918  
FXUS01 KWBC 120728  
PMDSPD  
 
SHORT RANGE FORECAST DISCUSSION  
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD  
227 AM EST MON FEB 12 2018  
 
VALID 12Z MON FEB 12 2018 - 12Z WED FEB 14 2018  
   
..WARMING TREND FOR MUCH OF THE NATION THROUGH WEDNESDAY
 
 
...HEAVY SNOW FOR THE SAN JUAN MOUNTAINS IN SOUTHERN COLORADO  
TODAY...  
 
THE UPPER PATTERN WILL FEATURE A SERIES OF UPPER LEVEL  
DISTURBANCES AND GENERAL UPPER LEVEL TROUGHING OVER THE WESTERN  
HALF OF THE NATION THROUGH MID-WEEK. AN UPPER LEVEL DISTURBANCE  
SINKING SOUTH THROUGH THE GREAT BASIN AND CALIFORNIA TODAY WILL  
COINCIDE WITH AN INCREASE IN MOISTURE AND PRECIPITATION ACROSS THE  
SOUTHWEST INTO THE FOUR CORNERS REGION TODAY WITH HIGHER ELEVATION  
SNOW FORECAST ACROSS NORTHERN ARIZONA, UTAH AND COLORADO. SNOWFALL  
WILL BE LOCALLY HEAVY ACROSS THE COLORADO ROCKIES, WITH FAVORED  
LOCATIONS WITHIN THE SAN JUAN MOUNTAINS IN PARTICULAR, EXPECTED TO  
RECEIVE OVER A FOOT OF NEW SNOW BY TUESDAY MORNING. RETROGRESSION  
OF THE UPPER DISTURBANCE NEAR CALIFORNIA WILL ALLOW PRECIPITATION  
TO DWINDLE ACROSS THE SOUTHWEST FOR TUESDAY.  
 
A SECOND UPPER LEVEL DISTURBANCE IS ON TRACK TO IMPACT THE  
NORTHWESTERN U.S. STARTING TUESDAY NIGHT AS A COLD FRONT SWEEPS  
ACROSS THE AREA. THE QUICK MOVING NATURE OF THE SYSTEM AND A LACK  
OF BETTER MOISTURE SHOULD KEEP RAIN/SNOWFALL TOTALS ON THE LIGHT  
SIDE.  
 
OUT EAST, LIGHT TO LOCALLY MODERATE RAIN WILL CONTINUE ACROSS THE  
MID-ATLANTIC COAST AND SOUTHEAST U.S. TODAY AS A COLD FRONT  
CONTINUES TO MOVE OFF INTO THE WESTERN ATLANTIC. HIGH PRESSURE  
WILL SLIDE EASTWARD AS THE FRONT MOVES SOUTH INTO FLORIDA THROUGH  
TUESDAY, ALLOWING FOR MOSTLY DRY WEATHER FOR THE MAJORITY OF THE  
EASTERN HALF OF THE COUNTRY TODAY INTO TUESDAY. SHOWERS ARE  
EXPECTED TO INCREASE DURING THE DAY ON TUESDAY FROM EASTERN TEXAS  
INTO THE LOWER MISSISSIPPI VALLEY AS MOISTURE AND WARMER AIR MOVES  
NORTHWARD FROM THE GULF OF MEXICO ACROSS THE WESTERN END OF A  
LINGERING FRONTAL BOUNDARY IN THE GULF. RAINFALL COVERAGE AND  
INTENSITY WILL EXPAND NORTH AND EAST INTO THE OHIO VALLEY AND  
APPALACHIANS FOR WEDNESDAY.  
 
AS HIGH PRESSURE MOVES INTO THE WESTERN ATLANTIC LATE TUESDAY INTO  
WEDNESDAY, RETURN FLOW AROUND THE WEST SIDE OF THE HIGH WILL ALLOW  
WARMER TEMPERATURES TO SPREAD NORTH INTO LOCATIONS EAST OF THE  
CONTINENTAL DIVIDE. THIS WILL ALLOW FOR SOME RATHER DRAMATIC  
TEMPERATURE CHANGES FOR THE PLAINS COMPARED TO TODAY. BY  
WEDNESDAY, HIGHS ACROSS OKLAHOMA AND KANSAS ARE EXPECTED TO REACH  
INTO THE 60S AND LOWER 70S. LINGERING SNOW COVER TO THE NORTH,  
FROM NEBRASKA, IOWA AND NORTHERN ILLINOIS/INDIANA NORTHWARD,  
SHOULD KEEP HIGH TEMPERATURES LOWER THAN WHAT THEY WOULD OTHERWISE  
BE. STILL, WEDNESDAY'S MAXIMUM TEMPERATURES SHOULD STILL RISE 10  
TO 20 DEGREES ABOVE AVERAGE FOR THE NORTH-CENTRAL U.S. AND  
MODESTLY ABOVE AVERAGE FOR THE REMAINDER OF THE LOWER 48, EXCEPT  
ALONG THE WEST COAST WHERE TEMPERATURES SHOULD STAY NEAR AVERAGE.  
 
OTTO  
 
GRAPHICS AVAILABLE AT  
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP  

 
 
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