Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 250430
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1130 PM CDT THU JUL 24 2014

.UPDATE...
ISSUED AT 1130 PM CDT THU JUL 24 2014

CLUSTER OF THUNDERSTORMS NOW MOVING INTO NORTHEAST NEBRASKA SEEMS
TO MAINTAINING ITSELF BASED ON RADAR/LIGHTNING/SATELLITE TRENDS...
AND COULD VERY WELL CONTINUE ROLL EAST SOUTHEAST AS IT REMAINS
WITHIN A LOW LEVEL MOIST JET AXIS TONIGHT. MOST RECENT HRRR MODEL
RUNS SEEM TO CAPTURE THIS TREND WELL...THUS THE FORECAST WAS
UPDATED TO AT LEAST INCLUDE SOME CHANCE OF RAIN ACROSS THE
REMAINDER OF THE FORECAST AREA. BEST CHANCES WILL LIE ALONG THE
PLATTE RIVER BASIN. FREEZING LEVEL IS AROUND 15000 FEET AND WET
BULB ZERO LEVELS AROUND 11600 FEET. THUS LARGE HAIL WILL BE HARD
TO ACHIEVE...BUT SMALL HAIL MAY BE POSSIBLE IN THE STRONGER STORMS.
30 TO 45 MPH GUSTY WINDS WILL BE POSSIBLE AS STORMS MOVE IN.

A COUPLE OF SPOTTY SHOWERS WERE ALSO TRYING TO DEVELOP AROUND THE
KSUX AREA...AND THIS MAY BE THE PRECURSOR TO ACTIVITY THAT WILL
MOVE THROUGH CENTRAL IOWA...BUT THE WESTERN EDGE COULD ALSO CLIP
OUR COUNTIES IN WESTERN IOWA AS WELL.

UPDATE ISSUED AT 847 PM CDT THU JUL 24 2014

ALTHOUGH 00Z OMAHA SOUNDING AND SPC MESO-ANALYSIS PAGE INDICATED A
FORMIDABLE CAP/WARM MID LEVEL TEMPERATURES ACROSS THE
FA...ELEVATED CONVECTION CONTINUED TO DEVELOP TOWARD NWRN ZONES
SHORTLY BEFORE 02Z. RADAR TRENDS WOULD PUT SCATTERED ACTIVITY
TOWARD ALBION BY 03-04Z. UPDATED GRIDS/ZONES TO INCLUDE POPS AS
FAR EAST AS LINCOLN TO NEAR FREMONT THROUGH 07Z BEFORE PRECIP
POSSIBLY SHUTS OFF DUE TO ITS FARTHER EAST REMOVAL OF ITS ELEVATED
ROOTS. HOWEVER...CONFIDENCE IS LOW IN THIS AND SOME SHORT RANGE
MODELS BROUGHT AN MCS ACROSS LINCOLN/OMAHA TONIGHT. SECOND AREA
WHERE DEVELOPMENT IS POSSIBLE LATER WOULD NEAR EDGE OF WARMER
TEMPS ALOFT/CAP...ACROSS FAR ERN ZONES. NO MENTION WAS MADE THERE
JUST YET. NEEDLESS TO SAY...RADAR IMAGERY WILL CONTINUED TO BE
MONITORED FOR ADDITIONAL UPDATES.

&&

.SHORT TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 316 PM CDT THU JUL 24 2014

MOST OF THE SENSIBLE WEATHER THIS FORECAST IS IN THE SHORT TERM.
TSRA ASSOCIATED WITH PERSISTENT WAA PATTERN CONTINUE TO RIDE THE
EDGE OF THE INCREASING CAP THIS AFTERNOON AND MAY CONT TO AFFECT
A SMALL PORTION OF OUR WESTERN IOWA COUNTIES FOR A COUPLE OF MORE
HOURS BEFORE THE CAPPING INVERSION BECOMES TO STRONG FOR OUR CWA.
OTHER CONVECTION WILL LIKELY GET GOING OVER THE HIGH PLAINS
ASSOCIATED WITH A LEE TROUGH WHERE TEMPERATURES HAVE SOARED INTO
THE LOWER 100S...AND LOW-LEVEL LAPSE RATES HAVE STEEPENED
SUFFICIENTLY TO ALLOW FOR CI. SOME HIGH-RES GUIDANCE INDICATES
THAT SOME OF THIS ACTIVITY MAY WANT TO TRY AND MAKE IT INTO NE NEB
LATE THIS EVENING BUT WE FEEL THIS APPEARS A BIT OVERDONE GIVEN
THE INCREASE CAP AHEAD OF THIS AREA OF DEEP MIXING. THUS IT SHOULD
BE A FAIRLY QUIET BUT WARM NIGHT WITH BREEZY SOUTH WINDS.

