335
FXUS02 KWBC 240713
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
213 AM EST SAT FEB 24 2024
VALID 12Z TUE FEB 27 2024 - 12Z SAT MAR 02 2024
..GUIDANCE/PREDICTABILITY ASSESSMENT
12 UTC ECMWF/UKMET AND ECMWF ENSEMBLES CONSTITUTE A CLUSTER OF
GUIDANCE THAT CONTINUE TO VANGUARD BETTER SEPARATED FLOW ACROSS
MUCH OF THE LOWER 48 NEXT WEEK THAN RECENT RUNS OF THE CANADIAN,
AND TO A LESSER EXTENT THE GFS/GEFS. THE WPC MEDIUM RANGE PRODUCT
SUITE WAS PRIMARILY DERIVED FROM THE ECMWF/UKMET/ECMWF ENSEMBLES
AS RECENT TRENDS IN GUIDANCE AND MACHINE LEARNING MODELS TOWARD
THIS TYPE OF SOLUTION CONTINUE TO BETTER FIT KNOWN FLOW BIASES AND
WPC CONTINUITY OVER THE PAST DAY.
..OVERVIEW AND WEATHER/HAZARDS HIGHLIGHTS
AN UPPER RIDGE TRAVERSING THE CENTRAL AND EASTERN U.S. FOR THE
FIRST HALF OF NEXT WEEK WILL SPREAD MUCH ABOVE NORMAL TEMPERATURES
FROM THE PLAINS THROUGH THE MIDWEST AND THEN THE EAST. AN EMERGING
PRECIPITATION PATTERN DEVELOPS INTO TUESDAY/WEDNESDAY FROM THE
MIDWEST/GREAT LAKES THROUGH THE EAST TO INCLUDE SOME MODERATELY
HEAVY ACTIVITY. SPC ALSO SHOWS SOME RISK FOR SEVERE WEATHER IN
THIS PERIOD WITH POSSIBLE FOCUS ACROSS THE MID-MISSISSIPPI AND
TENNESSEE VALLEYS AND VICINITY. A POST-FRONTAL SURGE OF A COLD
CANADIAN HIGH PRESSURE IN THE WAKE OF LOW SYSTEM PASSAGE ALSO
OFFERS SOME WRAP-BACK ENHANCED SNOW POTENTIAL FROM THE EASTERN
MIDWEST AND GREAT LAKES THROUGH THE NORTHEAST.
MEANWHILE, NORTHERN AND WEAKER SOUTHERN-STREAM TROUGHING FROM THE
PACIFIC LOOK TO SEPARATELY TRACK INTO THE WEST. THE NORTHERN
STREAM TROUGH WILL BRING COOLER TEMPERATURES, ELEVATION-DEPENDENT
RAIN/SNOW, AND WINDY CONDITIONS THROUGH PARTS OF THE INTERMOUNTAIN
WEST/ROCKIES THROUGH TUESDAY PASSAGE, WHILE SOUTHERN STREAM SYSTEM
EJECTION MAY BRING A MODERATE PRECIPITATION SWATH OVER THE
SOUTHWEST, THEN SOUTHERN ROCKIES/PLAINS INTO MIDWEEK. DOWNSTREAM
TRANSLATION MAY THEN SUPPORT SYSTEM GENESIS, WITH LEAD RETURN
MOISTURE SET TO FUEL INCREASING RAIN/CONVECTIVE CHANCES ACROSS THE
SOUTH LATER NEXT WEEK INTO NEXT WEEKEND.
FARTHER UPSTREAM, A GROWING GUIDANCE SIGNAL IN SUPPORT OF
AMPLIFYING UPPER TROUGH DEVELOPMENT OVER THE EAST PACIFIC/WEST
COAST SEEMS TO INCREASINGLY SUPPORT CHANCES FOR SOME MODERATE TO
HEAVIER PRECIPITATION FOCUS INTO THE PACIFIC NORTHWEST MID-LATER
WEEK THAT MAY SHIFT DOWN THE COAST THROUGH CALIFORNIA LATER WEEK
AND NEXT WEEKEND TO MONITOR. A WPC DAY 5/WEDNESDAY EXCESSIVE
RAINFALL OUTLOOK MARGINAL RISK AREA WAS INTRODUCED FOR COASTAL
AREAS OF THE PACIFIC NORTHWEST TO USHER IN THIS EMERGING WET
PATTERN. THIS INCLUDES HEAVY SNOW THREATS INLAND OVER FAVORED
TERRAIN/MOUNTAINS ACROSS THE NORTHWEST/NORTHERN ROCKIES AND DOWN
WITH SOME EMPHASIS DOWN THROUGH THE SIERRA LATER PERIOD.
AS FOR ANOMALOUS TEMPERATURES, THE CENTRAL U.S. WILL SEE QUITE
WARM TEMPERATURES EARLY NEXT WEEK UNDERNEATH AN UPPER RIDGE.
TEMPERATURES OF 20-35 DEGREES ABOVE AVERAGE WILL EXPAND FROM THE
PLAINS THROUGH THE MIDWEST INTO TUESDAY. WIDESPREAD WELL ABOVE
NORMAL AND RECORD-BREAKING TEMPERATURES WILL SPREAD EASTWARD
ACROSS THE EASTERN U.S. THROUGH MIDWEEK. THE UPPER TROUGH AND WELL
DEFINED COLD FRONT PRESSING SOUTHWARD AND EASTWARD SHOULD THEN
COOL TEMPERATURES DOWN CLOSER TO NORMAL OR A FEW DEGREES BELOW
ACROSS THESE BROAD REGIONS, BUT UNSEASONABLE WARMTH SHOULD REBOUND
LATER WEEK AND THE WEEKEND BACK OVER THE CENTRAL STATES.
SCHICHTEL
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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