Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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574
FXUS63 KOAX 051204
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
604 AM CST FRI FEB 5 2016

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 310 AM CST FRI FEB 5 2016

THE PRIMARY FORECAST CONCERNS ARE LIGHT SNOW CHANCES TODAY AND THE
POTENTIAL FOR STRONG WINDS ON SUNDAY.

A MULTI-STREAM SHORT-WAVE TROUGH OBSERVED EARLY THIS MORNING FROM
THE WRN DAKOTAS TO SRN HIGH PLAINS WILL AMPLIFY OVER THE NEXT 24
HOURS AS THE SYSTEM BECOMES LOOSELY PHASED WITH A INTENSE UPPER LOW
TRAVERSING THE WRN/SRN SHORES OF HUDSON BAY.  THE MAJORITY OF MID-
LEVEL HEIGHT FALLS/DCVA ASSOCIATED WITH THIS SHORT-WAVE TROUGH WILL
PASS TO THE SOUTH OF THE REGION WITH THE SRN-BRANCH VORTICITY LOBE.
HOWEVER...DCVA RELATED TO A WEAKER NRN-STREAM DISTURBANCE COUPLED
WITH WARM ADVECTION AT AROUND 850 MB AND ISENTROPIC UPGLIDE IN THE
280-290 K LAYER WILL CONTRIBUTE TO BAND OF LIGHT SNOW THAT WILL BE
MOST PROBABLE ACROSS THE NRN TWO-THIRDS OF THE FORECAST AREA
TODAY. SOME LIGHT SNOW SHOWERS MAY PERSIST OVER NERN NEB INTO THIS
EVENING WITHIN THE COLD CORE OF THE MID-LEVEL SYSTEM WHERE
850-500-MB LAPSE RATES WILL APPROACH 7 C/KM. SNOWFALL
ACCUMULATIONS SHOULD BE LESS THAN A HALF AN INCH.

TONIGHT THROUGH SUNDAY...WE WILL SEE A BRIEF PERIOD OF
RIDGING/SUBSIDENCE IN THE WAKE OF THE AFOREMENTIONED SHORT-WAVE
TROUGH AND AHEAD OF AN AMPLIFYING DISTURBANCE WHICH WILL TRACK
ALONG THE INTERNATIONAL BORDER FROM THE NRN HIGH PLAINS TO UPPER
GREAT LAKES BY SATURDAY NIGHT. A JET STREAK/VORTICITY MAXIMUM
WILL FOLLOW CLOSELY ON THE HEELS OF THE LEAD BORDER-REGION
IMPULSE...CONTRIBUTING TO CONSIDERABLE AMPLIFICATION OF A BROADER-
SCALE TROUGH OVER THE N-CNTRL U.S. FROM SATURDAY NIGHT THROUGH
SUNDAY. THE EFFECTS OF THIS PATTERN EVOLUTION ON SENSIBLE WEATHER
WILL BE SLIGHT WARMING TREND ON SATURDAY AHEAD OF A COLD FRONT
WHICH WILL BE SWEEPING SEWD THROUGH THE NRN PLAINS AND MID-MO
VALLEY SATURDAY NIGHT.

ON SUNDAY...STRONG LOWER TO MID-LEVEL COLD ADVECTION WILL YIELD
STEEPENING LAPSE RATES WITH THE POTENTIAL FOR LIGHT SNOW SHOWERS
GENERALLY ALONG AND EAST OF THE MISSOURI RIVER.  THESE LAPSE RATES
WILL ALSO PROMOTE THE DOWNWARD TRANSFER OF HIGH-MOMENTUM FLOW ALOFT
WITH WINDY CONDITIONS DEVELOPING ACROSS THE REGION.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 AM CST FRI FEB 5 2016

LATEST MEDIUM-RANGE GUIDANCE IS IN REASONABLY GOOD AGREEMENT IN
DEPICTING THE CONTINUED EVOLUTION OF A LARGE-SCALE TROUGH AND
ASSOCIATED CLOSED LOW OVER THE ERN HALF OF THE NATION ON MONDAY INTO
TUESDAY.  WE WILL REMAIN ON THE WRN FRINGE OF THE COLDER CONTINENTAL
POLAR AIR MASS WITH DAYTIME HIGHS FORECAST TO REMAIN SLIGHTLY BELOW
NORMAL. WINDS WILL REMAIN STRONG SUNDAY NIGHT THROUGH MONDAY
BEFORE WEAKENING BY TUESDAY. BY MID-WEEK...IT APPEARS THAT MID-
LEVEL FLOW BECOME MORE NWLY ACROSS THE NRN ROCKIES...PROMOTING THE
DEVELOPMENT OF A LEE TROUGH OVER THE HIGH PLAINS AND A SLIGHT
WARMING TREND IN THE WEDNESDAY-THURSDAY TIME FRAME. OUTSIDE OF A
SLIGHT CHANCE OF SNOW SHOWERS SUNDAY NIGHT INTO MONDAY...THE
FORECAST SHOULD REMAIN DRY THROUGH THE EXTENDED PERIOD.

&&

.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 601 AM CST FRI FEB 5 2016

PERIODS OF SNOW MAY BRING VISIBILITY TO THE MVFR OR EVEN IFR RANGE
TODAY...WITH CEILINGS ALSO REACHING MVFR RANGE FOR SOME TIME
TODAY. CONDITIONS SHOULD IMPROVE TO VFR (AND MAINLY SKC) AT
KOMA/KLNK BY AROUND 00Z...AND BY AROUND 06Z AT KOFK. LIGHT SOUTH
WINDS WILL BECOME NORTHWESTERLY AT ALL SITES...WITH SPEEDS
REMAINING 10KT OR LESS.

&&

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

$$

SHORT TERM...MEAD
LONG TERM...MEAD
AVIATION...MAYES



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