443
FXUS02 KWBC 250806
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
406 AM EDT FRI SEP 25 2026
VALID 12Z MON SEP 28 2026 - 12Z FRI OCT 02 2026
..EARLY SEASON NEW ENGLAND NOR'EASTER LINGERS EARLY NEXT WEEK
...MULTI-DAY FOUR CORNERS STATES TO PLAINS/MISSISSIPPI VALLEY
HEAVY RAIN/RUNOFF/TROPICAL MOISTURE CONNECTION THREAT NEXT WEEK...
..OVERVIEW
AN EARLY SEASON NOR'EASTER WILL LINGER OFF NEW ENGLAND EARLY NEXT
WEEK BEFORE EXITING INTO THE CANADIAN MARITIMES. STRONG/GUSTY WINDS
WITH POTENTIAL FOR COASTAL FLOODING, BEACH EROSION, AND RIP
CURRENTS ARE POSSIBLE, ALONG WITH HEAVY COASTAL RAINS. MEANWHILE,
AN UPPER TROUGH WILL WORK THROUGH THE WEST/SOUTHWEST EARLY NEXT
WEEK AND MOVE EAST AS NEXT WEEK PROGRESSES. HEAVY PRECIPITATION
WILL BE WIDESPREAD AHEAD OF THIS TROUGH AND WITH LEAD/WAVY MULTI-
STREAM FRONTAL SYSTEM INTERACTIONS. A TROPICAL MOISTURE CONNECTION
AS EAST PACIFIC HURRICANE POLO LANDFALL IN MEXICO FAVORS MULTIPLE
DAYS OF RAIN/STORMS AND SOME MOUNTAIN SNOWS IN THE FOUR CORNERS
STATES, WITH WIDESPREAD HEAVY RAINFALL/RUNOFF ISSUES SPREADING
ACROSS THE PLAINS AND MISSISSIPPI VALLEY AS NEXT WEEK PROGRESSES.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODELS AND ENSEMBLE FORECAST CONTINUITY AND CLUSTERING FOR FLOW
EMBEDDED SYSTEMS HAS PROVEN LESS THAN STELLAR OVER THE PAST FEW
CYCLES DESPITE REASONABLY SIMILAR LARGER SCALE PATTERN EVOLUTIONS.
FORECAST CONFIDENCE REMAINS HIGH WITH DEVELOPMENT AND LINGERING OF
AN EARLY SEASON NOR-EASTER AND ASSOCIATED THREATS EVEN THOUGH
DETAILS REMAIN LESS CERTAIN. MODEL AND ENSEMBLE GUIDANCE HAS
HIGHLIGHTED THE INTERACTION OF DEEP LEAD MOISTURE FROM MEXICO
LANDFALLING EAST PACIFIC HURRICANE POLO AND THE GULF INTO/AHEAD OF
AN EMERGING WEST/SOUTHWEST UPPER TROUGH AND WAVY MULTI-STREAM
FRONTAL SYSTEMS DOWNSTREAM OVER THE CENTRAL U.S.. WHILE DETAILS
AND AXIS/ORIENTATION ARE VARIED, THERE IS ABOVE NORMAL CONFIDENCE
IN THREAT DEVELOPMENT, LEANING MODELS AND ENSEMBLES TOWARD MACHINE
LEARNING GUIDANCE TO BETTER MATCH WITH THE LATEST NHC TRACK.
..WEATHER/HAZARDS HIGHLIGHTS
THE WESTERN ATLANTIC NOR'EASTER WILL LEAD TO BROAD ONSHORE FLOW
FROM THE MID-ATLANTIC TO THE NORTHEAST, CONTINUING EARLY NEXT
WEEK. THE LINGERING STORM COULD LEAD TO COASTAL FLOODING AND BEACH
EROSION, AS WELL AS MARINE HAZARDS LIKE RIP CURRENTS AND HIGH
SURF. HEAVY RAIN COULD CAUSE INLAND FLOODING ACROSS SOUTHEASTERN
NEW ENGLAND. SEE WPC'S KEY MESSAGES REGARDING THIS COASTAL LOW FOR
FURTHER INFORMATION.
DEEP TROPICAL PACIFIC AND GULF MOISTURE SHOULD RETURN AHEAD OF THE
LARGE-SCALE TROUGHING INTO AN UNSETTLED/COOLED WEST, BRINGING
WIDESPREAD RAIN TO THE FOUR CORNERS STATES NORTHWARD AND EASTWARD
INTO EARLY NEXT WEEK. MODERATE TO HEAVY RAIN SPREADS ACROSS THE
PLAINS AND MISSISSIPPI VALLEY INTO EARLY-MID NEXT WEEK. A SLOW
MOVING UPPER LOW WILL INTERACT WITH TROPICAL MOISTURE FROM POLO,
LEADING TO HEAVY TO EXCESSIVE RAINFALL THREATS ACROSS THE FOUR
CORNERS MONDAY TO TUESDAY/WEDNESDAY. A WPC EXCESSIVE RAINFALL
OUTLOOK (ERO) SLIGHT RISK AREA IS IN PLACE FOR MONDAY. VULNERABLE
SOILS FROM RECENT HEAVY RAINFALL COULD EXACERBATE FLASH FLOODING
CONCERNS. SOME SNOW IS POSSIBLE IN THE HIGHER PEAKS OF THE
INTERMOUNTAIN WEST/ROCKIES WITH THE PRECIPITATION, AS THE TROUGH
PUSHES EAST INTO THE PLAINS ON WEDNESDAY/THURSDAY AND COOLS
TEMPERATURES. A SLIGHT RISK ERO HAS ALSO BEEN INTRODUCED FOR THE
SOUTH-CENTRAL U.S. FOR TUESDAY, WITH LATER WEEK RISKS TO MONITOR.
MEANWHILE, EXPECT WHAT HAS BEEN A PROTRACTED WET PERIOD FOR FLORIDA
IS EXPECTED TO LINGER INTO EARLY OCTOBER AS ONSHORE MOISTURE FLOW
FUELS ENHANCED DAILY RAIN CHANCES.
WARMER THAN AVERAGE TEMPERATURES WILL PERSIST IN THE SOUTH-CENTRAL
U.S. INTO EARLY NEXT WEEK UNDER AN UPPER RIDGING, AND HIGHS IN THE
90S ARE FORECAST THROUGH THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
VALLEY. ON THE OTHER HAND, COOLER THAN AVERAGE TEMPERATURES
(ESPECIALLY FOR HIGHS) ARE FORECAST FOR THE WEST UNDER TROUGHING
ALOFT, GRADUALLY SPREADING EASTWARD EARLY NEXT WEEK AND HELPING TO
MODERATE TEMPERATURES IN THE PLAINS BY MIDWEEK. TEMPERATURES COULD
REACH AROUND 10 DEGREES ABOVE NORMAL IN THE EAST AHEAD OF THE
TROUGH WEDNESDAY-THURSDAY.
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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