772  
FXUS02 KWBC 221947  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
246 PM EST TUE FEB 22 2022  
 
VALID 12Z FRI FEB 25 2022 - 12Z TUE MAR 01 2022  
 
...HEAVY SNOW AND ICE THREAT SPREADS ACROSS THE NORTHERN  
MID-ATLANTIC AND NORTHEAST INTO FRIDAY...  
   
..OVERVIEW
 
 
A POTENT SHORTWAVE INTERACTING WITH NORTHERN STREAM ENERGY OVER  
THE OHIO VALLEY/GREAT LAKES TO START THE MEDIUM RANGE PERIOD  
FRIDAY WILL PROVIDE FORCING FOR A HEAVY SNOW AND ICE THREAT IN THE  
NORTHERN MID-ATLANTIC AND NORTHEAST. A FAIRLY PROGRESSIVE UPPER  
LEVEL PATTERN AND OVERALL DRIER CONDITIONS ARE EXPECTED BY THE  
WEEKEND INTO EARLY NEXT WEEK. GENERALLY COLDER THAN AVERAGE  
TEMPERATURES ARE FORECAST FOR MUCH OF THE COUNTRY, ESPECIALLY LATE  
THIS WEEK.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
MODEL GUIDANCE CONTINUES TO SHOW REASONABLY GOOD AGREEMENT TO  
START THE MEDIUM RANGE PERIOD FRIDAY WITH THE AFOREMENTIONED  
SHORTWAVE AND THE ASSOCIATED SURFACE LOW PRESSURE/FRONTAL SYSTEM,  
AND WITH THE POSITION OF A SECOND SHORTWAVE OVER THE NORTHERN  
ROCKIES FRIDAY. HOWEVER, THE LATTER SHORTWAVE SHOWS RUN TO RUN AND  
MODEL DIFFERENCES AS IT PROGRESSES EAST INTO THE WEEKEND. THE  
00Z/06Z SUITE OF GUIDANCE GENERALLY SHOWED LESS STREAM SEPARATION  
WITH THE WAVE COMPARED TO THE PREVIOUS CYCLE (ESPECIALLY  
YESTERDAY'S 12Z ECMWF) AND WPC FORECAST, AS RECENT GUIDANCE  
(INCLUDING THE NEW 12Z GUIDANCE) SHOWS IT SHEARING WITH MOST  
ENERGY PHASING WITH THE NORTHERN STREAM TROUGHING ENTERING THE  
GREAT LAKES LED BY AN UPPER LOW IN CANADA. THIS ALSO WOULD LEAD TO  
A QUICKER MOVING PRECIPITATION SWATH OVER THE SOUTHEASTERN  
QUADRANT OF THE U.S. OVER THE WEEKEND IF THIS MORE PHASED SOLUTION  
WITH A QUICKER SOUTHERN SHORTWAVE PLAYS OUT. THE WPC FORECAST  
UTILIZED A MULTI-MODEL COMPOSITE BLEND EARLY IN THE MEDIUM RANGE  
PERIOD, WITH THE BLENDING PROCESS SMOOTHING INDIVIDUAL  
DIFFERENCES, AND TRENDING TOWARD A WEAKER SHORTWAVE SOLUTION THAN  
THE PREVIOUS FORECAST GIVEN THE MODEL CONSENSUS.  
 
