350  
FXUS02 KWBC 071601  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1100 AM EST THU MAR 07 2019  
 
VALID 12Z SUN MAR 10 2019 - 12Z THU MAR 14 2019  
   
..WEATHER PATTERN OVERVIEW
 
 
THE STORMY WEATHER PATTERN CONTINUES AS TWO MAJOR SYSTEMS THRIVE  
DURING THE MEDIUM RANGE PERIOD. A LEAD GREAT LAKES STORM SUND WILL  
BRING WIDESPREAD RAIN/THUNDERSTORMS TO THE EASTERN U.S. AND HEAVY  
SNOW WITH A THREAT OF BLIZZARD CONDITIONS TO THE UPPER MIDWEST AND  
GREAT LAKES BEFORE EXITING INTO EASTERN CANADA MON. A SECOND  
POTENT SYSTEM WORKS FROM THE PACIFIC INLAND TO CA AND THE  
SOUTHWEST MON/TUE, WITH CENTRAL U.S. STORM GENESIS LIKELY THROUGH  
MIDWEEK.  
 
   
..GUIDANCE AND UNCERTAINTY ASSESSMENT
 
 
THE DETERMINISTIC MODELS ARE IN GOOD OVERALL AGREEMENT REGARDING  
THE PLACEMENT AND OVERALL STRENGTH OF THE SURFACE LOW CROSSING THE  
GREAT LAKES REGION ON SUNDAY AND INTO EASTERN CANADA BY MONDAY.  
SPEED DIFFERENCES ARE MUCH MORE APPARENT WITH THE GFS/GEFS MEAN  
AND TO A LESSER EXTENT THE FV3 REMAINING MORE PROGRESSIVE WITH THE  
MIDWEEK STORM SYSTEM ACROSS THE CENTRAL U.S. THAN THE  
ECMWF/UKMET/CMC AND ECMWF ENSEMBLE MEAN. THE INCREASINGLY SHORT  
WAVELENGTH SPACING WITH UPSTREAM KICKER ENERGY DIGGING THROUGH THE  
WEST NOW SEEMS SUFFICIENT TO TREND THE LATEST WPC PRODUCT SUITE TO  
A SOLUTION FASTER THAN WPC CONTINUITY. THE BOTTOM LINE IS THAT  
EVEN THOUGH TIMING HAS BEEN AN ISSUE WITH THIS STORM THREAT, THERE  
HAS BEEN A CONSISTENT AND STRONG SIGNAL FOR SIGNIFICANT STORM  
DEVELOPMENT THAT SHOULD NOT BE DOWNPLAYED IN A PATTERN RIPE WITH  
DEEP/DYNAMIC LOW DEVELOPMENTS.  
 
   
..WEATHER HIGHLIGHTS AND HAZARDS
 
 
HEAVY SNOW IS STILL EXPECTED ACROSS INTERIOR PORTIONS OF NEW  
ENGLAND AS THE SURFACE LOW LIFTS NORTHEASTWARD ACROSS EASTERN  
CANADA SUN INTO MON, AND HEAVY LAKE ENHANCED SNOW WILL PERSIST ON  
THE WINDY BACKSIDE FLOW AROUND THE EXITING DEEP LOW. AREAS OF RAIN  
AND THUNDERSTORM ACTIVITY WILL PERSIST ACROSS THE GULF COAST  
REGION AND OVER THE EAST SUNDAY UNDERNEATH ALONG/AHEAD OF A  
TRAILING COLD FRONT. SOME SEVERE THUNDERSTORMS WILL ALSO BE  
POSSIBLE ACROSS PARTS OF THE SOUTHEAST ON SUNDAY AHEAD OF THE COLD  
FRONT, AND THIS IS SOMETHING THAT THE STORM PREDICTION CENTER IS  
CONTINUING TO MONITOR.  
 
LOOKING AHEAD FOR EARLY-MID WEEK, THE PATTERN AGAIN FAVORS AN  
AMPLIFIED MID-UPPER LEVEL TROUGH DEVELOPING OFF THE WEST COAST  
THIS WEEKEND. THIS WILL SUPPORT ANOTHER ROUND OF PRECIPITATION  
OVER THE SOUTHWESTERN U.S. AS THE TROUGH MOVES INLAND ON MONDAY.  
ADDITIONAL WIDESPREAD RAIN IS EXPECTED TO DEVELOP ACROSS THE  
CENTRAL AND SOUTHERN PLAINS TO THE MISSISSIPPI VALLEY/MIDWEST  
DURING THE TUESDAY AND WEDNESDAY TIME PERIOD AS THE TROUGH INDUCES  
ANOTHER DEEPENING SURFACE LOW EAST OF THE ROCKIES. THERE IS ALSO  
THE POTENTIAL FOR SEVERE WEATHER WITH THIS STORM SYSTEM, AND  
DETAILS ON THIS WILL BECOME MORE EVIDENT IN THE UPCOMING DAYS.  
ANOTHER ROUND OF HEAVY SNOW AND POTENTIAL BLIZZARD CONDITIONS IS  
BECOMING MORE PROBABLE ACROSS PARTS OF THE CENTRAL PLAINS AND THE  
UPPER MIDWEST AS THE SURFACE LOW INTENSIFIES AND COLDER AIR IN  
DRAWN IN BEHIND THE LOW.  
 
SCHICHTEL  
 
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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