FXUS63 KABR 072118
AFDABR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ABERDEEN SD
318 PM CST MON DEC 7 2009

.SHORT TERM...THROUGH THURSDAY AM

THANKFULLY GUIDANCE TRENDS AND TRACK HAVE GOOD CONTINUITY WITH
UPCOMING STORM...THE ONLY CAVEAT IS FOR SOMEWHAT LATER ARRIVAL
TIMING ON SNOWFALL. CONDITIONS AHEAD OF THIS SYSTEM...MAINLY LOW
LEVEL LAPSE RATES AND TEMPERATURES...CONTINUE TO BE CONDUCIVE FOR
FLURRY ACTIVITY...SO SHOULD BE AN EASY TRANSITION TO LIGHT SNOW
WITH SEEDER FEEDER. MORE SIGNIFICANT SNOWFALL WILL OCCUR WITH
STRONGEST ISENTROPIC FORCING SOUTH OF I90. EXPECT VERY HIGH SNOW
TO LIQUID RATIOS UNDER PRESENCE OF ARCTIC AIRMASS. POPS WILL DROP
OFF RAPIDLY EARLY WEDNESDAY MORNING...HOWEVER WITHOUT SIGNIFICANT
SURFACE HIGH TO CLEAR OUT REGION...COMBINED WITH LOW LEVEL
TEMPERATURES IN THAT FAVORABLE DENDRITIC GROWTH ZONE...PERSISTENT
CLOUD COVER AND FLURRIES COULD CONTINUE INTO THURSDAY. AS FOR
WINDS...GIVEN LACK OF SIGNIFICANT FOLLOW ON HIGH PRESSURE...MODEST
PRESSURE GRADIENT WILL LEAD TO ONLY 1 TO 2 MB/6HR PRESSURE RISES.
BUFKIT HAS 30KTS AT H85 TRANSLATE DOWN TO 20-25KTS..AND GIVEN A
NEARLY -20C AIRMASS THROUGH H925...WIND CHILL READINGS WILL BE
DOWN TO -30F IN SPOTS WEDNESDAY AM.

.LONG TERM...THURSDAY THROUGH MONDAY
NO REAL GREAT CHANCE OF ANY SIGNIFICANT PRECIPITATION DURING THE
EXTENDED...SO MAIN FOCUS WILL BE ON TEMPERATURES. THE PERIOD
STARTS OFF WITH ELONGATED HIGH PRESSURE FROM THE PACIFIC
NORTHWEST TO THE GULF COAST. THIS HIGH SHIFTS EASTWARD
THURSDAY...WITH THE CENTRAL PORTION OF THE HIGH REMAINING OVER THE
NORTHERN PLAINS. H85 TEMPS WILL BE IN THE -15 TO -23 DEGREE
RANGE...WITH THE COLDEST TEMPS ACROSS THE NORTHEASTERN CWA. AS THE
PORTION OF THE HIGH OVER THE UNITED STATES CONTINUES TO PUSH
EASTWARD...AN ARCTIC FRONT APPROACHES FROM THE NORTHWEST FRIDAY
NIGHT...AND LOOKS TO BRING A REINFORCING SHOT OF COLD AIR TO THE
REGION OVER THE WEEKEND. MAY SEE JUST A BRIEF PERIOD OF WARMING
LATE SUNDAY NIGHT INTO EARLY MONDAY...THEN CANADIAN HIGH PRESSURE
DROPS BACK OVER THE NORTHERN AND CENTRAL PLAINS DURING THE DAY
MONDAY AFTERNOON AND MONDAY NIGHT.

&&

.AVIATION...
SCT-BKN MVFR CLOUDS BETWEEN 1500-2200 FEET WILL REMAIN OVER THE
AREA THROUGH THE EARLY EVENING HOURS. THE CLOUD COVERAGE WILL
INCREASE FROM SOUTH TO NORTH OVERNIGHT. LOOK FOR SNOW TO BEGIN
ACROSS THE FAR SOUTHERN CWA DURING THE EARLY MORNING HOURS...THEN
SPREAD NORTHWARD THROUGH THE MORNING TUESDAY. VSBYS WILL BE
UNRESTRICTED OVERNIGHT...THEN WILL FALL INTO THE MVFR RANGE WITH
THE SNOW ON TUESDAY.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&

$$
SHORT TERM...CONNELLY
LONG TERM...PARKIN
AVIATION...PARKIN

WEATHER.GOV/ABERDEEN