343
FXUS02 KWBC 291952
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
352 PM EDT SUN MAR 29 2026
VALID 12Z WED APR 01 2026 - 12Z SUN APR 05 2026
...HEAVY RAIN AND FLOODING POTENTIAL ACROSS THE EAST-CENTRAL U.S.
FROM MIDWEEK INTO NEXT WEEKEND...
..OVERVIEW
A COUPLE OF SHORTWAVE TROUGHS WILL PUSH A WAVY FRONTAL SYSTEM
THROUGH THE CENTRAL AND EASTERN U.S. AND SPREAD PRECIPITATION
ACROSS THE REGION FOR MIDWEEK. MEANWHILE MORE AMPLIFIED TROUGHING
IS FORECAST TO MOVE INTO THE NORTHWEST BY THURSDAY AND EASTWARD
INTO LATE WEEK, CONTINUING UNSETTLED WEATHER THERE, INCLUDING
RAIN/MOUNTAIN SNOW AND STRONG WINDS. AS THAT TROUGH PUSHES EAST
INTO THE PLAINS, ADDITIONAL MOISTURE WILL BE DRAWN NORTH AND RENEW
POTENTIAL FOR HEAVY RAIN AND STORMS IN THE MISSISSIPPI VALLEY AND
VICINITY ONCE AGAIN, ENDING UP WITH MULTIPLE DAYS OF FLOODING
CONCERNS IN THAT REGION. WINTRY WEATHER INCLUDING SNOW AND ICE ARE
POSSIBLE ON THE NORTHERN SIDE IN PARTS OF THE NORTHEAST.
..GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST DETERMINISTIC AND ENSEMBLE GUIDANCE REMAINS RELATIVELY
WELL CLUSTERED ON THE OVERALL PATTERN, AND SOME OF THE DETAILS HAVE
COME INTO BETTER FOCUS ESPECIALLY LATER THIS WEEK. FOLLOWING THE
DEPARTURE OF A NORTHERN STREAM WAVE THROUGH THE NORTHEAST, A
TRAILING FRONTAL BOUNDARY WILL BECOME THE FOCUS FOR UNSETTLED
WEATHER ACROSS THE CENTRAL AND EASTERN U.S. LATER THIS WEEK AND
INTO THE WEEKEND. WHILE THERE REMAINS SOME UNCERTAINTY WITH THE
TIMING OF A SOUTHERN STREAM SHORTWAVE EXPECTED TO SPIN UP A SURFACE
WAVE ALONG THE FRONTAL BOUNDARY, THE AXIS OF EXPECTED RAINFALL HAS
SETTLED ACROSS THE MIDDLE MISSISSIPPI VALLEY SOUTHWEST THROUGH THE
OZARKS AND INTO THE SOUTHERN PLAINS AFTER GUIDANCE HAD BEEN
SHOWING SIGNIFICANT SHIFTS RUN-TO-RUN. THE LAST COUPLE RUNS OF THE
GFS TENDED TO BE FASTER WITH THE UPPER-WAVE AND SURFACE REFLECTION
COMPARED TO THE ECMWF/CMC, WHICH STILL LEADS TO UNCERTAINTY
REGARDING THE MORE MESOSCALE DETAILS THAT WILL NEED TO BE
MONITORED. INTERESTINGLY, THE ECMWF AIFS SHOWED AN EVOLUTION MORE
SIMILAR TO THE GFS. GIVEN SOMEWHAT DIFFERENT BUT GENERALLY WELL
CLUSTERED SOLUTIONS, THE UPDATED WPF FORECAST USED A COMPOSITE
BLEND OF THE 06Z GFS AND 00Z ECMWF/ECMWF AIFS/CMC, WHICH ALSO
MAINTAINED GOOD FORECAST CONTINUITY.
