884  
FXUS02 KWBC 152025  
PMDEPD  
 
EXTENDED FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
424 PM EDT TUE MAR 15 2022  
 
VALID 12Z FRI MAR 18 2022 - 12Z TUE MAR 22 2022  
   
..OVERVIEW
 
 
A RELATIVELY PROGRESSIVE FLOW PATTERN WITH INCREASING AMPLITUDE IS  
EXPECTED TO BE IN PLACE ACROSS THE CONTINENTAL U.S. THROUGH THE  
UPCOMING WEEKEND. THE INITIAL SYSTEM OVER THE CENTRAL PLAINS  
FRIDAY WILL BE TRACKING NORTHEASTWARD TO THE GREAT LAKES AND THEN  
THE NORTHEAST THROUGH SUNDAY. BY LATE IN THE WEEKEND TO NEXT  
MONDAY, A MUCH STRONGER AND AMPLIFIED TROUGH WILL PROGRESS ACROSS  
THE WESTERN U.S., AND THEN REACHING THE PLAINS BY LATE MONDAY AND  
INTO TUESDAY, WITH THE OVERALL PATTERN BECOMING A BIT LESS  
PROGRESSIVE BY THEN. THIS WILL LIKELY BRING WIDESPREAD, BENEFICIAL  
RAINS TO THE WESTERN U.S., AND EVOLVE INTO A POTENTIALLY STRONG  
STORM SYSTEM OVER THE LOWER/MIDDLE MISSISSSIPPI VALLEY BY THE END  
OF THE FORECAST PERIOD. NO SIGNIFICANT ARCTIC AIR INTRUSIONS ARE  
CURRENTLY EXPECTED, AND TEMPERATURES WILL GENERALLY OSCILLATE  
BETWEEN NEAR NORMAL AND WELL ABOVE NORMAL AHEAD OF THE VARIOUS  
WAVES OF LOW PRESSURE.  
   
..GUIDANCE EVALUATION/PREDICTABILITY ASSESSMENT
 
 
THE 00Z GUIDANCE SUITE WAS IN GOOD AGREEMENT REGARDING THE  
EVOLUTION OF THE SYNOPTIC SCALE PATTERN ACROSS THE LOWER 48 DURING  
THE MEDIUM RANGE PERIOD. THEREFORE, A GENERAL MODEL BLEND OF THE  
00Z EC/CMC/UKMET AND THE 06Z GFS WERE APPLIED THROUGH DAY 5. THE  
06Z GFS WAS PHASED OUT BY DAYS 6 & 7 DUE TO A MARKEDLY DEEPER  
UPPER-TROUGH OVER THE WEST COMPARED TO MODEL CONSENSUS. AN  
ENSEMBLE BLEND CONSISTING OF THE ECE/GEFS/CMCE WITH SOME 00Z  
DETERMINISTIC EC WERE UTILIZED FOR DAYS 6 & 7.  
   
..WEATHER HIGHLIGHTS/THREATS
 
 
THE NEXT SYSTEM MOVING ACROSS THE PLAINS COULD BRING SOME MODERATE  
TO LOCALLY HEAVY RAINFALL AND SCATTERED THUNDERSTORMS TO PARTS OF  
THE OHIO/TENNESSEE VALLEYS AND SOUTHEAST ON FRIDAY. A NEW SYSTEM  
WILL EMERGE OVER THE PACIFIC NORTHWEST ON FRIDAY, SPREADING MUCH  
NEEDED RAIN SHOWERS ACROSS THE LOWER ELEVATIONS OF THE PACIFIC  
NORTHWEST/NORTHERN CALIFORNIA AS WELL AS MOUNTAIN SNOW OVER THE  
CASCADES AND ROCKIES THROUGH SATURDAY. THE SURFACE WAVE WILL THEN  
STRENGTHEN BENEATH AN AMPLIFYING UPPER-LEVEL TROUGH ON SUNDAY,  
ALLOWING FOR SNOW AND RAIN TO BLANKET THE ROCKIES THROUGH MONDAY.  
MODERATE TO HEAVY RAINFALL WILL SPREAD INTO THE SOUTHERN PLAINS ON  
MONDAY BEFORE EXPANDING INTO THE LOWER/MIDDLE MISSISSIPPI VALLEYS  
ON TUESDAY. THE AMPLIFIED SYNOPTIC PATTERN SUPPORTS SEVERE WEATHER  
ACTIVITY OVER PARTS OF EASTERN TEXAS INTO THE ARKLATEX ON MONDAY  
BEFORE SHIFTING INTO THE CENTRAL GULF COAST ON TUESDAY.  
 
KEBEDE/HAMRICK  
 
HAZARDS:  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE WESTERN WASHINGTON,  
FRI-SAT, MAR 18-MAR 19 AND MON-TUE, MAR 21-MAR 22.  
- HEAVY PRECIPITATION ACROSS PORTIONS OF THE SIERRA NEVADA, SAT,  
MAR 19.  
- HEAVY PRECIPITATION ACROSS NORTHERN MAINE, SAT-SUN, MAR 19-MAR  
20.  
- HEAVY RAIN ACROSS THE EASTERN PORTION OF THE SOUTHERN PLAINS,  
MON-TUE, MAR 21-MAR 22.  
- HEAVY RAIN ACROSS MUCH OF THE LOWER AND MID-MISSISSIPPI VALLEY,  
PORTIONS OF THE TENNESSEE AND OHIO VALLEYS, AND INTO THE MIDWEST,  
TUE, MAR 22.  
- SEVERE WEATHER ACROSS EASTERN/SOUTHERN TEXAS THROUGH MUCH OF THE  
DEEP SOUTH AND THE GULF COAST, MON-TUE, MAR 21-MAR 22.  
- SEVERE WEATHER ACROSS PORTIONS OF THE SOUTHEAST AND INTO THE  
CENTRAL/EASTERN GULF COAST, FRI, MAR 18.  
 
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  
 

 
 

 
 
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