897
FXUS02 KWBC 240710
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
310 AM EDT SUN MAY 24 2026
VALID 12Z WED MAY 27 2026 - 12Z SUN MAY 31 2026
...HEAVY RAIN AND THUNDERSTORMS EXPECTED TO CONTINUE ACROSS MUCH
OF THE SOUTHERN U.S...
..OVERVIEW
A COUPLE OF UPPER LEVEL SHORTWAVES AND PIECES OF ENERGY WILL PASS
THROUGH THE SOUTH-CENTRAL U.S. NEXT WEEK, PROVIDING LIFT FOR
WIDESPREAD RAIN AND THUNDERSTORMS IN A MOIST AND UNSTABLE
ENVIRONMENT. THE HEAVIEST RAIN LOOKS TO FOCUS IN PARTS OF TEXAS AND
THE LOWER MISSISSIPPI VALLEY, POTENTIALLY OVER AREAS THAT WILL
ALREADY HAVE WET ANTECEDENT CONDITIONS. OUT WEST, A MORE AMPLIFIED
PATTERN WILL EMERGE BY THE START OF THE PERIOD WITH A CLOSED LOW
MEANDERING OVER THE WEST BEFORE WEAKENING AND SHIFTING EAST. THIS
RESULTS IN COOLER TEMPERATURES AND PRECIPITATION FOR THE WEST. A
BLOCKY UPPER RIDGE WILL BE IN PLACE DOWNSTREAM IN THE EAST- CENTRAL
U.S., REACHING INTO THE UPPER MIDWEST/GREAT LAKES AND BRINGING
ABOVE AVERAGE TEMPERATURES THROUGH NEXT WEEKEND.
..GUIDANCE/PREDICTABILITY ASSESSMENT
AGREEMENT CONTINUES TO BE GOOD FOR THE UPPER LOW IN PLACE OVER THE
WEST BY THE MIDDLE OF NEXT WEEK. THE LOW WILL LIKELY LINGER INTO
LATE WEEK AND SLOWLY WEAKEN AS IT LIFTS NORTHEASTWARD AS ITS
BLOCKED BY A DOWNSTREAM RIDGE AND REPLACED BY THE NEXT ROUND OF
TROUGHING OVER THE PACIFIC NORTHWEST NEXT WEEKEND. A GENERAL MODEL
COMPROMISE WORKED WELL FOR THIS LOW, THOUGH THE CMC CONTINUES TO BE
ON THE SLOWER SIDE OF THE BETTER CONSENSUS.
TO THE EAST, UPPER RIDGING WILL STRETCH FROM THE SOUTHEAST
NORTHWESTWARD INTO THE MIDWEST AS SOUTHERN STREAM ENERGY CUTS INTO
IT IN THE SOUTH-CENTRAL U.S., WITH TYPICAL MODEL DIFFERENCES IN THE
DETAILS. AS THE SOUTHERN ENERGY WEAKENS AND MOVES EAST, THE RIDGE
LOOKS TO REFORM WITH A NEUTRAL TILT ACROSS THE PLAINS LATE WEEK
INTO THE WEEKEND. THE PATTERN STARTS TO LOOK MORE LIKE AN OMEGA
BLOCK AS TROUGHING RETROGRADES INTO THE NORTHEAST. THERE CONTINUES
TO BE QUITE A BIT OF UNCERTAINTY WITH THE NORTHEAST TROUGH, WITH
THE GFS MORE AMPLIFIED AND DEEPER WITH THE TROUGH OVER THE EAST
WHICH IMPACTS THE SHAPE AND DISTRIBUTION OF THE UPPER RIDGE. WPC
PROGS WERE WEIGHTED MORE TOWARDS THE ENSEMBLE MEANS WITH THE ECMWF
AND EC-AIFS FOR THE DAY 6 AND 7 FORECAST.
