593  
FXUS02 KWBC 100658  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
156 AM EST THU MAR 10 2022  
 
VALID 12Z SUN MAR 13 2022 - 12Z THU MAR 17 2022  
   
..OVERVIEW
 
 
AN AMPLIFIED TROUGH AND ASSOCIATED VERY DEEP CYCLONE WILL BE  
EXITING THE EAST COAST EARLY SUNDAY WITH A MODIFIED BUT CHILLY  
AIRMASS BEHIND. MEANWHILE, AN ACTIVE PATTERN LOOKS TO RETURN TO  
THE PACIFIC NORTHWEST WITH A COUPLE OF SHORTWAVES -- THE FIRST  
MOVING THROUGH ON SUNDAY AND THE NEXT ONE MONDAY INTO TUESDAY. THE  
FIRST WAVE WILL DIVE SOUTHEAST TO THE GULF COAST AND SHIFT ACROSS  
THE SOUTHEAST EARLY TO MID NEXT WEEK. THE SECOND, STRONGER WAVE,  
WILL BRING A QUICK ATMOSPHERIC RIVER TO THE REGION BEFORE BECOMING  
MORE POSITIVELY TILTED AND SLOWLY MAKE ITS WAY ACROSS THE WEST  
WEDNESDAY INTO THURSDAY. IN BETWEEN, UPPER RIDGING WILL BUILD  
ACROSS THE CENTRAL U.S. AND INTO THE MIDWEST.  
 
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
PLENTY OF UNCERTAINTY CONTINUES SURROUNDING THE INITIAL SHORTWAVE  
INTO THE PACIFIC NORTHWEST EARLY SUNDAY. RIGHT OFF THE BAT, THE  
12Z/MAR 9 CMC (MOST RECENT RUN AT FORECAST ISSUANCE TIME) WAS MUCH  
FLATTER THAN THE CONSENSUS, RESULTING IN A QUICKER WAVE THROUGH  
THE CENTRAL/EASTERN U.S., SO IT WAS EXCLUDED FROM THE MEDIUM RANGE  
BLEND TONIGHT. HOWEVER, THE NEW 00Z RUN DID COME IN LOOKING MORE  
AMPLIFIED AND USABLE. MODELS ARE BEGINNING TO COME TOGETHER ON THE  
IDEA THAT THIS WAVE MAY SPLIT, WITH NORTHERN STREAM ENERGY MOVING  
INTO THE MIDWEST/NORTHEAST AND AMPLIFYING SOUTHERN STREAM ENERGY  
WITH A POSSIBLE CLOSED LOW OVER THE GULF COAST/SOUTHEAST MID-NEXT  
WEEK. DESPITE THIS TREND, THERE REMAINS QUITE A BIT OF DEPTH AND  
TIMING ISSUES, WITH THE GFS CONSISTENTLY THE DEEPEST/SLOWEST OF  
THE SOLUTIONS (ALTHOUGH ALSO THE FIRST MODEL TO PICK UP ON THIS  
IDEA) AND ALSO SIGNIFICANTLY FASTER WITH THE NORTHERN STREAM  
ENERGY. THE ECMWF SEEMS A LITTLE MORE REASONABLE AND MORE IN LINE  
WITH RECENT ENSEMBLES. THE NEXT TROUGH INTO THE WEST EARLY NEXT  
WEEK CONTINUES TO SHOW AMPLE RUN TO RUN VARIABILITY AND TIMING,  
BUT AT LEAST DECENT AGREEMENT ON THE LARGER SCALE.  
 
THE WPC BLEND TONIGHT USED A BLEND OF THE GFS AND ECMWF, AND  
SMALLER AMOUNTS OF THE UKMET, THROUGH DAY 5. AFTER THIS, BEGAN  
INCREASING CONTRIBUTIONS FROM THE ENSEMBLE MEANS TO HELP MITIGATE  
THE DETAILS WITH BOTH THE SYSTEM IN THE SOUTHEAST AND THE WEST.  
 
   
..WEATHER HIGHLIGHTS/THREATS
 
 
A DEPARTING AND STILL RAPIDLY DEEPENING SURFACE LOW OUT OF THE  
NORTHEAST SHOULD CONTINUE TO BRING SOME GUSTY WINDS TO NORTHERN  
NEW ENGLAND INTO SUNDAY. AN ARCTIC AIRMASS WILL STILL BE IN PLACE  
ACROSS THE EAST THROUGH SUNDAY, WITH DAYTIME HIGHS SUNDAY  
AVERAGING 10-15 DEGREES BELOW NORMAL LIKELY. SUBFREEZING  
TEMPERATURES ARE LIKELY SUNDAY MORNING AS FAR SOUTH AS THE GULF  
COAST AND NORTHERN FLORIDA, WITH RECORD LOWS POSSIBLE IN SEVERAL  
LOCATIONS. AFTER SUNDAY, TEMPERATURES IN THE EAST SHOULD REBOUND  
BACK TO MORE SPRING LIKE WEATHER WITH ABOVE NORMAL TEMPERATURES  
PERSISTING THROUGH MUCH OF NEXT WEEK.  
 
MEANWHILE, RAIN AND MOUNTAIN SNOWS WILL ACCOMPANY THE FIRST  
SHORTWAVE PASSAGE THIS WEEK ACROSS THE WEST. AS THE SOUTHERN  
STREAM ENERGY AMPLIFIES INTO THE SOUTHEAST NEXT WEEK, IT SHOULD  
TAP GULF MOISTURE TO BRING INCREASING RAIN AND THUNDERSTORMS  
CHANCES ACROSS THE GULF COAST AND SOUTHEAST MONDAY-TUESDAY, AND  
MAYBE INTO WEDNESDAY DEPENDING ON THE PROGRESSION OF THE UPPER  
LOW/TROUGH. OUT WEST, THE SECOND TROUGH EARLY NEXT WEEK LOOKS TO  
DIRECT AN ATMOSPHERIC RIVER INTO THE PACIFIC NORTHWEST, BRINGING  
MOSTLY BENEFICIAL RAINFALL AND HIGHER ELEVATION SNOWS TO WESTERN  
WASHINGTON/OREGON AND NORTHERN CALIFORNIA. UPPER LEVEL RIDGING  
BETWEEN THESE TROUGHS WILL BUILD ACROSS THE CENTRAL U.S. WITH  
DAYTIME HIGHS 10 TO 25 DEGREES ABOVE NORMAL BY NEXT  
TUESDAY-WEDNESDAY FOR THE NORTHERN/CENTRAL PLAINS, WHICH SHOULD BE  
A WELCOME RELIEF TO THE VERY CHILLY WEATHER THERE CURRENTLY.  
 
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  
 
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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