501  
FXUS02 KWBC 272205  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
434 PM EST THU JAN 27 2022  
 
VALID 12Z SUN JAN 30 2022 - 12Z THU FEB 03 2022  
   
..OVERVIEW
 
 
BY THE START OF THE MEDIUM RANGE PERIOD EARLY SUNDAY, THE DEEP  
SYSTEM TRACKING JUST OFF THE EAST COAST LATE THIS WEEK INTO THE  
WEEKEND SHOULD REACH A POSITION EAST OR NORTHEAST OF MAINE, STILL  
SUPPORTING SOME STRONG WINDS EVEN IF PRECIPITATION TAPERS OFF.  
THIS STORM WILL CONTINUE MOVING RAPIDLY AWAY FROM NEW ENGLAND  
DURING THE DAY SUNDAY. FOR INFORMATION ON THE STORM'S EFFECTS  
BEFORE EARLY SUNDAY CONSULT THE WPC WEBSITE FOR UPDATED KEY  
MESSAGES AND CHECK YOUR LOCAL FORECAST AT WEATHER.GOV. THROUGH THE  
REST OF THE PERIOD, THE DOMINANT THEME WILL BE A SIGNIFICANT  
PATTERN CHANGE AS AN UPPER TROUGH STRONGLY AMPLIFIES FROM THE  
NORTHEASTERN PACIFIC INTO THE WESTERN/CENTRAL U.S. WHILE A STRONG  
RIDGE BUILDS AND THEN PERSISTS OVER THE EASTERN PACIFIC, AND  
ANOTHER RIDGE CROSSING THE EAST COAST TUESDAY SETTLES OVER THE  
WESTERN ATLANTIC THEREAFTER. THIS EVOLUTION WILL INITIALLY SPREAD  
PRECIPITATION ACROSS THE WEST AND THEN LIKELY PRODUCE SIGNIFICANT  
PRECIPITATION FARTHER EASTWARD AS A LEADING FRONT INTERACTS WITH A  
STRONG FLOW OF GULF MOISTURE, WITH THE POSSIBILITY OF WINTRY  
WEATHER ON THE BACKSIDE OF THE FRONT. AHEAD OF THE TROUGH, A  
SOUTHERN STREAM SHORTWAVE/UPPER LOW MAY GENERATE SOME ENHANCED  
RAINFALL ALONG/NORTH OF THE GULF COAST AROUND MONDAY.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
AN OPERATIONAL MODEL BLEND EARLY IN THE PERIOD FAVORING THE  
00Z/06Z GFS AND 00Z ECMWF AND CMC FOLLOWED BY A TRANSITION TOWARD  
ABOUT HALF THE TOTAL WEIGHT OF 06Z GEFS/00Z ECMWF MEANS CONTINUED  
TO PROVIDE A GOOD REPRESENTATION OF CONSENSUS IDEAS, WITH MAINLY  
JUST TYPICAL RUN-TO-RUN DETAIL CHANGES VERSUS PREVIOUS CYCLE. FOR  
THE STORM PRODUCING LINGERING EFFECTS OVER NEW ENGLAND, THERE ARE  
STILL MEANINGFUL DIFFERENCES IN THE SHORT RANGE DUE IN PART TO  
FINE-SCALE ISSUES WITH THE SUPPORTING UPPER LOW, SO THERE IS STILL  
A FAIR AMOUNT OF UNCERTAINTY OVER THE EXACT LOCATION/STRUCTURE OF  
THE STORM AS OF EARLY SUNDAY. OVERALL THE LATEST GFS/GEFS MEAN  
CONTINUE TO BE ON THE FASTER SIDE AND THE ECMWF/ECMWF MEAN ARE  
SLOWEST, CONFORMING TO LONG-HISTORICAL TENDENCIES.  
 