THE MODELS ARE IN BETTER AGREEMENT TODAY IN THE CDFNT TIMING FOR
FRI AS THE NAM HAS SLOWED THE PROGRESSION OF THE FRONT CLOSER TO
THE EC/GEM OF YESTERDAY. THUS HIGHS IN THE CNTRL/SRN CWA SHOULD
CLIMB INTO THE MID AND UPPER 90S...AND WITH DEW POINTS IN THE
LOWER TO MID 70S...WE WILL LIKELY SEE A PERIOD OF HEAT ADVISORY
CRITERIA BEING MET. THE FRONTAL BOUNDARY STILL LOOKS LIKE IT WILL
REMAIN CAPPED OVER THE FA GIVEN THE WARM MID-LEVEL TEMPERATURES
AND LACK OF LARGE-SCALE FORCING FOR ASCENT. THE COLD FRONT WILL
STALL NEAR THE KS/NEB BORDER ON FRI NIGHT WITH THE LOW-LEVEL FLOW
TURNING TO THE EAST OVERNIGHT KEEPING MOISTURE LOCKED INTO THE FA.
TSRA MAY STILL DEVELOP IN THE UPSLOPE REGIME OVER THE HIGH PLAINS
FRI AFTN AND ATTEMPT TO ROLL ALONG THE EDGE OF THE MID LEVEL
CAP/INSTABILITY GRADIENT OVER NRN NEB/SRN SD FRI NIGHT. THE
NAM/EC ARE THE STRONGEST WITH THIS PATTERN AS THE GFS SCOURS OUT
MORE OF THE MOISTURE POST FRONTAL. CURRENTLY WE PREFER MORE THE
EC/NAM LOOK TO THE PATTERN AND WILL CONT WITH SOME POPS AFTER 09Z
FRI NIGHT. SOME CONVECTION MAY TRY AND LINGER INTO THE DAY ON SAT
OR REGENERATE GIVEN THE RESIDUAL MOISTURE AND INVERTED TROUGH
SLIDING SEWD THROUGH THE CWA. CONFIDENCE IS LOWER DURING THIS
PERIOD...BUT SYNOPTIC PATTERN DOES FAVOR SOME CONVECTION ON
SAT...EITHER A CONTINUATION OF OVERNIGHT ACTIVITY OR NEW
DEVELOPMENT ALONG THE INVERTED TROUGH DURING THE AFTN. EFFECTIVE
SHEAR AND INSTABILITY WOULD SUPPORT AN ISO SVR THREAT IF THIS
PATTERN ENDS UP DEVELOPING. ONCE THE INVERTED TROUGH MOVES THROUGH
THE SOUTHERN CWA ON SAT EVENING THE CONVECTIVE CHANCES LOOK TO END
FOR THE REST OF THE SHORT TERM WITH MUCH COOLER AND DRIER AIR
MOVS INTO THE AREA FOR SUNDAY.

.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 316 PM CDT THU JUL 24 2014

MOST OF THE EXTENDED PERIOD STILL APPEARS QUIET WITH SEASONABLY
COOL AIR IN PLACE WITH NORTHWEST FLOW ALOFT. HIGHS IN THE UPPER
70S TO LOWER 80S APPEAR LIKELY FOR MON/TUE BEFORE TEMPERATURES
START TO SLOWLY MODERATE TOWARD NORMAL. AS RETURN FLOW DEVELOPS BY
MID WEEK WE WILL CONT TO MENTION THE CHANCES FOR MAINLY NOCTURNAL
SHOWERS AND THUNDERSTORMS TO END THE PERIOD.

&&

.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 PM CDT THU JUL 24 2014

WINDS WILL CONTINUE TO GRADUALLY VEER TONIGHT THROUGH FRIDAY.
INITIALLY...WINDS WILL BE SOUTHEAST AT 12 TO 15 KNOTS...WITH
GUSTS UP TO 20 TO 25 KNOTS...BECOMING SOUTHWEST AND EVENTUALLY
NORTHWEST THROUGH THE PERIOD. A FEW SHOWERS AND THUNDERSTORMS WILL
ALSO BE POSSIBLE BETWEEN 6-8Z AT KOFK AND 7-09Z AT KLNK AND 8-10Z
AT KOMA. BUT ANY STORMS THAT DO MAKE THEIR WAY TO THOSE SITES ARE
EXPECTED TO BE FAIRLY SHORT LIVED.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR NEZ065>068-078-
     088>093.

IA...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR IAZ079-080-090-
     091.

&&

$$

UPDATE...DEWALD
SHORT TERM...BOUSTEAD
LONG TERM...BOUSTEAD
AVIATION...DEWALD/GROSS


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