279
FXUS02 KWBC 271826
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
226 PM EDT WED MAY 27 2026
VALID 12Z SAT MAY 30 2026 - 12Z WED JUN 03 2026
..HEAVY RAIN/THUNDERSTORMS FOR THE SOUTH/SOUTHEAST U.S
..OVERVIEW
A BLOCKY UPPER FLOW PATTERN WILL BE IN PLACE TO START THE PERIOD
SATURDAY FEATURING TROUGHING OVER BOTH THE WEST AND EAST, WITH
RIDGING IN BETWEEN OVER THE CENTRAL U.S.. THE TROUGH OVER THE WEST
WILL WEAKEN AS IT LIFTS NORTHEASTWARD BRINGING HEAVY RAIN POTENTIAL
TO PARTS OF THE NORTHERN ROCKIES/HIGH PLAINS THIS WEEKEND. ANOTHER
SHORTWAVE WILL MOVE INTO THE PACIFIC NORTHWEST EARLY NEXT WEEK.
TROUGHING OVER THE EAST WILL BE REINFORCED THROUGH THE PERIOD, WITH
A FRONTAL BOUNDARY DRAPED ACROSS THE SOUTHERN EDGE OF IT ACROSS
THE SOUTH/SOUTHEAST. THIS, COMBINED WITH FORCING FROM SOUTHERN
STREAM ENERGY IN THE REGION AND AN INCREASINGLY FAVORABLE DEEP
MOISTURE INFLUX/SLOW SYSTEM TRANSLATIONS, WILL ALLOW FOR A
GENERALLY CONTINUED WET PATTERN ACROSS MUCH OF THE SOUTH/SOUTHEAST
WHERE THINGS HAVE BEEN VERY WET AS OF LATE, AND WILL CONTINUE TO BE
IN THE SHORT RANGE PERIOD AS WELL.
..GUIDANCE/PREDICTABILITY ASSESSMENT
GUIDANCE SOLUTION CLUSTERING HAS IMPROVED FOR THE WEEKEND INTO
MONDAY, BOLSTERING FORECAST CONFIDENCE. GUIDANCE FOR THE MOST PART
SHOWS GOOD AGREEMENT ON THE OVERALL SLUGGISH LARGE SCALE PATTERN
EVOLUTION THROUGH THE PERIOD, BUT STILL WITH PLENTY OF VARIABILITY
IN THE SMALLER SCALE DETAILS NEXT WEEK. OUT WEST, THE GUIDANCE
SHOWS REASONABLE CONSENSUS WITH THE UPPER LOW/TROUGH LIFTING
NORTHEASTWARD OUT OF THE GREAT BASIN BY THE WEEKEND, BUT A LOT OF
UNCERTAINTY ON SUBSEQUENT ENERGIES INTO THE OVERALL TROUGH. OVERALL
THOUGH, THE PATTERN SHOULD BECOME LESS AMPLIFIED OVER THIS REGION
WITH TIME. IN THE EAST, THERE REMAINS LOTS OF UNCERTAINTY STILL
WITH A VARIETY OF SHORTWAVES AS THEY DROP DOWN THE WESTERN SIDE OF
THE TROUGH TO REINFORCE AND DEEPEN MEAN TROUGHING OVER THE EAST.
THERE IS SOME INDICATION IS GUIDANCE FOR A POSSIBLE CUT OFF LOW
OVER THE EAST BY THE MIDDLE OF NEXT WEEK, BUT PLENTY OF RUN TO RUN
VARIABILITY ON THIS EVOLUTION TO BUY INTO ANY ONE SOLUTION AT THIS
POINT. FOR THE MOST PART, A BLEND OF THE MODELS AND ENSEMBLE MEANS
SEEMED TO PROVIDE A SOLID FORECAST BASIS THAT SEEMS TO MITIGATE
DIFFERENCES AS CONSISTENT WITH INDIVIDUAL PREDICTABILITY. THIS
SOLUTION IS GENERALLY IN LINE WITH THE NBM AND WPC PRODUCT
CONTINUITY AND FITS NATIONAL HURRICANE CENTER INSIGHT THAT
CONTINUES TO DISCOUNT TROPICAL MOISTURE FEED AND DEVELOPMENT
POTENTIAL BY RECENT GFS RUNS NORTHWARD OUT FROM THE CARIBBEAN.
