576  
FXUS02 KWBC 291907  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
206 PM EST SAT JAN 29 2022  
 
VALID 12Z TUE FEB 01 2022 - 12Z SAT FEB 05 2022  
 
...NEXT WEEK TO BRING HEAVY PRECIPITATION TO THE CENTRAL AND  
EASTERN U.S., INCLUDING WINTER WEATHER FROM THE CENTRAL PLAINS TO  
GREAT LAKES AND INTERIOR NORTHEAST AROUND MIDWEEK...  
 
   
..OVERVIEW
 
 
DURING THE MEDIUM RANGE PERIOD TUESDAY TO SATURDAY, AN UPPER LEVEL  
TROUGH INITIALLY DIGGING ACROSS THE WEST WILL PUSH EASTWARD AND  
EXPAND FROM ADDITIONAL DIGGING SHORTWAVE ENERGY THROUGH THE WEEK  
IN BETWEEN EASTERN PACIFIC AND WESTERN ATLANTIC RIDGING. AHEAD OF  
THE TROUGH AXIS, A POTENT COLD FRONT AND WIDESPREAD PRECIPITATION  
WILL TRACK ACROSS THE CENTRAL AND EASTERN U.S., WITH HEAVY RAIN IN  
THE WARM SECTOR AND INCREASING POTENTIAL FOR WINTRY WEATHER ON THE  
BACKSIDE OF THE SYSTEM.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
RECENT GUIDANCE REMAINS IN FAIRLY GOOD AGREEMENT WITH THE OVERALL  
LARGE SCALE PATTERN, BUT WITH SOME DETAIL DIFFERENCES REMAINING,  
PARTICULARLY LATER IN THE PERIOD. THE 00Z/06Z MODEL CYCLE  
CONTINUES TO SHOW A COMPACT SOUTHERN STREAM MID-UPPER LOW MOVING  
INTO THE GULF BY EARLY TUESDAY AND SHEARING OUT QUICKLY AFTER  
THAT. NORTHERN STREAM SHORTWAVES OVER THE NORTH-CENTRAL U.S. AND  
THE WESTERN ATLANTIC ALSO APPEAR AGREEABLE AT THE BEGINNING OF THE  
PERIOD. THUS A MULTI-MODEL DETERMINISTIC BLEND OF THE 00Z  
ECMWF/CMC/UKMET AND 06Z GFS WAS UTILIZED FOR THE EARLY PART OF THE  
WPC FORECAST.  
 
