077  
FXUS02 KWBC 101817  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
216 PM EDT WED APR 10 2019  
 
VALID 12Z SAT APR 13 2019 - 12Z WED APR 17 2019  
 
...LEAD HEAVY RAINFALL THREAT FOR THE MID-LOWER MISSISSIPPI/OHIO  
VALLEYS AND SOUTH...  
...A SECOND STORM THREAT THROUGH THE WEST TO THE EAST-CENTRAL U.S.  
NEXT WEEK...  
 
...WEATHER HIGHLIGHTS/HAZARDS AND GUIDANCE/PREDICTABILLITY  
ASSESSMENT...  
 
A MAJOR SYSTEM EXITS THE SOUTHWEST/SOUTHERN ROCKIES TO THE  
SOUTHERN PLAINS AND MID-LOWER MS/OH VALLEYS THIS WEEKEND, BRINGING  
WIDESPREAD ENHANCED RAINS/DEEPENING GULF MOISTURE WITH POTENTIAL  
OF EXCESSIVE RAINFALL, FLASH FLOODING, AND STRONG TO SEVERE LEAD  
WARM SECTOR CONVECTION OVER THE SOUTH. THE POTENT LOW AND WRAPPED  
PRECIPITATION WILL TRACK OVER THE NORTHEAST MONDAY AS ITS TRAILING  
COLD FRONT WORKS PRECIPITATION/CONVECTION UNDERNEATH ARCOSS THE  
SOUTHEAST AND EASTERN STATES BEFORE EXITING INTO THE GULF OF  
MEXICO AND WESTERN ATLANTIC. A COMPOSITE BLEND OF THE OVERALL  
COMPATABLE 06 UTC GFS AND 00 UTC ECMWF/UKMET SEEMS TO OFFER A  
REASONABLE DEPICTION OF THE STORM.  
 
MEANWHILE UPSTREAM, MODELS/ENSEMBLES OVERALL AGREE TO BRING  
ANOTHER POTENT MID-UPPER LEVEL TROUGH/AMPLE HEIGHT FALLS/FRONTAL  
PRECIPITATION INTO THE WEST COAST SUNDAY WITH A SUBSEQUENT  
EMPHASIS DIGGING DOWN ACROSS THE WEST TO THE SNOWY ROCKIES INTO  
MON-TUE BEFORE EMERGING OVER THE PLAINS INTO NEXT MIDWEEK. THE  
MODEL AND ENSEMBLE SIGNAL IS GROWING IN SUPPORT OF THIS SCENARIO  
WITH GFS/ECMWF AND GEFS LEADING THE WAY WITH MORE PRONOUNCED  
SOUTHERN STREAM FLOW SEPARATION THAT HAS BEEN THE CASE WITH RECENT  
SYSTEMS. THIS SUGGESTS POTENTIAL FOR DOWNSTREAM SOUTHERN PLAINS  
STORM GENESIS NEXT WED THAT PORTENDS A RENEWED LEAD RETURN FLOW OF  
DEEPENING GULF MOISTURE AND AN ENHANCING PRECIPITATION/CONVECTION  
SHIELD AND FLOODING THREAT OVER AN EAST-CENTRAL U.S. ALREADY  
WETTENED BY THE LEAD STORM.  
 
SCHICHTEL  
 
HAZARDS:  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE PACIFIC NORTHWEST AND  
THE NORTHERN GREAT BASIN, SUN-TUE, APR 14-APR 16.  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE CENTRAL ROCKIES, THE  
CENTRAL GREAT BASIN, THE NORTHERN ROCKIES, THE NORTHERN GREAT  
BASIN, AND THE NORTHERN PLAINS, MON-TUE, APR 15-APR 16.  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE NORTHERN ROCKIES AND  
THE NORTHERN GREAT BASIN, SUN-MON, APR 14-APR 15.  
- HEAVY RAIN ACROSS PORTIONS OF THE MID-ATLANTIC, THE LOWER  
MISSISSIPPI VALLEY, THE CENTRAL APPALACHIANS, THE TENNESSEE  
VALLEY, THE GREAT LAKES, THE MIDDLE MISSISSIPPI VALLEY, THE  
NORTHEAST, THE SOUTHERN APPALACHIANS, THE SOUTHEAST, THE SOUTHERN  
PLAINS, AND THE OHIO VALLEY, SAT-SUN, APR 13-APR 14.  
- HEAVY RAIN ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY, THE  
TENNESSEE VALLEY, THE MIDDLE MISSISSIPPI VALLEY, THE SOUTHERN  
APPALACHIANS, THE SOUTHEAST, THE SOUTHERN PLAINS, AND THE OHIO  
VALLEY, WED, APR 17.  
- HEAVY RAIN ACROSS PORTIONS OF THE NORTHEAST, MON-TUE, APR 15-APR  
16.  
- HEAVY SNOW ACROSS PORTIONS OF THE NORTHEAST, MON-TUE, APR 15-APR  
16.  
- SEVERE WEATHER ACROSS PORTIONS OF THE SOUTHEAST, THE LOWER  
MISSISSIPPI VALLEY, THE SOUTHERN PLAINS, AND THE TENNESSEE VALLEY,  
SAT, APR 13.  
- SEVERE WEATHER ACROSS PORTIONS OF THE SOUTHEAST, THE  
MID-ATLANTIC, THE SOUTHERN APPALACHIANS, AND THE TENNESSEE VALLEY,  
SUN, APR 14.  
- FLOODING POSSIBLE ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI  
VALLEY, THE GREAT LAKES, THE UPPER MISSISSIPPI VALLEY, AND THE  
NORTHERN PLAINS.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE LOWER  
MISSISSIPPI VALLEY, THE NORTHERN PLAINS, THE TENNESSEE VALLEY, THE  
NORTHERN ROCKIES, THE MIDDLE MISSISSIPPI VALLEY, THE NORTHERN  
GREAT BASIN, THE UPPER MISSISSIPPI VALLEY, THE PACIFIC NORTHWEST,  
AND THE OHIO VALLEY.  
- FLOODING LIKELY ACROSS PORTIONS OF THE CENTRAL PLAINS, THE  
NORTHERN PLAINS, THE NORTHERN GREAT BASIN, THE MIDDLE MISSISSIPPI  
VALLEY, THE UPPER MISSISSIPPI VALLEY, AND THE SOUTHERN PLAINS.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE CENTRAL  
PLAINS, THE CENTRAL ROCKIES, THE NORTHERN PLAINS, THE SOUTHERN  
ROCKIES, THE UPPER MISSISSIPPI VALLEY, AND THE SOUTHERN PLAINS,  
SAT-SUN, APR 13-APR 14.  
 
ADDITIONAL 3-7 DAY HAZARDS INFORMATION CAN BE FOUND ON THE WPC  
MEDIUM RANGE HAZARDS CHART AT:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION, 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/WWD/PWPF_D47/PWPF_MEDR.PHP?DAY=4  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/HEAT_INDEX.SHTML  
 

 
 
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