..WEATHER/HAZARDS HIGHLIGHTS
IT GENERALLY REMAINS THE CASE THAT PERSISTENT SHORTWAVE ENERGIES
AND A COUPLE OF WAVY FRONTAL BOUNDARIES WILL CONTINUE TO KEEP MUCH
OF THE SOUTH ACTIVE AND UNSETTLED INTO THE WEEKEND WITHIN A MOIST
AND UNSTABLE ENVIRONMENT AND DAILY THUNDERSTORM CHANCES. COMBINED
WITH WHAT HAS ALREADY BEEN A WET PATTERN ACROSS THIS REGION,
ISOLATED FLOODING COULD BE A CONCERN. FOR DAY 4/SATURDAY, A
MARGINAL RISK WAS MAINTAINED FOR PARTS OF THE SOUTHEAST NEAR A WAVY
THE FRONTAL BOUNDARY. SHOWERS AND STORMS WILL CONTINUE INTO SUNDAY
AS WELL ACROSS THE SOUTHERN PLAINS AND GULF COAST/FLORIDA.
HOWEVER, GIVEN HOW WET ITS BEEN IN MANY AREAS ACROSS THE SOUTH,
LOCALIZED FLOODING IS NOT OUT OF THE QUESTION AND SO ITS POSSIBLE
RISK AREAS MAY BE NEEDED IN FUTURE UPDATES IF THE SIGNAL FOR HEAVY
RAINFALL INCREASES AS IS A TREND FOR FLORIDA TO MONITOR NEXT WEEK.
OVER THE NORTHEAST, A VIGOROUS UPPER TROUGHING WORKING THROUGH
THIS WEEKEND MAY RESULT IN A PERIOD OF MODERATE TO HEAVIER RAINFALL
FOR PARTS OF NEW ENGLAND GIVEN WINDY OFFSHORE COASTAL LOW GENESIS.
OUT WEST...UPPER TROUGHING LIFTING OUT OF THE GREAT BASIN WITH A
WAVY FRONTAL SYSTEM AHEAD OF IT WILL ALLOW FOR INCREASED
PRECIPITATION ACROSS THE INTERMOUNTAIN WEST LINGERING INTO THE
WEEKEND. SNOW IS POSSIBLE ACROSS THE HIGHEST ELEVATIONS, THOUGH
WITH MINIMAL ACCUMULATION. THE SIGNAL FOR HEAVY RAINFALL HAS
INCREASED OVER PARTS OF WESTERN MONTANA AND VICINITY SO A MARGINAL
RISK AREA IS IN PLACE FOR DAY 4/SATURDAY ERO. RAIN WILL CONTINUE
INTO SUNDAY, BUT WITH LESS INTENSITY, SO NO RISK AREAS ARE DEPICTED
AT THIS TIME FOR THIS REGION. RAINFALL CHANCES ALSO INCREASE THIS
WEEKEND AND INTO NEXT WEEK FOR PARTS OF THE NORTHERN AND CENTRAL
PLAINS AHEAD OF AREAS OF UPPER TROUGHING LINGERING OVER THE WEST.
WITH THE CLOSED UPPER LOW OVER THE WEST DURING THE SHORT RANGE
WORKING TO LIFT OUT BY THIS WEEKEND, BELOW NORMAL TEMPERATURES
SHOULD MODERATE BACK TOWARDS NORMAL. SOME RIDGING BUILDING BACK
INTO THE REGION LATE IN THE PERIOD MAY BRING TEMPERATURES ABOVE
AVERAGE BY THEN. 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 EARLY IN THE PERIOD. PERSISTENT TROUGHING
OVER THE EAST WILL BRING SLIGHTLY BELOW NORMAL TEMPERATURES.
SANTORELLI/SCHICHTEL
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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