO MOVE INTO THE
PLAINS, WHILE THE CMC IS NOTICEABLY FASTER. THE ECMWF SEEMS TO BE
RIGHT IN THE MIDDLE OF THE TWO AND THE NEW 12Z RUN IS A TAD SLOWER
THAN IT'S PREVIOUS 00Z RUN, AND IT'S ALSO FAIRLY CONSISTENT WITH
THE ENSEMBLE MEANS. SO WITH THAT, THE LATE PERIOD BLEND FOR THE
WPC PROGS TODAY TRANSITIONED TO A 50/50 BLEND OF THE ENSEMBLES
WITH THE GFS/ECMWF.
..WEATHER/HAZARDS HIGHLIGHTS
AN UPPER LOW AND ITS SURFACE REFLECTION LOOK TO MEANDER IN THE
EASTERN PACIFIC LATE THIS WEEK, PERHAPS REACHING CLOSE ENOUGH TO
CALIFORNIA TO PROVIDE SOME SHOWER ACTIVITY. BUT BY SUNDAY INTO
MONDAY MODEL GUIDANCE IS MORE AGREEABLE THAT PRECIPITATION SHOULD
SPREAD INTO THE PACIFIC NORTHWEST AND CALIFORNIA WITH SOME
MOISTURE SPREADING FARTHER INLAND INTO THE INTERMOUNTAIN WEST.
SNOW AND RAIN SHOULD CONTINUE TO INCREASE IN INTERIOR PARTS OF THE
WEST INTO MONDAY-TUESDAY. HEAVY SNOW WITH THE HIGHEST LIKELIHOOD
FOR IMPACTS IS IN THE CASCADES SUNDAY-TUESDAY, BUT THE SNOW WILL
LIKELY CAUSE AT LEAST MINOR IMPACTS TO MUCH OF THE HIGHER
ELEVATION AREAS OF THE SIERRA INTO THE INTERMOUNTAIN WEST AND
ROCKIES. GUSTY WINDS ARE FORECAST FOR THE INTERIOR WEST BEHIND A
COUPLE OF COLD FRONTS ON MONDAY-TUESDAY AS WELL.
FARTHER EAST, LIGHT RAIN AND SNOW ARE POSSIBLE SATURDAY FOCUSED IN
THE SOUTHERN APPALACHIANS. A COLD FRONT TRACKING THROUGH THE
NORTHEASTERN U.S. COULD SPREAD SOME LIGHT TO MODERATE
PRECIPITATION FROM THE OHIO VALLEY INTO THE NORTHERN/CENTRAL
APPALACHIANS AND THE NORTHEAST ON SUNDAY. THEN AHEAD OF THE
APPROACHING UPPER TROUGH AND COLD FRONT, PRECIPITATION CHANCES
WILL INCREASE LATE MONDAY INTO TUESDAY IN THE MIDWEST TO THE OHIO
VALLEY AND GREAT LAKES. MOST PRECIPITATION WILL BE IN THE FORM OF
RAIN GIVEN THE ANOMALOUS WARMTH, BUT SOME SNOW IN THE NORTHEAST
AHEAD OF THE SYSTEM AND SOME SNOW ON THE BACKSIDE OF THE LOW IN
THE NORTH-CENTRAL U.S. IS POSSIBLE, THOUGH WITH LOW CONFIDENCE.
RAINFALL AMOUNTS COULD BE LOCALLY HEAVY IN THE OHIO VALLEY.
THE CENTRAL U.S. WILL SEE QUITE A MILD TO WARM WEEKEND TO EARLY
NEXT WEEK UNDERNEATH AN UPPER RIDGE. TEMPERATURES OF 15-25 DEGREES
ABOVE AVERAGE IN THE NORTH-CENTRAL U.S. ON SATURDAY WILL ONLY
INCREASE IN COVERAGE AND MAGNITUDE BY EARLY NEXT WEEK. HIGHS AND
LOWS THAT ARE 20-35 DEGREES ABOVE NORMAL SHOULD EXPAND SOUTHWARD
INTO THE PLAINS AND MISSISSIPPI VALLEY EARLY NEXT WEEK. THIS PUTS
ACTUAL TEMPERATURES INTO THE 80S AND EVEN 90S IN TEXAS
MONDAY-TUESDAY WHILE 60S REACH AS FAR NORTH AS SOUTH DAKOTA AND
IOWA, WITH POTENTIAL FOR WIDESPREAD RECORD DAYTIME HIGHS AND WARM
OVERNIGHT LOWS. A GRADUAL EASTWARD SPREAD/SHIFT SHOULD WARM THE
SOUTHEAST IN TO THE 70S NEXT WEEK. THE CENTRAL U.S. SHOULD
MODERATE CLOSER TO NORMAL BY MIDWEEK WHILE THE HIGHEST ANOMALIES
SHIFT INTO THE EAST, AFTER A COOL WEEKEND AND GRADUAL WARM-UP.
MEANWHILE THE WEST IS FORECAST TO SEE NEAR TO SLIGHTLY ABOVE
NORMAL TEMPERATURES LATE WEEK INTO THE WEEKEND, BUT COOLING TO
BELOW NORMAL PARTICULARLY IN TERMS OF HIGHS BY MONDAY-TUESDAY AS
UPPER TROUGHING COMES IN.
SANTORELLI/TATE
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 FORECAST, EXCESSIVE RAINFALL OUTLOOK,
WINTER WEATHER OUTLOOK PROBABILITIES, HEAT INDICES AND KEY
MESSAGES 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
HTTPS://WWW.WPC.NCEP.NOAA.GOV/#PAGE=OVW
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