109
FXUS02 KWBC 111947
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
347 PM EDT SAT APR 11 2026
VALID 12Z TUE APR 14 2026 - 12Z SAT APR 18 2026
***MULTIPLE ROUNDS OF HEAVY RAIN AND SEVERE WEATHER ACROSS THE
PLAINS NEXT WEEK***
..GENERAL OVERVIEW
AN AMPLIFIED UPPER LEVEL FLOW PATTERN WILL BE IN PLACE NEXT WEEK
ACROSS THE CONTINENTAL U.S., WITH AN UPPER RIDGE SITUATED EAST OF
THE MISSISSIPPI RIVER, AND A GENERAL TROUGH OVER THE WEST. MULTIPLE
IMPULSES WILL EJECT EASTWARD ACROSS THE PLAINS AND PROVIDE FORCING
FOR EPISODES OF HEAVY RAIN AND SEVERE THUNDERSTORMS FROM THE
SOUTHERN PLAINS TO THE GREAT LAKES. SUMMER-LIKE TEMPERATURES WILL
BE COMMONPLACE ACROSS THE EASTERN HALF OF THE COUNTRY WITH HIGHS
WELL INTO THE 80S AND LOWER 90S BY THE MIDDLE OF THE WEEK, WHILE
SNOW WILL BE LIKELY ACROSS THE CENTRAL AND NORTHERN ROCKIES.
...GUIDANCE/PREDICTABILITY ASSESSMENT
THE LATEST 00/06Z GUIDANCE REMAINS IN FAIRLY DECENT AGREEMENT ON
THE OVERALL PATTERN THROUGH MOST OF NEXT WEEK WITH MEAN UPPER-
RIDGING OVER THE EASTERN U.S., MEAN UPPER-TROUGHING OVER THE
WESTERN U.S., AND AN ACTIVE SOUTHWESTERLY FLOW PATTERN OVER THE
CENTRAL U.S. AS THESE FEATURES TEND TO REMAIN IN PLACE. THERE ARE
SOME DIFFERENCES IN THE EVOLUTION OF INDIVIDUAL SHORTWAVES WITH
SPLIT-STREAM FRONTAL SYSTEMS PROGRESSING THROUGH THE FLOW MID-
WEEK. THE GFS HAS REMAINED A BIT OF AN OUTLIER WITH A FASTER/WEAKER
UPPER-WAVE ROUNDING NORTH OF THE UPPER-RIDGE COMPARED TO THE
ECMWF/ECMWF AIFS/CMC WHICH ARE SLOWER AND RETAIN A STRONGER LOW
PRESSURE/FRONTAL SYSTEM PASSING THROUGH THE MIDWEST. DESPITE THE
COMPLEXITY OF THE PATTERN AND DIFFERENCES IN THE GUIDANCE THE NBM
QPF OVERALL LOOKED REASONABLE IN COVERAGE AND AMOUNTS AHEAD OF A
STALLING FRONT THE PLAINS TO MIDWEST AND THEN EAST NORTH OF THE
RIDGE, EXCEPT PERHAPS A BIT DRY FROM THE OHIO VALLEY TO NEW
ENGLAND. THERE REMAINS SOME UNCERTAINTY WITH THE PORTION OF THE
FRONT THROUGH THE NORTHEAST AND HOW FAR SOUTH IT COULD GET,
POTENTIALLY AFFECTING THE DURATION OF ANOMALOUS AND POSSIBLE
RECORD-TYING/BREAKING HEAT TO THE SOUTH FROM THE OHIO VALLEY TO THE
MID-ATLANTIC, THOUGH THE TREND HAS BEEN TO HOLD FURTHER NORTH.
THEREAFTER, THERE ARE GREATER DIFFERENCES WITH THE NEXT SYSTEM
UPSTREAM FROM THE WEST AND A POTENTIAL PATTERN CHANGE BY NEXT
WEEKEND. BOTH THE LATEST GFS AND CMC BRING AN UPPER-WAVE OVER THE
NORTHEASTERN PACIFIC EAST ALONG THE NORTHERN TIER TO THE CENTRAL
U.S., WITH A STRONG LEE LOW PRESSURE SYSTEM DEVELOPING BY FRIDAY.
ON THE OTHER HAND, THE UPPER-WAVE IN THE ECMWF DIGS SOUTHWARD OVER
THE WEST, HELPING TO REINFORCE THE MEAN UPPER-TROUGHING AND
DELAYING SYSTEM PROGRESSION EASTWARD INTO THE CENTRAL U.S. COMPARED
TO THE OTHER GUIDANCE. THE 12Z RUNS OF THE ECMWF AND GFS TENDED TO
CONVERGE A BIT ON THE EVOLUTION THOUGH THE ECMWF REMAINS SLOWER.
DESPITE THIS, QPF IN THE NBM LOOKED TO BE A REASONABLE COMPROMISE
SOLUTION FAVORING POTENTIAL PRECIPITATION OVER THE MIDWEST AND
CENTRAL/SOUTHERN PLAINS SIMILAR TO THE GEFS/ECENS MEANS. THE
UPDATED WPC FORECAST INITIALLY USED A COMPOSITE BLEND OF THE
ECMWF/ECMWF AIFS/CMC AND 06Z GFS BEFORE REDUCING THE CONTRIBUTION
OF THE GFS AS THE SYSTEM EVOLUTION OVER THE CENTRAL/EASTERN U.S.