THEREAFTER, WHILE GUIDANCE HAS COME INTO BETTER AGREEMENT AN
UPSTREAM UPPER-LOW FROM THE NORTHEASTERN PACIFIC DROPPING SOUTHWARD
ACROSS THE WESTERN U.S. AND THEN EMERGING ON THE PLAINS THIS
UPCOMING WEEKEND, THE SUBSEQUENT PROGRESSION/EVOLUTION REMAINS MORE
UNCERTAIN. THE 00/06Z GFS WAS MORE PROGRESSIVE COMPARED TO THE 00Z
ECMWF, AND THE 00Z CMC IS EVEN SLOWER. THE GFS ALSO LIFTS
NORTHWARD AS AN OPEN WAVE WHILE THE ECMWF AND CMC MAINTAIN A CLOSED
LOW. SUBSEQUENT SURFACE LOW DEVELOPMENT LIFTS FASTER ACROSS THE
MIDWEST AND INTO CANADA IN THE GFS WITH THE ECMWF SLOWER, WHILE THE
GEFS/ECENS/CMC MEANS TENDED TO REMAIN IN THE MIDDLE. THE CMC
SEEMED TO LIE OUTSIDE THIS ENVELOPE OF SOLUTIONS. WHILE THE TRACKS
ARE DIFFERENT, THE PROGRESSION OF A TRAILING COLD FRONT LOOKS TO
REMAIN MORE SIMILAR WITH SOUTHWEST EXTENT AT LEAST THROUGH
SATURDAY, BEFORE GUIDANCE BEGINS TO DIVERGE MORE WITH RESPECT TO
THIS FEATURE AS WELL. INTERESTINGLY, THE LATEST 00 ECMWF AIFS AND
00 AIGFS SHOWED A MORE PROGRESSIVE FRONT WITH THE QPF SHIFTING
SIGNIFICANTLY EAST OF THE CONSENSUS IN THE NBM, A TREND TO BE
MONITORED, AND THE 12Z ECMWF LOOKED TO BE TRENDING FASTER AS WELL.
FOR NOW, THE LATTER PART OF THE UPDATED WPC FORECAST USED THE
ECMWF/ECMWF AIFS/GFS WHICH REMAINED MORE SIMILAR TO THE MEANS, BUT
WITH AN INCREASED CONTRIBUTION OF THE MEANS AS THE DIVERGENCE IN
SOLUTIONS GROWS. FELT THE NBM QPF WELL REPRESENTED THE MODEL
CONSENSUS THROUGH MOST OF THE PERIOD, WITH POTENTIAL TRENDS TO
MONITOR WITH THE NOTED COLD FRONT PROGRESSION SATURDAY INTO SUNDAY.
..WEATHER/HAZARDS HIGHLIGHTS
A LOW PRESSURE/FRONTAL SYSTEM STRETCHING FROM THE NORTHEAST ACROSS
THE MID-SOUTH WILL TAP INTO GULF MOISTURE AND SPREAD RAIN AND
THUNDERSTORMS TO PORTIONS OF THE CENTRAL AND EASTERN U.S. MIDWEEK.
THE MOISTURE AND INSTABILITY ALONG WITH THE UPPER-LEVEL SUPPORT
COULD LEAD TO FLOODING CONCERNS ACROSS PARTS OF THE SOUTHERN PLAINS
TO LOWER/MIDDLE MISSISSIPPI VALLEY ON WEDNESDAY AS MULTIPLE ROUNDS
OF RAIN COULD OCCUR. A MARGINAL RISK REMAINS IN EFFECT FOR DAY
4/WEDNESDAY IN THOSE REGIONS. RECENT MODEL GUIDANCE HAS BEGUN TO
BETTER ZERO IN ON A CORRIDOR OF HIGHER RAIN TOTALS GENERALLY FROM
EASTERN OKLAHOMA INTO SOUTHWESTERN/CENTRAL MISSOURI, AND AN UPGRADE
TO A SLIGHT RISK SEEMS INCREASINGLY LIKELY. HOWEVER, THE TIMING OF
THE INCOMING SHORTWAVE/LIFTING WARM FRONT HAS REMAINED A TRICKIER
PART OF THE FORECAST, AND CONVECTION SOUTH ALONG THE COLD FRONT MAY
ALSO LIMIT INSTABILITY FURTHER NORTH/BECOME THE HIGHER THREAT. ON
THURSDAY, THE FRONTAL SYSTEM SHOULD GRADUALLY PUSH EAST, AND WITH
THE GENERALLY SIMILAR METEOROLOGICAL SETUP, WILL ONCE AGAIN SHOW A
BROAD MARGINAL RISK FROM THE LOWER/MIDDLE MISSISSIPPI VALLEY INTO
THE TENNESSEE AND OHIO VALLEYS INTO THE GREAT LAKES REGION FOR THE
DAY 5 ERO. PRECIPITATION IS LIKELY TO CONTINUE ACROSS THE EAST INTO
FRIDAY. CHILLIER AIR IN THE NORTHERN TIER COULD ALLOW WINTRY
WEATHER TO AFFECT THE GREAT LAKES TO INTERIOR NORTHEAST. THIS COULD
INCLUDE FREEZING RAIN/ICE ALONG WITH A FEW INCHES OF APRIL SNOW.
