173  
FXUS02 KWBC 112030  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
429 PM EDT MON MAR 11 2019  
 
VALID 12Z THU MAR 14 2019 - 12Z MON MAR 18 2019  
 
...HEAVY SNOW/WIND THREAT TO EXIT THE NORTH-CENTRAL U.S.  
THURSDAY...  
   
..HEAVY RAIN THREAT IN THE SOUTHEAST THURSDAY
 
 
   
..OVERVIEW AND GUIDANCE ASSESSMENT/PREFERENCES
 
 
THE RIDGING OVER THE WESTERN U.S. AND CANADA WILL SUPPORT THE  
TROUGH PERSISTING OVER THE EASTERN HALF OF THE CONUS OVER THE  
COURSE OF THIS COMING WEEK. A ROBUST WINTER STORM SYSTEM WILL LIFT  
NORTHEAST FROM THE CENTRAL PLAINS THROUGH THE GREAT  
LAKES/NORTHEAST BY LATE FRIDAY. THE TRAILING FLANK OF THIS FRONTAL  
BOUNDARY WILL STALL AND LINGER OVER SOUTH FLORIDA AND THE GULF OF  
MEXICO. A SERIES OF SYSTEMS WILL TRACK THROUGH THE GULF OF  
ALASKA/NORTH PACIFIC AND WEAKEN AS THEY APPROACH THE PACIFIC  
NORTHWEST COAST.  
 
THE MODELS/ENSEMBLES CONTINUE TO SHOW REASONABLE CLUSTERING  
THROUGH THE PERIOD AND A BLEND OF THE GFS/ECMWF WITH THEIR  
ENSEMBLE MEANS OFFERED A GOOD STARTING POINT THAT KEPT IN LINE  
WITH CONTINUITY. THE CMC AND ITS ENSEMBLE MEANS WERE LARGELY  
DISCOUNTED FOR MUCH OF THE EXTEND PERIODS AS IT INITIALIZED WELL  
TO THE NORTH/NORTHWEST OF THE REST OF THE CLUSTER.  
 
   
..WEATHER HIGHLIGHTS AND HAZARDS
 
 
LOW PRESSURE OVER IOWA THURSDAY MORNING WILL BRING STRONG, GUSTY  
WINDS THAT WILL CAUSE BLOWING AND DRIFTING SNOW ACROSS THE UPPER  
MIDWEST AND THEN GREAT LAKES AS IT EXITS THROUGH ONTARIO AND  
QUEBEC ON FRIDAY. TO THE SOUTH, INFLUX OF GULF MOISTURE WILL  
SUPPORT A CONTINUED THREAT FOR HEAVY RAINFALL AND EMBEDDED  
CONVECTION FROM ALABAMA/MISSISSIPPI EASTWARD AS THE COLD FRONT  
CONTINUES TO MOVE EASTWARD AND SOUTHWARD. MILD AIR DRAWN NORTHWARD  
AHEAD OF THE FRONT WILL BE REPLACED BY MUCH COOLER TEMPERATURES  
(5-10 DEGREES BELOW AVERAGE) THAT WILL FINALLY EXIT OUT OF THE  
WEST AND FOCUS ON THE CENTRAL STATES. BY SAT-MON, HIGH PRESSURE  
WILL BE IN CONTROL OF MUCH OF THE LOWER 48 WITH A DRY NORTHWEST  
FLOW OUT OF CANADA, SUPPORTING SOME LAKE-ENHANCED SNOWS.  
   
..BULLET POINTS FROM MEDIUM RANGE HAZARDES CHART
 
 
- HEAVY RAIN ACROSS PORTIONS OF THE SOUTHEAST, THE MID-ATLANTIC,  
THE SOUTHERN APPALACHIANS, AND THE TENNESSEE VALLEY, THU-FRI, MAR  
14-MAR 15.  
- HEAVY SNOW ACROSS PORTIONS OF THE CENTRAL PLAINS, THE UPPER  
MISSISSIPPI VALLEY, AND THE NORTHERN PLAINS, THU-FRI, MAR 14-MAR  
15.  
- FLOODING POSSIBLE FROM PORTIONS OF THE PLAINS TO THE GREAT  
LAKES, AND THE MIDDLE/UPPER MISSISSIPPI VALLEY.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE CENTRAL  
PLAINS, THE LOWER MISSISSIPPI VALLEY, THE TENNESSEE VALLEY, THE  
MIDDLE MISSISSIPPI VALLEY, THE SOUTHEAST, AND THE OHIO VALLEY.  
- FLOODING LIKELY ACROSS PORTIONS OF THE CENTRAL PLAINS, THE  
MIDDLE MISSISSIPPI VALLEY, AND THE UPPER MISSISSIPPI VALLEY.  
- HIGH WINDS ACROSS PORTIONS OF THE CENTRAL/NORTHERN PLAINS, AND  
THE UPPER/MIDDLE MISSISSIPPI VALLEYS, THU, MAR 14.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE HIGH  
PLAINS, THE CENTRAL/SOUTHERN ROCKIES, THU-SUN, MAR 14-MAR 17.  
 
CAMPBELL  
 
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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