Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000 FXUS63 KOAX 201049 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 549 AM CDT WED AUG 20 2014 .SHORT TERM...(TODAY THROUGH FRIDAY) ISSUED AT 323 AM CDT WED AUG 20 2014 MESO ANALYSIS THIS MORNING INDICATING HIGH DEGREE OF MOISTURE/INSTABILITY IN PLACE OVER THE REGION WITH PWS OVER 1.5" AND MUCAPES AROUND 2000 J/KG. MEANWHILE INTENSE LLVL MOISTURE ADV WAS FEEDING CONVECTIVE ACTIVITY WHICH HAS BLOSSOMED OVER CNTRL NEB AND CNTRL SD ALONG AXIS OF DEEP LYR MOIST CONVERGENCE/BNDRY LYR THETA-E ADV/315K ISENTROPIC UPGLIDE. LAST SEVERAL RUNS OF HIRES HRRR SUGGESTING LINE OF CONVECTION ORIENTED NW-SE WILL FIRE OVER THE CWA SOMETIME TWD SUNRISE THIS MORNING. HRRR THEN LIFTS ACTIVITY NEWD TWD THE UPPER MIDWEST AND OUT OF THE CWA BY 18Z THIS AFTN. HEADING INTO THIS WEEKEND...GOOD MODEL AGREEMENT HIGH PRESSURE DOME WILL BUILD OVER THE SERN STATES WILL ACT AS A BLOCK RESULTING IN UPSTREAM AMPLIFICATION OF UPPER TROF OVER THE WRN CONUS. IN ADDITION...BULK OF PCPN ACTIVITY IS PROGGED TO BE NOCTURNAL IN NATURE THE REST OF THIS WEEK WITH BULK OF RAINFALL FOUND MAINLY NORTH OF THE CWA. HOWEVER...QUITE PROBABLE THE CWA WILL SEE ITS FAIR SHARE OF MUCH NEEDED PCPN THE NEXT SEVERAL DAYS. TONIGHT...EXPECT CONVECTION TO FIRE FROM ERN SD TO SW NEB ALONG INSTABILITY AXIS WHERE BNDRY LYR THETA-E CONVG WILL BE MOST PREVALENT. ACTIVITY PROGGED TO EVENTUALLY ORGANIZE INTO A COMPLEX AND SLOWLY MIGRATE EWD OVER ERN SD OVERNIGHT. IS LIKELY THAT SRN PORTION OF MCS WILL PUSH DEEP INTO THE CWA...THUS FEEL COMPELLED PUSH POPS INTO THE LIKELY CAT DURING THE OVERNIGHT TONIGHT. THURSDAY NIGHT CONVECTION NOT LOOKING ALL THAT IMPRESSIVE AT THIS POINT AND ANY ACTIVITY THAT DOES DEVELOP WILL BE LIGHTLY SCATTERED IN NATURE AT BEST. THEREFORE TOKEN LOW POPS SEEM TO BE THE BEST FIT FOR NOW. FRIDAY NIGHT THOUGH LOOKING RATHER PROMISING FOR GENEROUS RAINFALL ASSOCIATED WITH ANTICIPATED NIGHTTIME COMPLEX. ENVIRONMENT AT THAT TIME WILL BE PRIME WITH WARM CLOUD DEPTH OF 4K METERS...PWS MORE THAN 2"...KI AOA 40...LLVL JET MOISTURE TRANSPORT FEED. MOST LIKELY THAT HEAVIER RAINFALL AMOUNTS WILL BE FOUND OVER THE NRN CWA...THUS WILL MENTION IN ZFP. .LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY) ISSUED AT 323 AM CDT WED AUG 20 2014 FEATURE OF INTEREST STILL IS UPPER TROF OVER WRN CONUS RESPONSE TO BLOCKING HIGH PRESSURE DOME OVER THE SERN CONUS WITH RATHER COOL CANADIAN AIRMASS SWEEPING INTO THE NRN/CNTRL PLAINS EARLY NEXT WEEK. GOING FCST WITH MAX TEMPS GENERALLY IN THE MID/UPPER 70S MON/TUES/WED STILL LOOK REASONABLE FOR NOW. PCPN CHANCES IN THE EXT PDS REMAINS CENTERED AROUND VERY SLOW MOVING COLD FRONTAL LEADING THE CANADIAN AIR MASS INTO THE REGION FOLLOWED BY POST FRONTAL PCPN ASSOCIATED WITH APPROACHING UPPER TROF. WITH ECM/GFS QPF IN RATHER GOOD AGREEMENT...HAVE DECIDED TO BUMP POPS UP MON-WED PDS. && .AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 550 AM CDT WED AUG 20 2014 CONVECTIVE ACTIVITY THIS MORNING SHOULD STAY NORTHEAST THROUGH EAST OF THE TAF SITES WITH A GENERAL THINNING OF CLOUDS THIS MORNING. OUTFLOW COULD BRING MORE OF A ENE COMPONENT TO SFC WINDS EARLY...ESPECIALLY AT KOFK...BUT THEY SHOULD BECOME SSE BY LATE MORNING AND BECOME GUSTY AT ALL LOCATIONS THIS AFTN. A LOW LEVEL JET WILL STRENGTHEN AGAIN TONIGHT AND IF SFC WINDS DECREASE ENOUGH...LOW LEVEL WIND SHEAR CONDITIONS COULD DEVELOP. THIS WILL BE FURTHER EVALUATED IN LATER TAFS. TSTMS WERE EXPECTED TO DEVELOP LATE THIS AFTN/TNGT EITHER NEAR A WARM FRONT ALONG THE SD BORDER OR IN AN AREA OF LOW PRESSURE OVER WRN NEBR. SOME OF THIS ACTIVITY COULD APPROACH THE KOFK SITE AND A PROB30 GROUP WAS CARRIED TO ACCOUNT FOR THE RISK THERE LATER TONIGHT. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DEE LONG TERM...DEE AVIATION...CHERMOK

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