Drought in Iowa, December 1 to 31, 2012

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1130 PM CST FRI NOV 30 2012

.AVIATION...

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

VISIBILITIES OF 5 OR 6 MILES WERE COMMON AS OF LATE EVENING. EXPECT
DETERIORTATING CONDITIONS OVERNIGHT. LOW CLOUDS CONTINUE TO STREAM
NORTHWARD INTO SOUTHEAST NEBRASKA AS OF 05Z. INITIALLY THESE WILL
PROBABLY HAVE BASES ABOVE 1000 FEET BUT THINK FOG WILL GET THICKER
AND THAT CEILINGS WILL DROP INTO THE IFR OR LIFR RANGE MAINLY
AFTER 09Z. IT APPEARS THAT CLOUDS MAY HOLD IN MUCH OF THE DAY AT
KOMA...BUT BREAK UP SOONER AT KLNK AND KOFK AS WINDS SHIFT TO THE
WEST WITH A DOWNSLOPE COMPONENT.

LOW LEVEL MOISTURE SHOULD MOVE EASTWARD OUT OF THE KOMA AREA BY
EARLY SATURDAY EVENING.

MILLER

&&

.PREV DISCUSSION...  /ISSUED 246 PM CST FRI NOV 30 2012/

SHORT TERM...TONIGHT THROUGH MONDAY.

TEMPERATURES WILL BE THE PRIMARY FORECAST CONCERN IN THE SHORT
TERM.

UPPER FLOW REMAINS ZONAL DURING THE PERIOD WITH SOUTH FLOW
DEVELOPING ACROSS THE AREA TONIGHT AS A SURFACE TROUGH MOVES INTO
WESTERN PARTS OF THE REGION. THE SOUTHERLY FLOW WILL SPREAD LOW
LEVEL MOISTURE AND CLOUDS INTO THE FORECAST AREA LATE TONIGHT WITH
POTENTIAL FOR DENSE FOG AND DRIZZLE THROUGH SATURDAY MORNING...
ESPECIALLY FOR EASTERN AREAS. SKIES ARE EXPECTED TO CLEAR SATURDAY
AFTERNOON AS TROUGH MOVES THROUGH AND WINDS VEER IN THE LOW LEVELS
WITH DRIER AIR WORKING INTO THE AREA. TIMING OF CLEARING WILL
HAVE IMPACT ON TEMPERATURES AND COULD HOLD FORECAST HIGHS DOWN IF
SLOWER THAN EXPECTED. SHOULD SEE THE WARMEST TEMPERATURES ON
SUNDAY ACROSS THE AREA AS LOW PRESSURE TRACKS INTO THE NORTHERN
ROCKIES AND LEE SIDE TROUGH DEVELOPS TO THE WEST. DRY AND MILD
SOUTH TO SOUTHWEST FLOW DEVELOPS ACROSS THE REGION AHEAD OF THIS
SYSTEM INTO EARLY MONDAY BEFORE A COLD FRONT MOVES THROUGH DURING
THE DAY. SOME COOLING BEHIND THE FRONT ON MONDAY BUT WITH UPPER
FLOW MAINTAINING A WESTERLY COMPONENT NORTH OF THE AREA NO REAL
COLD AIR AROUND SO TEMPERATURES EXPECTED TO REMAIN ABOVE SEASONAL
NORMALS.

FOBERT

LONG TERM...MONDAY NIGHT THROUGH FRIDAY.

MILD PATTERN WILL BE COMING TO AN END TOWARD THE END OF THE EXTENDED
PERIOD...HOWEVER NEXT WEEK WILL CONTINUE WITH AT LEAST 2 AND
PROBABLY 3 DAYS OF MUCH ABOVE NORMAL TEMPERATURES.  ALTHOUGH POST-
FRONTAL HIGH PUSHING ACROSS REGION EARLY TUESDAY COULD PROVIDE LOWS
A BIT COOLER THAN MODEL/PREV FORECAST BLEND...DECENT MODEL AGREEMENT
WITH ENSEMBLE CONSENSUS OF MUCH ABOVE NORMAL UPPER HGTS/H85
TEMPERATURES INTO MIDWEEK.  THUS WOULD SUSPECT LAST FEW MEX GUIDANCE
NUMBERS MAY PROVE CONSERVATIVE FOR TUE AND ESPECIALLY WEDNESDAYS
HIGHS. GENERALLY BUMPED UP MAX TEMPS ABOVE THE MODEL/PREV FORECAST
BLEND. ALSO BOOSTED WINDS ON WEDNESDAY GIVEN STRONG LOW LEVEL JET
FORECAST BY ALL MODELS.

NORTHERN PLAINS UPPER TROUGH ON TRACK TO SHOVE A COLD FRONT THROUGH
THE FORECAST AREA WITH TIGHTENING THERMAL GRADIENT PROVIDING A
PERIOD /S/ OF FRONTOGENETICAL FORCING.  LEFT POPS ON SMALL SIDE FOR
NOW AS ECMWF WAS FAIRLY PROGRESSIVE AND ENSEMBLE MEAN PROBABILITY OF
MEASURING OVER 0.05 WAS NEGLIGIBLE.  ALTHOUGH 12Z ECMWF/GFS COLLAPSE
H85 TEMPERATURES/THICKNESSES FAIRLY QUICKLY THU...LEFT PRECIP LIQUID
DURING THE DAY DUE TO THE WARM START TO H85 TEMPS.  FORECAST HIGHS
WILL BE A FUNCTION OF AMOUNT OF LOW CLOUDS PULLED UP AHEAD OF FRONT
AND FRONTAL TIMING ITSELF...BOTH OF WHICH COULD LIKELY CHANGE.  THUS
LITTLE/NO CHANGES TO TEMPERATURES WERE MADE.  LINGERED SMALL POPS
FAR SOUTH ON FRIDAY IN CASE GFS NOTION OF TRAILING ENERGY WOULD
VERIFY...BUT OTHERWISE BLUSTERY AND COLDER WEATHER ALMOST CERTAIN.

CHERMOK

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
405 PM CST FRI NOV 30 2012

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-011215-
MONONA-HARRISON-SHELBY-POTTAWATTAMIE-MILLS-MONTGOMERY-FREMONT-
PAGE-KNOX-CEDAR-THURSTON-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON-
STANTON-CUMING-BURT-PLATTE-COLFAX-DODGE-WASHINGTON-BUTLER-
SAUNDERS-DOUGLAS-SARPY-SEWARD-LANCASTER-CASS-OTOE-SALINE-
JEFFERSON-GAGE-JOHNSON-NEMAHA-PAWNEE-RICHARDSON-
405 PM CST FRI NOV 30 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA...NORTHEAST
NEBRASKA AND SOUTHEAST NEBRASKA.

.DAY ONE...TONIGHT AND SATURDAY

AREAS OF DENSE FOG ARE POSSIBLE LATE TONIGHT INTO SATURDAY
MORNING OVER SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.

.DAYS TWO THROUGH SEVEN...SATURDAY NIGHT THROUGH FRIDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT OR SATURDAY.

FOBERT