425  
FXUS02 KWBC 091605  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1104 AM EST SAT MAR 09 2019  
 
VALID 12Z TUE MAR 12 2019 - 12Z SAT MAR 16 2019  
 
...HEAVY SNOW/WIND THREAT FOR THE NORTH-CENTRAL U.S. WEDNESDAY AND  
THURSDAY...  
...HEAVY RAIN/STRONG THUNDERSTORM THREAT FROM THE SOUTH-CENTRAL  
PLAINS/MS VALLEY TO THE MID-SOUTH/SOUTHEAST TUESDAY TO FRIDAY...  
 
   
..OVERVIEW
 
 
IT SEEMS THAT THE LAST IN A SERIES OF POTENT STORM SYSTEMS IN THIS  
ACTIVE FLOW PATTERN WILL TREK OUT OF THE SOUTHWEST/FOUR CORNERS  
REGION TUESDAY AND LIFT NORTHEASTWARD TOWARD THE UPPER  
MIDWEST/GREAT LAKES BY THURSDAY. THIS WILL SPREAD A LARGE AREA OF  
POTENTIALLY HEAVY RAIN/SEVERE CONVECTION AND RUNOFF THREAT FROM  
THE CENTRAL/SOUTHERN PLAINS THROUGH THE MID-SOUTH/SOUTHEAST AS  
MARGINALLY COLD AIR TO THE NORTH SUPPORTS A HEAVY SNOW/WIND THREAT  
FOR THE NORTH-CENTRAL ROCKIES/PLAINS AND UPPER MIDWEST. BY NEXT  
WEEKEND, THE PATTERN APPEARS MUCH QUIETER WITH HIGH PRESSURE  
FORECAST TO DOMINATE THE WESTERN/CENTRAL PARTS OF THE LOWER 48.  
 
   
..GUIDANCE AND UNCERTAINTY ASSESSMENT
 
 
RECENT GUIDANCE HAS BEEN INCONSISTENT RUN TO RUN WITH THE TIMING  
OF DRIVING MID-UPPER LEVEL TROUGH ENERGY/HEIGHT FALLS. HOWEVER,  
GUIDANCE HAS BEEN QUITE CONSISTENT SHOWING ULTIMATE DEVELOPMENT OF  
YET ANOTHER MAJOR STORM TO TRAVERSE THE SOUTHWEST LEADING INTO  
POWERFUL STORM GENESIS OVER THE CENTRAL U.S. A CONCENSUS OF LATEST  
GUIDANCE OFFERS A SOLUTION IN LINE WITH WPC CONTINUITY.  
 
   
..WEATHER HIGHLIGHTS AND HAZARDS
 
 
MAIN SYSTEM OF INTEREST IN THE MEDIUM RANGE WILL LIFT OUT OF THE  
SOUTHWEST AND DEEPEN QUITE SMARTLY INTO SOUTHEASTERN COLORADO BY  
WEDNESDAY MORNING. PRECIPITATION WILL EXPAND IN COVERAGE OUT OF  
ARIZONA AND NEW MEXICO EASTWARD, FOCUSED ON THE CENTRAL/SOUTHERN  
PLAINS (NORTHERN TEXAS NORTHWARD) TUE/WED. TO THE EAST, A FRONT  
ACROSS THE GULF WILL LIFT NORTHWARD AS A WARM FRONT AND BRING  
WIDESPREAD RAINFALL AND EMBEDDED CONVECTION INTO THE  
MISSISSIPPI/TENNESSEE VALLEY WEDNESDAY THEN INTO  
ALABAMA/GEORGIA/SOUTHERN APPALACHIANS THURSDAY. THE POTENTIAL FOR  
SEVERAL INCHES OF RAIN EXISTS OVER A LARGE AREA THAT WILL BE  
FURTHER REFINED OVER THE NEXT SEVERAL DAYS, BUT ATMOSPHERIC AND  
ENSEMBLE SIGNALS CONTINUE TO BE STRONG. TO THE NORTH, COLD ENOUGH  
AIR WILL SUPPORT SNOW ON THE NORTHWEST/NORTH SIDE OF THE SURFACE  
LOW THAT WILL OCCUR WITH STRONG WINDS (I.E., POSSIBLE BLIZZARD  
CONDITIONS). A COLD RAIN (PERHAPS OVER AN INCH TO AN INCH AND A  
HALF) WILL FALL TO THE SOUTHEAST OF THE SURFACE LOW OVER SOME  
AREAS THAT WILL RECEIVE SIGNIFICANT SNOW IN THE SHORT TERM (E.G.,  
SOUTHERN MINNESOTA). THE SURFACE LOW WILL DEPART THROUGH SOUTHERN  
CANADA FRIDAY AS COLDER AIR IS DRAGGED IN BEHIND IT ACROSS THE  
GREAT LAKES, ENHANCING LAKE-EFFECT SNOWS.  
 
TEMPERATURES WILL REMAIN BELOW AVERAGE IN THE WEST BUT PERHAPS  
MODERATE JUST A BIT BY NEXT WEEKEND. IN THE EAST, POST-FRONT  
AIRMASS TUESDAY WILL BE CHILLY (BELOW AVERAGE BY A FEW DEGREES)  
BUT THEN WARM UP AHEAD OF THE CENTRAL STATES' SYSTEM BY THURSDAY  
INTO FRIDAY.  
 
FRACASSO/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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