MEANWHILE GUIDANCE CONTINUES TO CONSOLIDATE FOR THE HANDLING OF  
THE SOUTHERN STREAM SHORTWAVE/UPPER LOW EMERGING FROM THE  
SOUTHWEST, WITH THE 00Z UKMET STRAYING FASTER THAN MOST OTHER  
SOLUTIONS. THIS FEATURE SHOULD RAPIDLY SHEAR OUT BEYOND THE  
PLAINS. FARTHER WEST, THERE ARE STILL DIFFERENCES IN HOW SOME  
ENERGY PULLS OFF FROM THE SOUTHWESTERN PART OF THE SHORTWAVE  
APPROACHING THE WEST COAST SUNDAY BUT NOW WITH LESS PRONOUNCED  
SPREAD THAN IN PREVIOUS CYCLES. AS THE LARGER SCALE UPPER TROUGH  
DIGS INTO THE WESTERN/CENTRAL U.S. TUESDAY-THURSDAY, THE ENSEMBLE  
MEANS AND A MULTI-RUN AVERAGE OF OPERATIONAL RUNS SUGGEST ABOVE  
AVERAGE PREDICTABILITY FOR THE LARGE-SCALE FEATURE WHILE  
INDIVIDUAL MEMBERS/MODEL RUNS SHOW EMBEDDED DETAIL UNCERTAINTIES.  
EXAMPLES OF THE LATTER INCLUDE TO WHAT DEGREE FLOW MAY SEPARATE  
NEAR THE FOUR CORNERS REGION AROUND WEDNESDAY AND THE CHARACTER OF  
UPSTREAM ENERGY DROPPING INTO THE MEAN TROUGH BY THURSDAY. GFS  
RUNS HAVE BEEN PERSISTENT WITH A STRONGER FEATURE FOR THE LATTER  
COMPARED TO THE ECMWF RUNS, AND THESE DIFFERENCES DO AFFECT THE  
WIDTH OF THE TROUGHING AS WELL AS THE AXIS SOMEWHAT, AND THE  
TIMING OF THE SURFACE COLD FRONT PUSHING AHEAD OF THE TROUGH. THE  
BLEND OF DETERMINISTIC AND ENSEMBLE GUIDANCE USED FOR THE END OF  
THE PERIOD WORKED AS A COMPROMISE AT THIS POINT.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
EXPECT STRONG WINDS OVER NEW ENGLAND AT THE START OF SUNDAY TO  
MODERATE OVER THE COURSE OF THE DAY AS STRONG LOW PRESSURE TRACKS  
RAPIDLY AWAY FROM THE REGION. OTHERWISE THE EFFECTS OF THE INITIAL  
STORM WILL BE IN THE SHORT RANGE. SEE THE WPC WEBSITE FOR LATEST  
KEY MESSAGES ON THE SYSTEM AND ADDITIONAL INFORMATION IN THE  
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION, PLUS CHECK YOUR  
LOCAL FORECAST AT WEATHER.GOV.  
 
THE UPPER TROUGH/LOW REACHING THE SOUTHWEST BY EARLY SUNDAY SHOULD  
PRODUCE LITTLE IF ANY PRECIPITATION OVER THAT REGION. HOWEVER, AS  
THE FEATURE CONTINUES EASTWARD, THERE WILL BE SOME POTENTIAL FOR  
LOCALLY MODERATE TO HEAVY RAINFALL FROM EASTERN TEXAS ACROSS PARTS  
OF THE GULF COAST REGION DURING THE FIRST HALF OF THE WEEK. BEST  
POTENTIAL AT THIS TIME APPEARS TO BE OVER EASTERN TEXAS WITH LOWER  
CONFIDENCE IN DETAILS FARTHER EAST. SOME ASPECTS OF THIS EVENT MAY  
HINGE ON SMALL-SCALE DETAILS NOT EASILY RESOLVED VERY FAR IN  
ADVANCE. THE NORTHEASTERN PACIFIC UPPER TROUGH DIGGING INTO THE  
WEST SUNDAY-TUESDAY WILL SPREAD MODERATE AMOUNTS OF RAIN AND  
MOUNTAIN SNOW FROM THE PACIFIC NORTHWEST EASTWARD AND  
SOUTHEASTWARD INTO MUCH OF THE ROCKIES. HIGHEST TOTALS ARE LIKELY  
TO BE IN THE PACIFIC NORTHWEST BUT SHOULD NOT BE TOO EXTREME. IN  
GENERAL THE FORECAST REMAINS ON TRACK FOR A SIGNIFICANT INCREASE  
OF COVERAGE AND INTENSITY OF PRECIPITATION OVER THE EAST-CENTRAL  
U.S. BY WEDNESDAY-THURSDAY AS THE UPPER TROUGH EMERGES FROM THE  
ROCKIES AND THE LEADING COLD FRONT INTERACTS WITH A STRONG LOW  
LEVEL FEED OF GULF MOISTURE. AT THIS TIME THE BEST POTENTIAL FOR  
HEAVIEST RAINFALL EXTENDS ACROSS THE LOWER HALF OF THE MISSISSIPPI  
VALLEY INTO PARTS OF THE OHIO/TENNESSEE VALLEYS. WINTRY WEATHER  
WILL BE POSSIBLE ON THE NORTHWEST SIDE OF THE MOISTURE SHIELD,  
WITH AT LEAST SOME POTENTIAL FOR MEANINGFUL SNOW FROM THE  
CENTRAL/SOUTH-CENTRAL PLAINS NORTHEASTWARD THROUGH THE GREAT  
LAKES. WHILE CONFIDENCE IN A HEAVY RAIN AREA APPEARS BETTER THAN  
AVERAGE, DETAILS WITH THE WINTRY PRECIPITATION IN THE COLDER AIR  
MAY BE MORE DEPENDENT ON LOWER-CONFIDENCE DETAILS OF EJECTING  
SHORTWAVE ENERGY AND FRONTAL WAVES.  
 
