841  
FXUS02 KWBC 111857  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
156 PM EST FRI FEB 11 2022  
 
VALID 12Z MON FEB 14 2022 - 12Z FRI FEB 18 2022  
 
...MID-LATE WEEK SYSTEM TO BRING POTENTIAL FOR HEAVY RAIN FROM THE  
SOUTH-CENTRAL TO EAST-CENTRAL U.S. AND WINTRY WEATHER FROM THE  
MIDWEST THROUGH GREAT LAKES AND INTERIOR NORTHEAST...  
   
..OVERVIEW
 
 
THE DOMINANT FOCUS OF THE MEDIUM RANGE FORECAST WILL BE ON A  
POTENT UPPER LOW FORECAST TO ENTER THE PACIFIC NORTHWEST ON  
MONDAY. THIS FEATURE SHOULD DROP SOUTHEASTWARD ALONG THE WEST  
COAST EARLY IN THE WORKWEEK, CROSS THE SOUTHWEST AROUND LATE  
TUESDAY/WEDNESDAY, AND BECOME INCORPORATED INTO A  
PLAINS/EAST-CENTRAL U.S. MEAN TROUGH BY THE LATTER HALF OF THE  
WEEK. THIS EVOLUTION ALOFT WILL LEAD TO SURFACE CYCLOGENESIS AND  
STRONG FRONTAL SYSTEMS IN THE CENTRAL U.S., DRAWING MOISTURE  
NORTHWARD FROM THE GULF OF MEXICO AND PRODUCING NOTABLE  
PRECIPITATION FROM THE PLAINS EASTWARD NEXT WEDNESDAY INTO FRIDAY.  
EXPECT RAIN AND THUNDERSTORMS IN SOUTHERN AREAS, WHILE SNOW AND  
WINTRY WEATHER ARE LIKELY ON THE NORTHERN AND WESTERN SIDE OF THE  
PRECIPITATION SHIELD ACROSS THE CENTRAL ROCKIES/PLAINS AND THROUGH  
THE MIDWEST, GREAT LAKES, AND INTERIOR NORTHEAST.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
00Z/06Z GUIDANCE REMAINS MORE AGREEABLE AND CONSISTENT THAN  
AVERAGE FOR THE DAYS 3-5 MONDAY-WEDNESDAY PART OF THE FORECAST.  
CONSENSUS SHOWS A STRONG EAST PACIFIC RIDGE SUPPORTING A  
SOUTHEASTWARD TRACK FOR THE UPPER LOW OF INTEREST, FROM THE  
PACIFIC NORTHWEST DURING THE DAY MONDAY AND REACHING THE SOUTHWEST  
BY LATE TUESDAY-EARLY WEDNESDAY. MEANWHILE UPPER TROUGHING LIFTS  
AWAY FROM THE EAST AND AN INITIAL WESTERN U.S. RIDGE BROADENS AS  
IT CONTINUES EASTWARD. A BLEND OF THE GFS/ECMWF/CMC/UKMET FROM  
EACH MODEL'S LATEST AVAILABLE CYCLE REPRESENTED THE PREVAILING  
THEMES OF THE FORECAST WELL. NEW 12Z RUNS ARE SIMILAR EXCEPT FOR  
THE CMC THAT STRAYS WEAKER/SLOWER WITH THE UPPER SYSTEM TUESDAY  
ONWARD, AFFECTING ITS FORECAST FARTHER EAST THROUGH THE REST OF  
THE WEEK.  
 
