498 
FXUS63 KOAX 041130
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
530 AM CST FRI JAN 4 2013

.AVIATION...
12Z TAFS FOR KOMA...KOFK...KLNK
A STORM SYSTEM IS FORECAST TO TRACK ACROSS KANSAS INTO MISSOURI
THROUGH THE TAF PERIOD. VFR CONDITIONS WILL CONTINUE AS THE
CURRENT CLOUD TRAJECTORIES HOLD THE BULK OF THE CLOUDS SOUTH OF
THE AREA.

&&

.PREV DISCUSSION... /ISSUED 319 AM CST FRI JAN 4 2013/ 

DISCUSSION...
RELATIVELY TRANQUIL WEATHER LOOKS TO CONTINUE THROUGH THE WEEKEND 
WITH THE NEXT CHANCE FOR PRECIPITATION COMING SOME TIME NEXT WEEK. A 
TREND TOWARD MILDER TEMPERATURES STILL LOOKS ON TRACK THROUGH EARLY 
NEXT WEEK...WITH SUNDAY BEING COOLER BEHIND A COLD FRONT.

SOUTHWEST WINDS AND SUNNY SKIES WILL LEAD TO TEMPERATURES AT OR 
ABOVE NORMAL TODAY. MOS GUIDANCE NUMBERS NEAR FREEZING LOOK OKAY FOR 
SNOW COVERED AREAS...WHICH IS MOST OF OUR CWA. COULD SEE WARMER 
TEMPERATURES IN PARTS OF SOUTHWEST IOWA WHERE SNOW COVER IS NOT AS 
WIDESPREAD. THE SOUTHWEST FLOW CONTINUES OVERNIGHT WHICH SHOULD KEEP 
TEMPERATURES FROM FALLING OFF TOO FAR DESPITE CLEAR SKIES. MOS 
NUMBERS ARE IN THE SINGLE DIGITS...BUT HAVE TEMPERATURES CLOSE TO 
OUR CURRENT FORECAST IN THE TEENS. IF WINDS GO CALM FOR A 
TIME...THOSE SINGLE DIGITS COULD BE REALIZED.

ON SATURDAY...UPPER LOW CURRENTLY OVER NEW MEXICO WILL BE MOVING 
ACROSS KANSAS AND MISSOURI...BUT SHOULD ONLY AFFECT OUR AREA WITH A 
FEW MORE MID AND HIGH LEVEL CLOUDS. BEHIND THIS LOW...A POTENT 
SHORTWAVE DROPPING SOUTHEAST THROUGH THE DAKOTAS WILL DRIVE A COLD 
FRONT INTO OUR AREA. AHEAD OF THAT FRONT...SOUTHWEST WINDS AGAIN 
SHOULD PUSH HIGHS TO OR ABOVE FREEZING...GENERALLY IN AREAS ALONG 
AND SOUTHEAST OF INTERSTATE 80. TO THE NORTHWEST...A SWITCH TO 
NORTHWEST WINDS AND COLD ADVECTION DURING THE AFTERNOON WILL HALT 
WARMING IN THE UPPER 20S. GUSTY NORTHWEST WINDS BEHIND THE FRONT 
SATURDAY NIGHT WILL PROMOTE MIXING AND KEEP LOWS FROM FALLING PAST 
THE TEENS. 

ON SUNDAY...HIGH PRESSURE SETTLING INTO THE AREA BEHIND THE COLD 
FRONT WILL KEEP WINDS FAIRLY LIGHT. THE GFS KEEPS WINDS LIGHT MUCH 
OF THE DAY WHICH WOULD HOLD HIGHS IN THE 20S. HOWEVER THE NAM IS
FASTER IN MOVING THE HIGH TO OUR EAST AND BRINGS STRONGER WINDS TO
OUR WEST THROUGH THE DAY. A BLEND OF THESE SCENARIOS LOOKS OKAY
WITH HIGHS EAST OF THE MISSOURI RIVER STAYING COOL WHILE OUR FAR
WEST CWA REACHING THE LOWER 30S.

SOUTH WINDS INCREASE SUNDAY NIGHT AND MONDAY WITH SURFACE LOW 
PRESSURE DEEPENING ALONG THE LEE OF THE ROCKIES IN RESPONSE TO 
APPROACHING UPPER TROUGH. LOWS SUNDAY NIGHT WILL BE CLOSE TO
20...WITH PLENTY OF MIXING ON STRONG SOUTH WINDS PUSHING HIGHS
INTO THE MIDDLE AND UPPER 30S MONDAY AFTERNOON.

BEYOND MONDAY...MODELS ARE DIVERGING ON HANDLING THE MOVEMENT OF THE 
UPPER TROUGH IN THE WEST. THE OPERATIONAL GFS IS VERY PROGRESSIVE IN 
MOVING TROUGH AXIS INTO THE PLAINS ON TUESDAY. HOWEVER IT HAS ONLY 
TEPID SUPPORT FROM ITS ENSEMBLE MEMBERS WHILE AT LEAST HALF OF THOSE 
MEMBERS LOOK MORE LIKE THE 12Z ECMWF...WHICH KEEPS ENERGY
CONFINED TO AN UPPER LOW MOVING INTO WEST TEXAS BY WEDNESDAY. THAT
LOW EVENTUALLY LIFTS INTO OUR AREA WEDNESDAY NIGHT AND THURSDAY...
BRINGING A CHANCE FOR RAIN OR SNOW. THE GFS WOULD BRING A SMALL
CHANCE FOR PRECIPITATION ON TUESDAY THEN SHIFT THAT PRECIP EAST
BY WEDNESDAY. HPC IS SIDING MORE WITH THE ECMWF SCENARIO...HOLDING
OFF PRECIP CHANCES UNTIL WEDNESDAY/THURSDAY. AND NOW THE LATEST
00Z OPERATIONAL ECMWF LOOKS A LOT LIKE THE 12Z RUN...AND MAYBE A
TAD SLOWER IN LIFTING UPPER LOW TOWARD OUR AREA. GIVEN UNCERTAINTY
AND VARIED SOLUTIONS BETWEEN AND WITHIN EACH MODEL...WILL LEAVE
FORECAST BEYOND MONDAY MAINLY UNCHANGED FOR NOW...WHICH FOLLOWS
THE ECMWF SOLUTION MORE CLOSELY.

DERGAN

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

ZAPOTOCNY