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 020858 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 358 AM CDT SUN AUG 2 2015 .SHORT TERM...
-- Changed Discussion --
(TODAY THROUGH TUESDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 CHANCE FOR THUNDERSTORMS AND WARM TEMPERATURES TODAY...THEN OFF AND ON STORM CHANCES THROUGH TUESDAY...ARE THE PRIMARY FORECAST CONCERNS. SCATTERED THUNDERSTORMS POPPED UP EARLY THIS MORNING JUST AHEAD OF MID LEVEL WAVE DROPPING SOUTHEAST THROUGH EASTERN NEBRASKA AND SOUTHWEST IOWA AS PER WATER VAPOR AND RAP ANALYSIS. THIS WAVE WILL TRACK EAST OF OUR CWA EARLY IN THE DAYLIGHT HOURS...WITH SUBSIDENCE BEHIND WAVE KEEPING MUCH OF THE REST OF THE MORNING DRY. ANOTHER SHORTWAVE IN THE NORTHERN PLAINS INTO THE NORTHERN GREAT LAKES IS FORECAST TO SWEEP SOUTHEAST LATER TODAY...WITH SURFACE REFLECTION IN THE FORM OF A FRONT/WIND SHIFT SETTLING INTO NORTHEAST NEBRASKA THIS AFTERNOON. SURFACE DEW POINTS NEAR OR ABOVE 70F AHEAD OF THIS BOUNDARY ARE EXPECTED TO POOL IN EASTERN NEBRASKA AND WESTERN IOWA DURING PEAK HEATING. CONVERGENCE ALONG BOUNDARY SHOULD BE ENOUGH TO GET AT LEAST ISOLATED THUNDERSTORMS FIRING IN UNSTABLE ATMOSPHERE CHARACTERIZED BY MUCAPES OVER 2500 J/KG. MEANWHILE MODERATE MID LEVEL FLOW WILL HELP GENERATE NEAR 40KT OF BULK SHEAR WITH VECTORS NORMAL TO SURFACE CONVERGENCE...SUGGESTING DISCRETE AND ROTATING STORMS ARE LIKELY...SUPPORTING HAIL AND WIND POTENTIAL. ONLY MARGINAL RISK IN SPC OUTLOOK...AND CAN NOT ARGUE GIVEN EXPECTED SCANT COVERAGE. INITIATION LOOKS TO BE FARTHER NORTH THAN PREVIOUS MODEL RUNS WITH LATER ARRIVAL OF FRONT...MOSTLY LIKELY FIRING NEAR OR SOUTH OF A WAYNE TO ALBION LINE BETWEEN 3 AND 4 PM. EXPECT ISOLATED TO SCATTERED STORMS TO PROGRESS SOUTH THROUGH THE REST OF THE AFTERNOON INTO THE EVENING WITH FRONTAL BOUNDARY BEFORE EXITING SOUTHEAST NEBRASKA AND SOUTHWEST AROUND MIDNIGHT WHEN LAST OF 850 MOISTURE PLUME FINALLY DROPS SOUTH. AHEAD OF FRONT...TEMPERATURES ARE EXPECTED WELL INTO THE 90S ESPECIALLY IF CLOUD COVER FROM MORNING CONVECTION DISSIPATES AS EXPECTED. WILL LIKELY SEE SOME HEAT INDICES TOPPING 100 FOR A COUPLE OF HOURS THIS AFTERNOON. SHOULD SEE A DRY PERIOD AFTER MIDNIGHT TONIGHT...BUT LOWERING PRESSURES IN THE HIGH PLAINS WILL DRAW 850 MOISTURE BACK NORTH RATHER QUICKLY BY LATER MONDAY MORNING AS NORTHWEST MID LEVEL FLOW CONTINUES. WILL KEEP OUR SMALL POPS FOR OUR WESTERN CWA DURING THAT TIME PERIOD...WITH CHANCES/COVERAGE GRADUALLY INCREASING MONDAY AFTERNOON...BUT ESPECIALLY OVERNIGHT AND TUESDAY AS MAGNITUDE OF MOISTURE RETURN INCREASES. WILL MAINTAIN 30 TO 50 PERCENT STORM CHANCES DURING THE DAY TUESDAY. SEVERE THREAT SHOULD BE MINIMAL THEN AS INSTABILITY REMAINS WEAK DUE TO MUCH COOLER SURFACE TEMPERATURES. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 354 AM CDT SUN AUG 2 2015 UNSETTLED WEATHER PATTERN WITH OCCASIONAL RAIN/STORM CHANCES WILL CONTINUE THROUGH MUCH OF THE REST OF THE WEEK. MID LEVEL RIDGE IS FORECAST TO REMAIN FROM TEXAS WEST TO THE SOUTHWESTERN STATES AT LEAST THROUGH THURSDAY...KEEPING STORM TRACK ROLLING FROM THE CENTRAL/NORTHERN ROCKIES ACROSS THE PLAINS. SEVERAL SHORTWAVES COULD TRIGGER CONVECTION AT JUST ABOUT ANY TIME...WITH MORE POTENT WAVES MOVING THROUGH OUR AREA WEDNESDAY DURING THE DAY AND THURSDAY NIGHT AS PER ECMWF/GFS. WE SHOULD REMAIN ON THE COOL SIDE OF SURFACE FRONTAL SYSTEM...SO INSTABILITY PROGS SUGGEST SEVERE CHANCE WILL BE MINIMAL OVERALL WITH TEMPERATURES REMAINING IN THE 70S AND 80S MUCH OF THE WEEK.
-- End Changed Discussion --
&& .AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1152 PM CDT SAT AUG 1 2015 NOT MUCH CHANGE FROM PREVIOUS THINKING. ISOLATED TSTMS POSSIBLE THE NEXT 24 HOURS BUT CHANCES TOO LOW TO MENTION IN TAFS AT THIS TIME. LOOK FOR VFR CONDITIONS WITH ANY CEILINGS EXPECTED TO BE ABOVE 8000 FEET. BEST CHANCE OF TSRA WOULD BE WITH WIND SHIFT SUNDAY AFTERNOON/EVENING. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...MILLER

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