FXUS63 KOAX 231910
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
210 PM CDT THU SEP 23 2010
.SHORT TERM...TONIGHT
SFC CDFNT CONTINUES TO PROGRESS EWD INTO THE NORTHWESTERN
REACHES OF THE CWA. CLEARING JUST EAST OF THE FRONT HAS ALLOWED FOR
INCREASING INSTABILITY NEAR THE FRONTAL CIRCULATION. LATEST RADAR
TRENDS SHOW INCREASING ACTIVITY ALONG THE BOUNDARY AND EXPECT THIS
TO CONTINUE INTO THE EVENING HOURS AS THE FRONT PROGRESSES EWD. HOW
WIDESPREAD CONVECTION BECOMES IS STILL SOMEWHAT IN QUESTION. BOWING
SEGMENTS LOOK TO BE THE MAIN HAZARD IF ACTIVITY DOES GET GOING ALONG
WITH LOCALLY HEAVY RAIN BASED ON AVAILABLE DEEP LAYER MOISTURE.
LATEST RUC GUIDANCE SHOWS ALL CONVECTION OUT OF THE REGION BY 03Z.
KERN
.LONG TERM...FRIDAY THROUGH THURSDAY
CURRENT UPPR LVL LO THIS AFTN WL BE MAKING STEADY EWD PROGRESS
THRU THE DAY ON FRI WITH DRIER AND COOLER AIR MOVG INTO THE MO
RIVER VALLEY. WITH LARGE-SCALE SUBSIDENCE AND A FAIRLY DRY
ATMOSPHERE...SHLD SEE PLENTY OF SUN. MIXING TO H9 YIELDS HIGHS IN
THE 70S AND THIS SEEMS REASONABLE AND CLOSE TO GOING FORECAST.
NEXT SYSTEM FOR THE FA /CURRENTLY SPINNING THRU THE PAC NW PER AFTN
WV IMAGERY/ WL MOV INTO THE NRN PLAINS ON FRI NIGHT AND INTO THE
FA ON SAT. MODELS ARE IN FAIRLY DECENT AGREEMENT WITH THIS
SYSTEM...WITH MANY OF THE DIFFERENCES IN REGARDS TO HOW FAR WEST
THE LARGE-SCALE SUPPORT FROM THE SYSTEM WL MOV AS IT DROPS SWD
THRU IA. PRECIP FOR OUR CWA IS MOST LIKELY TO BE DRIVEN BY WAA
AHEAD OF THE SYSTEM. ISENTROPIC LIFT INCREASES LATE FRI NIGHT OVR
THE NW CWA WITH SATURATION OCCURRING CLOSE TO 12Z. THUS EXPECT
SOME LIGHT RAIN TO DEVELOP AND MOV INTO NE NEB LATE FRI NIGHT AND
HAVE KEPT IN THE CHC POPS. LAPSE RATES DO SEEM SUFFICIENTLY STEEP
FOR SOME ISO THUNDER MENTION AS WELL WITHIN THE WAA WING. THIS
BAND OF PRECIP /DRIVEN BE THE ISENTROPIC LIFT/ WL SWING THRU THE
FA ON SAT MRNG AND HAVE EXPANDED THE LIKELY POPS FARTHER S AND W
ATTM. PRECIP MAY TEND TO SHUT DOWN DURING THE AFTN AS WAA WING
SHIFTS EWD. LARGE-SCALE Q-G FORCING ASSOCIATED WITH THE CLOSED
SYSTEM WL BE MOVG SWD ON SAT AFTN THOUGH ASSOCIATED WITH THE MID
LVL COLD POCKET...BUT THIS MAY BE JUST E OF OUR FA. WL MAINTAIN
SOME CHC POPS /MAINLY THE ERN CWA SAT AFTN/ GIVEN SOME
UNCERTAINTY AS TO THE TRACK OF THE SYSTEM...BUT WLD EXPECT
ACTIVITY TO BE MORE ISO/SCT SAT AFTN. THE UPPER LVL LOW IS STILL
PROGGED TO DROP SWD INTO THE MID MS RIVER VALLEY ON SUN WITH THE
CWA CLEARING OUT OF CLDS AND PRECIP.
THERE IS STILL A GOOD DEAL OF UNCERTAINTY AS TO HOW FAST THIS
SYSTEM WL LIFT NEWD OUT OF THE REGION INTO THE GREAT LAKES EARLY
NEXT WEEK FM THE MID MS RIVER VALLEY...AND WL CONT TO PREFER THE
EC HERE. CWA SHLD BE NW OF THE EFFECTS OF THIS SYSTEM THOUGH WITH
UPPR LVL RIDGING BUILDING OVR THE FA. THUS WL MAINTAIN A DRY
FORECAST FOR MON THRU THUR WITH MODERATING TMPS ON MON-WED BEFORE
A COLD FRONT /WHICH APPEARS DRY ATTM/ MOVS THRU AND DROPS TMPS
BACK FOR THURS.
BOUSTEAD
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
-SHRA WL CONTINUE AHEAD OF SFC CDFNT ALONG WITH GUSTY SOUTHERLY SFC
WINDS TO NEAR 30KTS. SCATTERED TSTMS ARE EXPECTED ALONG THE CDFNT
WITH GUSTY NORTHWEST WINDS BEHIND THE FRONT TO NEAR 30KTS. VFR CIGS
ARE EXPECTED BEHIND THE FRONTAL BOUNDARY.
KERN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$