958  
FXUS02 KWBC 081600  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
1100 AM EST FRI MAR 08 2019  
 
VALID 12Z MON MAR 11 2019 - 12Z FRI MAR 15 2019  
   
..NORTH-CENTRAL U.S. HEAVY SNOW THREAT
 
 
...SOUTH-CENTRAL U.S. TO MID-SOUTH/SOUTHEAST HEAVY RAIN/CONVECTION  
THREAT...  
 
   
..OVERVIEW
 
 
DEEP MID-UPPER LEVEL TROUGHING NEAR CALIFORNIA MONDAY WILL HEAD  
EASTWARD THROUGH THE SOUTHEAST/MEXICO TUESDAY THEN NORTHEASTWARD  
OVER THE CENTRAL TO EAST-CENTRAL U.S. MIDWEEK THROUGH NEXT FRIDAY  
ATOP BUILDING RIDGING INTO THE SOUTHEAST U.S./CUBA. IN THIS  
PATTERN, YET ANOTHER ROBUST LATE WINTER STORM WILL LIFT OUT OF THE  
SOUTHWEST TUESDAY TOWARD THE UPPER MIDWEST BY THURSDAY. THIS WILL  
LIKELY LEAD TO ANOTHER ROUND OF HEAVY SNOW AND HIGH WINDS ACROSS  
THE NORTH-CENTRAL U.S. WITH HEAVY RAIN AND STRONG CONVECTION  
FOCUSED FROM THE SOUTH-CENTRAL U.S. TO THE MID-SOUTH/SOUTHEAST.  
SLOW MOVEMENT OF THE COLD FRONT ALONG THE GULF COAST MAY INCREASE  
THE THREAT OF LOCALLY HEAVY RAIN WITH THE POTENTIAL FOR MULTIPLE  
INCHES OF RAIN AND FLOODING CONCERNS GIVEN RATHER WET ANTECEDENT  
CONDITIONS.  
 
BY NEXT THU/FRI, THE SURFACE LOW WILL EXIT THROUGH THE GREAT LAKES  
AND SOUTHERN ONTARIO INTO QUEBEC BUT ITS ATTENDANT COLD FRONT WILL  
SLOW AS IT RUNS INTO THE RIDGING TO THE EAST AND BECOMES ORIENTED  
NEAR-PARALLEL TO THE UPPER FLOW. ADDITIONAL HEIGHT FALLS UPSTREAM  
THROUGH THE UNSETTLED/WINTRY GREAT BASIN AND ROCKIES THROUGH  
MID-LATE WEEK WILL ALSO ACT TO SLOW THE TROUGH PROGRESSION  
EASTWARD ALONG THE GULF COAST.  
   
..GUIDANCE AND UNCERTAINTY ASSESSMENT
 
 
THE 00 UTC GFS/ECMWF AND GEFS/ECMWF ENSEMBLE MEAN HAVE CONVERGED  
ON A MORE WELL CLUSTERED SOLUTION DAYS 3-7 AND A COMPOSITE WAS  
USED AS A STARTING TEMPLATE FOR THE WPC MEDIUM RANGE PRODUCT SUITE  
TODAY.  
 
   
..WEATHER HIGHLIGHTS AND HAZARDS
 
 
SNOW WILL EXIT NEW ENGLAND MONDAY THOUGH LAKE-ENHANCED SNOW WILL  
PERSIST ON THE WINDY BACKSIDE FLOW AROUND THE EXITING DEEP LOW  
UNTIL A SURFACE HIGH BUILDS IN BY TUESDAY. AREAS OF RAIN AND  
THUNDERSTORM ACTIVITY WILL PERSIST ACROSS THE GULF COAST REGION  
ALONG/AHEAD OF A FRONTAL BOUNDARY. COLDER THAN AVERAGE  
TEMPERATURES WILL PERSIST OVER MUCH OF THE WESTERN STATES ON THE  
ORDER OF 5-15F BELOW CLIMO. TEMPERATURES IN THE EAST WILL BE A BIT  
MORE VARIABLE--NEAR AVERAGE EARLY IN THE WEEK, BUT TRENDING MILDER  
LATER IN THE WEEK AHEAD OF THE CENTRAL PLAINS SYSTEM.  
 
MAIN SYSTEM OF INTEREST IN THE MEDIUM RANGE WILL START IN THE  
WEST/SOUTHWEST WITH PRECIPITATION MOVING THROUGH SOUTHERN  
CALIFORNIA AND THE SOUTHWEST DESERTS. PRECIPITATION WILL EXPAND IN  
COVERAGE FROM NEW MEXICO EASTWARD, FOCUSED ON THE CENTRAL/SOUTHERN  
PLAINS FROM KS SOUTHWARD TO NORTHERN TEXAS TUE/WED AS THE SURFACE  
LOW DEEPENS FROM NEW MEXICO INTO SOUTHWESTERN KANSAS. FRONT ACROSS  
THE GULF WILL LIFT NORTHWARD AS THE LOW HEADS TOWARD MINNESOTA BY  
THURSDAY MORNING WHICH WILL BRING WIDESPREAD RAINFALL AND EMBEDDED  
CONVECTION INTO THE MISSISSIPPI/TENNESSEE VALLEY. THE POTENTIAL  
FOR SEVERAL INCHES OF RAIN EXISTS OVER A LARGE AREA THAT WILL BE  
FURTHER REFINED OVER THE NEXT SEVERAL DAYS. ATMOSPHERIC AND  
ENSEMBLE SIGNALS WERE NOTABLE EVEN AT THIS LEAD TIME. 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).  
 
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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