010  
FXUS02 KWBC 031837  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
236 PM EDT SUN APR 03 2022  
 
VALID 12Z WED APR 06 2022 - 12Z SUN APR 10 2022  
   
..OVERVIEW
 
 
THE LOWER 48 WILL SEE AN AMPLIFIED UPPER PATTERN DURING THE MEDIUM  
RANGE PERIOD (WED-SUN). DURING THE MID TO LATE WEEK TIME FRAME THE  
DOMINANT FEATURES WILL BE A DEEP EAST-CENTRAL U.S. TROUGH ANCHORED  
BY AN UPPER MIDWEST INTO GREAT LAKES LOW, AND A WESTERN U.S.  
RIDGE. THE UPPER LOW/TROUGH AND ASSOCIATED SURFACE EVOLUTION WILL  
PRODUCE A BROAD AREA OF PRECIPITATION ACROSS THE NORTHERN PLAINS  
AND EASTERN HALF OF THE COUNTRY (WITH SOME POCKETS OF LOCALLY  
HEAVY TOTALS POSSIBLE) WHILE THE WESTERN RIDGE WILL SUPPORT MUCH  
ABOVE NORMAL TEMPERATURES, INCLUDING POTENTIAL FOR SOME RECORD  
HIGHS/WARM LOWS OVER CALIFORNIA AND VICINITY. BY THE WEEKEND  
EXPECT A PACIFIC TROUGH TO MOVE INTO THE WEST, LEADING TO A  
COOLING TREND AND SOME PRECIPITATION, WHILE PROGRESSION OF THE  
EASTERN TROUGH TO EAST COAST SHOULD FAVOR DRIER WEATHER OVER THE  
EAST.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
IN THE EAST, THE 00Z CMC AND UKMET CONTINUED TO BE FARTHER WEST  
WITH IT'S TRACK THAN CONSENSUS WITH THE INITIAL WAVE IN THE  
MID-ATLANTIC ON WEDNESDAY. UPSTREAM, CONCERNING THE MIDWEST CLOSED  
LOW, THE 00Z UKMET IS QUICKEST TO OPEN UP THE LOW, LEADING TO A  
FASTER PROGRESSION OF THE SYSTEM AS A WHOLE. LATER 12Z RUNS OF THE  
CMC AND UKMET SEEM TO SHOW BETTER CONSISTENCY WITH THE GFS AND  
ECMWF FOR BOTH FEATURES. LATER IN THE PERIOD, THE TROUGH IN THE  
EAST SHOULD LINGER/BECOME ELONGATED AS RIDGING AMPLIFIES INTO THE  
CENTRAL U.S.. THERE ARE SOME TIMING CONCERNS FOR THE FRONT LATE  
PERIOD, BUT MOSTLY NOT UNTIL IT'S WELL OFF THE COAST.  
 
OUT WEST, PLENTY OF UNCERTAINTY CONTINUES TO SURROUND THE  
EVOLUTION OF TROUGHING INTO THE REGION BY NEXT WEEKEND. MODELS  
SHOW AN INITIAL WAVE MOVING THROUGH ON FRIDAY, WITH A BIGGER  
CLOSED LOW DROPPING DOWN FROM THE GULF OF ALASKA BY SUNDAY.  
BIGGEST OUTLIER WAS THE 00Z CMC WHICH WAS QUITE A BIT  
DEEPER/AMPLIFIED WITH THE FIRST SYSTEM RESULTING IN ANOTHER  
BUILDING RIDGE OVER THE WEST COAST NEXT WEEKEND AND LESS  
PROGRESSIVE GULF OF ALASKA LOW. THE GFS AND ECMWF WERE A LITTLE  
BIT MORE IN LINE, RACING THE INITIAL SHORTWAVE OFF INTO CENTRAL  
CANADA AS THE NEXT LOW REACHED THE COAST BY SUNDAY. THIS GENERAL  
EVOLUTION WAS ALSO BETTER SUPPORTED IN THE ENSEMBLES. THE 12Z RUN  
HOWEVER OF THE CMC HAS ABANDONED THIS IDEA AND SEEMS TO HAVE COME  
MUCH MORE INTO LINE WITH THE GFS/ECMWF AND ENSEMBLE MEANS. BUT  
DETAIL DIFFERENCES AMONG MODEL RUNS AND ENSEMBLE MEMBERS CONTINUE  
TO SUGGEST LOWER PREDICTABILITY FOR THIS OVERALL TROUGH VERSUS THE  
RIDGE/TROUGH CONFIGURATION FARTHER EAST.  
 
