877 FXUS63 KOAX 270506 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1206 AM CDT MON MAY 27 2013 .UPDATE... BOW ECHO OVER NORTHEAST NEBRASKA CONTINUES TO MOVE EAST AND SOUTHEAST...WE SHOULD CONTINUE TO SEE SOME DEVELOPMENT INTO SOUTHEAST NEBRASKA AND SOUTHWEST IOWA OVERNIGHT. MILLER && .AVIATION... 06Z TAFS FOR KOMA...KLNK...KOFK. TSRA SHOULD CONTINUE IN THE KOFK AREA THE NEXT SEVERAL HOURS... WITH THE STRONGEST ACTIVITY LIKELY BEFORE 07Z. THERE IS STILL SOME UNCERTAINTY HOW FAR SOUTHEAST STORMS WILL REACH OVERNIGHT... BUT HRRR MODEL DEVELOPS ACTIVITY TOWARD NORTHEAST KANSAS AND NORTHWEST MISSOURI BY A LITTLE AFTER SUNRISE. EXPECT A GRADUAL DECREASE IN CEILINGS THROUGH 14Z...THEN A GRADUAL UPWARD TREND TOWARD VFR CONDITIONS AT ALL THREE SITES BY EARLY AFTERNOON MONDAY. MILLER && .PREV DISCUSSION... /ISSUED 249 PM CDT SUN MAY 26 2013/ DISCUSSION... VERY ACTIVE WEEK ON TAP OVER THE CNTRL PLAINS WITH POTENTIAL SVR ACTIVITY ALONG WITH PROLONGED/EXCESSIVE PCPN. MORNING PRECIP WATER PLOTS WERE SHOWING AMPLE GULF MOISTURE IN PLACE WITH VALUES ROUGHLY 150% OF NORM. LATEST MESOSCALE ANALYSIS INDICATING STOUT MOISTURE STILL STREAMING INTO THE REGION...AND MODELS ARE IN GOOD AGREEMENT THIS INFLUX OF MOISTURE WILL CONTINUE THRU AT LEAST MIDWEEK...GUARANTEEING ENVIRONMENTAL MOISTURE CONTENT WILL REMAIN QUITE HIGH. AS A MATTER OF FACT...THE GFS IS SUGGESTING TOTAL PCPN AMOUNTS REACHING 400% OF NORM OVER IA BY NEXT SUNDAY GIVEN SUSTAINED PCPN EFFICIENCY. MEANWHILE...MODELS ARE AGAIN IN GOOD AGREEMENT LARGE SCALE FLOW THRU THIS WEEK WILL GRADUALLY TRANSITION FROM A LARGE CLOSED LOW CURRENTLY SITTING OVER THE PAC NW TO A RATHER IMPRESSIVE DEEP ELONGATED LONGWAVE TROF WITH THE AXIS EXTENDING FROM THE ALASKAN GULF TO THE SRN TIP OF TX. HEADING INTO NEXT WEEKEND THEN...MODELS PROG THE WRN CONUS TROF BECOMING MORE BROAD IN NATURE WITH LITTLE MOVEMENT. FOR TONIGHT...STOUT 310K ISENTROPIC UPGLIDE IS THE DRIVING FORCE FOR CONVECTIVE ACTIVITY. LIFT WILL BE FURTHER ENHANCED VIA UPPER DIVG ASSOCIATED WITH RRQ OF JET MAX. MODELS ADVERTISE ENVIRONMENTAL INSTABILITY WILL REMAIN HIGH OVERNIGHT WITH THE AXIS FOCUSED WEST OF THE CWA WITHIN AREA OF BEST DEEP LYR SHEAR/MUCAPES. LATEST HRRR INITIATES CONVECTION THIS EVEN INVOF THE INSTABILITY AXIS...THEN GRADUALLY PUSHES IT EWD OVERNIGHT. AT THIS POINT CANNOT DISCOUNT A FEW STORMS PRODUCING HAIL AND/OR STRONG WIND GUSTS. AS FOR SVR POTENTIAL...SPC CONVECTIVE OUTLOOK KEEPS THE CWA IN THE SLGT RISK THRU DAY 3. LOOKING AT MONDAY AFTN/EVENING...FAVORABLE CONDITIONS APPEAR TO BE FOCUS INVOF THE SRN CWA ALONG A WARM FRONT EXTENDING ALONG THE NEB/KS BORDER. COMBINATION OF DEEP LYR SHEAR/EFFECTIVE SRH/MLCAPE/ML LCL SUGGEST AN ISOLATED TORNADO OR 2 WILL BE POSSIBLE. TUES AFTN/EVENING THEN...SVR POTENTIAL REMAINS FOCUSED OVER THE SRN CWA ALONG A SFC BNDRY ALONG THE NEB/KS BORDER. ENVIRONMENTAL CONDITIONS WILL QUITE SIMILAR WITH THE POTENTIAL FOR PRODUCING AN ISOLATED TORNADO OR 2. IN REGARDS TO POPS THE REST OF THIS WEEK...AM COMPELLED TO MAINTAIN PCPN CHANCES THRU THE MAJORITY OF THE FCST PERIOD GIVEN MODELS ADVERTISING PERSISTENT FORCING VIA UPPER LEVEL DIVERGENCE...SERIES OF VORT IMPULSES...ISENTROPIC UPGLIDE...MEANDERING SFC BOUNDARIES...AS WELL AS GENEROUS MOISTURE TO TAP INTO. DEE && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$