522 
FXUS63 KOAX 260528
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1128 PM CST FRI JAN 25 2013

.AVIATION...06Z TAFS FOR KOFK...KLNK AND KOMA.

VFR CONDITIONS ARE EXPECTED THROUGH SATURDAY EVENING. HOWEVER
LOWERING CIGS ARE EXPECTED NEAR THE END OF THE TAF PERIOD AND
AFTER AS AN AREA OF RAIN MOVES IN FROM THE SOUTHEAST. SCATTERED TO
BROKEN MID AND HIGH CLOUDS WILL PERSIST BEFORE 06Z SUNDAY WITH
WINDS BECOMING SOUTHERLY 10 TO 20KT. RAIN AND LOWERING CIGS/VSBYS
WILL COMMENCE AFTER 06Z SUNDAY.

DERGAN

&&

.PREV DISCUSSION... /ISSUED 339 PM CST FRI JAN 25 2013/

SHORT TERM...TONIGHT THROUGH MONDAY.

THE FORECAST CONCERNS IN THE SHORT TERM WILL BE TEMPERATURES
BEHIND THE COLD FRONT TONIGHT...ONSET OF PRECIPITATION SATURDAY
NIGHT AND SUNDAY AND PRECIPITATION TYPE...AND PRECIPITATION AND
PRECIP TYPE WITH MONDAY SYSTEM.

TEMPERATURES AHEAD OF A COLD FRONT HAVE WARMED INTO THE 40S AND
50S...HOWEVER MUCH COLDER AIR LIES TO THE NORTH WITH TEENS AS FAR
SOUTH AS HURON SD. THIS COLD FRONT WILL PUSH THROUGH PARTS OF THE
FORECAST AREA. THE RAP SEEMS TO HAVE A GOOD HANDLE ON THE COLD
AIR. THE BRUNT OF THE COLD AIR AND SUB-ZERO READINGS WILL HOLD
OVER IN SD AND MN...TEMPERATURES IN THE TEENS (POSSIBLY SINGLE
DIGITS NEAR WAYNE AND MAPLETON) SHOULD MAKE IT INTO THE NORTHEAST
HALF OF THE FORECAST AREA WITH 20S FOR THE SOUTH. SOME CIRRUS
TONIGHT ALONG WITH SOME PATCHY LOW AND MID CLOUDS NORTH. SURFACE
WINDS BECOME LIGHT SOUTHEAST TONIGHT AND HAVE A DECENT GRADIENT IN
DEWPOINTS AND TEMPERATURES FROM MAPLETON TO THE SOUTHWEST TOWARD
FAIRBURY.

WITH THE STORM SYSTEM FOR THE WEEKEND STILL OFF THE CA/MEXICAN
COAST...THERE COULD BE SAMPLING ISSUES AND OPENS THE FORECAST UP
TO TIMING CHANGES. FOR NOW...THERE IS DECENT AGREEMENT BETWEEN THE
SHORT RANGE MODELS THAT THE SHORTWAVE TROF WILL MOVE THROUGH THE
SOUTHWEST U.S. SATURDAY WITH SURFACE LOW PRESSURE OVER THE
WESTERN PLAINS AND A STRENGTHENING LOW LEVEL JET OVER THE PLAINS.
LIFT ASSOCIATED WITH THE TROF AND WARM AIR ADVECTION BRING
INCREASING CLOUDS AND SPREAD PRECIPITATION FROM THE SOUTHWEST U.S.
INTO THE PLAINS. THE ONSET OF THE PRECIPITATION SHOULD MAINLY BE
AFTER MIDNIGHT...ALTHOUGH COULD EASILY START IN THE EVENING TOWARD
THE KANSAS/NEBRASKA BORDER...AND MOVE NORTHEAST ACROSS EASTERN
NEBRASKA AND IOWA DURING THE DAY SUNDAY. THE PRECIPITATION COULD
START OUT AS FREEZING RAIN WHERE TEMPERATURES ARE AT OR BELOW ZERO
(MAINLY NORTH OF A NORFOLK TO TEKAMAH TO OAKLAND)...HOWEVER HAVE
THE BULK OF THE PRECIPITATION STARTING OUT AS RAIN. THE BEST LIFT
APPEARS FROM AROUND 10Z TO 20Z SUNDAY. THE SOUTHWEST FLOW ALOFT
WILL BRING HIGH PRECIP WATER VALUES TO THE REGION... .5 INCH TO 1
INCH. FOR NOW A BEST ESTIMATE OF AMOUNTS WITH THE STORM IS LESS
THAN A TENTH OF AN INCH OF WATER AT NORFOLK NORTHWESTWARD...A
QUARTER OF AN INCH OR SO OMAHA TO LINCOLN AND A HALF AN INCH
TOWARD FALLS CITY. HIGHS SATURDAY AND SUNDAY SHOULD BE IN THE 30S
AND 40S. A FEW LOCATIONS MAY HIT THE 50S SOUTH.

