522
FXUS02 KWBC 072000
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EST SAT MAR 7 2026
VALID 12Z TUE MAR 10 2026 - 12Z SAT MAR 14 2026
...THREAT OF MULTI-DAY HEAVY RAIN/FLOODING APPEARS TO LESSEN
MIDWEEK ACROSS THE EAST-CENTRAL U.S. INTO THE SOUTH BUT WIDESPREAD
SEVERE WEATHER REMAINS A CONCERN...
..PATTERN OVERVIEW
THE DEGREE OF INTERACTION BETWEEN A SOUTHERN STREAM UPPER LOW AND
A NORTHERN STREAM UPPER TROUGH CONTINUES TO INTRODUCE UNCERTAINTIES
IN THE MEDIUM RANGE FORECASTS ACROSS THE EAST-CENTRAL U.S. INTO THE
MID-SOUTH FOR MIDWEEK. THE THREAT OF MULTI-DAY HEAVY RAIN AND
FLOODING IN THESE AREAS APPEARS TO HAVE DECREASED. SOME SNOW AND
MIXED PRECIPITATION CAN BE EXPECTED ON THE NORTHERN EDGE OF THE
PRECIPITATION SHIELD FROM THE GREAT LAKES TO THE INTERIOR
NORTHEAST. AN ATMOSPHERIC RIVER REMAINS ON TRACK TO BRING MODERATE
TO HEAVY PRECIPITATION INTO THE PACIFIC NORTHWEST WEDNESDAY AND
THURSDAY FOLLOWED BY A CLIPPER SYSTEM TO BRING HIGH WIND THREATS
ACROSS THE ROCKIES INTO THE HIGH PLAINS.
..GUIDANCE/PREDICTABILITY ASSESSMENT
AGREEMENT AMONG THE LATEST MODEL GUIDANCE TODAY CONTINUES TO
IMPROVE FOR THE MEDIUM RANGE FORECAST PERIOD. THE GREATEST AREA OF
UNCERTAINTY REMAINS ACROSS THE EAST-CENTRAL U.S. INTO THE MID-SOUTH
WHERE AN UPPER LOW EJECTING OUT OF MEXICO IS FORECAST TO INTERACT
WITH THE NORTHERN STREAM AMPLIFYING TROUGH. MODELS THIS MORNING
CONTINUES WITH A GRADUAL TREND TOWARD A FASTER EASTWARD PROGRESSION
OF THE FRONT ACROSS THE EASTERN U.S. MIDWEEK ALONG WITH A STRONGER
LOW PRESSURE SYSTEM TO TRACK ACROSS THE GREAT LAKES. THE INCREASE
IN FORWARD MOTION OF THE FRONT HAS RESULTED IN A GENERAL LOWERING
OF THE RAINFALL AMOUNTS IN THE AFFECTED AREAS. THE STRONGER LOW
PRESSURE SYSTEM HAS ALSO LED TO A SOUTHWARD PENETRATION OF COLD AIR
AND THE SOUTHWARD EXTENT OF WINTRY PRECIPITATION TO POSSIBLY THE
INTERIOR NORTHERN MID-ATLANTIC. THE EC-AIFS CONTINUES TO FAVOR A
SLOWER SOUTHERN STREAM PROGRESSION BUT THE LATEST (12Z) ECMWF
FURTHER HASTEN THE EASTWARD PROGRESSION OF THE ENTIRE SYSTEM.
ACROSS THE PACIFIC NORTHWEST, THE TIMING OF THE MODERATE TO HEAVY
PRECIPITATION REMAINS ON TRACK MIDWEEK.
A GENERAL BLEND OF THE DETERMINISTIC GUIDANCE SERVED AS A GOOD
STARTING POINT FOR THE FIRST HALF OF THE FORECAST PERIOD. INCREASED
WEIGHTING OF THE ENSEMBLE MEANS OFFERS A GOOD STARTING POINT FOR
THE LATTER PORTION OF THE FORECASTS, WITH REASONABLY GOOD AGREEMENT
WITH THE PREVIOUS WPC FORECAST PACKAGE.
