Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

Home | Current Version | Previous Version | Graphics & Text | 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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS63 KOAX 192021 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 321 PM CDT SAT APR 19 2014 .SHORT TERM...
-- Changed Discussion --
(TONIGHT THROUGH TUESDAY) ISSUED AT 309 PM CDT SAT APR 19 2014 RAIN/THUNDERSTORM CHANCES THROUGH MONDAY MORNING ARE THE PRIMARY FORECAST CONCERNS. FRONTAL BOUNDARY HAS SLIPPED INTO NORTHEAST NEBRASKA THIS AFTERNOON. AHEAD OF THE FRONT...TEMPERATURES HAVE CLIMBED WELL INTO THE 70S ON BRISK SOUTH TO SOUTHWEST WINDS...HOWEVER MOISTURE HAS BEEN SLOW TO RETURN. DEW POINTS WERE GENERALLY IN THE MID AND UPPER 40S...WITH LOWER 50S READINGS WELL SOUTH IN CENTRAL KANSAS AND OKLAHOMA. A WEAK MID LEVEL WAVE AS SEEN IN WATER VAPOR IMAGERY AND RAP HEIGHT FIELDS WAS MOVING THROUGH NORTHEAST NEBRASKA...AND WAS TRIGGERING MID LEVEL RETURNS ON RADAR ACROSS NORTHEAST NEBRASKA AND EASTERN SOUTH DAKOTA. HOWEVER ONLY VIRGA IS EXPECTED THERE AS LOW HUMIDITIES EXIST BELOW MID LEVEL CLOUD LAYER. CONGESTUS CLOUDS WERE ALSO NOTED IN SOUTH CENTRAL NEBRASKA IN AREA OF INCREASING BUT STILL WEAK INSTABILITY. MEANWHILE...UPPER TROUGH DRIFTING EAST THROUGH ARIZONA WILL GRADUALLY WORK TOWARD THE PLAINS OVERNIGHT AND EVENTUALLY EAST OF THE AREA MONDAY. AHEAD OF THIS TROUGH...A COUPLE OF MID LEVEL WAVES WILL RIPPLE NORTHEAST ACROSS NEBRASKA...AND SHOULD TRIGGER SCATTERED SHOWERS OR STORMS FOCUSED NEAR SURFACE FRONT. BEST CHANCE FOR THUNDERSTORMS APPEARS TO COME LATER THIS EVENING AND OVERNIGHT AS CONVECTION EXPECTED TO DEVELOP IN NORTH CENTRAL KANSAS OR SOUTH CENTRAL NEBRASKA MOVES INTO OUR AREA. THE SLOW MOISTURE RETURN WAS HOLDING INSTABILITY IN CHECK THIS AFTERNOON BUT IS EXPECTED TO INCREASE LATE IN THE DAY OR EARLY EVENING. MID LEVEL LAPSE RATES OF 8.5-9 C/KM WERE ALREADY IN PLACE IN WESTERN KANSAS/NEBRASKA OVER TOP OF INCREASING LOW LEVEL CONVERGENCE NORTHEAST OF SURFACE LOW IN EASTERN COLORADO. VARIOUS SYNOPTIC AND MESO SCALE MODELS (NAM/GFS/RAP/HRRR/HOPWRF) INDICATE CONVECTION POPPING IN NORTH CENTRAL KANSAS AND SOUTH CENTRAL NEBRASKA SOMETIME IN THE 23Z TO 02Z TIMEFRAME...AND DEVELOP/SPREAD THIS NORTHEAST ALONG FRONTAL ZONE DURING THE EVENING. SEVERE PARAMETERS ARE NOT IMPRESSIVE WHEN STORMS ARRIVE OVERNIGHT...ELEVATED CAPE 800 J/KG AND 0-6KM SHEAR NEAR 25KT...SO NOT EXPECTING MORE THAN SMALL HAIL AND GUSTY WINDS. CHANCES WILL DECREASE FROM SOUTHWEST TO NORTHEAST AFTER MIDNIGHT AS THIS COMPLEX ROLLS OUT OF OUR AREA. THEN CHANCES BEGIN TO INCREASE AGAIN SUNDAY MORNING WITH THE APPROACH OF UPPER TROUGH. SURFACE DEW POINTS WILL CONTINUE TO RISE...LIKELY INTO THE MID TO UPPER 50S BY AFTERNOON...WITH COLD FRONT BRIDGING NORTH TOWARD THE SOUTH