384  
FXUS01 KWBC 202000  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
400 PM EDT FRI APR 20 2018  
 
VALID 00Z SAT APR 21 2018 - 00Z MON APR 23 2018  
 
...HEAVY RAINFALL TO SET UP OVER THE ARKLATEX INTO THE LOWER  
MISSISSIPPI VALLEY AND MID-SOUTH REGION...  
 
...CONTINUED DRY, WINDY CONDITIONS WILL SUPPORT A THREAT FOR  
DANGEROUS WILDFIRE DEVELOPMENT OVER SOUTHERN NEW MEXICO INTO FAR  
WEST TEXAS...  
 
AN EXPANSIVE UPPER LOW SPINNING OVER THE FOUR CORNERS REGION WILL  
CONTINUE MIGRATION EASTWARD DURING THE NEXT COUPLE OF DAYS. AS THE  
SYSTEM TREKS TOWARD THE SOUTHERN/CENTRAL HIGH PLAINS, A MARKED  
UPTICK IN GULF MOISTURE TRANSPORT WILL LEND ITSELF TO AN ORGANIZED  
HEAVY RAINFALL THREAT FROM THE ARKLATEX EASTWARD. BEFORE THIS  
OCCURS, SOME OF THE INITIAL CONVECTION INVIGORATING ALONG THE NEW  
MEXICO/TEXAS BORDER MAY TAKE ON SEVERE CHARACTERISTICS WITH LARGE  
HAIL AND DAMAGING WINDS THE MOST LIKELY HAZARDS. AS THE CONVECTIVE  
ACTIVITY BEGINS TO CONSOLIDATE, THE SYSTEM SHOULD SHIFT TOWARD  
BEING HEAVY RAINFALL PRODUCER. THIS WILL PARTICULARLY BE THE CASE  
FROM THE RED RIVER EASTWARD THROUGH THE LOWER MISSISSIPPI VALLEY  
AND INTO SECTIONS OF MISSISSIPPI AND ALABAMA. AS SUCH, POCKETS OF  
FLASH FLOODING ARE EXPECTED OVER THE ARKLATEX REGION TOWARD THE  
SOUTHERN U.S. WHILE WIDESPREAD RAINFALL AMOUNTS WILL RESIDE IN THE  
1 TO 2 INCH RANGE, SPOTS OF LOCALLY HEAVIER AMOUNTS ARE LIKELY  
WHERE TRAINING AND REPEAT CONVECTION OCCURS.  
 
WHILE SEVERE WEATHER AND FLASH FLOODING ARE POSSIBILITIES WITH  
THIS MENTIONED SYSTEM, IT WILL ALSO PRODUCE HIGHER ELEVATION SNOWS  
ACROSS THE COLORADO ROCKIES WHILE ALSO CONTINUING THE THREAT FOR  
WILDFIRE PRODUCTION OVER SOUTHERN NEW MEXICO INTO WEST TEXAS. DRY,  
WINDY CONDITIONS ON TOP OF ALREADY DRY SOILS ACROSS THE REGION  
WILL CONTINUE TO FOSTER THE DEVELOPMENT OF ADDITIONAL FIRE-RELATED  
ISSUES. BY EARLY IN THE WEEKEND, THE THREAT AREA SHOULD ONLY COVER  
FAR WEST TEXAS INTO THE BIG BEND REGION AS THE SYSTEM TRANSLATES  
EASTWARD.  
 
A SYSTEM ACCELERATING THROUGH THE PACIFIC NORTHWEST WILL SPREAD  
MODEST PRECIPITATION AMOUNTS OVER THE OLYMPICS AND WASHINGTON  
CASCADES. GIVEN APPRECIABLE COLD AIR ALOFT ACCOMPANYING THIS  
TROUGH, SOME SNOWFALL ACCUMULATIONS ARE POSSIBLE ACROSS THE HIGHER  
ELEVATIONS OF THE MENTIONED TERRAIN.  
 
REGARDING TEMPERATURES, MOST LOCATIONS FROM THE SOUTHERN/CENTRAL  
ROCKIES EASTWARD CAN EXPECT BELOW AVERAGE READINGS GIVEN EXTENSIVE  
CLOUD COVER AND WIDESPREAD PRECIPITATION. DEPARTURES FROM  
CLIMATOLOGY MAY REACH THE 10 TO 15 DEGREE RANGE UNDERNEATH THE  
UPPER LOW ITSELF WHICH COVERS MUCH OF KANSAS AND OKLAHOMA.  
OTHERWISE, EXPECT SLIGHTLY ABOVE AVERAGE READINGS OVER THE WESTERN  
STATES, PARTICULARLY OVER THE CENTRAL GREAT BASIN.  
 
RUBIN-OSTER  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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