911  
FXUS02 KWBC 171958  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
358 PM EDT THU SEP 17 2026  
 
VALID 12Z SUN SEP 20 2026 - 12Z THU SEP 24 2026  
 
   
..HEAVY RAINFALL THREATENS THE MIDWEST AND NORTHEAST SUNDAY
 
 
...MONSOON STORMS REIGNITE OVER THE SOUTHERN HIGH PLAINS/ROCKIES  
MIDDLE OF NEXT WEEK...  
 
   
..OVERVIEW
 
 
A TROUGH MOVING OVER THE NORTH-CENTRAL PLAINS LOOKS TO PRODUCE  
HEAVY RAINFALL OVER PORTIONS OF THE MIDWEST THROUGH THE NORTHEAST  
SUNDAY INTO MONDAY BEFORE A STORM LINGERS OFF THE MID-ATLANTIC  
MIDWEEK. A COLD AIR DAMMING RIDGE OF SURFACE HIGH PRESSURE BUILDS  
DOWN EAST OF THE APPALACHIANS AND BRINGS COOLER/WET CONDITIONS FOR  
THE MIDDLE OF NEXT WEEK. AN EAST PACIFIC TROUGH ENTERS THE WEST  
COAST WHICH WILL REIGNITE MONSOON STORMS OVER MUCH OF NEW MEXICO  
AND THE TEXAS PANHANDLE BEGINNING ON TUESDAY. A WEAK DISTURBANCE  
LINGERING AROUND THE FLORIDA PENINSULA WILL BE RESPONSIBLE FOR  
DAILY HEAVY RAINFALL POTENTIAL.  
 
   
..GUIDANCE/PREDICTABILITY ASSESSMENT
 
 
12Z GLOBAL MODELS ARE IN GOOD AGREEMENT ON THE ON THE NORTH-CENTRAL  
WAVE THAT LINGERS OVER THE GREAT LAKES WITH COLD AIR DAMMING FOR  
THE EAST COAST AND TROUGH/LOW OVER CALIFORNIA MON/TUES. THE 00Z  
ECMWF/06Z EC-AIFS WERE PREFERRED IN THE MORNING MODEL BLEND WITH  
PREFERENCE A GENERAL MODEL BLEND FOR DAYS 6/7. NBM QPF WAS  
AMENDED WITH THE 00Z EC/06Z EC-AIFS FOR MAGNITUDE, INCLUDING LOWER  
MAGNITUDE FOR NEW MEXICO DAYS 5-7.  
 
   
..WEATHER/HAZARDS HIGHLIGHTS
 
 
A LOW PRESSURE SYSTEM WITH ATTENDANT SURFACE FRONTS DRAPED ACROSS  
THE CENTRAL U.S., MIDWEST AND EAST COAST WILL ACT AS A FOCUS FOR  
SCATTERED SHOWERS AND THUNDERSTORMS OVER THE NORTHERN/CENTRAL  
PLAINS AND NORTHEAST ON SUNDAY INTO MONDAY. SOME FLASH FLOOD RISK  
IS POSSIBLE, PLEASE SEE THE EXCESSIVE RAINFALL OUTLOOK THROUGH DAY  
5. COLD AIR DAMMING DEVELOPS MIDWEEK ALONG THE EASTERN SEABOARD  
WITH BELOW NORMAL TEMPERATURES AND ONSHORE FLOW.  
 
ELSEWHERE, A WEST COAST TROUGH AND RETROGRADING SOUTHERN U.S. RIDGE  
WILL CREATE A CORRIDOR FOR MONSOON MOISTURE TO LIFT NORTH THROUGH  
BEGINNING MONDAY NIGHT. STORMS SHOULD PROLIFERATE ACROSS NEW  
MEXICO AND THE TEXAS PANHANDLE BEGINNING ON TUESDAY AND CONTINUING  
THROUGH THE REST OF THE WEEK. ISOLATED TO SCATTERED FLASH FLOODING  
CAN BE EXPECTED FOR THOSE AREAS. BURN SCARS IN THE SANGRE DE CRISTO  
AND SACRAMENTO MOUNTAINS, AS WELL AS SLOT CANYONS, DRY WASHES, AND  
RECENTLY SATURATED SOILS WILL BE ESPECIALLY SUSCEPTIBLE TO FLASH  
FLOODING FROM NEXT WEEK'S ROUNDS OF MONSOON STORMS.  
 
JACKSON  
 
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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