THE WPC BLEND FOR TODAY UTILIZED A NON-UKMET CONSENSUS FOR THE  
FIRST HALF OF THE PERIOD IN THE EAST. OUT WEST, THE CMC WAS LEFT  
OUT IN FAVOR OF INCREASING WEIGHTING TOWARDS THE ENSEMBLE MEANS TO  
HELP MITIGATE THE WESTERN U.S. UNCERTAINTIES. THIS PROVIDED VERY  
GOOD CONTINUITY WITH THE PREVIOUS WPC FORECAST AS WELL.  
 
   
..WEATHER HIGHLIGHTS/THREATS
 
 
THE DEEP-LAYER LOW TRACKING OVER THE UPPER MIDWEST INTO GREAT  
LAKES, ALONG WITH A LEADING TRIPLE POINT WAVE THAT MAY BECOME THE  
PRIMARY SYSTEM BY THE END OF THE WEEK--PLUS THE TRAILING COLD  
FRONT--SHOULD SUPPORT MULTIPLE AREAS OF ENHANCED PRECIPITATION  
MID-LATE WEEK. SPECIFICS FOR HEAVIEST TOTALS ARE STILL FAIRLY  
UNCERTAIN THOUGH. ONE AREA OF FOCUS MAY BE FOR SOME COMBINATION OF  
RAIN AND/OR SNOW OVER OR A LITTLE WEST/SOUTH OF LAKE SUPERIOR,  
JUST NORTH OF THE PARENT LOW'S TRACK. MEANWHILE THE WAVE EXPECTED  
TO TRACK FROM THE MID-ATLANTIC NORTHEASTWARD MAY PRODUCE SOME  
LOCALLY MODERATE TO HEAVY RAINFALL. FAR INTERIOR SECTIONS OF NEW  
ENGLAND MAY SEE SOME WINTRY WEATHER ON THE LEADING SIDE OF THE  
MOISTURE. MORE LOCALIZED POCKETS OF ENHANCED RAINFALL ARE POSSIBLE  
FARTHER SOUTH ALONG THE TRAILING COLD FRONT. THE STORM PREDICTION  
CENTER IS MONITORING POTENTIAL FOR SEVERE THREATS ACROSS THE  
SOUTHERN TIER. CHECK THEIR LATEST OUTLOOKS FOR MORE INFORMATION.  
EXPECT LINGERING SHOWERY PRECIPITATION, POSSIBLY INCLUDING SOME  
SNOW FROM THE MIDWEST INTO THE APPALACHIANS, UNDER THE COLD UPPER  
TROUGH INTO SATURDAY. THE UPPER TROUGH PUSHING INTO THE WEST BY  
THE WEEKEND SHOULD BRING MOSTLY LIGHT TO MODERATE RAIN AND HIGH  
ELEVATION SNOW INTO THE NORTHWEST STARTING FRIDAY OR SATURDAY.  
 
THE UPPER RIDGE BUILDING INTO THE WEST WILL SPREAD A BROAD AREA OF  
WELL ABOVE NORMAL TEMPERATURES ACROSS THE REGION MID-LATE WEEK.  
HIGHEST TEMPERATURES WILL LIKELY BE ON THURSDAY-FRIDAY WHEN PARTS  
OF CALIFORNIA AND OREGON INTO THE GREAT BASIN COULD SEE READINGS  
15-25F ABOVE NORMAL. SOME DAILY RECORDS FOR HIGHS/WARM LOWS WILL  
BE POSSIBLE. THE UPPER TROUGH ARRIVING FROM THE PACIFIC WILL BRING  
A RAPID COOLING TREND DURING THE WEEKEND, WITH MUCH OF THE WEST  
SEEING NEAR TO BELOW NORMAL HIGHS BY SUNDAY. FARTHER EAST, HIGHS  
GENERALLY 5-15F OR SO BELOW NORMAL WILL PROGRESS FROM THE NORTHERN  
PLAINS/NORTHERN-CENTRAL ROCKIES INTO THE EAST DURING  
WEDNESDAY-SATURDAY UNDER THE DEEP UPPER TROUGH. EXPECT  
TEMPERATURES TO MODERATE NOTICEABLY BY NEXT SUNDAY. FLOW AHEAD OF  
THE UPPER TROUGH WILL BRING A COUPLE DAYS OF ABOVE NORMAL READINGS  
(ESPECIALLY FOR MORNING LOWS) TO THE EAST AROUND  
WEDNESDAY-THURSDAY.  
 
SANTORELLI/RAUSCH  
 
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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