FXUS63 KOAX 310758
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
258 AM CDT SUN OCT 31 2010
.DISCUSSION...
MAIN CONCERN FOR TODAY IS POSSIBLE LIGHT PCPN. TEMPERATURES SHOULD
PROVIDE THE MAIN CHALLENGES AFTER TODAY.
UPPER AIR CHARTS FROM LAST EVENING SHOWED A FAIRLY DECENT SYSTEM
OVER THE ROCKIES. 12 HOUR 500 MB HEIGHT FALLS ESTIMATED AT AROUND
120 METERS OVER UTAH. SYSTEM IS NOW MOVING EASTWARD FROM WYOMING
AND COLORADO. THERE WAS SOME CLOUD TO GROUND LIGHTNING ACTIVITY LAST
EVENING OVER THE ROCKIES. SYSTEM WILL CONTINUE TO MOVE EAST THROUGH
MID AMERICA TODAY...BUT PCPN SHOULD BE LIGHT. MODELS STILL SHOW THAT
850 MB TO 700 MB LAYER WILL BE FAIRLY DRY...AND BEST CHANCE FOR
ANYTHING TO REACH THE GROUND AND MEASURE WOULD BE ACROSS NORTHEAST
NEBRASKA. WILL CARRY A SLIGHT CHANCE OF SHOWERS AND/OR SPRINKLES
FARTHER SOUTH INTO PARTS OF SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
CLOUD COVER AND POOR MIXING WINDS SHOULD HELP KEEP HIGHS IN THE 50S
THIS AFTERNOON.
LARGE SCALE MID TROPOSPHERIC FLOW WILL UNDERGO SOME CHANGES THE NEXT
FEW DAYS...WITH FLOW AMPLIFICATION. A FAIRLY DEEP TROUGH DEVELOPS IN
THE PACIFIC ALONG ABOUT 160 TO 140 W...AND A RIDGE STRENGTHENS OVER
THE WESTERN U.S. AND WESTERN CANADA. AN IMPRESSIVE 500 MB TROUGH IS
ALSO EXPECTED TO DEVELOP TO OUR EAST. THIS PUTS OUR AREA IN NORTH OR
NORTHWEST FLOW ALOFT...AND SHOULD ALLOW SOME COOLER AIR TO MOVE INTO
THE AREA LATER IN THE WEEK. ONE COLD FRONT SHOULD MOVE THROUGH
TUESDAY NIGHT AND EARLY WEDNESDAY. DID NOT MENTION ANY PCPN...BUT
MODELS (ESPECIALLY 00Z ECMWF) SUGGEST LIGHT PCPN POSSIBLE OVER PARTS
OF IOWA...MINNESOTA...WISCONSIN. CUT BACK TEMPERATURES WEDNESDAY
INTO FRIDAY (ESPECIALLY HIGHS) AS COOL HIGH PRESSURE BUILDS OVER
MONTANA AND WYOMING WEDNESDAY. 1000-500 MB THICKNESS VALUES DROP TO
LESS THAN 540 DM BY 12Z THURSDAY ACCORDING TO THE 00Z ECMWF. THE 00Z
GFS WAS NOT QUITE AS COOL...BUT HAS TRENDED COOLER SINCE YESTERDAY.
DID NOT MENTION ANY PCPN THURSDAY...BUT AGAIN MODELS SUGGEST AT
LEAST SOME LIGHT PCPN POSSIBLE TO OUR NORTHEAST AND EAST.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
06Z TAFS
A SHORTWAVE TROF OVR COLORADO WILL MOVE ACROSS NEBRASKA THRU THIS
EVENING. THERE WERE A COUPLE OF LIGHTNING STROKES OVR CO WHERE MID
LEVEL LAPSE RATES WERE QUITE STEEP. THIS FEATURE WILL PUSH EAST AND
LOOK FOR INCREASING HIGH CLOUDS AND THEN THICKENING MID CLOUDS
AROUND 14-15K FEET. DESPITE UVV AND MID LEVEL LAPSE RATES AROUND
7DEG C/KM...CONDITIONS WILL REMAIN VFR WITH DRY CONDITIONS BELOW 12K
FEET. LIGHT SFC WINDS WILL BECOME MORE EAST AND SOUTHEAST...
INFLUENCED BY SFC HIGH PRESSURE OVER MN AND THE GRTLKS AND AN AREA
OF SURFACE LOW PRES OVER OK/TX. WINDS SPEEDS SHOULD GENERALLY BE
12KT OR LESS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
DISCUSSION...MILLER
AVIATION...ZAPOTOCNY