THE MAIN MID LEVEL TROF IS STILL TO THE WEST AND THE LOW LEVEL
MOISTURE DOES NOT GET SCOURED OUT. WITH THE WEAK FLOW DO HAVE SOME
FOG MENTIONED AND WILL HAVE TO WATCH FOR FREEZING FOG CONDITIONS.
A STRONGER PUSH OF COLD AIR OCCURS MONDAY. MAY SEE SOME LIGHT RAIN
OR DRIZZLE FOR PARTS OF THE AREA MONDAY AND BEHIND THE H85 COLD
FRONT A BAND OF SNOW MAY DEVELOP IN NORTHEAST NEBRASKA.

ZAPOTOCNY 

LONG TERM...MONDAY NIGHT THROUGH FRIDAY. 

THE MAIN STORY IN THE EXTENDED IS STILL THE LARGE-SCALE TROUGH TO 
MOVE THROUGH THE AREA TUESDAY AND THEN SOME SEASONABLY CHILLY AIR 
FOR THE REST OF THE PERIOD. THE GLOBAL MODELS ARE STILL SHOWING 
SIGNIFICANT RUN TO RUN FLUCTUATION IN REGARDS TO THE TROUGH AS IT 
CROSSES THE CENTRAL CONUS. THE 12Z ECMWF HAS TRENDED TOWARD A MORE 
CONSISTENT GFS/GEM WITH REGARDS TO THE INTERACTION OF THE NRN AND 
SRN STREAM SHORTWAVE IN THE LARGER MEAN TROUGH BUT STILL THE MODELS 
DIFFER ON THE SENSIBLE WEATHER THAT WILL MOVE THE CWA. THERE IS A 
GOOD DEAL OF CONFIDENCE THAT A CDFNT WILL MOVE THROUGH THE FA ON MON 
NIGHT AS LOW PRESSURE MOVES THROUGH KS/MO AND STARTS TO DEEPEN OVER 
THE GREAT LAKES. MID LEVEL FRONTOGENESIS BEHIND THE FNT COULD LEAD 
TO A LITTLE -RA/SN MIX ON MON NIGHT INTO TUE MORNING AS THIS SYSTEM 
MOVES THROUGH...BUT THE THREAT FOR WIDESPREAD OR SIGNIFICANT PRECIP 
LOOKS VERY LOW ATTM. WE WILL MAINTAIN SOME CHC/SCHC POPS FOR THESE 
TWO PERIODS. OTHERWISE SURFACE HIGH PRESSURE WILL BUILD SOUTH INTO 
THE CENTRAL AND NORTHERN PLAINS FOR TUE NIGHT THRU FRI WITH DRY 
WEATHER THESE PERIODS. THE DEGREE OF COLD AIR WILL LIKELY ONCE AGAIN 
BE MODIFIED BY THE LACK OF SNOW COVER ACROSS THE REGION...BUT 
OVERALL BELOW NORMAL TEMPERATURES APPEAR LIKELY.

BOUSTEAD

&&

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

$$