FXUS63 KOAX 192141
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
341 PM CST FRI NOV 19 2010
.SHORT TERM...TONIGHT THROUGH MONDAY.
THE MAIN CONCERNS IN THE SHORT TERM WILL BE THE POTENTIAL FOR
LIGHT PRECIPITATION...PRECIPITATION TYPE AND TEMPERATURES.
OF NOTE ON THE MORNING UPPER AIR CHARTS WAS THE NEARLY STACKED LOW
NEAR LAKE WINNIPEG. 130M+ HT FALLS WERE NOTED NEAR LAKE
WINNIPEG...HOWEVER MID TO UPR LEVEL FLOW WAS ZONAL ACRS THE CNTRL
PLAINS. AT 21Z...THE SFC COLD FRONT HAD JUST PUSHED SOUTH OF FALL
CITY. THERE WAS A MIX OF CLOUDS AND SUN WITH CIRRUS CLOUDS. TEMPS
IN THE NORTH WERE IN THE 30S...AND IN THE SOUTH IN THE 50S. THIS
ZONAL FLOW WILL RESULT IN THE SFC FRONT STALLING OUT OVER KANSAS
AND MISSOURI.
DRIER SFC FLOW MOVES IN TONIGHT WITH DEWPOINTS IN THE TEENS TO
LOWER 20S NORTH HOWEVER...H85 FLOW BEGINS TO INCREASE ACRS THE SRN
CWA...THICKENING CLOUDS. THIS FLOW WILL CONTINUE OVERNIGHT AND
PUSH NORTHWARD DURING THE DAY SATURDAY. SINCE THE SFC REMAINS IN
THE SHALLOW COOL AIR...LOOK FOR CLOUDS TO DEVELOP WITH ISENTROPIC
UPGLIDE ON THE 285K SFC. WITH THE DRY AIR IN PLACE...DIFFICULT TO
SAY HOW MUCH DRIZZLE WILL DEVELOP. DID MENTION PATCHY DRIZZLE IN A
WEST TO EAST BAND FM LNK AND OLU EASTWARD SATURDAY.
SATURDAY NIGHT...STRONGER H85 FLOW DEVELOPS WITH GOOD WAA. THIS
SHOULD INCREASE THE COVERAGE OF LIGHT PRECIP AND WILL LIFT THE
WARM FRONT NORTH. CHOSE TO MENTION DRIZZLE (AND LIGHT RAIN FOR
PARTS OF WRN IA) FOR NOW...AND FREEZING DRIZZLE IN THE NORTH AND
ALSO AREAS OF FOG INTO SUNDAY MORNING.
HIGHS SATURDAY ARE HELD TO THE 30S NORTH AND 40S SOUTH. MUCH
WARMER FOR SUNDAY WITH HIGHS IN THE 40S NORTH TO AROUND 60 FAR
SOUTH AHEAD OF THE NEXT FROPA SUNDAY AFTERNOON. THE BRUNT OF THE
PRECIP WITH THE NRN SHORTWAVE TROF SUNDAY SHOULD BE NORTH AND EAST
OF THE FCST AREA. THE H85 FNT LAGS SUNDAY NIGHT AND EARLY MONDAY
WITH YET ANOTHER SHORTWAVE TROF IN THE SW FLOW ALOFT...THERE MAY
BE ENOUGH LIFT FOR LIGHT SNOW IN THE NORTH MONDAY.
MEANWHILE...THERE MAY BE SOME LINGERING DRIZZLE OR LIGHT RAIN IN
FAR SOUTHEAST NEB. MONDAY SHOULD ALSO SEE A GRADIENT IN
TEMPERATURES FROM NW TO SE WITH HIGHS IN THE 30S NORTH...AND
SHOULD BE IN THE 40S AND LOWER 50S SOUTH.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
MEDIUM RANGE MODELS ALL ADVERTISING A LONGWAVE TROF PATTERN
ENVELOPING THE CONUS WITH ACCOMPANYING ARCTIC INTRUSION PENETRATING
SWD AND PREDOMINATELY AFFECTING THE NRN/CNTRL PLAINS...UPPER
MIDWEST...MID MS VLY. QUICK COMPARISON SHOWS THE CMC WITH A CLOSED
500MB LOW CROSSING THE NRN TIER STATES THRU THE ENTIRE FCST
PD...WHILE THE ECM/GFS MAINTAIN A WELL AMPLIFIED TROF.
MEANWHILE...THE GFS/CMC SFC FEATURES ARE SIMILAR PROJECTING LEE-SIDE
SFC CYCLOGENESIS IN ERN CO WITH ATTENDANT THERMAL BOUNDARY EXTENDING
EWD INVOF THE NEB/KS BORDER. BOTH GFS/CMC SHOW THE SFC LOW FIZZLING
OUT TUESDAY NIGHT AS THE ARCTIC AIR POURS SWD INTO THE PLAINS.
APPEARS TO BE A CHANCE FOR SOME SNOW WITH THE FROPA TUESDAY
NIGHT/WED MORNING TIME FRAME WHEN MID LYR AGEOSTROPHIC LIFT IS
MAXIMIZED OVER THE CWA. HOWEVER GIVEN TRACK OF 500MB HFC...SFC LOW
TRACK...MID LYR LAPSE RATES....THINK THAT GREATEST SNOW TOTALS WILL
BE REALIZED IN THE DAKOTAS/MN ON WEDNESDAY. FOR OUR AREA...AM
GUESSING 2 INCHES OR SO BY EARLY WED MORNING. NIL MID/UPPER QVEC
CONVG SUGGESTING THE DEEP CAA WILL OVERCOME ANY DPVA BY AFTN THEN.
FOR THURSDAY AND FRIDAY...LONGWAVE TROF WILL GRADUALLY BE REPLACED
BY EWD BUILDING UPPER RIDGE.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
COLD FRONT HAD PASSED ALL TAF SITES THROUGH 18Z...WITH A BRIEF
WINDOW FOR SOME MVFR CIGS FOR AN HOUR OR TWO BEHIND THE FRONT AT
KOMA/KLNK THROUGH ABOUT 20Z. OTHERWISE...VFR CONDITIONS PREVAIL
OVERNIGHT AS THE FRONT CONTINUES TO DRIFT SOUTH. THE FRONT IS
EXPECTED TO STALL AND LIFT BACK NORTH ON SATURDAY. THIS SHOULD ALLOW
MVFR CIGS TO REDEVELOP FROM SOUTH TO NORTH FROM 13-16Z. GFS WAS
INDICATING MORE POTENTIAL FOR SOME DRIZZLE TO DEVELOP AT KLNK/KOMA
THAN THE NAM...AND FOR NOW...OPTED TO LEAVE IT OUT THROUGH
18Z...ALTHOUGH DRIZZLE AND EVENTUALLY IFR CIGS ARE LIKELY FROM
20/18Z AND BEYOND.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/DEE/DEWALD