Cold in Nebraska, December 1, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1120 PM CST SAT NOV 30 2013

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

HIGHS PRESSURE WILL BE BUILDING SOUTH OUT OF THE DAKOTAS AND MN
OVERNIGHT AND ALLOW FOR GENERALLY LIGHT NORTH WINDS TO CONTINUE. A
WEAK STORM SYSTEM OVER MT/WY THIS EVENING WILL BE MOVING INTO THE
REGION ON SUNDAY AND WILL ALLOW FOR AN INCREASE IN MID AND HIGH
LEVEL CLOUDS AT ALL SITES. WE WILL ALSO SEE THE LIGHT WINDS BECOME
SOUTH DURING SUNDAY AFTERNOON.

BOUSTEAD

&&

.PREV DISCUSSION... /ISSUED 256 PM CST SAT NOV 30 2013/

SHORT TERM...TONIGHT THROUGH TUESDAY

UNSEASONABLY WARM WEATHER CONTINUES ACROSS THE AREA. SUBJECTIVE 12Z
UPPER AIR ANALYSIS INDICATES LARGELY ZONAL FLOW ACROSS THE
CONUS...WITH AN UPPER-LEVEL TROUGH FROM UT TOWARD UPPER LOW OFF THE
COAST OF SOUTHERN CA.  WARM AIR WAS OVERSPREADING THE PLAINS AT
850MB...WITH TEMPS OVER THE HIGH PLAINS AS HIGH AS 10-12C...AND 8C+
ACROSS MUCH OF THE CENTRAL PLAINS.  WEAK AID DIFFUSE SURFACE TROUGH
EXTENDED FROM NORTHEAST WI THROUGH IA/EASTERN AND CENTRAL
NEB/SOUTWHEST KS.  DESPITE WEAK SURFACEW INDS...TEMPS HAD CLIMBED
INTO THE MID TO UPPER 50S ACROSS MUCH OF THE AREA.

WITH BENIGN WEATHER THROUGH TUESDAY...MAIN FORECAST CONCERNS ARE
IMPACT OF SHORTWAVE ON CLOUDS AND TEMPERATURES SUNDAY/SUNDAY
NIGHT...AND APPROACH OF COLD FRONT MID-WEEK.  FAST-MOVING SHORTWAVE
IS PROGGED TO SLIDE ACROSS SD INTO MN ON SUNDAY...WHICH SHOULD BRING
INCREASING CLOUDS FOR SUNDAY AFTERNOON INTO SUNDAY NIGHT.  LOW-LEVEL
AIRMASS IS A LITTLE TOO DRY...AND WAVE A LITTLE TOO TRANSIENT...TO
WORRY ABOUT PRECIPITATION...THOUGH WOULD NOT BE SURPRISED BY A
SPRINKLE SOMETIME IN THE LATER AFTERNOON/EVENING.  SHORTWAVE ALSO
WILL 850MB TEMPS DOWN A FEW DEGREES...AND THAT COMBINED WITH CLOUDS
SHOULD HOLD TEMPERATURES BACK IN THE 40S SUNDAY. ONCE THE SHORTWAVE
SCOOTS AWAY...TEMPS SHOULD REBOUND NICELY ON MONDAY UNDER FAIR
SKIES...WITH ANY SHOT OF PRECIP OR EVEN MUCH CLOUDINESS WELL NORTH.
GIVEN HOW EASILY WARMING HAS OCCURRED YESTERDAY AND TODAY...HAVE
BUMEPD TEMPS A COUPLE OF DEGREES ON MONDAY.  TUESDAY IS A LITTLE
MORE COMPLICATED...AS GFS/NAM TRY TO DRIVE THE FRONT TOWARD THE
WESTERN CWA BY LATE TUESDAY AFTERNOON...WHILE ECMWF/GEM STAY THE
COURSE IN HOLDING OFF UNTIL TUESDAY NIGHT.  LEANED TOWARD THE MORE
CONSISTENT ECMWF/GEM GUIDANCE...ALLOWING TEMPS TO REACH THE UPPER
40S NORTH TO MID 50S SOUTH UNDER WARMEST 850MB TEMPS OF THIS
STRETCH.

