523  
FXUS02 KWBC 052002  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
301 PM EST TUE MAR 05 2019  
 
VALID 12Z FRI MAR 08 2019 - 12Z TUE MAR 12 2019  
 
...A STORMY PATTERN WITH MULTIPLE HAZARDS CONTINUES OVER THE  
NATION...  
   
..MODEL GUIDANCE EVALUATION AND PREFERENCES
 
 
THE WPC MEDIUM RANGE PRODUCT SUITE WAS MAINLY DERIVED FROM A  
COMPOSITE BLEND OF WELL CLUSTERED GUIDANCE FROM THE LATEST  
GFS/ECMWF AND GEFS/ECMWF ENSEMBLE MEANS IN A STORMY PATTERN WITH  
ABOVE NORMAL FORECAST PREDICTABILITY. ADJUSTED BLEND WEIGHTINGS  
GRADUALLY FROM MODEL GUIDANCE TO THE ENSEMBLES OVER TIME  
CONSISTENT WITH GRADUALLY GROWING FORECAST SPREAD.  
 
   
..WEATHER HIGHLIGHTS AND HAZARDS
 
 
A LEAD SYSTEM WORKS THROUGH AND THE EAST-CENTRAL THEN EASTERN  
STATES FRIDAY INTO SATURDAY THAT OFFERS MODEST BUT WIDESPREAD  
MOISTURE/PRECIPITATION POTENTIAL. THIS WILL INCLUDE SOME SNOW/ICE  
THREAT POTENTIAL TO THE NORTH OF AN ASSOCIATED WAVY FRONT AND  
MODEST COASTAL LOW AS MOISTURE SPREADS OVER SLOW TO RECEDE  
COLD/DAMMED HIGH PRESSURE.  
 
MEANHWHILE, HEAVY SNOWS WILL LIKELY CONTINUE ON FRIDAY FOCUSING  
INTO FAVORED TERRAIN OF THE INTERMOUNTAIN WEST AND ROCKIES AS THE  
STRONG PACIFIC DISTURBANCE CROSSES THE REGION. TOTAL SNOWFALL  
AMOUNTS ON THE ORDER OF 1 TO 2 FEET ARE POSSIBLE ACROSS PARTS OF  
THE CENTRAL AND NORTHERN ROCKIES, BEFORE EASING THIS WEEKEND IN A  
PATTERN WITH SECONDARY NORTHERN STREAM ENERGIES AND ASSOCIATED  
COLD SURGE WORKS DOWN THROUGH THE WEST.  
 
AMPLE MID-UPPER LEVEL TROUGH ENERGY MOVING OUT OF THE WEST WILL  
LEAD TO CYCLO/FRONTOGENESIS OVER THE CENTRAL U.S. WIDESPREAD RAIN  
AND THUNDERSTORMS ARE THEN SLATED TO DEVELOP FROM THE GULF COAST  
TO THE OHIO VALLEY AND SOUTHERN APPALACHIANS THIS WEEKEND AS A  
RICH SUPPLY OF GULF MOISTURE SURGES NORTHWARD AHEAD OF A STRONG  
COLD FRONT FROM THE SURFACE LOW. THE HEAVIEST RAINFALL IS LIKELY  
FROM EASTERN TEXAS AND TENNESSEE VALLEY/MID-SOUTH TO THE SOUTHERN  
APPALACHIANS, WHERE HEAVY RAINS/REPEAT CELLS ARE LIKELY TO LEAD TO  
SOME FLOODING ISSUES. THERE IS A SIGNIFICANT THREAT FOR HEAVY  
WRAPPING SNOW/ICE AND A CORRIDOR OF BLIZZARD CONDITIONS ACROSS  
PARTS OF THE NORTHERN PLAINS, UPPER MIDWEST, AND WESTERN GREAT  
LAKES REGION. ANOTHER FACET TO THIS DEEP LOW WILL BE POTENTIAL FOR  
STRONG TO SEVERE THUNDERSTORMS TO DEVELOP IN THE WARM SECTOR THAT  
THE STORM PREDICTION CENTER IS CURRENTLY MONITORING.  
 
UPSTREAM, THE PATTERN AGAIN FAVORS AMPLIFIED MID-UPPER LEVEL  
TROUGH DEVELOPMENT OFF THE WEST COAST THIS WEEKEND. THIS WILL  
SUPPORT MODEST PRECIPITATION OVER THE PACIFIC NORTHWEST BUT MORE  
AMPLE HEIGHT FALLS AND COOLING ARE SLATED FOR CALIFORNIA AND THE  
SOUTHWEST EARLY NEXT WEEK. THIS WOULD ENHANCE PRECIPITATION FOCUS,  
THOUGH CURRENT FORECAST AMOUNTS ARE MAINLY MODERATE. ADDITIONAL  
WIDESPREAD RAIN MAY THEN DEVELOP ACROSS THE S-CENTRAL U.S. IN  
ABOUT A WEEK AS THE SYSTEM WORKS INTO THE REGION TO SPAWN ANOTHER  
ROUND OF CYCLO/FRONTOGENESIS.  
 
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  
 
HAZARDS:  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE NORTHEAST, SUN, MAR  
10.  
- HEAVY RAIN FROM MUCH OF THE LOWER AND MID-MISSISSIPPI VALLEY  
INTO PARTS OF THE TENNESSEE AND OHIO  
VALLEYS, AS WELL AS THE INTERIOR SOUTHEAST INTO THE SOUTHERN  
APPALACHIANS, FRI-SAT, MAR 8-MAR 9.  
- HEAVY RAIN ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN PLAINS,  
INTO THE LOWER AND MID-MISSISSIPPI  
VALLEY, TUE, MAR 12.  
- HEAVY SNOW ACROSS PORTIONS OF THE CENTRAL PLAINS, THE MIDDLE  
MISSISSIPPI VALLEY, THE UPPER  
MISSISSIPPI VALLEY, AND THE NORTHERN PLAINS, TUE, MAR 12.  
- HEAVY SNOW ACROSS PORTIONS OF THE CENTRAL PLAINS, THE GREAT  
LAKES, THE UPPER MISSISSIPPI VALLEY,  
AND THE NORTHERN PLAINS, SAT-SUN, MAR 9-MAR 10.  
- SEVERE WEATHER ACROSS PORTIONS OF THE CENTRAL PLAINS, THE LOWER  
MISSISSIPPI VALLEY, THE TENNESSEE  
VALLEY, THE MIDDLE MISSISSIPPI VALLEY, THE SOUTHEAST, THE SOUTHERN  
PLAINS, AND THE OHIO VALLEY,  
SAT, MAR 9.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE LOWER  
MISSISSIPPI VALLEY, THE TENNESSEE  
VALLEY, THE MIDDLE MISSISSIPPI VALLEY, THE MID-ATLANTIC, THE  
SOUTHEAST, AND THE OHIO VALLEY.  
- FLOODING LIKELY ACROSS PORTIONS OF THE SOUTHEAST AND THE  
MID-ATLANTIC.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE NORTHERN  
AND CENTRAL PLAINS INTO PARTS OF  
THE UPPER MIDWEST, FRI-TUE, MAR 8-MAR 12.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE NORTHEAST,  
THE CENTRAL APPALACHIANS, THE  
MID-ATLANTIC, THE SOUTHERN APPALACHIANS, THE GREAT LAKES, AND THE  
OHIO VALLEY, FRI, MAR 8.  
 
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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