106  
FXUS02 KWBC 082127  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
425 PM EST TUE MAR 08 2022  
 
VALID 12Z FRI MAR 11 2022 - 12Z TUE MAR 15 2022  
 
...WINTER STORM THREATS FOR PARTS OF THE MID-SOUTH TO THE INTERIOR  
NORTHEAST FRIDAY-SATURDAY...  
 
...HEAVY RAINFALL LIKELY ACROSS PORTIONS OF THE SOUTHEAST ON  
FRIDAY...  
 
   
..OVERVIEW
 
 
A POTENT SHORTWAVE IN THE SOUTHERN ROCKIES AND A NORTHERN STREAM  
SHORTWAVE THROUGH THE MIDWEST EARLY FRIDAY WILL COMBINE TO SUPPORT  
STRONG CYCLOGENESIS INTO THE EASTERN U.S. BY SATURDAY. THIS  
CLASSIC SPRING SYSTEM WILL FEATURE SNOW AND COLD TO THE  
NORTH/NORTHWEST OF THE SURFACE LOW, AND WARM/WET CONDITIONS AHEAD  
OF THE COLD FRONT. UPPER FLOW SHOULD THEN BECOME QUASI-ZONAL  
SUNDAY-MONDAY WITH A WEAK SHORTWAVE INTO THE NORTHWEST, THOUGH MAY  
AMPLIFY WITH TIME AS IT REACHES THE EAST ON TUESDAY. THE NEXT  
SHORTWAVE SHOULD REACH THE PACIFIC NORTHWEST BY NEXT TUESDAY AS  
WELL.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
THE LATEST RUNS OF THE MODELS CONTINUE TO GAIN CONFIDENCE WITH THE  
MELDING OF THE TWO STREAMS TO PRODUCE A WINTER STORM SYSTEM THAT  
WILL IMPACT THE CENTRAL AND EASTERN U.S. FRIDAY INTO SATURDAY.  
THERE REMAINS SOME TIMING DIFFERENCES WITH THE PASSAGE OF THE COLD  
FRONT WHICH IS BEING REFLECTED IN THE PLACEMENT OF THE QPF AND THE  
EXPECTED AMOUNTS. THE GFS HAS ISOLATED MAXIMUMS FOCUSED ON GULF  
SIDE OF FLORIDA, WHILE OTHERS HAVE STREAKS OF HIGHER AMOUNTS  
ACROSS NORTHERN/NORTHEAST FLORIDA AND INTO THE CAROLINAS. AS  
PREVIOUSLY NOTED, GFS HAD BEEN RUNNING FASTER BUT IT (ALONG WITH  
THE UKMET) ARE NOW IN WITHIN THE CLUSTER OF ACCEPTABLE GUIDANCE.  
WPC CONTINUED TO FAVOR A SLIGHTLY SLOWER, YET PROGRESSIVE  
EVOLUTION FOR THIS FEATURE WHICH CONSISTED OF A BLEND OF THE 00Z  
ECWMF/CMC/UKMET AND 06/00Z GFS THROUGH THE WEEKEND/EARLY NEXT WEEK  
BEFORE INCLUDING INCREASING WEIGHTS OF THE ECWMF ENSEMBLE MEAN AND  
GEFS MEAN FOR THE REMAINDER OF THE FORECAST. AFTER THE EXIT OF THE  
EASTERN U.S. SYSTEM THE MODELS ARE STRUGGLING A BIT WITH THE  
QUASI-ZONAL FLOW OVER WESTERN HALF OF THE COUNTRY. THE PACIFIC  
NORTHWEST WILL HAVE AN INCREASE IN PRECIPITATION AS SHORTWAVE  
ENERGY TRACKS THROUGH. INCLUSION OF THE MEANS FOR THE LATTER HALF  
OF THE FORECAST HELPS TO REDUCE THE NOISE AND UNCERTAINTY. THESE  
ARE DETAILS THAT WILL TAKE UNTIL THE SHORT RANGE PERIOD TO FULLY  
RESOLVE. SO IT'S HARD TO THROW ANY SOLUTION OFF THE TABLE AT THIS  
POINT.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
DEEP MOISTURE DRAWN NORTHWARD UP THE SOUTHEAST/MID-ATLANTIC STATES  
WILL AID IN SUSTAINING SHOWERS AND THUNDERSTORMS NEAR THE FRONTAL  
BOUNDARY OVER THE REGION. THERE WILL BE PERIODS OF MODERATE TO  
HEAVY RAINFALL, ESPECIALLY FOR PORTIONS OF FLORIDA AND SOUTHEAST  
GEORGIA. THIS BOUNDARY SHOULD FINALLY BECOME ABSORBED/PUSHED  
EAST/LIFT NORTHWARD WITH THE STRONG COLD FRONT ON SATURDAY THOUGH.  
RAINFALL WILL COME IN WAVES OVER THE SOUTHEAST, SOME OF WHICH  
COULD BE HEAVY AND FLOODING/FLASH FLOODING MAY BE A THREAT  
ESPECIALLY WHERE MULTIPLE ROUNDS OF CONVECTION TRAIN OVER THE SAME  
AREAS AND COMBINED WITH HEAVY RAINFALL THE PREVIOUS DAY IN THE  
SAME REGION. GIVEN THIS POTENTIAL, THE WPC DAY 4 (FRIDAY) NEWLY  
EXPERIMENTAL EXCESSIVE RAINFALL OUTLOOK HIGHLIGHTS A SLIGHT RISK  
AREA FROM THE FLORIDA BIG BEND TO SOUTHEAST GEORGIA. COLD AIR  
POURING INTO THE CENTRAL U.S. BEHIND THE DEVELOPING STORM SYSTEM  
INTO FRIDAY WILL SUPPORT RAIN CHANGING TO SNOW BEHIND THE FRONT  
FRIDAY EVENING, WITH ACCUMULATIONS POSSIBLE AS FAR SOUTH AS THE  
LOWER MISSISSIPPI VALLEY. THE CENTRAL LOW PRESSURE ASSOCIATED WITH  
THIS SYSTEM IS EXPECTED TO DEEPEN RAPIDLY OVER THE NORTHEAST,  
WHICH MAY ALLOW FOR AREAS OF HEAVY SNOWFALL FOR THE GREAT LAKES  
AND INTERIOR NORTHEAST.  
 