FARTHER WEST, AGREEMENT IS GOOD FOR A RIDGE AXIS TO ENTER THE WEST  
COAST LATE FRIDAY INTO SATURDAY AND PROGRESS EASTWARD INTO THE  
ROCKIES AND PLAINS EARLY NEXT WEEK. HOWEVER, AMPLE MODEL  
DIFFERENCES UPSTREAM OF THE RIDGE REMAIN WITHIN MEAN TROUGHING  
ENTERING THE WEST EARLY NEXT WEEK, WITH VARIABILITY IN STRENGTH  
AND TRACK OF MULTIPLE SHORTWAVES. THIS LEADS TO LOW CONFIDENCE IN  
THE EVOLUTION OF ANOTHER SOUTHERN STREAM FEATURE POSSIBLY IN THE  
SOUTHWESTERN QUADRANT OF THE COUNTRY BY MONDAY AND TUESDAY. THE  
CMC AND ECMWF RUNS REMAIN STRONGER WITH THIS FEATURE THAN GFS  
RUNS, AND PREFERRED A SOLUTION SLIGHTLY ON THE MORE AMPLIFIED SIDE  
OF THE FULL ENVELOPE OF SOLUTIONS, MOST IN LINE WITH THE ECMWF  
ENSEMBLE MEAN.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
A POTENT EJECTING SOUTHERN STREAM SHORTWAVE WILL INTERACT WITH  
NORTHERN STREAM ENERGIES OVER THE GREAT LAKES/OHIO VALLEY FRIDAY,  
AS MOISTURE STREAMS OVER A LEADING FRONT TO FUEL ENHANCED  
PRECIPITATION ACROSS THE HIGH PRESSURE/COLD AIR DAMMED NORTHERN  
MID-ATLANTIC AND NORTHEAST. FRONTAL WAVE APPROACH AND COASTAL LOW  
REFORMATION WILL FAVOR A PRONOUNCED SWATH OF SIGNIFICANT SNOW AND  
ICE ON THE NORTHERN/WESTERN SIDE OF THE PRECIPITATION SHIELD, WITH  
LIFT ENHANCED IN THE RIGHT ENTRANCE REGION OF A STRONG UPPER JET.  
AFTER THAT EVENT, THE UPCOMING WEATHER PATTERN SHOULD FAVOR DRIER  
CONDITIONS FOR MANY. AN EXCEPTION MAY BE ACROSS THE SOUTH-CENTRAL  
TO SOUTHEASTERN U.S. WHERE PRECIPITATION COULD INCREASE ONCE AGAIN  
OVER THE WEEKEND, MAINLY IN THE FORM OF RAIN BUT WITH A NONZERO  
CHANCE OF WINTRY WEATHER ON THE NORTHERN SIDE. RAINFALL AMOUNTS  
ARE NOT EXPECTED TO BE AS HEAVY AS THE PAST COUPLE OF EVENTS, BUT  
WILL CONTINUE TO MONITOR, AS THERE COULD BE ISSUES IF RAIN FALLS  
OVER AREAS THAT SAW HEAVY RAINFALL IN THE ONGOING/SHORT RANGE  
EVENTS. IN ADDITION, MODEST PRECIPITATION IS EXPECTED FOR THE  
PACIFIC NORTHWEST STARTING THIS WEEKEND WITH THE LIKELY SLOW  
APPROACH OF NORTHEAST PACIFIC SYSTEMS. PRECIPITATION TOTALS ARE  
FORECAST TO INCREASE THERE BY NEXT MONDAY-TUESDAY.  
 
COLD HIGH PRESSURE WILL SETTLE ACROSS MUCH OF THE COUNTRY IN THE  
WAKE OF THE INITIAL SYSTEM. RECORD-SETTING COLD IS POSSIBLE IN  
POCKETS OF THE WEST AND PLAINS ON FRIDAY, WHILE PREFRONTAL WARMTH  
UNDER AMPLIFIED UPPER RIDGING IN THE SOUTHEAST COULD SET DAILY  
WARM RECORDS ON FRIDAY BEFORE MODERATING OVER THE WEEKEND. BELOW  
AVERAGE TEMPERATURES WILL LINGER ACROSS THE INTERMOUNTAIN  
WEST/ROCKIES AND SOUTHERN PLAINS SATURDAY. ANOTHER PERIOD OF BELOW  
NORMAL TEMPERATURES TRAVERSES THE NORTH-CENTRAL TO NORTHEASTERN  
U.S. EARLY NEXT WEEK WHILE THE REST OF THE LOWER 48 MODERATES NEAR  
TO SLIGHTLY ABOVE NORMAL.  
 
TATE/SCHICHTEL  
 
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 SNOW ACROSS PORTIONS OF THE NORTHEAST AND THE GREAT LAKES,  
FRI, FEB 25.  
- FREEZING RAIN ACROSS PORTIONS OF THE MID-ATLANTIC, THE  
NORTHEAST, AND THE CENTRAL APPALACHIANS,  
FRI, FEB 25.  
- FLOODING POSSIBLE ACROSS PORTIONS OF THE NORTHEAST, THE CENTRAL  
APPALACHIANS, THE TENNESSEE  
VALLEY, THE MIDDLE MISSISSIPPI VALLEY, THE MID-ATLANTIC, THE  
SOUTHERN APPALACHIANS, THE GREAT  
LAKES, AND THE OHIO VALLEY.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE MIDDLE  
MISSISSIPPI VALLEY AND THE GREAT  
LAKES.  
- FLOODING LIKELY ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY  
AND THE GREAT LAKES.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE CENTRAL  
PLAINS, THE CENTRAL ROCKIES, THE  
CENTRAL GREAT BASIN, THE NORTHERN PLAINS, THE NORTHERN ROCKIES,  
THE SOUTHERN ROCKIES, CALIFORNIA,  
THE NORTHERN GREAT BASIN, THE PACIFIC NORTHWEST, AND THE  
SOUTHWEST, FRI-SUN, FEB 25-FEB 27.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE CENTRAL  
PLAINS, THE LOWER MISSISSIPPI  
VALLEY, THE NORTHERN PLAINS, THE NORTHERN ROCKIES, THE CENTRAL  
ROCKIES, THE MIDDLE MISSISSIPPI  
VALLEY, THE UPPER MISSISSIPPI VALLEY, AND THE SOUTHERN PLAINS,  
FRI-SAT, FEB 25-FEB 26.  
- MUCH BELOW NORMAL TEMPERATURES ACROSS PORTIONS OF THE GREAT  
LAKES, THE UPPER MISSISSIPPI VALLEY,  
AND THE NORTHERN PLAINS, FRI, FEB 25 AND SUN-MON, FEB 27-FEB 28.  
 
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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