..WEATHER/HAZARDS HIGHLIGHTS
PERSISTENT SOUTHERN STREAM ENERGY WILL CONTINUE TO KEEP MUCH OF
THE SOUTHERN PLAINS TO THE SOUTHEAST ACTIVE AND UNSETTLED WELL INTO
NEXT WEEK WITHIN A VERY MOIST AND UNSTABLE ENVIRONMENT AND DAILY
THUNDERSTORM CHANCES. THIS COULD BE ESPECIALLY IMPACTFUL FOR PARTS
OF TEXAS AND THE LOWER MISSISSIPPI VALLEY WHERE RECENT RAINS AND
ADDITIONAL RAIN IN THE SHORT TERM HAS LEAD TO RATHER SATURATED
GROUNDS. FOR THE DAY 4/WEDNESDAY ERO, A BROAD MARGINAL RISK IS IN
PLACE ACROSS MUCH OF THE SOUTHERN U.S., AND CONTINUE TO HIGHLIGHT
AN EMBEDDED SLIGHT RISK FOR SOUTHEAST TEXAS TO WESTERN LOUISIANA. A
BROAD MARGINAL RISK IS IN PLACE ON THE DAY 5/THURSDAY ERO FOR THE
LOWER AND MIDDLE MISSISSIPPI VALLEY, AND DEPENDING ON PREVIOUS DAYS
RAINFALL, MAY ALSO NEED A SLIGHT RISK UPGRADE AT SOME POINT. THE
EXACT LOCATIONS OF HEAVIER RAINFALL ON BOTH DAYS WILL LIKELY CHANGE
AS MODELS COME INTO BETTER AGREEMENT, BUT THE PATTERN OVERALL
FAVORS HEAVY RAINFALL POTENTIAL WITH FLOODING AN INCREASING CONCERN
GIVEN THE POTENTIALLY CONCERNING ANTECEDENT CONDITIONS. THE
PATTERN EVOLUTION MAY GRADUALLY SUPPORT DRIER CONDITIONS FOR TEXAS
BY NEXT WEEKEND, BUT THE WET PATTERN LOOKS TO CONTINUE ALONG THE
GULF COAST AND ESPECIALLY FLORIDA THROUGH NEXT WEEKEND. A MARGINAL
RISK WAS ADDED FOR THE URBAN CORRIDOR OF SOUTHEAST FLORIDA ON
THURSDAY, WITH HEAVY RAINFALL POTENTIAL TRENDING UPWARDS BEYOND AS
WELL.
UPPER TROUGHING ACROSS THE NORTHWEST AND MEANDERING AROUND THE
GREAT BASIN WITH A FRONTAL SYSTEM AHEAD OF IT WILL ALLOW FOR
INCREASED PRECIPITATION ACROSS THE PACIFIC NORTHWEST TO
INTERMOUNTAIN WEST FOR MULTIPLE DAYS. SNOW IS POSSIBLE AT THE
HIGHEST ELEVATIONS OF THE CASCADES TO ROCKIES. COMBINING ENERGIES
WILL ALLOW RAIN CHANCES TO STRETCH EAST INTO THE CENTRAL PLAINS AND
MIDWEST FOR MIDWEEK AND BEYOND.
WITH THE CLOSED UPPER LOW OVER THE WEST, TEMPERATURES SHOULD TREND
COOLER IN THIS REGION THROUGH THURSDAY, WITH SOME MODERATING BACK
TOWARDS NORMAL AS THE TROUGH WEAKENS AND DRIFTS. THE UPPER RIDGE TO
ITS EAST WILL ALLOW FOR WARMER THAN AVERAGE TEMPERATURES ACROSS
THE NORTH-CENTRAL U.S. THROUGH MUCH OF NEXT WEEK, WITH DAYTIME
HIGHS 10-20 DEGREES ABOVE NORMAL, WITH GREATEST ANOMALIES THROUGH
AROUND MID TO LATE WEEK.
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, 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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