COLD CONDITIONS NEAR THE EAST COAST WILL EXTEND THROUGH SUNDAY  
WITH MANY AREAS 10-20F BELOW NORMAL. SUBFREEZING LOWS SHOULD  
EXTEND INTO PORTIONS OF FLORIDA AND PARTS OF THE FLORIDA PENINSULA  
MAY CHALLENGE DAILY RECORDS FOR BOTH MORNING LOWS AND DAYTIME  
HIGHS. MUCH OF THE PLAINS WILL SEE ABOVE NORMAL TEMPERATURES  
SUNDAY INTO THE FIRST PART OF NEXT WORK WEEK, WITH SOME  
NORTHERN/CENTRAL AREAS POSSIBLY SEEING PLUS 20F OR GREATER  
ANOMALIES ON ONE OR TWO DAYS. THIS WARM AIR WILL PROGRESS INTO THE  
EASTERN HALF OF THE COUNTRY TUESDAY-THURSDAY, BRINGING A BROAD  
AREA OF TEMPERATURES 10-20F ABOVE NORMAL AND PERHAPS GREATER  
ANOMALIES FOR LOWS OVER THE NORTHEAST BY THURSDAY. ALSO DURING  
TUESDAY-THURSDAY MUCH OF THE WEST AND THEN INTO THE PLAINS WILL  
SEE AN EPISODE OF CHILLY TEMPERATURES WITH THE ROCKIES AND PLAINS  
SEEING THE BEST POTENTIAL FOR READINGS 10-20F BELOW NORMAL.  
 
RAUSCH/TATE  
 
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  
 
HAZARDS:  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI  
VALLEY, THE GREAT LAKES, AND THE  
OHIO VALLEY, WED, FEB 2.  
- HEAVY RAIN ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY AND  
THE SOUTHERN PLAINS, MON, JAN 31.  
- HEAVY RAIN ACROSS PORTIONS OF THE MIDDLE/LOWER MISSISSIPPI  
VALLEY, THE CENTRAL APPALACHIANS, THE  
TENNESSEE VALLEY, THE CENTRAL/SOUTHERN APPALACHIANS, THE  
SOUTHEAST, AND THE OHIO VALLEY, WED-THU,  
FEB 2-FEB 3.  
- HIGH WINDS ACROSS PORTIONS OF THE MID-ATLANTIC AND THE  
NORTHEAST, SUN, JAN 30.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE PLAINS,  
THE ROCKIES, THE UPPER/MIDDLE  
MISSISSIPPI VALLEY, THE CENTRAL GREAT BASIN, AND THE UPPER GREAT  
LAKES, WED-THU, FEB 2-FEB 3.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE NORTHEAST,  
THE CENTRAL/SOUTHERN  
APPALACHIANS, THE TENNESSEE VALLEY, THE MID-ATLANTIC, THE  
SOUTHEAST, THE GREAT LAKES, AND THE OHIO  
VALLEY, SUN, JAN 30.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE SOUTHEAST,  
SUN-MON, JAN 30-JAN 31.  
 
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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