..WEATHER/HAZARDS HIGHLIGHTS
RETURN FLOW FROM THE GULF AND INSTABILITY AHEAD OF THE BAJA UPPER
LOW CONTINUE TO BRING A THREAT OF HEAVY RAIN MIDWEEK ACROSS THE
EAST-CENTRAL U.S. INTO THE MID-SOUTH MIDWEEK, WITH POTENTIAL
SEVERE THUNDERSTORMS AND FLASH FLOODING. ALTHOUGH THESE THREATS
HAVE DECREASED BASED ON THE FASTER MODEL CONSENSUS TODAY, A
MARGINAL RISK AREA FOR EXCESSIVE RAINFALL IS HIGHLIGHTED FROM THE
SOUTHERN PLAINS TO THE MIDWEST ON TUESDAY, FOLLOWED BY AN EASTWARD
SHIFT OF THE MARGINAL RISK ACROSS THE MID-SOUTH AND THE OHIO
VALLEY/MIDWEST ON WEDNESDAY. SPC IS ALSO HIGHLIGHTING SEVERE
WEATHER POTENTIAL IN SIMILAR REGIONS FOR BOTH DAYS. RAINFALL WILL
THEN EXPAND INTO THE EASTERN U.S. AHEAD OF THE MAIN COLD FRONT,
BUT THE OVERALL FLOOD THREAT LOOKS LIMITED AS THE FRONTAL BOUNDARY
SHOULD BE MUCH MORE PROGRESSIVE BY THAT TIME. SOME SNOW OR WINTRY
MIX IS POSSIBLE ON THE NORTHERN EDGE OF THE PRECIPITATION SHIELD
FROM THE GREAT LAKES INTO THE INTERIOR NORTHEAST, AND POSSIBLY AS
FAR SOUTH AS THE INTERIOR NORTHERN MID-ATLANTIC PER THE LATEST FROM
GUIDANCE.
A COUPLE OF SHORTWAVES SHOULD KEEP THE PACIFIC NORTHWEST WET
THROUGH MUCH OF THE PERIOD. THE HEAVIEST RAINFALL SHOULD BE
ASSOCIATED WITH AN ATMOSPHERIC RIVER GETTING READY TO ENTER THE
REGION WEDNESDAY. HEAVY SNOWS ARE POSSIBLE IN THE HIGHER
ELEVATIONS, WITH EVEN SOME LIGHT RAIN/SNOW MIX POSSIBLE AT LOWER
ELEVATIONS ON TUESDAY INTO WEDNESDAY AS TEMPERATURES COULD BE COLD
ENOUGH IN THE MORNINGS.
DEEP SYSTEMS AND TIGHT PRESSURE GRADIENTS WILL SUPPORT HIGH WINDS,
ESPECIALLY FOR THE NORTHWEST-ROCKIES-HIGH PLAINS DURING THE LATTER
HALF OF NEXT WEEK. GUSTY WINDS MAY ALSO ACCOMPANY THE COLD FRONT
AS IT SLIDES THROUGH THE MIDWEST AND INTO THE EAST MID TO LATE
WEEK.
A SIGNIFICANT SPRINGTIME WARM-UP IS EXPECTED AHEAD OF THE FRONT
FROM THE OHIO VALLEY INTO THE NORTHEAST WITH DAYTIME HIGHS 20 TO 30
DEGREES ABOVE NORMAL WITH DAILY WIDESPREAD RECORDS IN THE FORECASTS.
VALUES SHOULD MODERATE BACK TOWARDS NORMAL BY FRIDAY FOLLOWING THE
FRONTAL PASSAGE. ABOVE NORMAL TEMPERATURES ARE ALSO EXPECTED TO
EXPAND WITH TIME ACROSS THE SOUTHWEST INTO THE PLAINS AND THE SOUTH
WITH BELOW NORMAL TEMPERATURES ACROSS THE FAR NORTHERN TIER.
KONG/SANTORELLI
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 (QPF), EXCESSIVE RAINFALL
OUTLOOK (ERO), WINTER WEATHER OUTLOOK (WWO) PROBABILITIES, HEAT
INDICES, AND KEY MESSAGES CAN BE ACCESSED FROM:
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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