314  
FXUS02 KWBC 040653  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
152 AM EST FRI MAR 04 2022  
 
VALID 12Z MON MAR 07 2022 - 12Z FRI MAR 11 2022  
   
..HEAVY RAIN POTENTIAL ACROSS THE OHIO VALLEY INTO MONDAY
 
 
   
..OVERVIEW
 
 
THE MEDIUM RANGE PERIOD BEGINS MONDAY WITH BROAD TROUGHING (WITH  
EMBEDDED SHORTWAVES) ACROSS THE CENTRAL U.S. PUSHING A COLD FRONT  
INTO THE EAST. THIS SETUP BRINGS A THREAT FOR HEAVY TO EXCESSIVE  
RAINFALL ACROSS THE OHIO VALLEY, WITH SNOW TO THE NORTH.  
SHORTWAVES SHOULD WEAKEN IN THE FLOW AS THEY PROGRESS DOWNSTREAM  
AS HEIGHTS BEGIN TO RISE OVER THE EAST COAST. OUT WEST, A STRONG  
RIDGE OVER THE EAST PACIFIC SHOULD ALLOW FOR SHORTWAVES TO KEEP  
REINFORCED TROUGHING OVER THE ROCKIES, WHICH EVENTUALLY SHOULD  
PRESS EAST INTO THE PLAINS BY LATE NEXT WEEK.  
 
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
RECENT MODEL GUIDANCE CONTINUES TO SHOW GOOD AGREEMENT IN THE  
LARGE SCALE PATTERN THROUGH MUCH OF THE PERIOD, WITH MOSTLY  
TYPICAL TIMING AND DETAIL DIFFERENCES NEEDING TO BE WORKED OUT.  
GOOD CONSENSUS EXISTS THAT A SURFACE WAVE (OR TWO) WILL DEVELOP  
ALONG THE COLD FRONT OVER THE OHIO VALLEY ON MONDAY, PROGRESSING  
INTO THE MID-ATLANTIC BY TUESDAY. THERE CONTINUES TO BE SOME  
SUBTLE TIMING DIFFERENCES WITH THIS LOW, WHICH STEMS FROM  
DIFFERENCES ALOFT IN THE SHORTWAVE. THE CMC AND UKMET ARE A HAIR  
FASTER THAN THE GFS/ECMWF AND ENSEMBLE MEANS, BUT A GENERAL BLEND  
OF THE GUIDANCE DOES OFFER A GOOD STARTING POINT ON POSITION.  
 
FARTHER WEST, ENERGY DIVING SOUTH ALONG THE WEST COAST ON MONDAY  
PRODUCES DIFFERENCES THAT BECOME MORE NOTABLE TUESDAY AND BEYOND.  
BEFORE THE NEW 00Z RUNS THIS MORNING, THE CMC APPEARED TO BE AN  
OUTLIER WITH A SLOWER/MORE AMPLIFIED SOLUTION CLOSING OFF A LOW  
OVER THE SOUTHWEST ON TUESDAY AND THE REMAINDER OF THE GUIDANCE  
MORE OPEN/FASTER (TO VARYING DEGREES). HOWEVER, THE NEW 00Z  
GUIDANCE ARRIVING THIS MORNING FROM THE GFS, THE ECMWF, AND THE  
UKMET HAS ALSO TRENDED TOWARDS THE CMC WITH A CLOSED LOW. THE WPC  
FORECAST FOR OVERNIGHT LEANED MORE ON THE FASTER SIDE OF THE  
ENVELOPE GIVEN THE CMC SEEMED AN OUTLIER, BUT WITH THE NEW 00Z  
RUNS (WHICH WERE NOT AVAILABLE AT FORECAST ISSUANCE), EVEN THE WPC  
FORECAST MAY NOW BE TOO FAST MID WEEK AND BEYOND WITH THE ENERGY  
AS IT MOVES INTO THE CENTRAL PLAINS. IN OTHER WORDS, THIS REMAINS  
A VERY LOW CONFIDENCE FORECAST.  
 
