082
FXUS02 KWBC 261955
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
355 PM EDT TUE MAY 26 2026
VALID 12Z FRI MAY 29 2026 - 12Z TUE JUN 02 2026
..HEAVY RAIN/THUNDERSTORMS FOR PARTS OF THE SOUTHERN U.S
..OVERVIEW
A BLOCKY UPPER FLOW PATTERN WITH EMBEDDED SHORTWAVE ENERGIES
AFFECTING PORTIONS DOWN THROUGH THE SOUTHERN TO SOUTHEAST U.S.
THROUGH THIS FORECAST PERIOD IN TWO STREAMS WILL CONTINUE TO BRING
PERIODS WITH WIDESPREAD RAIN AND THUNDERSTORMS WITHIN A MOIST AND
UNSTABLE ENVIRONMENT. HEAVY RAIN IS POSSIBLE, AND GIVEN HOW WET A
LOT OF THIS REGION HAS BEEN LATELY AND WILL BE IN THE SHORT RANGE
AS WELL, FLOODING COULD BE A CONCERN IN SOME PLACES. OUT WEST, A
CLOSED UPPER LOW OVER THE CENTRAL GREAT BASIN FRIDAY SHOULD LIFT
NORTHEASTWARD AND WEAKEN INTOTHE WEEKEND AS ANOTHER SHORTWAVE
SLIDES THROUGH THE PACIFIC NORTHWEST LATER IN THE PERIOD. THIS
SHOULD RESULT IN PRECIPITATION CHANCES FOR THE INTERMOUNTAIN
WEST/NORTHERN ROCKIES, WITH LEAD FORCING/ACTIVITY OVER THE PLAINS.
REINFORCING TROUGHING OVER THE NORTHEAST SHOULD RESULT IN NEAR TO
BELOW NORMAL TEMPERATURES AND PRECIPITATION CHANCES. MEANWHILE, IN
BETWEEN, A BLOCKY RIDGE WILL BRING PRE-FRONTAL ABOVE NORMAL
TEMPERATURES TO MUCH OF THE NORTH-CENTRAL U.S. THROUGH THE PERIOD.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS SHOW GOOD AGREEMENT ON THE OVERALL LARGE SCALE PATTERN
EVOLUTION THROUGH THE PERIOD, BUT WITH MUCH IN THE WAY OF SMALLER
SCALE LOCAL FOCUS AND GUIDANCE DIFFERENCES TO DECIPHER THROUGH THE
FORECAST PERIOD, BUT ESPECIALLY LATER IN THE PERIOD. SOME
INCREASING UNCERTAINTY BY EARLY NEXT WEEK ACROSS THE NORTHWEST
REGARDING THE EVOLUTION AS THE INITIAL UPPER LOW WEAKENS AND
ANOTHER SHORTWAVE MOVES INTO THE REGION. THERE IS QUESTION ON HOW
QUICKLY THIS PUSHES OUT OF THE REGION AND HOW STRONG RIDGING IS
ACROSS THE REGION EARLY NEXT WEEK. A LOT OF THIS SEEMS TO BE
RELATED TO A LARGE UPPER LOW ACROSS THE NORTHEAST PACIFIC. THERE
REMAINS UNCERTAINTY IN THE NORTHEAST TOO WITH VARIOUS WAVES OF
ENERGY MOVING THROUGH THE GREAT LAKES TO REINFORCE A MEAN TROUGH
OVER MUCH OF THE EAST THROUGH THE PERIOD. THIS ALSO IMPACTS THE
STRUCTURE AND STRENGTH OF A MEAN RIDGE OVER THE NORTH-CENTRAL
U.S.. FOR THE MOST PART, A BLEND OF THE MODELS AND ENSEMBLE MEANS
SEEMED TO WORK OUT WELL TO MITIGATE THESE DIFFERENCES AS CONSISTENT
WITH INDIVIDUAL PREDICTABILITY. THIS SOLUTION IS GENERALLY IN LINE
WITH THE NBM AND WPC PRODUCT CONTINUITY, BUT AS PER THE NATIONAL
HURRICANE CENTER CONTINUES TO DISCOUNT TROPICAL MOISTURE FEED AND
DEVELOPMENT POTENTIAL BY RECENT GFS RUNS OVER/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 VERY
MOIST AND UNSTABLE ENVIRONMENT AND DAILY THUNDERSTORM CHANCES.
COMBINED WITH WHAT HAS ALREADY BEEN A WET PATTERN ACROSS THIS
REGION, FLOODING IS A CONCERN. FOR DAY 4/FRIDAY, A BROAD MARGINAL
RISK IS IN PLACE ON THE ERO FROM THE LOWER/MIDDLE MISSISSIPPI
VALLEY TO THE SOUTHEAST. FOR SATURDAY, THE HEAVIEST RAIN SHOULD
FOCUS ALONG A FRONTAL BOUNDARY SINKING THROUGH THE SOUTHEAST, WHERE
A MARGINAL RISK IS IN PLACE ON THE ERO. MOISTURE AND PRECIPITATION
LOOKS TO RENEW ACROSS TEXAS BY THE WEEKEND AS WELL, AND A MARGINAL
RISK WAS INTRODUCED FOR THAT REGION ON DAY 5. FLORIDA WILL REMAIN
WITHIN A WET PATTERN, AIDED BY TROPICAL MOISTURE. MARGINAL RISKS
ARE IN PLACE BOTH FRIDAY AND SATURDAY FOR WHAT SHOULD BE MAINLY A
URBAN FLASH FLOOD THREAT. PRECIPITATION ACROSS THE SOUTH WILL
CONTINUE INTO EARLY NEXT WEEK, BUT SHOULD SHIFT SOUTHWARD WITH TIME
AS THE TROUGH OVER THE EAST DEEPENS, THOUGH CONTINUING BACK ACROSS
TEXAS AND THE SOUTHERN PLAINS.
TO THE NORTH OVER THE NORTHEAST, A VIGOROUS VORT MOVING THROUGH
LATE THIS WEEK MAY RESULT IN A PERIOD OF MODERATE TO HEAVIER
RAINFALL FROM PARTS OF NEW ENGLAND GIVEN WINDY OFFSHORE LOW
GENESIS, WITH LIGHT AMOUNTS SOUTHWARD TO THE CENTRAL APPALACHIANS.
OUT WEST...UPPER TROUGHING MEANDERING AROUND THE GREAT BASIN WITH
A WAVY FRONTAL SYSTEM AHEAD OF IT WILL ALLOW FOR INCREASED
PRECIPITATION ACROSS THE INTERMOUNTAIN WEST FOR THE END OF THIS
WEEK. SNOW IS POSSIBLE ACROSS THE HIGHEST ELEVATIONS, THOUGH WITH
MINIMAL ACCUMULATION. AS THE UPPER LOW WEAKENS AND SHIFTS
NORTHEAST, RAIN CHANCES SHOULD INCREASE INTO THE NORTH-CENTRAL
ROCKIES/PLAINS.
WITH THE CLOSED UPPER LOW OVER THE WEST, TEMPERATURES SHOULD BE
BELOW NORMAL THROUGH ABOUT FRIDAY, WITH SOME MODERATING BACK
TOWARDS NORMAL AS THE TROUGH WEAKENS AND DRIFTS NEXT WEEKEND.
RIDGING BUILDING BACK INTO THE REGION LATE IN THE PERIOD MAY BRING
VALUES SLIGHTLY ABOVE AVERAGE. 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. PERSISTENT TROUGHING OVER THE EAST MAY BRING SLIGHTLY
BELOW NORMAL TEMPERATURES THROUGH THE PERIOD.
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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