THE TROUGH DEEPENING IN THE WEST ON TUESDAY-WEDNESDAY SHOWS A GOOD  
CONSENSUS FOR AXIS AND AMPLITUDE EVEN AS MULTIPLE SHORTWAVES  
COMBINE TO CREATE IT. THERE ARE SOME SLIGHT TIMING DIFFERENCES  
WITH THE EASTERN SIDE OF THE TROUGH AS IT SHIFTS EASTWARD BY  
AROUND THURSDAY, WHICH CAUSES SOME SLIGHT TIMING DIFFERENCES WITH  
THE ASSOCIATED POTENT COLD FRONT AN PLACEMENT OF WAVES OF LOW  
PRESSURE ALONG IT. GENERALLY THE 00Z ECMWF AND ITS ENSEMBLE MEAN  
WERE A BIT EAST COMPARED TO THE 00Z/06Z GFS SUITE. MOST GUIDANCE  
CONTINUES TO SHOW COMBINED NORTHERN/SOUTHERN STREAM TROUGHING  
THROUGH EARLY THURSDAY, WITH THE EXCEPTION OF THE UKMET WITH MORE  
SEPARATION. MEANWHILE ON THE WESTERN SIDE OF THE TROUGH,  
ADDITIONAL SHORTWAVE ENERGY WILL LIKELY DIVE THROUGH AROUND  
THURSDAY AND THEN COULD CREATE SOME NORTHERN/SOUTHERN STREAM  
SEPARATION IN THE OVERALL TROUGHING BY AROUND FRIDAY, BY HOLDING  
BACK SOUTHERN STREAM ENERGY IN THE SOUTHWEST. THE 00Z GFS WAS  
STRONGEST WITH THIS FEATURE AMONG THE DETERMINISTIC GUIDANCE AND  
MOST ENSEMBLE MEMBERS DURING THE 00/06Z CYCLE AND COMPARING TO THE  
NEW 12Z CYCLE AS WELL. MEANWHILE THE 00Z CMC KEEPS THE STREAMS A  
LITTLE MORE JOINED AND ENDS UP FASTER ESPECIALLY BY SATURDAY,  
WHILE THE 00Z ECMWF SEEMED TO BE THE BEST MIDDLE GROUND POSITION.  
THE LATTER PART OF THE FORECAST WAS BASED ON A BLEND FAVORING THE  
00Z ECMWF FOR THIS REASON, WITH LESSER INCLUSION OF THE 06Z GFS  
(WHICH WAS NOT QUITE AS HELD BACK AS THE 00Z), AS WELL AS SOME  
ENSEMBLE MEAN INCORPORATION, ESPECIALLY THE 00Z GEFS MEAN AS IT  
DISPLAYED HINTS OF THE STREAM SEPARATION THAT IS BECOMING THE  
CONSENSUS LATE IN THE PERIOD.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
THE DEEPENING TROUGH IN THE WEST WILL INITIALLY HELP CAUSE LIGHT  
TO MODERATE PRECIPITATION IN THE INTERMOUNTAIN WEST ON TUESDAY  
INTO WEDNESDAY, PARTICULARLY MOUNTAIN SNOW IN THE ROCKIES. BUT AS  
THE TROUGH AND THE COLD FRONT PUSHING AHEAD OF IT SHIFT EASTWARD,  
AMPLE GULF MOISTURE WILL BE DRAWN NORTHWARD AND CAUSE WIDESPREAD  
PRECIPITATION ACROSS MUCH OF THE CENTRAL AND EASTERN U.S.  
BEGINNING TUESDAY AND LASTING THROUGH THE WORKWEEK AS IT SLOWLY  
TRACKS EASTWARD. THE BEST CHANCE FOR HEAVY RAINFALL EXTENDS FROM  
THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY INTO PARTS OF THE  
OHIO/TENNESSEE VALLEYS TO THE APPALACHIANS AND THE EAST. FLASH  
FLOODING IS POSSIBLE IN THIS PATTERN, BUT MAY BE LIMITED BY LACK  
OF INSTABILITY, AND THE LOCATION OF HEAVY RAINFALL CAUSING ANY  
FLOODING/FLASH FLOODING IS ALSO UNCERTAIN. MEANWHILE IN THE COOLER  
AIR ON THE BACKSIDE OF THE SYSTEM, WINTRY WEATHER IS LIKELY, WITH  
POTENTIAL FOR NOTABLE SNOW FROM CENTRAL/SOUTH-CENTRAL PARTS OF THE  
PLAINS AND MISSISSIPPI VALLEY NORTHEASTWARD THROUGH THE GREAT  
LAKES AND THE INTERIOR NORTHEAST. SLEET AND FREEZING RAIN ARE ALSO  
POSSIBLE IN THE TRANSITION ZONE BETWEEN RAIN AND SNOW, BUT AT THIS  
POINT THE DETAILS OF THE WINTRY PRECIPITATION REMAIN IN FLUX  
DEPENDING ON LOWER-CONFIDENCE DETAILS OF EJECTING SHORTWAVE ENERGY  
AND FRONTAL WAVES.  
 
ABOVE AVERAGE TEMPERATURES BY AROUND 10-15F FOR HIGHS WILL SPREAD  
EASTWARD TUESDAY-THURSDAY ACROSS THE EASTERN THIRD OF THE COUNTRY  
WITH DAYTIME HIGHS GENERALLY 15-20 DEGREES ABOVE NORMAL ALONG THE  
EAST COAST ON THURSDAY. AT THE SAME TIME, ARCTIC HIGH PRESSURE  
DIVES INTO THE CENTRAL U.S. BEHIND THE COLD FRONT MIDWEEK,  
BRINGING CHILLY AND MUCH BELOW NORMAL TEMPERATURES ALL THE WAY  
FROM THE NORTHERN ROCKIES/HIGH PLAINS SOUTHWARD INTO TEXAS.  
WIDESPREAD DAYTIME HIGHS (AND SLIGHTLY LESS EXTREME OVERNIGHT  
LOWS) AS MUCH AS 10-25 DEGREES BELOW AVERAGE ARE LIKELY. THESE  
TEMPERATURES MAY MODERATE SLIGHTLY AS THEY SHIFT EAST INTO THE  
OHIO VALLEY/GULF COAST STATES NEXT FRIDAY AND THE EAST ON  
SATURDAY, THOUGH TEXAS REMAINS BELOW AVERAGE THROUGH THE END OF  
THE WEEK. THE WEST COAST STATES SHOULD BE NEAR NORMAL THROUGH MUCH  
OF NEXT WEEK OWING TO AMPLIFIED RIDGING ACROSS THE EAST PACIFIC.  
 
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  
 
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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