FXUS63 KTOP 141745
AFDTOP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1145 AM CST MON DEC 14 2009
.UPDATE...
UPDATED FOR 18Z TAFS
&&
.DISCUSSION...
SEE PREVIOUS DISCUSSION
&&
.AVIATION...
EXPECT CONDITIONS TO REMAIN VFR THROUGH THE TAF PERIOD. FLURRIES
CONTINUE TO FALL OVER TOP/FOE THROUGH 20Z...BUT EXPECT SOME
CLEARING TO OCCUR AS DRIER AIR WORKS IN. QUESTION AS TO WHAT
CLOUD SHIELD OVER NEBRASKA WILL DO. CONDITIONS REMAIN MVFR OVER
MUCH OF NEB...AND WERE SLIDING SE VIA RECENT SATELLITE TRENDS.
BASES OF THIS CLOUD DECK HAVE BEEN RISING OVER THE PAST COUPLE OF
HOURS...BUT HOVER AROUND MVFR/VFR THRESHOLDS. QUESTION REMAINS AS
TO WHERE CIGS WILL ACTUALLY COME IN AT ONCE THE CLOUD SHIELD
INVADES TAF SITES.
BYRNE
&&
PREV DISCUSSION... /ISSUED 349 AM CST MON DEC 14 2009/
DISCUSSION...
COLD FRONT WAS MOVING SOUTHEAST ACROSS THE CWA THIS MORNING AND AT
09Z EXTENDED FROM TOPEKA TO WICHITA. TEMPERATURES HAVE PLUMMETED
INTO THE TEENS BEHIND THE FRONT SO FAR THIS MORNING. GIVEN UPSTREAM
SINGLE DIGIT ABOVE AND BELOW ZERO DO NOT SEE ANY CHANCE OF A DIURNAL
RISE IN TEMPERATURES AND ADJUSTED HOURLY TEMPERATURES FOR A GRADUAL
FALL INTO THE EARLY EVENING. IN ADDITION WITH THE COMBINATION OF
WINDS AND TEMPERATURES WIND CHILL VALUES WILL BE AROUND MINUS 12 IN
THE NORTHWEST THIS MORNING AND WILL CONTINUE TO HIT IN THE HWO. LIFT
AHEAD OF EJECTING WAVE OVER WESTERN KANSAS AND SOUTHWEST NEBRASKA
WAS PRODUCING SOME LIGHT SNOW IN NEBRASKA AND INTO PARTS OF NORTH
CENTRAL KANSAS THIS MORNING. WILL MENTION FLURRIES THROUGH THE
MORNING HOURS ACROSS MUCH OF THE NORTHERN CWA AND A FLURRY OR PATCHY
DRIZZLE MIX IN THE NORTHEAST THROUGH NOON. FORECAST SOUNDING WOULD
SUPPORT THE FREEZING DRIZZLE BUT TEMPS COOLING ENOUGH FOR ICE
CRYSTAL GROWTH BEHIND THE FRONT. LIFT SHIFTS EAST THIS AFTERNOON
WITH THE DEPARTING MID LEVEL WAVE.
TONIGHT THE ARCTIC AIR WILL CONTINUE TO POUR INTO NORTH CENTRAL AND
NORTHEAST KANSAS WITH LOWS FALLING TO THE SINGLE DIGITS BELOW ZERO
IN NORTH CENTRAL KANSAS. WIND CHILLS TONIGHT WILL APPROACH ADVISORY
LEVELS IN THE NORTH AND RANGE FROM MINUS 10 TO MINUS 15. LATER
SHIFTS WILL NEED TO MONITOR FOR POSSIBLE ADVISORY LATER TODAY.
ON TUESDAY THE CENTER OF THE HIGH WILL BE OVER SOUTHWEST IOWA BY 00Z
WEDNESDAY. HIGHS TUESDAY WILL ONLY REACH INTO THE TEENS NORTH TO THE
20S SOUTH IN THE SNOW FREE AREAS.
TEMPERATURES REBOUND ON WEDNESDAY WITH WARM AIR ADVECTION ON THE
BACK SIDE OF THE SURFACE HIGH. AND MADE ONLY A SLIGHT ADJUSTMENT TO
CURRENT HIGHS IN THE 30S TO LOW 40S.
NO CHANGE TO THE REST OF THE FORECAST ATTM AS MEDIUM RANGE MODELS
DIVERGE ON LATE WEEK SYSTEM WITH THE ECMWF DEEPER AND FURTHER SOUTH
WITH THE UPPER LOW IN THE NORTHERN STREAM WHILE THE GEM AND GFS ARE
WEAKER AND FURTHER NORTHEAST WITH THE UPPER TROUGH.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
BYRNE