DAKOTA BORDER. AFTERNOON SURFACE CAPES SHOULD APPROACH 1500 J/KG BUT SHEAR IS LIMITED. SO AGAIN SEVERE CHANCES ARE SMALL...BUT CONTINUED DEVELOPMENT OF SHOWERS/STORMS APPEARS LIKELY THROUGH THE AFTERNOON AND EVENING GIVEN COOLING ALOFT FROM UPPER TROUGH. WILL HAVE FAIRLY HIGH PRECIP CHANCES SUNDAY AFTERNOON AND NIGHT FOR MUCH OF THE SOUTHERN TWO- THIRDS OF THE CWA BEFORE FRONT FINALLY BEGINS MOVING SOUTHEAST LATE SUNDAY NIGHT. LINGERING SHOWERS/STORMS NEAR I-80 AND SOUTH WILL REMAIN IN THE FORECAST MONDAY MORNING...THEN CLEARING SKIES WITH SURFACE HIGH PRESSURE AND RIDGING ALOFT BUILDING IN WILL RULE THE FORECAST INTO TUESDAY. .LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY) ISSUED AT 309 PM CDT SAT APR 19 2014 THE LONGER TERM PERIOD WILL BEGIN WITH UPPER RIDGE AXIS SHIFTING OFF TO THE EAST WITH THE APPROACH OF ANOTHER TROUGH SLIDING INTO THE ROCKIES. THAT TROUGH WILL WORK THROUGH THE PLAINS WEDNESDAY AND THURSDAY BEFORE LIFTING THROUGH THE GREAT LAKES FRIDAY AND SATURDAY. WILL HAVE PRECIPITATION CHANCES IN THE FORECAST UNTIL THAT PASSES BY...WITH A CHANCE FOR SEVERE STORMS AT MID WEEK. THUNDERSTORMS ARE POSSIBLE TUESDAY NIGHT AS WARM ADVECTION COMMENCES UNDER DIFFLUENT MID LEVEL FLOW AHEAD OF WESTERN TROUGH. MID LEVEL INSTABILITY IS NOT THAT STRONG THEN...BUT SCATTERED SHOWERS/STORMS ARE CERTAINLY POSSIBLE. ON WEDNESDAY...SURFACE LOW PRESSURE WILL INTENSIFY IN THE HIGH PLAINS WITH DRYLINE SETTING UP IN WESTERN NEBRASKA. WARM ADVECTION CONTINUES OVER OUR AREA LEADING TO LINGERING CHANCE FOR SHOWERS/STORMS. BUT BETTER CHANCES COME WEDNESDAY NIGHT AS LOW/FRONT/DRYLINE MOVE INTO EASTERN NEBRASKA UNDER DYNAMIC MID LEVEL FLOW AND 60KT LOW LEVEL JET. TIMING AND MAGNITUDE OF THESE FEATURES WILL STILL HAVE TO BE FINE-TUNED WITH LATER FORECASTS...BUT THIS CERTAINLY BEARS WATCHING. MOST OF THE THUNDERSTORM ACTIVITY WILL BE EXITING THURSDAY MORNING...BUT COULD SEE SOME REDEVELOPMENT OF SHOWERS ESPECIALLY IN OUR NORTH AND EAST DURING THE AFTERNOON AS MID LEVEL COLD POOL ROTATES THROUGH THE REGION. COOLER AIR WILL FOLLOW WITH HIGHS GENERALLY IN THE 60S TO END THE WEEK.
-- End Changed Discussion --
&& .AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.) ISSUED AT 1246 PM CDT SAT APR 19 2014 VFR CONDITIONS ARE EXPECTED THROUGH THIS AFTERNOON. A COLD FRONT WILL CONTINUE TO SLOWLY MOVE SOUTHEAST ACROSS THE AREA. MVFR CIGS AND VISIBILITIES ARE POSSIBLE FOR THE REMAINDER OF THE TAF PERIOD AS THE COLD FRONT BEGINS TO STALL. THE FRONT WILL BE THE FOCUS FOR SHOWERS...ESPECIALLY FROM NEAR 02-10Z AND AGAIN AT KOFK FROM 12-18Z SUN. MORE SHOWERS AND POTENTIAL THUNDERSTORMS ARE POSSIBLE FOR KLNK AND KOMA AFTER 18Z SUNDAY. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ SHORT TERM...DERGAN LONG TERM...DERGAN AVIATION...KERN

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