FXUS63 KOAX 030237
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
937 PM CDT TUE AUG 2 2011
.DISCUSSION...
CLOUDS WHICH FORMED NEAR AND N OF COLD FRONT THIS AFTERNOON
CONTINUE TO DISSIPATE WITH LOSS OF HEATING...AND THE FEW SHOWERS THAT
DOTTED THE AREA ALSO DIED OUT SEVERAL HOURS AGO. HAVE CONTINUED A
SLIGHT CHANCE POP FOR THE REST OF TONIGHT IN OUR FAR SE NE
COUNTIES...BUT BELIEVE THIS THREAT SHOULD PRIMARILY BE TIED TO
CONVECTION THAT WILL FORM OVER KANSAS DURING THE PREDAWN HOURS.
GOING TEMP TRENDS LOOK GOOD...SO ONLY MADE A FEW COSMETIC TWEEKS.
UPDATED ZONES ON THE WAY.
&&
.PREV DISCUSSION... /ISSUED 316 PM CDT TUE AUG 2 2011/
SHORT TERM...TONIGHT.
CURRENT SURFACE ANALYSIS AND VISIBLE SATELLITE SHOWS SFC COLD
FRONT EXITING THE SE CWA INTO NRN KANSAS/MISSOURI. THE N/NW FLOW
BEHIND THE FRONT HAS ALLOWED FOR LOWER DEW POINTS IN THE UPPER
60S/LOW 70S TO FILTER INTO THE NRN ZONES WHILE DWPTS IN THE UPPER
70S REMAIN ALONG AND JUST BEHIND THE FRONT. HEAT INDEX VALUES AT
200 PM RANGED FROM AROUND 90 IN THE NORTHERN AREA...TO 108 AT
FALLS CITY, OFFUTT AFB REPORTING 110, AND PLATTSMOUTH AND BEATRICE
AT 105.
THERE WILL CONTINUE TO BE A THREAT FOR ISOLD THUNDERSTORMS THROUGH
THE EVENING AS MID LEVEL LAPSE RATES INCREASE IN THE WAKE OF THE H85
TROUGH. KEPT 20 POPS WITH ISOLD THUNDER WORDING FOR SRN HALF OF CWA
TONIGHT. LIMITING FACTOR WILL BE LINGERING H70 CAP AND LACK OF MID
LEVEL MOISTURE AS HIGH PRESSURE BUILDS IN FROM THE DAKOTAS.
OVERNIGHT TEMPERATURES WILL FALL TO MORE SEASONAL READINGS IN THE
MID 60S TO LOW 70S.
LONG TERM...WEDNESDAY THROUGH THURSDAY.
COOLER AIR WILL CONTINUE TO MOVE INTO THE AREA BEHIND THE COLD
FRONT THE NEXT COUPLE OF DAYS. LOWER DEW POINTS WILL ALSO FILTER
INTO THE AREA...SO ALL IN ALL THE NEXT FEW DAYS WILL FEEL QUITE
COMFORTABLE AFTER THE EXTREME HEAT AND HUMIDITY OF THE LAST FEW
DAYS. PRECIPITATION CHANCES WILL ALSO BE ON THE
INCREASE...ESPECIALLY WEDNESDAY NIGHT THROUGH THURSDAY MORNING.
MODELS/ENSEMBLES DURING THIS TIME AGREE THAT A FAIRLY POTENT WAVE
WILL EJECT NORTHEAST ACROSS THE AREA ON THE NORTHERN PERIPHERY OF
THE SOUTHERN PLAINS RIDGE. APPEARS A COMPLEX OF SHOWERS AND TSTMS
WILL MOVE ACROSS THE AREA LATE WEDNESDAY NIGHT INTO THURSDAY
MORNING IN ASSOCIATION WITH THIS WAVE. MODELS MAY BE A LITTLE ON
THE SLOW SIDE WITH THE TIMING OF THE WAVE AND PRECIP...AND HAVE
PRECIP WINDING DOWN BY NOON ON THURSDAY. HAVE CONTINUED THE SLIGHT
TO LOW CHANCE POPS FOR THURSDAY NIGHT INTO FRIDAY...BUT NOT REAL
CONFIDENT ON PRECIP CHANCES DURING THIS TIME IN THE WAKE OF
WEDNESDAY NIGHT/THURSDAY MORNING SYSTEM.
THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL SLOWLY RETROGRADE FROM
THE SOUTHERN PLAINS THIS WEEKEND...TO THE FOUR CORNERS AREA EARLY
NEXT WEEK. THIS PUTS NEBRASKA BACK INTO A RING OF FIRE TYPE
PATTERN ON THE NORTHERN PERIPHERY OF THE RIDGE. SEVERAL SHORTWAVE
DISTURBANCES WILL BRING PERIODIC SHOWER AND THUNDERSTORM CHANCES.
AT THIS TIME IT IS DIFFICULT TO PINPOINT THE TIMING OF THE
WAVES...BUT MODELS HAVE BEEN SOMEWHAT CONSISTENT ON A COMPLEX OF
STORMS MOVING ACROSS NORTHEAST NEBRASKA SATURDAY NIGHT. WILL
CONTINUE THE CHANCE POPS ALREADY IN THE FORECAST TO ACCOUNT FOR
THIS...OTHERWISE HARD TO JUSTIFY MORE THAN SLIGHT CHANCES DUE TO
TIMING AND STRENGTH ISSUES OF THE WAVES. TEMPERATURE WISE...WITH
THE RIDGE ALOFT SUPPRESSED TO OUR SOUTH...THE EXTREME HEAT AND
HUMIDITY WILL REMAIN TO OUR SOUTH AS WELL. HIGH TEMPERATURES WILL
AVERAGE IN THE MID 80S...WITH LOWS IN THE MID 60S TO LOWER 70S.
AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
VFR CONDITIONS WILL PREVAIL THROUGH TAF PERIOD. NORTHWEST WINDS WILL
GUST AROUND 20KT THIS AFTERNOON...VEERING NORTH AND DECREASING 5 TO
10 KT OVERNIGHT. LEFT OUT MENTION OF THUNDER...BUT INTRODUCED CB
THIS AFTERNOON TO ACCOUNT FOR MID LEVEL INSTABILITY BEHIND DEPARTING
COLD FRONT. HOWEVER...THUNDER THREAT IS LOW AND IF ANY STORMS CAN
DEVELOP THEY ARE EXPECTED TO BE ISOLATED AND SHORT LIVED.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...TRUETT