DIVERGED FROM THE OTHER GUIDANCE. THEN, FOR THE MID- TO LATTER PART
OF THE FORECAST, THE ECMWF IS REDUCED AND EVENTUALLY REMOVED WHILE
RETAINING THE ECMWF AIFS/CMC/GFS GIVEN ITS NOTED OUTLIER SOLUTION
OVER THE WEST. A CONTRIBUTION FROM THE ECENS/GEFS MEANS IS STEADILY
INCREASED TO 45% OF THE BLEND BY THE END OF THE PERIOD AS THE
DETERMINISTIC GUIDANCE BEGINS TO DIVERGE, PARTICULARLY WITH THE
PROGRESSION OF THE NEXT SYSTEM OVER THE CENTRAL U.S.
..WEATHER/HAZARDS HIGHLIGHTS
A VERY ACTIVE WEATHER PATTERN DEVELOPS ACROSS THE CENTRAL U.S.
THROUGH THE MIDDLE TO END OF THE WEEK, WITH MULTIPLE ROUNDS OF
STRONG TO SEVERE THUNDERSTORMS EXPECTED FROM TEXAS TO THE MIDWEST
STATES, GIVEN FAVORABLE WIND SHEAR AND INSTABILITY IN PLACE. THE
MOISTURE WILL BE CHANNELED NORTHWARD FROM THE WESTERN GULF TO THE
MIDWEST BETWEEN THE EASTERN U.S. UPPER RIDGE AND THE TROUGH OVER
THE ROCKIES, AND THE LIMITED EASTWARD PROGRESSION EACH DAY WILL
LIKELY RESULT IN AREAS THAT HAVE EXCESSIVE RAINFALL LEADING TO SOME
INSTANCES OF FLASH FLOODING. MARGINAL RISK AREAS WILL BE VALID
ACROSS PORTIONS OF THE MIDWEST TO THE WESTERN GREAT LAKES TUESDAY
INTO WEDNESDAY WHERE A FEW MESOSCALE CONVECTIVE SYSTEMS ARE LIKELY
TO DEVELOP. ADDITIONAL HEAVY RAINFALL IS LIKELY BEYOND THIS TIME
ACROSS PORTIONS OF THE CENTRAL/SOUTHERN PLAINS AND THE MIDWEST.
OUT WEST, AN AMPLIFYING SHORTWAVE AND ASSOCIATED COLD FRONT WILL
BRING A RENEWED ROUND OF COASTAL RAIN AND MOUNTAIN SNOW TO THE
PACIFIC NORTHWEST TUESDAY INTO WEDNESDAY, WITH POTENTIALLY 1-2+
FEET OF SNOW FOR THE CASCADES. THIS MOISTURE THEN MOVES INLAND
ACROSS THE NORTHERN ROCKIES THROUGH THE MIDDLE OF THE WEEK, WITH
MODERATE TO LOCALLY HEAVY SNOW FROM NORTHERN IDAHO TO NORTHWESTERN
WYOMING. LIGHTER SNOWS WILL BE POSSIBLE ACROSS THE HIGHER TERRAIN
OF UTAH AND COLORADO. PERIODIC GUSTIER WINDS CAN ALSO BE EXPECTED
THROUGH THE NORTHERN/CENTRAL ROCKIES AND INTO THE ADJACENT HIGH
PLAINS THROUGH THE PERIOD WITH MULTIPLE SYSTEM PASSAGES.
TEMPERATURES WILL ALSO BE MAKING WEATHER HEADLINES NEXT WEEK
ACROSS MUCH OF THE EASTERN U.S., WITH HIGHS REACHING INTO THE MID
TO UPPER 80S FOR MANY AREAS, AND EVEN SOME LOWER 90S ACROSS THE
SOUTHEAST AND MID-ATLANTIC REGION GOING INTO THE MIDDLE OF THE WEEK
AS THE EARLY SEASON HEATWAVE REACHES IT PEAK. NUMEROUS DAILY
RECORD HIGHS WILL BE POSSIBLE, ESPECIALLY WEDNESDAY AND THURSDAY.
ALTHOUGH THESE TEMPERATURES AND HUMIDITY WILL GENERALLY REMAIN
LOWER THAN MORE CONCERNING CONDITIONS OVER THE SUMMER, A COUPLE
DAYS OF HIGHS IN THE LOW TO MID-90S AND OVERNIGHT LOWS THAT MIGHT
REMAIN NEAR 70 COULD LEAD TO A LOCALLY HIGHER RISK OF HEAT STRESS
ACROSS PORTIONS OF CENTRAL/SOUTHERN VIRGINIA BY THURSDAY,
PARTICULARLY GIVEN THE EARLY NATURE OF THE HEAT COMPARED TO
AVERAGE. THERE SHOULD BE A MODEST COOLING TREND TOWARDS THE END OF
THE WEEK AS THE FRONTAL BOUNDARY DROPS SOUTHWARD FROM THE OHIO
VALLEY TO THE MID- ATLANTIC, AND REMAINING HOT ACROSS THE DEEP
SOUTH AND THE CAROLINAS. OUT WEST, READINGS SHOULD GENERALLY BE
NEAR TO BELOW AVERAGE WITH THE UPPER TROUGH IN PLACE AND INCREASED
CLOUD COVER AND PRECIPITATION.
PUTNAM/HAMRICK
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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