FXUS63 KOAX 212123
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
323 PM CST SUN NOV 21 2010
.SHORT TERM...TONIGHT THROUGH WEDNESDAY.
SHORT TERM CONCERNS WILL CONTINUE TO BE LIGHT
PRECIPITATION...PRECIPITATION TYPE...AND TEMPERATURES.
AT 21Z...THE SFC LOW PRES CENTER WAS EAST OF DES MOINES NEAR
WATERLOO IOWA...WITH THE TRAILING SFC COLD FRONT THRU KANSA CITY
NOTED BY THE FALLING TEMPERATURES AND NORTHWEST SFC WINDS.
TEMPERATURES ACRS THE LOCAL AREA WERE MOSTLY IN THE 30S UNDER
CLOUDY SKIES. OF NOTE ON THE 12Z OAX SOUNDING WAS THE MOIST COLD
CONDITIONS BELOW 5K FEET...IN CONTRAST TO A MILD H8 TEMP AROUND
+11 DEG C. THIS SHALLOW COLD AIR WILL REMAIN A FORECAST ISSUE
THROUGH THE PERIOD. FROM THE 12 UPPER AIR MAPS...A 110+ KT UPR
LEVEL JET WAS DIVING SWD FM WRN CANADA TO CA...MEANWHILE...A 120KT
JET STRETCHED FM SW TO NE INTO THE CNTRL PLAINS. THE H5 LONGWAVE
TROF CONTINUED TO EXTEND FM CANADA BACK TOWARD MT/CA. THE LONGWAVE
PATTERN WAS STACKED AND LOOKED SIMILAR AT H7 AND AT H85. THE H85
TEMP GRADIENT WAS STRONG NEAR THE NEB/KS BORDER...WITH MILD 10+
DEG C READINGS ACRS KS AND MUCH COLDER +5 TO -5 DEG C TEMPS ACRS
NEBRASKA. WATER VAPOR STLT IMAGERY AND LIGHTNING SHOW AN AREA OF
MID LEVEL LOW PRES OVER CNTRL CA.
TONIGHT...THE SHORT WAVE TROF OVER CNTRL CALIFORNIA IS ALREADY
MOVING INTO UT AND WILL DEEPEN AS IT MOVES INTO WY AND ERN MT BY
12Z. AN AREA OF WIDSPREAD SNOW IS EXPECTED TO DEVELOP OVER THE
DAKOTAS TONIGHT AND INTO MINNESOTA AS THE MID TROPOSPHERIC WAVE
MOVES INTO MINNESOTA MONDAY. FOR OUR AREA WILL INITIALLY BE UNDER
SUBSIDENCE AND HAVE SEEN SOME THINNING. WE WILL SEE THE NEXT STORM
SYSTEM BRING MID LEVEL UVV AND AFFECT THE H85 FLOW OVERNIGHT. H85
WAA INCREASES WITH 25-30KT H85 WINDS INCREASING TO 40 TO 50KTS
ACRS SRN NEB AND KS. MEANWHILE...SFC LOW PRES IN ERN CO WILL SHIFT
EASTWARD ACRS KS TOWARD NORTHEAST KS BY 12Z. THIS LIFT OF WARM
MOIST AIR ABOVE THE SHALLOW COLD LAYER SHOULD REINFORCE THE
STRATUS AND RESULT IN AREAS OF FOG/DRIZZLE/FREEZING FOG/FREEZING
DRIZZLE DEPENDING ON THE SFC TEMPERATURES. THESE CONDITIONS SHOULD
LINGER THROUGH MONDAY MORNING WITH IMPROVEMENT AS THE SFC LOW
AGAIN MOVES TOWARD DES MOINES BY 15Z. HAVE HIGHLIGHTED IN THE HWO
AND MAY ISSUE AN SPS REGARDING THE FREEZING DRIZZLE
OVERNIGHT...BUT WILL NOT ISSUE ANY HEADLINES ATTM. FORECAST
SOUNDINGS SCOUR OUT THE LOW CLDS ACRS THE SRN CWA MONDAY...SO
ALTHOUGH WILL REMAIN COLD IN THE NORTH MONDAY...SHOULD SEE HIGH IN
THE 40S FOR THE SOUTHERN HALF OF THE FCST AREA.