TROUGHING MOVING THROUGH THE WEST WILL PROVIDE SUPPORT FOR
MODERATE PRECIPITATION WEDNESDAY-FRIDAY. SOME ENHANCED QPF IS
LIKELY ACROSS THE PACIFIC NORTHWEST TO NORTHERN CALIFORNIA ON
WEDNESDAY, BUT THE ATMOSPHERIC RIVER IS FORECAST TO REMAIN TOO WEAK
TO CAUSE FLOODING ISSUES. RAIN AND MOUNTAIN SNOW IS FORECAST TO
GRADUALLY OVERSPREAD THE INTERMOUNTAIN WEST. GUSTY WINDS COULD BE A
CONCERN ACROSS THE INTERMOUNTAIN WEST TO ROCKIES AND PLAINS WITH
THIS TROUGHY PATTERN. BY FRIDAY, A PRIMARY FOCUS OF HEAVIER RAIN
WILL RETURN BACK WEST INTO THE CENTRAL PLAINS/MIDDLE MISSISSIPPI
VALLEY FRIDAY IN RESPONSE TO THE UPPER TROUGH MAKING ITS WAY INTO
THE CENTRAL U.S. PULLING IN ADDITIONAL MOISTURE. BY SATURDAY THERE
MAY BE A SIMILAR HEAVY RAINFALL FOOTPRINT TO THE MIDWEEK RAIN
(ACROSS PARTS OF THE MS/TN/OH VALLEYS), POTENTIALLY EXACERBATING
FLOODING CONCERNS, SO WILL CONTINUE TO MONITOR. BREEZY CONDITIONS
COULD REACH THE MIDWEST BY THE WEEKEND DEPENDENT ON THE LOW TRACK.
WARMER THAN AVERAGE TEMPERATURES ARE FORECAST FOR THE SOUTHERN
TIER INTO THE EASTERN SEABOARD ON WEDNESDAY, WITH HIGHS IN THE 80S
REACHING INTO THE MID-ATLANTIC. THE EASTERN SIDE OF THE FRONT WILL
PUSH THROUGH PARTS OF THE EAST THURSDAY AND FRIDAY (ALBEIT WITH
UNCERTAINTY HOW FAR SOUTH IT SETS UP), BUT THE SOUTHEAST SHOULD
HANG ONTO WARMER TEMPERATURES UNDER THE INFLUENCE OF A BERMUDA
HIGH. ROUNDS OF COOLER THAN AVERAGE CONDITIONS ARE LIKELY TO MOVE
THROUGH THE NORTH-CENTRAL U.S. BEHIND COLD FRONTS. THE WEST CAN
GENERALLY EXPECT NEAR TO SLIGHTLY BELOW AVERAGE CONDITIONS THROUGH
THE LATTER PART OF THE WEEK, BUT WARMING TO ABOVE AVERAGE OVER THE
WEEKEND AS UPPER RIDGING POTENTIALLY COMES IN BEHIND THE TROUGH
ALOFT.
PUTNAM/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 (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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