Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 311130 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 630 AM CDT SUN AUG 31 2014 .SHORT TERM...(TODAY THROUGH TUESDAY) ISSUED AT 340 AM CDT SUN AUG 31 2014 TSTMS THE NEXT 24 HOURS AND THE SEVERE WEATHER POTENTIAL MAINLY THIS AFTN AND EVENING ARE THE PRIMARY FORECAST CONCERNS. WE WILL MAY ALSO NEED A FLASH FLOOD WATCH AT SOME POINT LATER TODAY. UPPER AIR CHARTS FROM LAST EVENING HAD THE FOLLOWING MAIN FEATURES OF INTEREST. AT 300 MB A JET SEGMENT OF AROUND 105 KNOTS WAS NEAR THE CA/OR BORDER AND ANOTHER WAS JUST OFF SHORE. 12 HOUR HEIGHT FALLS OF UP TO 60 METERS WERE NOTED AT 500 MB WITHIN THE TROUGH OVER THE URN AND CONTROL ROCKIES. RIDGE AT 700 MB STRETCHED FROM THE FOUR CORNERS REGION INTO THE WRN HIGH PLAINS. 700 MB AND 850 MB MOISTURE WAS A BIT LACKING IN THE REGION...WITH THE 00Z KOAX SOUNDING ONLY HAVING 0.91 INCHES OF PRECIPITABLE WATER. ISOLD TO SCT CONVECTION MAY MOVE ACROSS THE FCST AREA THIS MORNING...WHICH MAY COMPLICATE CONVECTIVE INITIATION LATER TODAY. STORMS THIS MORNING WILL BE ELEVATED AND SHOULD BE MOSTLY BELOW SEVERE LIMITS. STORMS SHOULD GET GOING EARLY/MID AFTN IN NCTRL NE AND THEN MOVE/DEVELOP EWD INTO ERN NE DURING THE MID TO LATE AFTN. DEVELOPMENT INITIALLY MAY BE TIED TO THE COLD FRONT AND POSSIBLY NEAR A PRE-FRONTAL TROUGH AS UPPER LEVEL LARGE SCALE LIFT MOVES IN FROM THE WEST. SFC DEWPOINTS WILL INCREASE INTO THE 65-70 DEGREE RANGE WHILE TEMPERATURES CLIMB INTO THE 80S. THIS SHOULD YIELD ML CAPE VALUES OF 2000-3000 J/GAG. MODELS FCST PRECIPITABLE WATER VALUES TO REACH CLOSE TO 2 INCHES BY LATE AFTERNOON. STORMS MAY INITIALLY BE SOMEWHAT DISCRETE THEN FORM INTO CLUSTERS AND/OR LINEAR STRUCTURES DURING THE EVENING. TORNADO RISK WILL BE SLIGHTLY ENHANCED NEAR ANY LOW LEVEL CONVERGENCE ZONES...BUT THE LACK OF A WARM FRONT IN OUR AREA MAY BE A LIMITING FACTOR. STORM CHANCES CONTINUE MOST AREAS TONIGHT BUT WILL BE DECREASING FROM NORTHWEST TO SOUTHEAST AS THE NIGHT GOES ON. HEAVY RAIN POTENTIAL SHOULD BE HIGHEST FROM 6 PM TO 2 AM. LOOK FOR LOWS TONIGHT MAINLY IN THE 60S...COOLEST NORTHWEST/WARMEST SOUTHEAST. A COLD FRONT SHOULD EXTEND FROM WRN WI THROUGH SERN IA AND THEN INTO CNTRL KS BY 12Z MONDAY. STORMS COULD LINGER IN SERN NE AND SWRN IA AT LEAST MONDAY MORNING. ENERGY MOVING SEWD FROM THE DKTS COULD BRING SOME SHOWERS/THUNDERSTORMS TO MAINLY NERN NE MONDAY NIGHT...SO KEPT SOME POPS GOING THERE IN THE EVENING AND SPREAD THEM TO ALL OF THE AREA LATER MONDAY NIGHT. TUESDAY LOOKS MAINLY DRY. HIGH PRESSURE WILL INITIALLY BE OVER THE AREA BUT SLIDE SEW DURING THE DAY. SOUTHERLY WINDS WILL INCREASE AND HELP PUSH HIGHS TO THE LOWER AND MID 80S. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 340 AM CDT SUN AUG 31 2014 THINKING FROM THE PAST FEW DAYS IN THIS PERIOD HAS NOT CHANGED MUCH. INITIALLY FAST ZONAL FLOW AT 500 MB WILL BE IN PLACE ACROSS THE NRN UNITED STATES. THIS FLOW BECOMES MORE SOUTHWESTERLY AS A TROUGH DEVELOPS FROM CANADA TO NRN CA BY THURSDAY. STORM CHANCES SHOULD INCREASE THURSDAY NIGHT INTO SATURDAY BEHIND A COLD FRONT THAT WILL MOVE THROUGH THE AREA THURSDAY. 00Z GFS AND ECMWF HAVE SOME DIFFERENCES IN PCPN COVERAGE LATE IN THE WEEK. DECIDED TO KEEP ABOUT AN EVEN BLEND OF THE MODELS FOR NOW IN THOSE PERIODS. .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1125 PM CDT SAT AUG 30 2014 VFR CONDITIONS WITH SCATTERED TO BROKEN HIGH CLOUDS ARE FORECAST THROUGH MID MORNING. LOW LEVEL WIND SHEAR IS LIKELY 09Z TO 15Z AT ALL TAF SITES AS SOUTHWESTERLY LOW LEVEL JET KICKS UP TO 40 TO 50KT RANGE. GUSTY SOUTH WINDS 15 TO 25KT ARE EXPECTED AFTER 15Z AHEAD OF A COLD FRONT MOVING INTO EASTERN NEBRASKA. THUNDERSTORMS ARE FORECAST TO FIRE ALONG THAT FRONT AFTER 21Z...MOST LIKELY JUST SOUTHEAST OF KOFK AREA. STRONG STORMS COULD MOVE THROUGH KOMA AND KLNK TAF SITES AFTER 00Z. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 615 AM CDT SUN AUG 31 2014 AVN CONCERN THIS MORNING IS DETERIORATING CONDITIONS REVOLVING AROUND STRONG/SEVERE +TSRA ASSOCIATED WITH COLD FRONT MOVING ACROSS ERN NEB. EXPECT TSTM ACTIVITY TO STRENGTHEN BY LATE THIS AFTN AS FRONTAL BNDRY APPROACHES TAF SITES WITH DISTINCT POSSIBILITY OF SEVERE STORMS AT KOFK BY LATE AFTN...AND EARLY EVENING AT KOMA/KLNK. EXPECT STORMS THEN TO ORGANIZE INTO MCS AND QUICKLY PUSH INTO WRN IA SHORTLY AFTN 06Z TONIGHT. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...MILLER LONG TERM...MILLER AVIATION...DEE

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