FXUS63 KUNR 040959
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
300 AM MST FRI DEC 4 2009

.DISCUSSION...CURRENT SURFACE ANALYSIS HAS HIGH PRESSURE OVER THE 
ROCKIES REGION...WITH PRESSURE GRADIENT WEAKENING ACROSS THE PLAINS. 
UPPER LEVEL ANALYSIS SHOWS LOW OVER THE SOUTHERN HUDSON BAY 
REGION...WITH TROF STRETCHING FROM THE HIGH PLAINS EASTWARD TO THE 
GREAT LAKES REGION. WEAK SHORTWAVE RIDGE IS LOCATED OVER THE 
NORTHERN ROCKIES.  

COLD AND SOMEWHAT UNSETTLED WX IS IN STORE FOR THE FORESEEABLE 
FUTURE. ANOTHER LOW PRESSURE SYSTEM IS MOVING SOUTHEASTWARD ACROSS 
BC NOW AND WILL BRING ANOTHER SHOT OF ARCTIC AIR AND SPOTTY LIGHT 
SNOW OVER THE WEEKEND.

WILL SEE A LITTLE BREAK FROM THE COLD TODAY AS THE RIDGE 
SLIDES EAST INTO THE HIGH PLAINS. SKIES WILL BE MOSTLY SUNNY IN 
GENERAL. SOME MILDER AIR WILL ADVECT IN...ALLOWING TEMPS TO GET INTO 
THE MID 20S TO LOWER 30S AT MOST LOCATIONS WITH LIGHT SOUTH TO 
SOUTHWEST WINDS.    

TEMPS WILL DROP INTO THE SINGLE DIGITS AND TEENS TONIGHT...WITH SOME 
INCREASING CLOUDINESS AS UPPER LOW MOVES INTO THE NORTHERN ROCKIES. 
COLD FRONT WILL PASS THROUGH EARLY SATURDAY AS UPPER LOW SLIDES INTO 
WY. BRISK NW WINDS WILL DEVELOP BEHIND THE FRONT WITH COLDER AIR 
ADVECTING IN. HIGHS WILL BE SIMILAR TO TODAY...BUT A FEW DEGREES 
COOLER ACROSS NORTHERN AND WESTERN AREAS. MAIN PUSH OF COLDER AIR 
WILL HOLD OFF UNTIL SATURDAY NIGHT AND SUNDAY. 

SOME LIGHT SNOW WILL DEVELOP ACROSS THE AREA OVER THE WEEKEND...WITH 
BETTER CHANCES LOOKING TO BE ACROSS NORTHEASTERN WY AND FAR WESTERN 
SD LATE SATURDAY INTO SUNDAY. SOME LIGHT ACCUMULATIONS LOOK POSSIBLE 
...BUT TRACK AND EVOLUTION OF LOW AS IT MOVES INTO THE CENTRAL 
ROCKIES IS STILL NOT CLEAR. AT THIS POINT...NOT EXPECTING MORE 
THAN AN INCH OR TWO OF ACCUMULATION IN SOME SPOTS. HAVE RAISED POPS 
FOR SATURDAY AFTERNOON THROUGH SUNDAY...BUT WILL HOLD OFF ON ANY 
LIKELY POPS AT THIS POINT UNTIL IT BECOMES CLEARER WHERE THE BETTER 
CHANCES WILL BE. HIGHS WILL ONLY BE IN THE TEENS AT MOST LOCATIONS 
ON SUNDAY...WITH LOWS NEAR OR BELOW ZERO SUNDAY NIGHT IN MANY 
LOCATIONS.   

EXTENDED...ANOTHER UPPER TROF IN WRN CONUS WILL MV SLOWLY ACRS 
REGION MON/TUES BRINGING A CHC OF SNOW WITH IT. COLD NW FLOW WL CONT 
ACRS AREA WED/THU BEFORE A MILDER ZONAL FLOW DEVELOPS LATE IN THE 
WEEK. TEMPS WILL REMAIN WELL BELOW NORMAL THROUGH THURSDAY...WARMING 
TO NEAR NORMAL ON FRIDAY.

&&

.AVIATION...VFR CONDS ARE EXPECTED THRU THE FCST PERIOD.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&

$$