Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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632 FXUS63 KOAX 070915 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 315 AM CST SUN FEB 7 2016 .SHORT TERM...
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(TODAY THROUGH TUESDAY) ISSUED AT 314 AM CST SUN FEB 7 2016 THE PRIMARY FORECAST CONCERN IS THE POTENTIAL FOR STRONG WINDS....SNOW SHOWERS AND AREAS OF BLOWING SNOW LATER TODAY INTO MONDAY. 00Z 500-MB ANALYSIS SHOWED A CORRIDOR OF SIGNIFICANT HEIGHT FALLS FROM THE CANADIAN PRAIRIE PROVINCES INTO NRN HIGH PLAINS WHICH ARE ASSOCIATED WITH A SHORT-WAVE TROUGH WHICH WILL UNDERGO SIGNIFICANT AMPLIFICATION ALONG THE MS VALLEY OVER THE NEXT 24 HOURS. ACTUALLY...THIS SYSTEM IS COMPRISED OF TWO SEPARATE ENTITIES: A LEAD IMPULSE OVER MN WHICH WILL FORM A CLOSED MID-LEVEL LOW OVER THE UPPER MIDWEST...AND A MID TO UPPER-LEVEL JET STREAK TRANSLATING FROM THE NRN HIGH PLAINS INTO LOWER MS VALLEY BY TONIGHT. AT THE SURFACE...THERE IS NOT MUCH BAROCLINICITY NOTED WITH THE TROUGH MOVING THROUGH THE MID-MO VALLEY EARLY THIS MORNING...WITH THE MORE PRONOUNCED TEMPERATURE GRADIENT /AND ASSOCIATED COLD ADVECTION/ OCCURRING IN THE 850-500-MB LAYER. THIS COLD ADVECTION ALOFT WILL AID IN STEEPENING OF LOW-LEVEL LAPSE RATES TODAY WHICH IN TURN WILL ALLOW FOR THE DOWNWARD TRANSFER OF HIGH MOMENTUM FLOW ALOFT. FORECAST SOUNDINGS AND PLAN VIEW DATA FROM HIGHER- RESOLUTION MODEL GUIDANCE INDICATE THAT THE STRONGEST WINDS WILL OCCUR OVER NERN NEB THROUGH THE PEAK OF THE DIURNAL HEATING CYCLE...WHICH IS IN GOOD AGREEMENT WITH THE CURRENT WIND ADVISORY AREA. THE COLD ADVECTION AND RESULTANT STEEP LAPSE RATES WILL ALSO BE SUPPORTIVE OF SNOW SHOWER ACTIVITY WHICH WILL SPREAD SEWD INTO PORTIONS OF NERN NEB LATER THIS AFTERNOON. BANDS OF SNOW SHOWERS WILL MOVE/DEVELOP INTO AT LEAST ERN PORTIONS OF THE FORECAST AREA TONIGHT...POSSIBLY LINGERING INTO MONDAY MORNING. DUE TO THE CONVECTIVE NATURE OF THE PRECIPITATION...SNOWFALL AMOUNTS WILL BE SPOTTY WITH SOME LOCATIONS SEEING UP TO AN INCH BY MONDAY MORNING. STRONG NORTHWEST WINDS WILL LOCALLY REDUCE VISIBILITIES IN BLOWING SNOW. AT THIS POINT...WE WILL LET THE DAYSHIFT EVALUATE THE SITUATION...AND AN EXTENSION OF THE WIND ADVISORY OR THE ISSUANCE OF A WINTER WEATHER ADVISORY MAY BE REQUIRED FOR TONIGHT INTO EARLY MONDAY. WINDS WILL REMAIN STRONG THROUGH MONDAY AFTERNOON BEFORE GRADUALLY WEAKENING BY EVENING. FLURRIES MAY PERSIST MONDAY ACROSS THE ERN CWA...THOUGH MEASURABLE PRECIPITATION CHANCES SHOULD DIMINISH. THERE IS SOME INDICATION IN ECMWF/GFS/NAM GUIDANCE THAT A N-S-ORIENTED BAND OF LIGHT SNOW COULD DEVELOP FROM CNTRL SD INTO N-CNTRL NEB MONDAY NIGHT OR TUESDAY. WE WILL NOT INCLUDE A MENTION AT THIS TIME...THOUGH LOW POPS MAY EVENTUALLY BE REQUIRED IN SOME OF OUR NWRN COUNTIES. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 314 AM CST SUN FEB 7 2016 LATEST MEDIUM-RANGE GUIDANCE REMAINS IN REASONABLE AGREEMENT IN DEPICTING THE SLOW EWD SHIFT AND GRADUAL DE-AMPLIFICATION OF THE LONG-WAVE TROUGH OVER THE ERN HALF OF THE NATION DURING THE LATTER HALF OF THE UPCOMING WEEK. AT THE SAME TIME...THE WRN U.S. RIDGE WILL ALSO TEMPORARILY DE-AMPLIFY...YIELDING A MORE NWLY MID- LEVEL FLOW REGIME FROM THE NRN HIGH PLAINS INTO MID-MS VALLEY. THE MEAN LOW-LEVEL BAROCLINIC ZONE WILL ALIGN IN SIMILAR FASHION...FROM THE NRN HIGH PLAINS INTO THE MID AND LOWER MO VALLEY. AS MENTIONED LAST NIGHT...ANY WEAK PERTURBATIONS TRANSLATING THROUGH THE NWLY FLOW ALOFT WILL CAUSE LATITUDINAL OSCILLATIONS IN THIS BAROCLINIC ZONE...CASTING CONSIDERABLE UNCERTAINTY IN THE TEMPERATURE FORECAST THROUGH MUCH OF THE EXTENDED. IN GENERAL...WE CAN SAY THAT THE WARMEST TEMPERATURES WILL EXIST IN THE SWRN CWA WITH THE COOLEST IN THE NORTHEAST. THERE STILL APPEARS TO BE A LOW-PROBABILITY CHANCE OF LIGHT SNOW ON FRIDAY.
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&& .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1128 PM CST SAT FEB 6 2016 VFR CONDITIONS ARE FORECAST INTO SUNDAY AFTERNOON WITH BROKEN MID LEVEL CLOUDS EXPECTED. WINDS WILL TURN FROM SOUTHWEST TO WEST- NORTHWEST BY 15Z...AND BEGIN TO INCREASE INTO THE 20 TO 30KT RANGE BY EARLY AFTERNOON. STRONG WINDS OF 25 TO 35KT ARE EXPECTED AT KOFK FROM 21Z ON. WIDELY SCATTERED SNOW SHOWERS ARE FORECAST NEAR KOFK AND KOMA AFTER 00Z...WHICH COULD BRING BRIEF MVFR CIGS/VSBYS SUNDAY EVENING...BUT EXPECTED COVERAGE PRECLUDES A MENTION IN THE TAF RIGHT NOW. && .OAX WATCHES/WARNINGS/ADVISORIES...
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NE...WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR NEZ011-012-015>018-030>034-042>044-050. IA...WIND ADVISORY FROM NOON TODAY TO 9 PM CST THIS EVENING FOR IAZ043.
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&& $$ SHORT TERM...MEAD LONG TERM...MEAD AVIATION...DERGAN

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