Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS63 KOAX 221143 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 543 AM CST MON DEC 22 2014 .SHORT TERM...(TODAY THROUGH WEDNESDAY) ISSUED AT 341 AM CST MON DEC 22 2014 COMPLEX FORECAST THIS MORNING AS RAIN/SNOW MOVES OVER THE REGION THROUGH THE NEXT 36 HOURS. 00Z UPPER AIR ANALYSIS SAMPLED A STRONG 150KT 300MB JET OVER SEATTLE AND THIS WILL CONTINUE TO DIG A MID/UPPER LEVEL TROUGH MOVING INTO THE THE CENTRAL STATES. THERE WAS A BROAD AREA OF 50-70M HEIGHT FALLS AT 500MB WITH WATER VAPOR IMAGERY SHOWING A POTENT LITTLE SHORTWAVE DIGGING ACROSS COLORADO WHERE A FEW LIGHTNING STRIKES SHOWED UP LAST EVENING. AHEAD OF THIS...AN UPPER LEVEL TROUGH AXIS EXTENDED FROM WESTERN NORTH DAKOTA INTO EASTERN NEBRASKA. THE SFC LOW REFLECTION WAS CENTERED OVER THE CENTRAL DAKOTAS WITH THE TROUGH AXIS EXTENDING INTO CENTRAL NEBRASKA. WIDESPREAD LIGHT RAIN OR DRIZZLE CONTINUES OVER THE CWA THIS MORNING IN SOUTHERLY FLOW AHEAD OF THIS SFC TROUGH. WE DO EXPECT WIDESPREAD RAIN TO CONTINUE THROUGH THE MORNING AND INTO THE AFTERNOON HOURS AS THE UPPER TROUGH CONTINUES TO DIG INTO THE CENTRAL CONUS. THERE MAY BE A BREAK IN ACTIVITY ACROSS OUR WEST EARLY THIS EVENING AS THE SFC TROUGH SLIDES EAST OF THE AREA BY 00Z. THE PAST TWO TO THREE MODEL RUNS HAVE DEEPENED THE MID LEVEL TROUGH AS IT EVOLVES INTO A CLOSED LOW OVER CENTRAL/ERN NEBRASKA AND INTO NORTHWEST MISSOURI TONIGHT. THE SFC LOW PIVOTS FROM EASTERN NEBRASKA ACROSS NORTHERN MO THIS EVENING AND THEN LIFTS NORTH ACROSS EASTERN IOWA TUESDAY MORNING. A SECONDARY SURGE OF PCPN WILL DROP SOUTH OUT OF SOUTH DAKOTA OVERNIGHT ALONG THE BACK SIDE OF THE UPPER LOW. THIS IS WHERE TEMPERATURES WILL BE COLDER FOR A LONGER PERIOD TO SUPPORT ACCUMULATING SNOW OF NEAR 1-2"...MAINLY ASSOCIATED WITH THE DEFORMATION ZONE BEHIND THE UPPER LOW. THERE IS ALSO POTENTIAL FOR AN ENHANCED AREA OF HEAVIER PCPN ACROSS EAST CENTRAL NEBRASKA AND SOUTHWEST IOWA LATE TONIGHT INTO TUESDAY MORNING...WHERE MODELS HAVE BEEN SUGGESTING VERY STRONG VERTICAL MOTION FOR ASCENT. SOUNDING PROFILES SHOW RAIN MIXING WITH SNOW BEFORE EVENTUALLY TRANSITIONING TO ALL SNOW MAINLY AFTER 03Z AT OMAHA AND 06Z IN OUR FAR SOUTH. THIS SYSTEM IS LACKING ARCTIC AIR SO A LONG DURATION OF RA/SN MIX IS POSSIBLE THROUGH MUCH OF THE TIME IN THE SOUTHERN COUNTIES. THIS LACK OF ARCTIC AIR ALSO MAKES FORECASTING HOW MUCH SNOWFALL ACCUMULATES ON THE GROUND QUITE COMPLEX. A VERY CONCERNING ISSUE IS THE POTENTIAL FOR HEAVIER SNOWFALL AMOUNTS FROM NEAR THE OMAHA METRO AREA AND POINTS SOUTHEAST OVERNIGHT. MODEL QPF CONTINUES TO COME IN HIGHER WITH EACH CONSECUTIVE RUN AND THE PREVIOUS MENTIONED STRONG FORCING FOR ASCENT IS CONFINED IN EAST CENTRAL NEBRASKA AND SOUTHWEST IOWA FROM 03Z-12Z. HAVE INCREASED SNOWFALL AMOUNTS IN THESE AREAS...BUT AGAIN...SFC TEMPERATURES AND THE POTENTIAL FOR A RA/SN MIX MAKE THIS FORECAST VERY COMPLICATING AND UNCERTAIN. MID LEVEL TROUGH AXIS WILL REMAIN ACROSS IA/NRN MO AND INTO EASTERN KANSAS THROUGH TUESDAY NIGHT BEFORE FINALLY KICKING OUT WEDNESDAY. AS A RESULT...HAVE CONTINUED POPS ACROSS THE CWA INTO TUESDAY EVENING WHEN WE MAY SEE SOME LIGHT SNOWFALL ACCUMULATIONS AS WELL. LOOKS LIKE THE AREA MAY ACTUALLY SEE SUNSHINE BY WEDNESDAY AS UPPER LEVEL RIDGING BUILDS OVERHEAD INTO THURSDAY. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 341 AM CST MON DEC 22 2014 THE NEXT UPPER LEVEL TROUGH WILL ROUND THE FOUR CORNERS REGION 00Z FRIDAY. AHEAD OF THIS...STRONG WAA IS EXPECTED ON CHRISTMAS DAY WHICH SHOULD PUSH HIGHS INTO THE 40S. THE GFS AND ECMWF ARE FINALLY COMING INTO BETTER AGREEMENT WITH THE PLACEMENT AND TIMING OF THE LARGE SCALE FEATURES INTO EARLY NEXT WEEKEND. THE UPPER TROUGH AXIS SHOULD QUICKLY SWING THROUGH OUR CWA FRIDAY NIGHT WHICH COULD GIVE OUR NORTHERN HALF OF THE CWA A BRIEF SHOT AT SNOW FRIDAY. ANOTHER TROUGH IS FORECAST TO DIG ACROSS THE WEST AND INTO THE CENTRAL PLAINS EARLY NEXT WEEK. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 533 AM CST MON DEC 22 2014 IFR CIGS ARE PREVALENT AT THE TAF SITES THIS MORNING WITH LIGHT RAIN. THE BAND OF LIGHT RAIN IS SWINGING THROUGH NOW AND SHOULD DECREASE IN INTENSITY FROM WEST TO EAST AS SURFACE WINDS SHIFT FROM THE SOUTH TO THE SOUTHWEST...THEN NORTHWEST. THIS WIND SHIFT WILL TRY TO LIFT CIGS TO MVFR AT KOFK AND KLNK. BEHIND THE COLD FRONT...NORTHWEST WINDS INCREASE TO 10 TO 15KT. A RAIN SNOW MIX SHOULD WRAP AROUND LATER TODAY AND TONIGHT. KOFK LOOKS TO TURN TO ALL SNOW AFTER 00Z...HOWEVER AT KLNK/KOMA...MAY SWITCH BACK AND FORTH...SO LEFT A MIX IN DURING THE OVERNIGHT HOURS. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...KERN LONG TERM...KERN AVIATION...ZAPOTOCNY

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.