053  
FXUS02 KWBC 071827  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
126 PM EST MON MAR 07 2022  
 
VALID 12Z THU MAR 10 2022 - 12Z MON MAR 14 2022  
 
...WINTER STORM THREATS FOR PARTS OF THE CORN BELT/GREAT LAKES  
THURSDAY-FRIDAY AND FROM THE MID-SOUTH TO THE INTERIOR NORTHEAST  
FRIDAY-SATURDAY...  
 
...HEAVY RAINFALL LIKELY ACROSS PORTIONS OF THE SOUTHEAST  
THURSDAY-FRIDAY...  
 
   
..OVERVIEW
 
 
A STRONG SHORTWAVE IN THE GREAT BASIN/SOUTHWEST EARLY THURSDAY  
WILL BRING RECORD COLD TO SOME AREAS OF THE INTERIOR WEST. THIS  
WILL MOVE INTO THE MID-SOUTH BY EARLY SATURDAY AS A NORTHERN  
STREAM SHORTWAVE DIGS THROUGH THE UPPER MIDWEST INTO THE GREAT  
LAKES. THESE FEATURES WILL LIKELY COMBINE/INTERACT TO SUPPORT  
STRONG CYCLOGENESIS INTO THE APPALACHIANS IN A CLASSIC SPRING  
SYSTEM FEATURING SNOW AND COLD TEMPERATURES TO THE NORTH/NORTHWEST  
OF THE SURFACE LOW WITH WARM/WET CONDITIONS AHEAD OF THE COLD  
FRONT. BY NEXT WEEK, PATTERN MAY BECOME QUASI-ZONAL WITH QUIETER  
CONDITIONS IN THE EAST IN THE WAKE OF THE DEPARTING SYSTEM, WITH  
WEAK/MODEST SYSTEMS INTO THE PACIFIC NORTHWEST.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
TREND IN THE GUIDANCE FOR THE CENTRAL/EASTERN SYSTEM HAS BEEN  
OVERALL SLOWER, FAVORING MORE INTERACTION BETWEEN THE  
NORTHERN/SOUTHERN STREAM, BUT WITH CONTINUED DIFFERENCES IN HOW  
THE SURFACE LOW QUICKLY EVOLVES OUT OF THE LOWER MISSISSIPPI  
VALLEY INCLUDING ITS TRACK TO THE NORTHEAST. THE 06Z GFS WAS  
CLOSER TO THE 00Z ECMWF THAN ITS 00Z RUN, AND THIS AGREEMENT  
CARRIED ACROSS TO THEIR ENSEMBLE MEANS AS WELL, FORMING THE BASIS  
FOR THE SURFACE PROGS. THE 00Z CANADIAN WAS CLOSE TO THIS  
CONSENSUS AS WELL, THOUGH IT WAS A LITTLE SLOWER WITH THE SOUTHERN  
TROUGH AND QUICKER WITH THE NORTHERN TROUGH, YIELDING A WEAKER  
SYSTEM OVERALL. THE 00Z UKMET WAS MOST OUTSIDE THE CONSENSUS AS A  
LOW PROBABILITY SOLUTION. OVERALL PATTERN REMAINS RATHER  
PROGRESSIVE DESPITE THE RAPID DEEPENING OF THE SURFACE LOW (A BIT  
CHARACTERISTIC OF THIS WINTER PATTERN), BUT FURTHER REFINEMENTS  
SLOWER OR FASTER ARE PROBABLE.  
 
FOR NEXT WEEK, DETERMINISTIC MODELS DIVERGE (RATHER EXPECTEDLY) IN  
THE QUASI-ZONAL PATTERN. TRENDED TOWARD A MAJORITY ENSEMBLE MEAN  
CONSENSUS WITH WEAKER SYSTEMS OUT OF THE PACIFIC HAVING LOWER  
PREDICTABILITY.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
SHOWERS AND THUNDERSTORMS SHOULD BE ONGOING BY THURSDAY ACROSS THE  
SOUTHEAST AS A FRONTAL BOUNDARY SETTLES OVER THE REGION WITH AMPLE  
MOISTURE AND INSTABILITY PRESENT. THIS BOUNDARY SHOULD FINALLY  
BECOME ABSORBED/PUSHED EAST/LIFT NORTHWARD WITH THE STRONG COLD  
FRONT ON SATURDAY. RAINFALL WILL COME IN WAVES OVER THE SOUTHEAST,  
SOME OF WHICH COULD BE HEAVY AND FLOODING/FLASH FLOODING MAY BE A  
THREAT ESPECIALLY WHERE MULTIPLE ROUNDS OF CONVECTION TRACK OVER  
THE SAME AREAS DURING THE PERIOD, DESPITE THE DRY SOIL MOISTURE  
CURRENTLY THAT MAY ABATE STARTING JUST BEFORE THE MEDIUM RANGE  
PERIOD.  
 
TROUGHING IN THE WEST WILL SUPPORT A MULTI-WAVE AND DYNAMIC STORM  
SYSTEM THAT WILL FIRST SPREAD SNOWFALL ACROSS THE CORN BELT  
THURSDAY AHEAD OF THE STRONG ARCTIC FRONT TO THE NORTHWEST. AS THE  
SOUTHERN PORTION OF THE SYSTEM DEVELOPS, COLD AIR WILL POUR  
THROUGH THE CENTRAL PLAINS AND COULD SUPPORT RAIN CHANGING TO SNOW  
BEHIND THE FRONT FRIDAY EVENING WITH SOME ACCUMULATION EVEN INTO  
THE LOWER MISSISSIPPI VALLEY. AS THE SURFACE LOW RAPIDLY DEEPENS  
AND MOVES INTO THE INTERIOR NORTHEAST, RAINFALL WILL SURGE  
NORTHWARD THROUGH ALL OF NEW ENGLAND WITH SNOW, POSSIBLY HEAVY,  
OVER THE EASTERN GREAT LAKES THAT WILL MOVE EASTWARD AS COLD AIR  
WRAPS AROUND THE LOW. PRECIPITATION WILL BE MUCH LIGHTER NEXT WEEK  
IN THE PACIFIC NORTHWEST AS WELL AS INTO THE GREAT LAKES AS A  
CLIPPER SYSTEM MOVES THROUGH.  
 
ARCTIC-SOURCED AIR WILL BLEED THROUGH THE INTERIOR WEST AND SPILL  
INTO THE PLAINS ON THE BACKSIDE OF THE FRONT, WITH DAYTIME HIGHS  
20-30+ DEGREES BELOW NORMAL AS FAR SOUTH AS TEXAS THROUGH FRIDAY.  
OVERNIGHT LOWS ACROSS THE NORTHERN PLAINS AND IN HIGHER ELEVATIONS  
OF THE ROCKIES ARE LIKELY TO BE NEAR OR BELOW ZERO FOR MANY  
LOCATIONS WITH RECORD LOWS POSSIBLE IN SOME LOCATIONS. AHEAD OF  
THE COLD FRONT, ABOVE NORMAL TEMPERATURES SHOULD SPREAD ACROSS THE  
EASTERN THIRD OF THE COUNTRY THURSDAY AND FRIDAY BEFORE BEING  
REPLACED BY BELOW NORMAL TEMPERATURES THIS COMING WEEKEND  
FOLLOWING THE PASSAGE OF THE COLD FRONT. MEANWHILE, BY NEXT WEEK  
PARTS OF THE WEST AND CENTRAL U.S. MAY SEE MODERATELY ABOVE NORMAL  
TEMPERATURES AS PERIODIC UPPER RIDGING SLIDES THROUGH.  
 
FRACASSO/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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