High Wind in South Dakota, April 15, 2008

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
343 PM CDT MON APR 14 2008

.SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT
FIRE DANGER AND WINDS ARE TOPS FOR THIS DISCUSSION. FOR TNT WE ARE
BOUNCING OFF WIND CRITERIA OVER PARTS OF THE CWA BUT ITS NOT A
SLAM DUNK AREAL COVERAGE-WISE...AND FEEL THAT SOME DECOUPLING WILL
OCCUR THIS EVENING. THE ONE POTENTIAL PROBLEM COULD BE THE HIGHER
ELEVATIONS IN THE NORTHEAST CWA...SAY AROUND K8D3. BUT ONCE AGAIN AM
CONCERNED THAT AREAL COVERAGE WOULD NOT BE ENOUGH TO WARRANT AN
ADVISORY. DECIDED ALONG WITH ADJACENT OFFICES THAT GOING WITH ONE
TOWARD MORNING AND INCLUDING THE REST OF THE CWA WOULD WORK OKAY
FOR MUCH OF THE DAY ON TUESDAY...EVEN THOUGH TIMING IS A BIT EARLY
FOR PARTS OF THE AREA. WINDS ARE FULLY EXPECTED TO BE IN THE 25 TO
45 MPH RANGE ON TUESDAY OUT AHEAD OF FRONTAL BOUNDARY WITH TIGHT
SFC GRADIENT. ALSO...TEMPERATURES ON TUESDAY SHOULD BE FAIRLY
WARM AND MOS LOOKED OKAY EXCEPT OVER NORTHEAST CWA SNOWFIELD WHICH
HAS BEEN TOUGH TO GET RID OF. BACKED OFF SOME ON THE MERCURY FOR
THEM. WOULD LIKE TO SEE WINDS FAVOR A BIT MORE OF A SOUTHWEST
DIRECTION FOR BEST MIXING BUT THAT MAY NOT HAPPEN EXCEPT OVER
WESTERN CWA.

FOR TUESDAY NIGHT AND WEDNESDAY SYSTEM COMES OUT OF THE ROCKIES
WITH AN ENERGY SPLIT...ONE CHUNK HEADING INTO THE SOUTHERN PLAINS
WITH THE OTHER HEADING ACROSS NORTHERN PLAINS. WHILE MOST OF THE
ENERGY BYPASSES THE ABR CWA...THE MODELS ARE STILL PREDICTING SOME
LATE DAY INSTABILITY AND MOISTURE RETURN AHEAD OF BOUNDARY. MID LEVEL
LAPSE RATES ALSO QUITE STEEP SO A SHOWER NOT OUT OF THE QUESTION.
HEADING INTO WEDNESDAY THE MID LEVELS REALLY COOL OFF AND LAPSE
RATES REMAIN VERY STEEP IN THE LOW TO MID LEVELS. WOULD NOT BE
SURPRISED TO SEE ISOLATED ACTIVITY...ESPECIALLY IN THE AFTERNOON.
MEANWHILE TEMPERATURES ON WEDNESDAY WILL BE SOMEWHAT COOLER AND
FELT MOS WAS A BIT OPTIMISTIC BASED ON H85/H925 TEMPS.

.LONG TERM...THURSDAY THROUGH MONDAY
CONDITIONS SHOULD BE STABILIZING ON THURSDAY WITH HIGH PRESSURE
BUILDING INTO THE FORECAST AREA...BOTH AT THE SURFACE AND ALOFT.
SOME COOLER AIR WILL BE IN PLACE ACROSS THE FORECAST AREA ON
THURSDAY...COMPARED TO EARLIER IN THE WEEK...WITH 925HPA TEMPS
ONLY TOPPING OUT AROUND +7C TO +11C DURING PEAK HEATING/MIXING.
HOWEVER...WEAK WAA SETS UP FOR FRIDAY WITH SOME STRONGER WAA FOR
FRIDAY NIGHT THROUGH SATURDAY NIGHT...AS UPPER LEVEL STEERING FLOW
BECOMES QUITE AMPLIFIED WHEN DEEP LONGWAVE TROFFING OVER THE
WESTERN CONUS SETS UP BY THIS WEEKEND. THE BIG QUESTION FOR THIS
WEEKEND SURROUNDS TIMING OF INDIVIDUAL UPPER WAVES ROTATING
THROUGH THE BASE OF THE UPPER TROF AND LAUNCHING OUT ONTO THE
CENTRAL AND NORTHERN PLAINS LATE IN THE WEEKEND AND INTO EARLY
NEXT WEEK. CONSENSUS IN MEDIUM RANGE MODELS AND ALL THEIR ENSEMBLE
RUNS SUGGESTS THERE IS A CHANCE FOR SOME PRECIPITATION ACROSS THIS
AREA...MOST LIKELY CONVECTIVE IN NATURE ON SUNDAY AND STRATIFORM
IN NATURE ON MONDAY. SO...HAVE ACCEPTED GUIDANCE POPS AN INSERTED
SOME RW-/R- MENTION IN THE GRIDS FOR THE LATER PORTION OF THE
EXTENDED FORECAST.

&&
.AVIATION...
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS WITH
UNRESTRICTED VSBYS AND CLOUDS AOA 15K FEET. HOWEVER...WINDS WILL
BE STRONG FROM THE SOUTH/SOUTHEAST THROUGH TUESDAY.
&&

.FIRE WEATHER...
TUESDAY SHOULD AGAIN FEATURE AN EXTREME FIRE DANGER THREAT OVER
AREAS WEST OF THE JAMES VALLEY. AFTERNOON RELATIVE HUMIDITIES
AROUND 20 PERCENT AND WINDS OF 20 TO 40 MPH SHOULD PROMOTE
EXTREMELY DANGEROUS FIRE CONDITIONS FOR THE AFTERNOON AND EVENING.
&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
     EVENING FOR LOWER BAD RIVER-MISSOURI COTEAU-UPPER CHEYENNE-
     UPPER MISSOURI COTEAU.

     WIND ADVISORY FROM 4 AM CDT /3 AM MDT/ TO 9 PM CDT /8 PM MDT/
     TUESDAY FOR BROWN-BUFFALO-CAMPBELL-CLARK-CODINGTON-CORSON-
     DAY-DEUEL-DEWEY-EDMUNDS-FAULK-GRANT-HAMLIN-HAND-HUGHES-HYDE-
     JONES-LYMAN-MARSHALL-MCPHERSON-POTTER-ROBERTS-SPINK-STANLEY-
     SULLY-WALWORTH.

MN...WIND ADVISORY FROM 4 AM TO 9 PM CDT TUESDAY FOR BIG STONE-
     TRAVERSE.

&&

SHORT TERM...TDK
LONG TERM...DORN
AVIATION...TDK

WEATHER.GOV/ABERDEEN