700
FXUS02 KWBC 110714
PMDEPD
EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
314 AM EDT SUN OCT 11 2026
VALID 12Z WED OCT 14 2026 - 12Z SUN OCT 18 2026
...HEAVY RAINFALL THREAT FOR THE SOUTH-CENTRAL U.S. WEDNESDAY AND
THURSDAY...
...RECORD HEAT FOR THE SOUTHERN PLAINS, MID-SOUTH, AND SOUTHEAST
THROUGH THURSDAY...
..OVERVIEW
AN UPPER LOW LINGERING OVER THE INTERMOUNTAIN WEST THROUGH MID
WEEK WILL ALLOW FOR MOISTURE FROM EX- SIMON TO STREAM NORTHWARD AS
THE PERIOD BEGINS, WITH AN EXPANDING AREA OF RAIN OVER THE CENTRAL
U.S.. DESPITE MODEL GUIDANCE WAFFLING, IT APPEARS MOST LIKELY THAT
ENERGY FROM THIS TROUGH WILL COMBINE WITH STRONG NORTHERN STREAM
ENERGY TO ESTABLISH DEEP TROUGHING INTO THE CENTRAL AND EASTERN
U.S. FRIDAY-SATURDAY. BEFORE THEN, STRONG UPPER RIDGING OVER THE
SOUTH- CENTRAL TO SOUTHEASTERN U.S. EARLY IN THE PERIOD SHOULD
ALLOW FOR MUCH ABOVE NORMAL TO RECORD- SETTING WARM TEMPERATURES
INTO AT LEAST MIDWEEK, SLOWLY MODERATING WITH TIME.
..GUIDANCE/PREDICTABILITY ASSESSMENT
MODEL GUIDANCE BEGINS IN FAIRLY GOOD AGREEMENT WITH AN UPPER LOW
OVER THE CENTRAL GREAT BASIN ON WEDNESDAY, WITH UPPER RIDGING IN
PLACE OVER THE SOUTHEAST, AND A FEW WEAK SHORTWAVES SLIDING THROUGH
THE NORTHERN TIER. AFTER THURSDAY ESPECIALLY, SPREAD AND FORECAST
UNCERTAINTY QUICKLY INCREASES AS GUIDANCE CONTINUES TO STRUGGLE
WITH HOW MUCH NORTHERN STREAM ENERGY FROM WESTERN CANADA WILL DIVE
SOUTHEAST INTO THE NORTH-CENTRAL U.S. AND IF IT WILL COMBINE WITH
THE PREEXISTING TROUGH OVER THE WEST. INCLUDING THE 00Z GUIDANCE
TONIGHT, THERE MAY FINALLY BE A TREND TOWARDS MORE PHASING WITH THE
TWO SYSTEMS, LEADING TO A BIT SLOWER AND MORE AMPLIFIED TROUGH
INTO THE EAST LATE PERIOD. THE ECMWF AND UKMET ARE NOW LOOKING MORE
LIKE OUTLIERS WANTING TO HOLD THE UPPER LOW BACK OVER THE WEST,
WEAKENING AND EVENTUALLY GETTING PICKED UP BY THE NEXT DEEP TROUGH
TOWARDS THE WEST NEXT WEEKEND. GIVEN THE UNCERTAINTY, THE WPC
FORECAST TONIGHT LEANED CLOSEST TO THOSE MORE PHASED MODELS
INCLUDING THE GFS, CMC, AND EC- AIFS, WITH MORE ENSEMBLE MEAN
INCLUSION LATE IN THE PERIOD. DESPITE SOME BETTER CONSENSUS, THIS
REMAINS A LOW CONFIDENCE FORECAST.
..WEATHER/HAZARDS HIGHLIGHTS
THE LOW ALOFT OVER THE WEST WILL CONTINUE TO BRING SNOW TO
PORTIONS OF THE NORTHERN/CENTRAL ROCKIES WEDNESDAY AND PERHAPS INTO
THURSDAY. AHEAD OF THIS UPPER LOW, A PLAINS LEE LOW PRESSURE
SYSTEM AND MOISTURE FROM WHAT IS LEFTOVER FROM SIMON WILL STREAM
NORTHWARD AND AID IN PRODUCING A WIDESPREAD AREA OF RAIN IN THE
CENTRAL U.S. WEDNESDAY AND THURSDAY. THUNDERSTORMS AND HEAVY
RAIN/FLOODING POTENTIAL ARE LIKELY IN THE SOUTHERN/CENTRAL PLAINS
TO LOWER/MIDDLE MISSISSIPPI VALLEY AHEAD OF A COLD FRONT WITH WPC
SLIGHT RISK AREAS IN PLACE ON THE WEDNESDAY AND THURSDAY EXCESSIVE
RAINFALL OUTLOOKS. FARTHER NORTH, THERE IS SOME UNCERTAINTY WITH
HOW PROGRESSIVE THE TROUGH AND SURFACE LOWS COULD BE, BUT THE
CURRENT FORECAST IS FOR RAIN TO SHIFT ACROSS THE NORTH- CENTRAL
U.S. WEDNESDAY-THURSDAY AND TOWARD THE NORTHEAST FRIDAY. GUSTY
WINDS MAY ACCOMPANY THE SURFACE LOW THROUGH THE NORTH-CENTRAL U.S.
AND GREAT LAKES. SHOWERS AND STORMS WILL ACCOMPANY THE FRONT AS IT
PUSHES THROUGH FLORIDA LATE WEEK AS WELL.
AHEAD OF THE FRONT, TEMPERATURES IN THE SOUTHERN PLAINS TO THE
SOUTHEAST WILL BE WELL ABOVE NORMAL AND LIKELY SET NEW DAILY HIGH
TEMPERATURE RECORDS (UPPER 80S TO THE MID 90S). LOW TEMPERATURES
MAY ONLY FALL INTO THE 70S FOR SEVERAL NIGHTS, WITH THE COMBINATION
YIELDING WIDESPREAD MODERATE HEATRISK AND PERHAPS REACHING MAJOR
OVER SOUTH TEXAS. THE WARMER TEMPERATURES IN THE 90S WILL GRADUALLY
COOL BACK INTO THE 80S AS FRONTS APPROACH. MEANWHILE, THE UPPER
TROUGH IN THE WEST WILL BRING BROADLY BELOW AVERAGE TEMPERATURES
FROM THE SOUTHWEST INTO THE INTERMOUNTAIN WEST, ALONG WITH
FROST/FREEZE THREATS. GRADUAL WARMING IS LIKELY IN THE WEST AFTER
THAT AS UPPER RIDGING COMES IN. MODERATELY BELOW NORMAL
TEMPERATURES WILL PROGRESS ACROSS THE CENTRAL INTO EASTERN U.S.
DURING THE LATTER HALF OF THE WEEK.
SANTORELLI/TATE
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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