UNCERTAINTY AND GUIDANCE SPREAD/RUN-TO-RUN VARIABILITY INCREASE  
SOMEWHAT DURING THE LATTER HALF OF THE PERIOD. CONTRIBUTORS TO THE  
DIFFERENCES INCLUDE UPSTREAM SHORTWAVE ENERGY FORECAST TO DROP  
INTO AND THROUGH THE WEST DURING MID-LATE WEEK AS WELL AS  
IMPORTANT SPECIFICS OF NORTHERN STREAM FLOW THAT MAY INTERACT WITH  
THE LEADING UPPER LOW AS IT EJECTS BEYOND THE ROCKIES/PLAINS.  
THESE ISSUES WILL AFFECT THE TIMING, STRENGTH, AND TRACK OF LOW  
PRESSURE AS IT PROGRESSES FROM NEAR THE SOUTH-CENTRAL PLAINS  
NORTHEASTWARD AFTER MIDWEEK. IN RECENT RUNS THE GFS HAS TENDED TO  
BE A BIT ON THE DEEPER SIDE OF THE OPERATIONAL MODEL SPREAD (AND  
WITHIN THE DEEPER PART OF THE GEFS ENVELOPE) AT SOME VALID TIMES  
BUT HAS BEEN TRENDING WEAKER SINCE THE 00Z RUN. THE CMC HAS BEEN  
ON THE WEAKER/SHEARED SIDE. FOR EARLY NEXT THURSDAY THE 12Z UKMET  
HAS COME IN HALFWAY BETWEEN THE 12Z GFS AND 00Z ECMWF FOR DEPTH.  
MEANWHILE THE ECMWF HAS TRENDED FASTER OVER THE PAST COUPLE DAYS  
AND THE NEW 12Z RUN IS A BIT WEAKER AND FARTHER EAST VERSUS THE  
00Z RUN. TRANSITIONING THE 00Z/06Z MODEL BLEND TO INCLUDE SOME 06Z  
GEFS/00Z ECMWF MEAN INPUT BY DAYS 6-7 THURSDAY-FRIDAY ACCOUNTED  
FOR THE GRADUAL INCREASE OF UNCERTAINTY AND PROVIDED GOOD  
CONTINUITY IN PRINCIPLE. THE FORECAST YIELDED A MODESTLY STRONGER  
SYSTEM TRACKING NORTHEAST FROM THE PLAINS, WITH ADDITIONAL ROOM  
FOR REFINEMENT IF CONFIDENCE INCREASES.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
THE UPPER LOW/TROUGH DROPPING INTO THE WEST EARLY IN THE WEEK WILL  
SPREAD AN AREA OF PRECIPITATION ACROSS THE REGION, BUT TOTALS OF  
COASTAL/LOWER ELEVATION RAIN AND MOUNTAIN SNOW SHOULD REMAIN LIGHT  
TO MODERATE. HOWEVER, WIDESPREAD SHOWERS AND THUNDERSTORMS ARE  
LIKELY TO DEVELOP OVER THE CENTRAL U.S. BY WEDNESDAY INTO THURSDAY  
AS SURFACE LOW PRESSURE CONSOLIDATES IN THE HIGH PLAINS AND  
ADVECTS SUBSTANTIAL MOISTURE FROM THE GULF OF MEXICO NORTHWARD  
INTO THE PLAINS, MISSISSIPPI/TENNESSEE/OHIO VALLEYS, AND  
EVENTUALLY THE EASTERN SEABOARD. STRONG STORMS COULD BE POSSIBLE,  
WITH THE CURRENT DAYS 6-7 STORM PREDICTION CENTER OUTLOOK SHOWING  
SOME SEVERE THREAT FROM PARTS OF THE SOUTHERN PLAINS INTO  
TENNESSEE VALLEY AND VICINITY. THERE WILL ALSO BE FLASH FLOODING  
CONCERNS WHERE HEAVY RAINFALL OCCURS. CONTINUE TO MONITOR  
FORECASTS AS UNCERTAIN DETAILS OF THESE POTENTIAL THREATS BECOME  
BETTER REFINED. AT THE SAME TIME, EXPECT A BAND OF SNOW IN THE  
COLDER AIR ON THE NORTHWESTERN PERIPHERY OF THE SYSTEM. THE BEST  
POTENTIAL FOR MEANINGFUL ACCUMULATIONS CURRENTLY EXTENDS FROM  
CENTRAL PARTS OF THE PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY AND  
MIDWEST/GREAT LAKES REGION INTO INTERIOR NEW ENGLAND, WHILE MIXED  
PRECIPITATION/ICE CANNOT BE RULED OUT IN THE TRANSITION ZONE  
BETWEEN THE SNOW AND RAIN. TOTALS/LOCATION OF ANY SNOW WILL BE  
VERY SENSITIVE TO PRECISE STRENGTH AND TRACK OF THE SYSTEM. STRONG  
WINDS MAY BE POSSIBLE IN THE GRADIENT BETWEEN THE SURFACE LOW AND  
HIGH PRESSURE TO THE NORTHWEST, AND THEN POSSIBLY ALONG PARTS OF  
THE EAST COAST WITHIN THE SOUTHERLY FLOW AHEAD OF THE STORM.  
 
THE CHANGE AND PROGRESSION OF THE OVERALL PATTERN WILL BE EVIDENT  
IN TEMPERATURES OVER THE COURSE OF NEXT WEEK. WARMER THAN AVERAGE  
TEMPERATURES ACROSS THE CENTRAL GREAT BASIN AND SOUTHWEST MONDAY  
WILL MODERATE TO NEAR NORMAL OR SLIGHTLY BELOW TUESDAY AND  
WEDNESDAY UNDERNEATH THE INCOMING UPPER TROUGH/LOW. WEST COAST  
STATES SHOULD SEE READINGS REBOUND TO MODERATELY ABOVE NORMAL FOR  
THE LATTER HALF OF THE WEEK. MEANWHILE A WARMING TREND OVER THE  
CENTRAL U.S. SHOULD PEAK AROUND TUESDAY-WEDNESDAY AS HIGH  
TEMPERATURES REACH 10-20F ABOVE NORMAL BOTH DAYS WITH LOWS 15-25F  
ABOVE NORMAL WEDNESDAY. THE SYSTEM/COLD FRONT EMERGING FROM THE  
WEST WILL THEN QUICKLY DROP TEMPERATURES TO 5-15F OR SO BELOW  
NORMAL FOR THURSDAY-FRIDAY. MEANWHILE THE MIDWEEK WARMTH OVER THE  
PLAINS WILL MOVE INTO THE EAST FOR THURSDAY-FRIDAY WITH ONE OR TWO  
DAYS OF HIGHS UP TO 10-20F ABOVE NORMAL AND LOWS EXCEEDING 20F  
ABOVE NORMAL OVER SOME AREAS. THIS WILL REPRESENT A SIGNIFICANT  
WARMING TREND FOR THE EASTERN SEABOARD WHICH CAN EXPECT TO START  
THE WEEK WITH TEMPERATURES 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  
 
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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