FXUS63 KOAX 212029
AFDOAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
329 PM CDT THU JUL 21 2011
.SHORT TERM...TONIGHT.
LINGERING OVERNIGHT CONVECTION CONTINUES TO DIMINISH WITH ONLY
REMNANT SHOWERS REMAINING OVER THE NORTHEASTERN CWA PER LATEST RADAR
TRENDS. RAINFALL ESTIMATES OVERNIGHT SHOWED THE HEAVIEST RAIN FELL OVER
PORTIONS OF BOONE..MADISON...PLATTE AND STANTON COUNTIES. KOAX RADAR
ESTIMATED AS MUCH AS 4-6 INCHES MAY HAVE FALLEN IN THIS
AREA...THOUGH OBSERVER REPORTS SUGGEST THIS MAY BE A BIT OVERDONE.
OTHERWISE SOUTH OF A LINE FROM SIOUX CITY TO NORFOLK MOST AREAS SAW
A HALF TO ONE INCH...TO THE NORTH LITTLE IF ANY PRECIPITATION WAS
REPORTED. AS OF 19Z SKIES WERE ATTEMPTING TO CLEAR OUT...THIS HAS
ALLOWED AREAS IN SOUTH EASTERN NEBRASKA TO HIT 90...ELSEWHERE CLOUDS
HAVE LIMITED HEATING AND GENERALLY ONLY UPPER 70S TO MID 80S HAVE
BEEN REALIZED ELSEWHERE IN THE CWA.
LATEST WV/400MB RUC ANALYSIS SHOWS BROAD UPPER LEVEL RIDGING OVER
THE SOUTHEASTERN CONUS WITH SHORTWAVE TROUGHS DIGGING INTO THE
BACKSIDE OF THIS RIDGE INTO THE CENTRAL PLAINS. AT THE SURFACE...A
STATIONARY FRONT EXTENDS INTO NORTHERN KANSAS WHILE SFC RIDGING IS
PRESENT INTO THE NORTHERN PLAIN STATES. THIS FRONT WILL LINGER
ACROSS THE CENTRAL PLAINS THROUGHOUT THE NIGHT...AND WILL BE THE
FOCUS FOR REDEVELOPMENT LATER THIS AFTERNOON AND THIS EVENING. THE
LATEST REGIONAL RADAR VIEW SHOWS DEVELOPMENT IS BEGINNING..YET
STRUGGLING...ACROSS NORTHWESTERN KANSAS. THE SHORTWAVE ASSOCIATED
WITH THIS DEVELOPMENT WILL SHIFT INTO THE CWA THIS EVENING ALLOWING
FOR REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS. MODEL CONSENSUS IS
ALL OVER THE PLACE AS TO TIMING AND PLACEMENT...BUT REDEVELOPMENT
LOOKS TO BE A GOOD BET. FOR NOW POP GRIDS REFLECT THE SOUTHERN HALF
OF THE CWA HAS THE BEST SHOT WHERE BETTER INSTABILITY/SFC HEATING IS
PRESENT. MODERATE INSTABILITY AND 30-40KT 0-6KM SHEAR VALUES WILL WARRANT
A CONTINUED THREAT FOR SEVERE WEATHER WITH THIS DEVELOPMENT THROUGH
TONIGHT.
.LONG TERM...FRIDAY THROUGH THURSDAY.
ADDED SMALL THUNDERSTORM CHANCES SERN 1/2 FRIDAY MORNING TO
ACCOUNT FOR THE POSSIBILITY OF CONVECTION THAT DEVELOPS THROUGH
THIS EVENING ALONG/NW OF BOUNDARY OVER SWRN NEBR/NW KS VICINITY
COULD LINGER ACROSS THAT AREA. OTHERWISE WARM FRONT APPARENTLY WILL
BE WASHING OUT OR REDEVELOPING NORTH OF FORECAST AREA AS NEXT
UPPER TROUGH BRINGS FALLING SURFACE PRESSURES TO WRN SD/ERN WY.
