902  
FXUS02 KWBC 221901  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 PM EDT THU SEP 22 2022  
 
VALID 12Z SUN SEP 25 2022 - 12Z THU SEP 29 2022  
   
..BREWING TROPICAL ACTIVITY TO MONITOR FROM THE CARIBBEAN
 
 
   
..PATTERN OVERVIEW
 
 
UPPER RIDGE AMPLIFIES OVER WESTERN CONUS BEGINNING THIS WEEKEND  
AND CONTINUING INTO NEXT WEEK WHILE SOUTHEASTERN RIDGE RETRACTS.  
THIS TRANSITION WILL ALLOW ENERGETIC MID-LATITUDE AND NORTHERN  
STREAM SHORTWAVE TROUGHS TO MORE ROBUSTLY DIG DOWNSTREAM AND CARVE  
OUT AN AMPLIFIED EAST-CENTRAL NORTH AMERICAN UPPER TROUGH TO FOCUS  
COOLER/UNSETTLED WEATHER AND OFFER SOME CONNECTION TO POSSIBLE  
TROPICAL ACTIVITY TO MONITOR BY MID-LATER NEXT WEEK.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
MODEL AND ENSEMBLE SOLUTIONS REMAIN WELL CLUSTERED SUNDAY INTO  
MONDAY AND A COMPOSITE OF THE GFS/ECMWF/UKMET/CANADIAN ALONG WITH  
THE NATIONAL BLEND OF MODELS (NBM) SEEMS TO PROVIDE A GOOD BASIS  
FOR THE FORECAST DURING THAT PERIOD, WITH ENHANCED DETAIL  
CONSISTENT WITH A PATTERN WITH ABOVE NORMAL FORECAST  
PREDICTABILITY. FORECAST SPREAD AND UNCERTAINTY GROWTH INTO LONGER  
TIME FRAMES AND TROPICAL SYSTEM DIFFERENCES IN PARTICULAR PROMPTED  
A SWITCH TO FORECAST USAGE OF THE ECMWF ENSEMBLE MEAN TO MAINTAIN  
WPC MAX PRODUCT AND NHC PREFERENCE CONTINUITY NEXT WEEK.  
   
..WEATHER/HAZARDS HIGHLIGHTS
 
 
UPPER RIDGE AMPLIFICATION OVER THE WEST WILL SUPPORT GENERALLY DRY  
AND WARMER THAN AVERAGE TEMPERATURES EARLY-MID NEXT WEEK AND SET  
THE STAGE FOR DOWNSTREAM FLOW AMPLIFICATION AS SHORTWAVES ACROSS  
THE NORTH-CENTRAL U.S. AND ENERGY FROM CANADA CARVE OUT A COOLING  
EAST-CENTRAL U.S. TROUGH. THIS UPPER TROUGH AND DEEPENED SURFACE  
LOW WILL COMBINE TO INCREASE LEAD FRONTAL AND WRAP-AROUND RAINFALL  
CHANCES FROM THE GREAT LAKES THROUGH THE  
APPALACHIANS/NORTHEAST/MID-ATLANTIC SUNDAY INTO MONDAY, WITH LAKE  
ENHANCED RAINFALL IN THE WAKE OF SYSTEM PASSAGE THROUGH TUESDAY.  
LEAD HOT WEEKEND TEMPERATURES OVER PARTS OF THE SOUTH THIS WEEKEND  
WILL THEN BE REFRESHED WITH TRAILING COLD FRONTAL PASSAGE ACROSS  
MUCH OF THE CENTRAL AND EASTERN U.S. AS CANADIAN HIGH PRESSURE  
BUILDS DOWN ACROSS THE BROAD REGION. THE FRONT SHOULD STALL ACROSS  
THE GULF OF MEXICO AND THE FLORIDA PENINSULA WHERE SHOWERS AND  
STORMS MAY INCREASE IN COVERAGE TUESDAY ONWARD WITH POTENTIAL  
INFLUX OF TROPICAL MOISTURE. WPC AND THE NATIONAL HURRICANE CENTER  
ARE CONTINUING TO MONITOR THE TROPICS REGARDING INVEST 98L, WHICH  
MAY FORM INTO A TROPICAL CYCLONE. LATEST NBM TAMPED UP QPF FROM  
OVERNIGHT OVER THE FLORDIA PENINSULA WHICH IS CONSISTENT WITH THE  
OVERALL DETERMINISTIC AND ENSEMBLE GUIDANCE.  
 
SCHICHTEL/KEBEDE  
 
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, EXPERIMENTAL EXCESSIVE RAINFALL  
OUTLOOK, WINTER WEATHER OUTLOOK PROBABILITIES AND HEAT INDICES 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  
 

 
 

 
 
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