THE ARCTIC AIRMASS BEHIND THE FRONT WILL BRING DAYTIME HIGHS  
20-30+ DEGREES BELOW NORMAL AS FAR SOUTH AS TEXAS ON FRIDAY.  
OVERNIGHT LOWS ACROSS THE NORTHERN PLAINS AND IN HIGHER ELEVATIONS  
OF THE ROCKIES ARE LIKELY TO BE NEAR OR BELOW ZERO FOR MANY  
LOCATIONS. MODIFYING SOME WITH TIME, THE COLD AIR WILL SHIFT INTO  
THE MIDWEST ON SATURDAY AND THE EASTERN U.S. ON SUNDAY FOLLOWING  
THE FRONTAL PASSAGE (WITH ABOVE NORMAL TEMPS AHEAD OF IT). EVEN  
FOR PARTS OF NORTHERN FLORIDA AND THE SOUTHEAST, LOW TEMPERATURES  
SUNDAY MORNING COULD BE NEAR OR BELOW FREEZING WITH RECORD LOWS  
POSSIBLE IN SOME LOCATIONS. BY NEXT WEEK, PARTS OF THE WEST AND  
CENTRAL U.S. MAY SEE MODERATELY ABOVE NORMAL TEMPERATURES AS  
PERIODIC UPPER RIDGING SLIDES THROUGH.  
 
CAMPBELL/SANTORELLI  
 
HAZARDS:  
- HEAVY SNOW ACROSS MUCH OF THE INTERIOR NORTHEAST, THE UPPER OHIO  
VALLEY AND NEARBY APPALACHIANS, FRI-SAT, MAR 11-MAR 12.  
- HEAVY PRECIPITATION ACROSS THE HIGHER ELEVATIONS OF THE PACIFIC  
NORTHWEST, SAT-TUE, MAR 12-MAR 15.  
- HEAVY RAIN ACROSS THE LOWER ELEVATIONS OF THE PACIFIC NORTHWEST  
INTO NORTHWESTERN CALIFORNIA, SUN-MON, MAR 13-MAR 14.  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE INTERIOR MID-ATLANTIC  
INTO NEW ENGLAND, FRI-SAT, MAR 11-MAR 12.  
- HEAVY RAIN ACROSS PORTIONS OF THE SOUTHEAST AND THE  
MID-ATLANTIC, FRI-SAT, MAR 11-MAR 12.  
- HEAVY RAIN ACROSS PORTIONS OF SOUTHEASTERN NEW ENGLAND AND  
SOUTHERN/DOWNEAST MAINE, SAT, MAR 12.  
- HEAVY SNOW ACROSS PORTIONS OF THE NORTHERN ROCKIES, SUN, MAR 13.  
- HIGH WINDS ACROSS MUCH OF THE NORTHEAST INTO THE MID-ATLANTIC,  
SAT-SUN, MAR 12-MAR 13.  
- SEVERE WEATHER ACROSS PORTIONS OF THE SOUTHEAST, FRI, MAR 11.  
- FLOODING POSSIBLE ACROSS PORTIONS OF THE OHIO VALLEY.  
- FLOODING OCCURRING OR IMMINENT ACROSS PORTIONS OF THE  
OHIO/TENNESSEE VALLEY.  
- MUCH BELOW NORMAL TEMPERATURES THROUGH THE GREAT PLAINS AND INTO  
THE CENTRAL/SOUTHERN ROCKIES, FRI-SAT, MAR 11-MAR 12.  
- MUCH BELOW NORMAL TEMPERATURES FROM THE GREAT LAKES AND OHIO  
VALLEY DOWN THROUGH THE DEEP SOUTH, SOUTHERN APPALACHIANS, AND  
MUCH OF THE SOUTHEAST, SAT-SUN, MAR 12-MAR 13.  
 
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  
 
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  
 

 
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab HPC Page Main Text Page