HOWEVER...A POSSIBLE REMNANT BOUNDARY NR KS/MO BORDERS WILL HAVE
TO BE WATCHED AS MODELS WANT TO DEVELOP CONVECTION NEAR THERE
FRIDAY AFTERNOON. WITH SOME RESIDUAL CLOUDS REMAINING ON FRIDAY WAS
A BIT RELUCTANT TO FOLLOW WARMER NAM WITH A MODEL BLEND USED MOST
AREAS WHICH WAS A BIT ABOVE MAV GUIDANCE. HEAT INDEX VALUES COULD
PROMPT HEADLINES PARTS OF SE ON FRIDAY AND MORE OF THE AREA
SATURDAY AND THIS WILL HAVE TO BE ADDRESSED IN OVERNIGHT SHIFT AS
CONVECTIVE DEBRIS COVERAGE FOR FRIDAY BECOMES MORE APPARENT. DID
LEAVE IN SMALL TSTM CHANCES NRN ZONES FRIDAY NIGHT IN CASE
DEVELOPMENT OCCURS W OF THAT REGION LATE IN THE AFTERNOON WOULD
CATCH THAT AREA OVERNIGHT...ALTHOUGH MODEL FOCUS NEAR WARM FRONT
APPEARS TO BE NORTH OF FORECAST AREA.
NEXT THROUGH WILL BE DRIVING COLD FRONT ACROSS AREA SATURDAY NIGHT
WITH TEMPERATURES AHEAD OF IF SATURDAY PROBABLY SIMILAR TO
TUE/WED. THIS NEXT FRONT WILL BE PUSHING SEWD INTO EVEN HIGHER
UPPER HEIGHTS AS RIDGE BUILDS OVER CO/KS REGION AND LOW LEVEL JET
IMPINGING ON IT NOT QUITE AS GREAT AS LAST NIGHT. THUS LEFT ONLY
MODEST CHANCE POPS SAT NIGHT AND SLIGHT CHANCE SUNDAY. DID NOT
INCLUDE ANY CHANCE SAT AFTERNOON SINCE FRONT YESTERDAY HAD
LITTLE/NO SUCCESS IN DEVELOPMENT DURING AFTERNOON PLUS FRONT
DOESN/T EVEN ARRIVE TILL MOSTLY AFTER 00Z SUN.
SLIGHT CHANCE POPS STILL APPEARS WARRANTED SUNDAY NIGHT AS WARMER
AIR ATTEMPTS TO RETURN NORTHWARD. CONFIDENCE IN EXTENDED REDUCED
BY LATEST GFS WHICH BUILDS UPPER RIDGE EVEN MORE BRINGING NWRLY
UPPER FLOW TO AREA ON TUESDAY WITH SECONDARY COLD FRONT PUSHING
ACROSS THE AREA INSTEAD OF REMAINING FARTHER NE PER 00Z ECMWF.
IF GFS WOULD VERIFY TEMPERATURES COULD BE COOLER THAN MONDAY AND
THIS FORECAST WHICH LEANED A LITTLE CLOSER TO 00Z ECMWF. A LITTLE
BETTER AGREEMENT ON WEDNESDAY BEING THE WARMEST DAY AHEAD OF NEXT
UPPER TROUGH/FRONT. ADDED SMALL PRECIP CHANCES TUE NGT AND
WEDNESDAY NIGHT IN LOW LEVEL JET AXIS IN FORMER AND AS POSSIBLE
FRONT ARRIVES IN LATTER. FOR NOW COOLED MOST TEMPS OFF A LITTLE
WITH FRONT ON THURSDAY...BUT FURTHER ADJUSTMENTS LIKELY AS
STRENGTH/TIMING BECOME MORE APPARENT.
&&
.AVIATION...
TAF SITES KOFK/KOMA/KLNK
18Z TAFS
ONGOING CONVECTION IS DIMINISHING...SO FOR A NEXT HOUR OR SO OMA AND
LNK COULD STILL SEE THUNDERSTORMS. REDEVELOPMENT IS EXPECTED LATER
THIS AFTERNOON AND CONTINUING INTO THE OVERNIGHT HOURS. THOUGH THE
CHANCES FOR THIS ARE FAVORED AT OMA/LNK...CLOSER TO STRONGER SFC
HEATING AFTER SOME CLEARING TODAY. AREAS WHICH SAW APPRECIABLE RAINS
LAST NIGHT AND THIS MORNING HAVE FOG POTENTIAL AS WINDS DECOUPLE
OVERNIGHT AFTER ANY SHOWERS OR THUNDERSTORMS MOVE OUT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
CHERMOK/PEARSON