MAYES

LONG TERM...TUESDAY NIGHT THROUGH SATURDAY

TEMPERATURES WILL ONLY GET COLDER DURING THE LONG TERM PERIOD AS
DEEP MID LEVEL TROUGH SLOWLY PROGRESSES INTO THE PLAINS WEDNESDAY
THROUGH SATURDAY.

A COLD FRONT WILL BE MOVING THROUGH OUR AREA TUESDAY NIGHT AS PER
ECMWF/CANADIAN SOLUTIONS...WHICH ARE QUITE A BIT SLOWER THAT GFS.
MOISTURE PROFILE WITH FRONT IS RATHER MEAGER...BUT MODELS ARE
PAINTING LIGHT QPF WITH IT. LIFT ALONG BOUNDARY COMBINED WITH WEAK
MID LEVEL IMPULSE WARRANTS KEEPING A SMALL CHANCE FOR RAIN OR
RAIN/SNOW TUESDAY NIGHT INTO WEDNESDAY. HOWEVER THE STRONG COLD
ADVECTION BEHIND BOUNDARY LOOKS TO BE THE MAIN WEATHER STORY. 850
TEMPERATURES IN THE 5-10C RANGE AT 00Z WEDNESDAY DROP 10 TO 15
DEGREES BY 00Z THURSDAY...AND BY 12Z THURSDAY WILL RANGE FROM -7C IN
OUR SOUTHEAST TO -19C IN OUR NORTHWEST. THESE NUMBERS SUGGEST LITTLE
RISE IN TEMPERATURES WEDNESDAY FROM THE UPPER 20S TO MIDDLE 30S
EARLY IN THE DAY...REACHING ONLY THE 30S OR LOWER 40S IN THE EARLY
AFTERNOON...THEN DROPPING WELL INTO THE TEENS WEDNESDAY NIGHT.

BOTH ECMWF AND CANADIAN INDICATE WEAK IMPULSES WILL RIDE THROUGH
SOUTHWEST FLOW ALOFT OVER TOP OF COLD SURFACE AIR FROM WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT BEFORE AXIS OF UPPER TROUGH APPROACHES.
MOISTURE IN DENDRITIC TEMPERATURE ZONE ALONG WITH WEAK LIFT POINTS
TO A CHANCE FOR LIGHT SNOW THROUGH THIS PERIOD...BUT AMOUNTS DO NOT
LOOK TO BE TOO IMPRESSIVE YET.

ANY PRECIP SHOULD END BY FRIDAY MORNING AS MOISTURE IS SHUNTED EAST
AND SOUTHEAST...BUT THE COLDEST AIR WITH THIS PATTERN WILL BE
SETTLING INTO THE REGION AT THIS TIME. ALL OF THE CWA WILL SEE 850
TEMPERATURES IN THE 15-20C BELOW RANGE ON FRIDAY BEFORE MODERATING
SLIGHTLY ON SATURDAY. SINGLE DIGIT LOWS ARE LIKELY FRIDAY AND
SATURDAY MORNING...WITH HIGHS IN THE TEENS OR LOWER 20S FRIDAY AND
IN THE 20S ON SATURDAY. BUT IF SNOW DOES PAN OUT ON THURSDAY...THESE
TEMPERATURES WILL BE WAY TOO OPTIMISTIC.

AND LOOKING BEYOND SATURDAY...ANOTHER CHUNK OF ARCTIC AIR OVER
ALBERTA AND MONTANA IS POISED TO ROLL INTO OUR AREA SUNDAY THROUGH
TUESDAY. SO MUCH COLDER THAN NORMAL TEMPERATURES SHOULD CONTINUE.

DERGAN

&&

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

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
329 PM CST SAT NOV 30 2013

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-011200-
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-
329 PM CST SAT NOV 30 2013

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 SUNDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH FRIDAY

A STRONG COLD FRONT WILL MOVE INTO THE REGION MID-WEEK. THE
SHARPLY COLDER AIR AND SEVERAL DISTURBANCES MOVING ACROSS THE
PLAINS COULD BRING LIGHT ACCUMULATING SNOW TO PARTS OF THE AREA
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED TONIGHT OR SUNDAY.

MAYES