097  
FXUS02 KWBC 260701  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
300 AM EDT TUE MAR 26 2019  
 
VALID 12Z FRI MAR 29 2019 - 12Z TUE APR 02 2019  
   
..OVERVIEW AND WEATHER HIGHLIGHTS AND HAZARDS
 
 
DYNAMIC UPPER TROUGH ENERGY IS SLATED TO PUNCH INLAND OVER THE  
WEST TO THE S-CENTRAL GREAT BASIN AND ROCKIES BY FRIDAY. THESE  
SOUTHERN STREAM HEIGHT FALLS WILL THEN WORK EASTWARD OVER THE  
CENTRAL AND EASTERN STATES OVER THE WEEKEND, INTERACTING WITH  
AMPLIFYING NORTHERN STREAM TROUGH ENERGIES DIGGING DOWN FROM  
CANADA. PLAINS CYCLOGENESIS AND SUBSEQUENT MOVEMENT THROUGH THE MS  
VALLEY/MIDWEST MAY COMBINE WITH A LEAD SURGE OF DEEPENING  
MOISTURE/WARMTH FROM THE GULF OF MEXICO TO FUEL A PERIOD OF  
ENHANCED RAIN/THUNDERSTORMS IN THOSE AREAS WITH ONGOING FLOODING  
FRIDAY INTO SATURDAY. THERE IS ALSO SOME RISK OF HEAVY SNOW  
FRI-SUN ON THE COOLED NORTHWEST TO NORTHERN PERIPHERY OF THE  
PRECIPITATION SHIELD FROM THE NORTHERN/CENTRAL ROCKIES/PLAINS TO  
THE MIDWEST/GREAT LAKES THEN NORTHERN NEW ENGLAND.  
   
..GUIDANCE ASSESSMENT/PREFERENCES
 
 
MODEL AND ENSEMBLE SOLUTIONS SEEM REASONABLY WELL CLUSTERED FRI  
INTO SAT FOR MID-LARGER-SCALE FEATURES AND A COMPOSITE BLEND  
FOCUSES LESS EMPHASIS ON THE LESS PREDICTABLE SMALLER SCALE  
FEATURES. THIS BLEND INCLUDES THE LATEST GFS, ECMWF, UKMET, AND  
CANADIAN THAT CLUSTER WELL WITH THE LATEST GEFS/ECMWF ENSEMBLE  
MEANS DURING THIS TIME PERIOD. FORECAST SPREAD AND RUN-RUN  
CONTINUITY ISSUES BECOME MORE PROBLEMATIC THIS WEEKEND INTO EARLY  
NEXT WEEK. THIS BEGINS WITH QUESTIONS ABOUT THE DEGREE OF  
SEPARATION IN THE NORTHERN AND SOUTHERN STREAMS, NAMELY THE MANNER  
IN WHICH A DEEP UPPER TROUGH IN EAST-CENTRAL CANADA PHASES WITH  
SOUTHERN STREAM TROUGHING TRAVERSING OVER THE CENTRAL CONUS.  
RECENT ECMWF RUNS/ECMWF ENSEMBLE MEANS SHOW MORE STREAM PHASING  
THAN RECENT GFS AND TO A LESSER EXTENT THE FV3 AND GEFS MEANS.  
PREFERRED A BLEND OF THE GEFS/ECMWF ENSEMBLE MEANS GIVEN  
UNCERTAINTY, BUT APPLIED MORE WEIGHT TO ECMWF ENSEMBLES FOR BETTER  
CONTINUITY INTO DAY 7.  
 
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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