Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Text Only | 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 180451 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1151 PM CDT SUN AUG 17 2014 .SHORT TERM...(TONIGHT THROUGH WEDNESDAY) ISSUED AT 305 PM CDT SUN AUG 17 2014 ...OUR PATTERN REMAINS UNSETTLED...AND WARMER THIS WEEK... FORECAST CHALLENGES FOR THE SHORT TERM WILL BE THUNDERSTORM CHANCES AND SEVERE POTENTIAL TONIGHT THROUGH MONDAY EARLY AFTERNOON. IT LOOKED FAIRLY QUIET WEATHER TO BEGIN THIS EVENING...HOWEVER IT SEEMS LIKE THE SHORT RANGE MODELS ARE A BIT UNDERDONE WITH THE CONVECTION OVER CENTRAL SOUTH DAKOTA BASES ON THE LATEST RADAR. THE HRRR HAS A SHORTWAVE AND CONVECTION THAT DROPS SOUTHEAST ACROSS THE FORECAST AREA. THIS EVENING...WHILE THE OTHER MODELS ARE SLOWER AND LESS AGGRESSIVE UNTIL LATER TONIGHT. EVEN THE 18Z NAM IS STILL DRY THIS EVENING. NOT SURE HOW HIGH TO GO EARLY...BUT WILL INCLUDE ISOLATED THUNDERSTORMS FOR PARTS OF NORTHEAST NEBRASKA EARLY THIS EVENING. THE STORM PREDICTION CENTER DOES HAVE A SEVERE THUNDERSTORM WATCH OUT FOR COUNTIES JUST TO THE WEST OF OUR FORECAST AREA THIS EVENING AND THE SLIGHT RISK FOR SEVERE WEATHER DOES CLIP OUR WESTERN FORECAST AREA COUNTIES. THE 12Z UPPER AIR MAPS SHOWED A RIDGE OVER THE SOUTHWEST U.S. WITH A CLOSED LOW OVER SASKATCHEWAN AND LEADING SHORTWAVE TROF ENERGY OVER MINNESOTA. THE STRONGER HEIGHT FALLS AT H5 WERE NOTED OVER CANADA...ASSOCIATED WITH THIS NORTHERN SYSTEM. THERE WERE RIBBONS OF POOLED H7 MOISTURE OVER THE PLAINS WITH THE H7 THERMAL RIDGE OVER WESTERN NEBRASKA AND COLORADO. SIMILAR PATTERNS WERE NOTED AT H85. THE OAX SOUNDING HAD A PWAT OF 1.44 INCHES WHICH WAS 134% OF NORMAL. A MAX OF 185% OF NORMAL WAS CENTERED OVER KMPX. AS THE EVENING PROGRESSES...A LOW LEVEL JET INCREASES TO 35-40KTS OVER CENTRAL NEBRASKA...MEANWHILE THE SHORTWAVE TROF ENERGY OVER CANADA EXTENDS SOUTHWARD INTO THE PLAINS. UPPER LEVEL JET SUPPORT...OMEGA... FRONTOGENESIS AND THETA-E ADVECTION ALL INCREASE. AS A RESULT...THE DETERMINISTIC MODELS INCREASE CONVECTION OVER THE DAKOTAS AND THIS CONVECTION EXTENDS SOUTHWARD INTO EASTERN NEBRASKA AND IOWA TONIGHT AND MONDAY. THERE IS A GOOD H7 WARM AIR ADVECTION SIGNAL AND GOOD 7-8 DEG C H7 DEWPOINTS. EXPECTED TRENDS LATER TONIGHT ARE WELL HANDLED BY THE CURRENT FORECAST WITH INCREASING POPS INTO THE LIKELY CATEGORY AND WILL TREND FARTHER SOUTH TO COVER POTENTIAL FOR INCREASED CONVERGENCE CLOSER TO THE SURFACE LOW. DEEP LAYER SHEAR IS FROM 30- 40KTS TONIGHT...HOWEVER DROPS CLOSER TO 30KTS MONDAY. THE SURFACE AND H85 FRONT ARE STILL IN EASTERN NEBRASKA MONDAY MORNING...AND GRADUALLY PUSH OUT OF THE FORECAST AREA BY 00Z MONDAY. INSTABILITY IS 500-2000J/KG TONIGHT...BUT INCREASES TO 3000+ MONDAY. FORECAST SOUNDINGS LOOK TO FAVOR ELEVATED STORMS TONIGHT...HOWEVER THEY ARE MORE SURFACE BASED FOR MONDAY. ALTHOUGH FREEZING LEVELS ARE HIGHER AND INSTABILITY IS O.K. STRONGER SHEAR...PLUME OF STEEPER LAPSE RATES AND BETTER LOW AND MID LEVEL FORCING MAY SUPPORT SOME SEVERE STORMS. SEVERE WEATHER CHANCES CONTINUE INTO MONDAY AS THUNDERSTORMS WILL BE ONGOING WITH INCREASED INSTABILITY...ALTHOUGH FORCING AND SHEAR APPEAR TO BE NOT AS HIGH. TREND WITH HIGHER POPS IN THE AM...DECREASING FROM WEST TO EAST IN THE AFTERNOON. STORM MOTION IS AROUND 20KTS...BUT WITH HIGH PWATS/H7 DEWPOINTS AND POTENTIAL FOR STORMS MOVING OVER THE SAME AREA COULD PRODUCE HEAVY RAIN. MAINLY DRY FOR MONDAY NIGHT INTO TUESDAY WITH A WARM FRONT SITUATED OVER NORTHERN KANSAS. THERE IS LIFT OVER THE FRONT AND THE FRONT LIFTS NORTH TUESDAY NIGHT AND WEDNESDAY...SO HAVE SCATTERED THUNDERSTORMS MENTIONED. WARMER HIGHS IN THE 90S CAN BE EXPECTED SOUTH OF THE FRONT. .LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY) ISSUED AT 305 PM CDT SUN AUG 17 2014 STILL QUITE A FEW MODEL DIFFERENCES WEDNESDAY NIGHT THROUGH SUNDAY. IT LOOKS LIKE A FRONT WILL BE IN THE AREA WEDNESDAY NIGHT THROUGH FRIDAY...WITH A MID LEVEL RIDGE TO OUR SOUTH AND A FLATTER...TROF INFLUENCE TO OUR NORTH. WARM H85 TEMPS FROM 20-24 DEG C PERSIST THROUGH FRIDAY NIGHT...HOWEVER THE EC BRINGS COOLER WEATHER IN FOR SATURDAY...WHILE THE GFS HOLDS OFF UNTIL SUNDAY NIGHT. && .AVIATION...
-- Changed Discussion --
(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1150 PM CDT SUN AUG 17 2014 SHOWERS AND THUNDERSTORMS WILL CONTINUE TO PUSH THROUGH LNK AND OMA SITES EARLY IN THE PERIOD. BEHIND THE RAIN MVFR VSBYS WILL BE POSSIBLE AT BOTH OFK AND OMA AS LIGHT WINDS AND AMPLE MOISTURE ALLOW FOG TO FORM. A FRONTAL BOUNDARY WILL THEN MAKE ITS WAY THROUGH THE REGION TOMORROW MORNING...BRINGING VFR CONDITIONS AND GRADUALLY TURNING WINDS TO THE NORTH MONDAY AFTERNOON.
-- End Changed Discussion --
&& .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...ZAPOTOCNY LONG TERM...ZAPOTOCNY AVIATION...KG

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