517
FXUS02 KWBC 251900
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
300 PM EDT TUE MAR 25 2025
VALID 12Z FRI MAR 28 2025 - 12Z TUE APR 01 2025
..OVERVIEW
LATEST GUIDANCE SHOWS A MODERATELY PROGRESSIVE PATTERN THAT WILL
BRING ACTIVE WEATHER TO PORTIONS OF THE LOWER 48. A SOUTHERN STREAM
SHORTWAVE WILL PROMOTE A THREAT OF HEAVY RAIN ALONG THE WESTERN-
CENTRAL GULF COAST LATE THIS WEEK. BEHIND THIS FEATURE, EASTERN
PACIFIC INTO WESTERN U.S. DYNAMICS WILL SPREAD PRECIPITATION ACROSS
NORTHERN PARTS OF THE WEST AND THEN DEVELOP ONE OR MORE
WAVES/FRONTS FROM THE PLAINS EASTWARD WITH ASSOCIATED AREAS OF
ENHANCED RAINFALL AS WELL AS WINTER WEATHER POTENTIAL OVER FAR
NORTHERN LATITUDES. ANOTHER PACIFIC SYSTEM SHOULD SPREAD
PRECIPITATION INTO THE WEST FROM LATE WEEKEND INTO EARLY NEXT WEEK.
VERY WARM TEMPERATURES WILL PREVAIL AHEAD OF THE OVERALL AREA OF
PLAINS LOW PRESSURE, WHILE TRAILING COOLER AIR WILL BRING READINGS
BACK DOWN TO NEAR OR SLIGHTLY BELOW NORMAL.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE MAIN AREA OF UNCERTAINTY IN THE MODELS EXISTS AROUND THE WEST
TO CENTRAL GULF COAST SYSTEM LATER THIS WEEK. NON-GFS MODELS TENDED
TO CLUSTER BETTER TOGETHER THAN PRE-12Z GFS/GEFS GUIDANCE ON THE
TIMING OF THE SHORTWAVE PROPAGATING ACROSS THE WESTERN GULF COAST
ON FRIDAY INTO SATURDAY. ELSEWHERE, THE NBM PROBABILITIES OF > 0.25
IN. OF SNOW OR FREEZING RAIN WERE NOTABLY LOWER THAN THE ENSEMBLE
MEANS.
A GENERAL MODEL BLEND WEIGHTED TOWARDS THE EURO/EURO ENSEMBLE MEAN
WERE UTILIZED THROUGH DAY 5. ENSEMBLE MEANS DOMINATED THE BLEND
BEYOND THAT.
..WEATHER/HAZARDS HIGHLIGHTS
LATEST GUIDANCE IS CONSISTENT WITH THE GENERAL THEME OF HEAVY RAIN
POTENTIAL ALONG AND NEAR THE WEST-CENTRAL INTO CENTRAL GULF COAST,
AS AN UPPER TROUGH INTERACTS WITH LOW LEVEL GULF MOISTURE AND A
WARM FRONT. THE DAY 4/FRIDAY EXCESSIVE RAINFALL OUTLOOK HAS
INTRODUCED A SLIGHT RISK AREA COVERING PARTS OF SOUTHEASTERN TEXAS
AND SOUTHWESTERN LOUISIANA, WITH MODELS/ENSEMBLES NOW CLUSTERING
BETTER FOR THIS REGION SEEING THE BEST FOCUS. BY DAY 5/SATURDAY,
GUIDANCE BECOMES MUCH MORE DIFFUSE WITH THE RAINFALL SIGNAL. RECENT
ECMWF/ECMWF AIFS/UKMET RUNS SHOW THE MOST AGREEABLE THEME OF SOME
ACTIVITY FROM FRIDAY-FRIDAY NIGHT CONTINUING INTO SATURDAY, WITH
SOME INSTABILITY, BEFORE TRENDING LIGHTER. THUS THE DAY 5 ERO
DEPICTS A MARGINAL RISK AREA ALONG AND NORTH OF THE CENTRAL GULF
COAST REGION.
ELSEWHERE, RAIN AND HIGH ELEVATION SNOW WILL CROSS THE NORTHERN
HALF OF THE WEST LATE THIS WEEK, FOLLOWED BY AN INCREASING AREA OF
PRECIPITATION FROM THE NORTH-CENTRAL PLAINS THROUGH NORTHEAST AND
EXTENDING SOUTHWARD THROUGH THE MISSISSIPPI VALLEY AND POINTS EAST
DURING THE WEEKEND INTO EARLY NEXT WEEK AS ONE OR MORE FRONTAL
WAVES EVOLVE AND THE OVERALL FRONTAL SYSTEM EVENTUALLY PUSHES
EASTWARD. IT MAY BE COLD ENOUGH TO SUPPORT WINTRY PRECIPITATION
TYPES FOR A TIME FROM THE NORTHERN PLAINS THROUGH THE UPPER GREAT
LAKES INTO NORTHERN NEW ENGLAND. TO THE SOUTH, SOME RAIN COULD BE
LOCALLY HEAVY OVER THE NORTH CENTRAL PLAINS AS WELL AS FROM THE
MISSISSIPPI VALLEY EASTWARD. IN ADDITION, THE STORM PREDICTION
CENTER IS MONITORING THE POTENTIAL FOR SEVERE WEATHER FROM PARTS OF
THE EASTERN PLAINS INTO A LARGE PART OF THE EAST- CENTRAL U.S.
DURING THE WEEKEND. CHECK LATEST SPC OUTLOOKS FOR THE LATEST INFO
ON SEVERE THREATS.
AFTER A BRIEF BREAK, ANOTHER AREA OF PRECIPITATION SHOULD SPREAD
ACROSS THE WEST FROM SUNDAY INTO EARLY NEXT WEEK. THERE IS STILL A
DECENT AMOUNT OF UNCERTAINTY FOR THE SPECIFICS OF SUPPORTING
EASTERN PACIFIC LOW PRESSURE, BUT CURRENTLY EXPECT HIGHEST TOTALS
TO BE OVER THE CENTRAL WEST COAST/NORTHERN CALIFORNIA.
VERY WARM TEMPERATURES WILL PREVAIL IN THE WARM SECTOR AHEAD OF
THE WAVY FRONTAL SYSTEM EVOLVING OVER THE PLAINS AND THEN PUSHING
EASTWARD. SOME AREAS FROM THE CENTRAL HIGH PLAINS INTO THE MIDWEST
MAY SEE HIGHS 20-30F ABOVE NORMAL ON FRIDAY. THE WARMTH WILL SHIFT
SOUTH AND EAST OVER THE WEEKEND WITH PLUS 20F OR GREATER ANOMALIES
FOR MORNING LOWS REACHING FROM THE MIDWEST INTO THE OHIO VALLEY
WHILE PLUS 10-20F ANOMALIES FOR HIGHS EXTEND FROM THE SOUTHERN HALF
OF THE PLAINS INTO THE MID-ATLANTIC AND SOUTHEAST. CONTINUED
FRONTAL PROGRESSION WILL CONFINE ABOVE NORMAL READINGS TO THE EAST
COAST BY MONDAY. HOWEVER THE NORTHEAST WILL BE ON THE COOL SIDE, TO
THE NORTH OF A FRONT SETTLING OVER OR NEAR THE NORTHERN MID-
ATLANTIC. BEHIND THE MAIN FRONTAL SYSTEM, MODESTLY BELOW NORMAL
HIGHS WILL PROGRESS FROM THE WEST LATE THIS WEEK INTO THE GREAT
LAKES/OHIO VALLEY BY NEXT TUESDAY.
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 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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