THE NEXT SHORTWAVE ARRIVES INTO THE PACIFIC NORTHWEST AROUND  
WEDNESDAY-THURSDAY WHICH SHOULD HELP TO REINFORCE BROAD TROUGHING  
OVER THE ROCKIES WHICH EVENTUALLY PUSHES INTO THE CENTRAL U.S. BY  
THE END OF THE WEEK. THERE ARE SOME TIMING DIFFERENCES REGARDING  
BOTH THE TROUGH AXIS AND THE ASSOCIATED SURFACE FRONT. THE 18Z/MAR  
3 GFS WAS FASTER THAN THE ECMWF WITH THE ENSEMBLE MEANS ALSO MAYBE  
MORE IN LIKE WITH THE SLOWER ECMWF. THE WPC FORECAST LEANED  
HEAVILY ON THE ENSEMBLE MEANS FOR THIS SYSTEM GIVEN THE LATE  
PERIOD/LOW PREDICTABILITY WITH SOME INCLUSION OF THE DETERMINISTIC  
RUNS FOR A LITTLE ADDED SYSTEM DEFINITION.  
 
   
..WEATHER HIGHLIGHTS/THREATS
 
 
RAIN AND THUNDERSTORMS WILL BE WIDESPREAD ALONG AND AHEAD OF THE  
COLD FRONT MOVING THROUGH THE EASTERN U.S. EARLY NEXT WEEK. THE  
AXIS OF THE HEAVIEST RAIN BY MONDAY IS FORECAST FROM THE LOWER  
OHIO VALLEY INTO THE CENTRAL APPALACHIANS AND NORTHERN  
MID-ATLANTIC. FLOODING AND FLASH FLOODING ARE POSSIBLE  
PARTICULARLY IN AREAS THAT SEE REPEAT/TRAINING CONVECTION AND IN  
AREAS WHERE SOILS ARE ALREADY WET, AND NEWLY EXPERIMENTAL SLIGHT  
RISKS OF EXCESSIVE RAINFALL REMAIN IN PLACE FOR DAY 4. A SWATH OF  
WINTRY PRECIPITATION COULD DEVELOP ON THE NORTH SIDE, WITH LIGHT  
TO MODERATE AMOUNTS POSSIBLE FROM INTO THE GREAT LAKES AND  
INTERIOR NORTHEAST. THEN BY THE MIDDLE OF NEXT WEEK, GULF MOISTURE  
COULD RETURN TO THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST, BUT  
UNCERTAINTY REMAINS WITH RESPECT TO RAINFALL TOTALS, ALL DEPENDENT  
ON A STALLING BOUNDARY AND POSSIBLE WAVES OF LOW PRESSURE.  
 
THE WEST SHOULD SEE A BREAK IN THE PRECIPITATION ON MONDAY, BUT  
MOUNTAINS SNOWS RETURN BY TUESDAY AND BEYOND FOR THE PACIFIC  
NORTHWEST AND ESPECIALLY THE ROCKIES. THERE REMAINS SOME  
POTENTIAL, BUT LOW CONFIDENCE, ON SNOWFALL INTO THE NORTHERN  
PLAINS/UPPER MIDWEST LATE WEEK AS LOW PRESSURE TRIES TO DEVELOP  
OVER THE CENTRAL STATES.  
 
TEMPERATURES SHOULD FEEL VERY MILD FOR THE SOUTH-CENTRAL TO  
EASTERN PART OF THE U.S. ON MONDAY AHEAD OF THE COLD FRONT, WITH  
TEMPERATURES 10 TO 30 DEGREES ABOVE AVERAGE AND DOZENS OF DAILY  
RECORD HIGH MINIMUM AND MAXIMUM TEMPERATURES POSSIBLE.  
TEMPERATURES SHOULD MODERATE BACK TO NEAR NORMAL AFTER THE FRONTAL  
PASSAGE ON TUESDAY. THE WEST AND PARTS OF THE CENTRAL U.S. WILL  
GENERALLY BE COOLER THAN AVERAGE UNDERNEATH PERSISTENT TROUGHING  
THROUGH MUCH OF THE PERIOD. ALTHOUGH WITH MORE SUBSTANTIAL  
TROUGHING INTO THE REGION MID TO LATE NEXT WEEK, TEMPERATURES  
SHOULD TREND COOLER WITH ANOMALIES 10 TO 30 DEGREES BELOW NORMAL  
POSSIBLE ACROSS THE NORTHERN AND CENTRAL PLAINS, AND AS FAR SOUTH  
AS TEXAS AND OKLAHOMA.  
 
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  
 
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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