238  
FXUS02 KWBC 141858  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
257 PM EDT THU APR 14 2022  
 
VALID 12Z SUN APR 17 2022 - 12Z THU APR 21 2022  
 
...OVERVIEW AND GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT..  
 
IT REMAINS EVIDENT THAT COMPARED TO WHAT HAS BEEN A PRETTY  
AMPLIFIED AND ACTIVE WEATHER PATTERN THE PAST FEW DAYS, RELATIVELY  
LOW AMPLITUDE MEAN FLOW SHOULD CONTINUE THROUGH ABOUT SUNDAY OR  
MONDAY ACROSS MUCH OF THE LOWER 48. THIS FEATURES SHORTWAVE ENERGY  
THROUGH THE NORTHEAST, WITH A POSSIBLE CLOSED LOW DEVELOPMENT OVER  
THE CANADIAN MARITIMES, WHILE A SHORTWAVE AND ASSOCIATED SURFACE  
LOW PRESSURE SYSTEM MOVES OVER THE NORTHERN TIER. CHANCES ARE  
INCREASING THAT THIS MAY BRING ANOTHER ROUND OF SPRING SNOW TO  
PARTS OF THE NORTHERN PLAINS ON SUNDAY INTO MONDAY. AFTER THIS,  
THE PATTERN IS EXPECTED TO TRANSITION TO A MORE AMPLIFIED FLOW, AS  
AN UPPER TROUGH/CLOSED LOW REACHING THE WEST COAST BY TUESDAY  
SHOULD ACT TO BUILD A DOWNSTREAM RIDGE AND AMPLIFY THE NORTHERN  
TIER SHORTWAVE AS IT DIGS THROUGH THE GREAT LAKES AND NORTHEAST BY  
MID NEXT WEEK. MEANWHILE, AS THE WESTERN U.S. TROUGH ENERGY  
PROGRESSES THROUGH THE NORTHWEST, IT COULD AGAIN FACE  
AMPLIFICATION IN RESPONSE TO YET ANOTHER UPPER LOW/AMPLIFIED  
TROUGH TOWARDS THE WEST COAST NEXT WEDNESDAY-THURSDAY.  
 
THE WPC MEDIUM RANGE PRODUCT SUITE WAS PRIMARILY DERIVED FROM A  
BLEND OF THE GFS/ECMWF/UKMET/CANADIAN, THE GEFS/ECMWF ENSEMBLE  
MEANS AND WPC CONTINUITY ALONG WITH THE 13 UTC NBM. WHILE GUIDANCE  
CLUSTERING HAS IMPROVED FROM THE PAST FEW DAYS THROUGH MEDIUM  
RANGE TIME SCALES, BOLSTERING FORECAST CONFIDENCE, MULTIPLE SYSTEM  
DIFFERENCES REMAIN WITH THE AMPLITUDE OF SYSTEMS AND QPF. NBM 4.0  
QPF REMAINS PARTICULARLY LIGHT WITH QPF ACROSS THE EAST-CENTRAL  
U.S., AND WPC CORRECTED UPWARDS GIVEN SUPPORT.  
 
OVERALL, THIS BLEND PLAN SEEMS TO ADAQUATELY MITIGATE THE BLENDING  
PROCESS WHILE STILL MAINTAINING DECENT DETAIL CONSISTENT WITH  
PREDICTABILITY.  
 
   
..WEATHER HIGHLIGHTS/THREATS
 
 
IT REMAINS THE CASE THAT MOISTURE AND INSTABILITY INTERACTING WITH  
A WARM FRONT LIFTING THROUGH THE SOUTH/SOUTHEAST THIS WEEKEND AND  
APPROACH OF A COLD FRONT FROM THE NORTH SHOULD BRING AREAS OF  
MODERATE TO LOCALLY HEAVY RAINFALL TO PARTS OF THOSE AREAS, BUT  
WITH LOWER CONFIDENCE IN EXACT PLACEMENT OF HEAVIEST TOTALS.  
FARTHER NORTH, A LOW PRESSURE SYSTEM INTO THE NORTHERN PLAINS ON  
SUNDAY MAY AGAIN BRING A ROUND OF ACCUMULATING SPRING SNOW TO  
NORTHERN LOCATIONS, WITH RAINFALL FARTHER SOUTH ALONG THE  
ATTENDENT COLD FRONT INTO THE MIDWEST. MOISTURE REACHES THE EAST  
EARLY NEXT WEEK, WITH SOME POTENTIAL OVER THE SOUTHEAST AS WELL AS  
PRECIPITATION NORTH AND WEST OF A SURFACE LOW TO AFFECT NEW  
ENGLAND. THIS WILL INCLUDE A THREAT OF HIGHER TERRAIN ENHANCED  
SNOW OVER THE INTERIOR NORTHEAST. SOME GUSTY WINDS ARE ALSO  
POSSIBLE ACROSS THE NORTHEAST TUESDAY INTO WEDNESDAY. OUT WEST,  
EXPECT ANOTHER EPISODE OF PRECIPITATION FROM THE PACIFIC  
NORTHWEST/NORTHERN CALIFORNIA INTO THE NORTHERN ROCKIES THROUGH  
EARLY NEXT WEEK, WITH SOME ENHANCED TOTALS POSSIBLE OVER FAVORED  
COASTAL/TERRAIN AREAS. PRECIPITATION POTENTIAL MAY INCREASE AGAIN  
INTO NEXT WED/THU WITH APPROACH OF ANOTHER AMPLIFIED UPPER TROUGH  
AND ASSOCIATED AND SLOWED FRONTAL PROGRESSION.  
 
THE CORE OF BELOW NORMAL TEMPERATURES ACROSS THE NORTHERN PLAINS  
AND VICINITY WILL LIKELY PERSIST INTO EARLY NEXT WEEK, WITH  
DAYTIME HIGHS GENERALLY 20-30F BELOW NORMAL, AND MODERATING SLOWLY  
WITH TIME. THE SYSTEM REACHING THE MIDWEST/EAST EARLY NEXT WEEK  
COULD DRAW SOME OF THE CHILLY NORTHERN PLAINS AIR SOUTHWARD AND  
EASTWARD BEHIND IT, WITH EXPANDING COVERAGE OF MINUS 10-20F  
ANOMALIES SUNDAY-TUESDAY. WARM ANOMALIES ACROSS THE SOUTHERN  
PLAINS AND SOUTHWEST ON SUNDAY SHOULD PROGRESS SLOWLY NORTH AND  
EASTWARD AS UPPER LEVEL RIDGING BUILDS AND MOVES THROUGH.  
 
SCHICHTEL/SANTORELLI  
 
ADDITIONAL 3-7 DAY HAZARD INFORMATION CAN BE FOUND ON THE WPC  
MEDIUM RANGE HAZARDS OUTLOOK CHART AT:  
HTTPS://WWW.WPC.NCEP.NOAA.GOV/THREATS/THREATS.PHP  
 
WPC MEDIUM RANGE 500MB HEIGHTS, SURFACE SYSTEMS, WEATHER GRIDS,  
QUANTITATIVE PRECIPITATION, EXPERIMENTAL EXCESSIVE RAINFALL  
OUTLOOK, 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/#PAGE=ERO  
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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