MONDAY NIGHT...ANOTHER RIPPLE IN THE FLOW ALOFT TRACKS EASTWARD...IN
THE NOW MORE ZONAL MID LEVEL FLOW. THIS WILL ALLOW A WEAK WIND
SHIFT WILL SLIP THROUGH AND COLD TEMPERATURES TO BE REINFORCED ACRS
THE STATE THROUGH TUESDAY.
TUESDAY NIGHT...THE SFC HIGH PRESSURE SHIFTS EAST AND ATTENTION
TURNS TO THE STORM SYSTEM WHICH WILL MOVE INTO THE PLAINS FOR THE
PEAK HOLIDAY TRAVEL PD. AS LOW PRES ORGANIZES OVR THE ROCKIES
SOUTHEAST WINDS WILL INCREASE...MODIFYING LOW TEMPS WED MORNING AND
AGAIN WRMING H85 TEMPS. THIS STRONG WAA PATTERN ABOVE THE SHALLOW
COLD AIR WILL AGAIN RESULT IN THE RISK OF LIGHT FREEZING
DRIZZLE/FREEZING RAIN...CHANGING TO RAIN. AT THIS TIME THE MORE
ORGANIZED PRECIPITATION STILL LOOKS TO BE TO THE NORTH AND
SOUTH/EAST THROUGH WEDNESDAY...HOWEVER EVEN SMALL AMOUNTS OF
FREEZING DRIZZLE AND FREEZING RAIN CAN STILL MAKE TRAVEL A
CHALLENGE. TEMPERATURES WEDNESDAY COULD BE MUCH WARMER IN THE
SOUTH...AND WILL WAIT UNTIL THERE IS BETTER CONTINUITY TO WARM
INTO THE 50S.
.LONG TERM...WEDNESDAY NIGHT THROUGH THURSDAY.
FAIRLY BENIGN WEATHER IS EXPECTED THROUGH THE EXTENDED
PERIOD...WHICH IS PREFERRED GIVEN THE THANKSGIVING HOLIDAY. RATHER
BLUSTERY DAY IN STORE FOR THURSDAY THOUGH WITH NORTHWEST WINDS AT
15/25 MPH AND FAIRLY CHILLY TEMPERATURES IN THE MID/UPPER 20S. AN
UPPER LOW IS PROGGED TO MOVE THROUGH THE DAKOTAS THOUGH WITH SOME
SNOW POTENTIAL THERE ON THURSDAY...BUT WILL KEEP OUR FORECAST DRY
ATTM. BEYOND THEN...A WEAK RIDGE BUILDS ACROSS THE PLAINS THROUGH
THE REMAINDER OF THE WEEKEND WITH MODERATING TEMPERATURES BACK
INTO THE MID/UPPER 40S FOR SATUDAY AND SUNDAY.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
MIX OF MVFR/IFR CIGS CURRENTLY COVERING ERN NEB THIS AFTN WITH THE
SATURATED LAYER STILL CONFINED TO LOWEST 5KFT LAYER AND EXPECT
AMPLE BNDRY LYR MOIST WILL REMAIN IN PLACE THRU THE FCST PD.
CONDITIONS WILL DETERIORATE AT ALL SITES TO IFR BY 22/06Z WITH
OCCASIONAL LIFR MOSTLY BTWN 22/09Z-13Z...WITH -FZDZ/BR AT KOFK...AND
-DZ/BR AT KOMA/KLNK. ALSO...MOD/HIGH ICING POTENTIAL GENERALLY
FL020-030 AGL MAINLY AFT 22/00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY/DEWALD/DEE