Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 092327
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
627 PM CDT WED APR 9 2014

.SHORT TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 306 PM CDT WED APR 9 2014

POTENT SHORTWAVE TROUGH MOVING ACROSS SOUTHERN CANADA THIS
AFTERNOON WILL ALLOW FOR A COLD FRONT TO SWEEP THROUGH THE AREA
OVERNIGHT. ONLY MID AND HIGH LEVEL MOISTURE IS ASSOCIATED WITH THE
SYSTEM FOR OUR AREA...AND LIFT IS ALSO VERY WEAK...THUS
MEASURABLE PRECIP APPEARS UNLIKELY TONIGHT. WILL LOWER BUT
MAINTAIN SOME SCHC POPS ACROSS THE NRN AND ERN CWA...BUT WE ARE
EXPECTING MOST AREAS TO REMAIN DRY. COOLER WEATHER IS ON TAP FOR
THU BUT WITH A DRY ATMOSPHERE AND DECENT SUN WE SHOULD SEE MIXING
TO AROUND 800 MB AND TEMPERATURES WARM WELL INTO THE 60S. A WEAK
SHORTWAVE TROUGH THEN SLIDES SEWD IN THE NORTHWEST FLOW FOR THU
NIGHT AND COULD BRING A FEW SHOWERS OVERNIGHT. ANOTHER GOOD MIXING
DAY IS EXPECTED ON FRIDAY AND AS 850 MB TEMPERATURES WARM A COUPLE
OF DEGREES WE SHOULD SEE HIGHS BACK IN THE 70S.

A 40 TO 50 KT LOW-LEVEL JET IS EXPECTED TO DEVELOP OVER THE
SRN/CNTRL PLAINS ON FRI NIGHT LEAD TO BROAD ISENTROPIC LIFT AND
AN AREA OF THETA-E ADVECTION OVER THE ERN DAKOTAS. THIS MAY LEAD
TO A FEW SHOWERS OR ISO TSRA...MAINLY TO THE N OF THE FA LINGERING
INTO SAT MORNING. DURING THE DAY ON SAT THE MODELS CONT TO
ADVERTISE A SHORTWAVE TROUGH MOVING INTO THE ROCKIES IN THE
NORTHERN STREAM WHILE THE CLOSED LOW /CURRENTLY OFF THE SW US
COAST AROUND 140 W/ MOVES INTO THE DESERT SW. AHEAD OF THESE
SYSTEMS RETURN FLOW WILL ALLOW FOR MOISTURE TO INCREASE INTO THE
FA WITH SFC DEWPOINTS AOA 50. THIS MOISTURE INCREASE WILL OCCUR
BELOW STEEP MID-LEVEL LAPSE RATES OF 8 TO 8.5 C/KM FROM 700 TO 500
MB CREATING MLCAPE OF 1000-1500 J/KG BY AFTERNOON. MODELS DEPICT
HEIGHT FALLS TO SPREAD ACROSS THE PLAINS WEAKENING THE CONVECTIVE
INHIBITION ALONG THE CDFNT. THIS SHOULD ALLOW FOR TSRA TO LIKELY
FIRST DVLP IN IA AND THEN BACKBUILD INTO SE NEB DURING THE
AFTERNOON. EFFECTIVE BWD OF 30 TO 35 KT MAY LEAD TO SOME
ORGANIZATION OF THE STORMS AND AN ISO SVR STORM APPEARS
POSSIBLE...MAINLY ALONG AND S OF I80. THE LOW-LEVEL FLOW BECOMES
WEAK DURING THE AFTERNOON...AND THE FLOW WILL VEER AS WELL
LIMITING THE THREAT TO HAIL/WIND.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 306 PM CDT WED APR 9 2014

TSRA WILL CONT TO DRIFT SWD SAT EVENING INTO NE KS/NW MO. THE
MODELS THEN DIVERGE AS TO HOW THE TWO STREAMS WILL INTERACT AS
THEY MOVE THROUGH THE PLAINS. IT APPEARS MID-LEVEL FRONTOGENESIS
WILL INCREASE DURING THE DAY ON SUNDAY...ALONG WITH BROAD LARGE-
SCALE FORCING FOR ASCENT LEADING TO A BAND OF RA FOR A GOOD PART
OF THE FA. THIS MAY LINGER INTO SUN NIGHT WITH A MIX OF RA/SN
BEFORE ENDING. MUCH COLDER WEATHER IS EXPECTED FOR SUNDAY INTO
EARLY NEXT WEEK BEHIND THE SYSTEM/COLD FRONT. THE EXTENDED DOES
APPEAR DRY THOUGH FOR MON-WED.

&&

.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 625 PM CDT WED APR 9 2014

VFR CONDITIONS EXPECTED AT TAF SITES THROUGH THE PERIOD...WITH
WINDS THE PRIMARY FORECAST ISSUE. SOUTHWEST WINDS AHEAD OF A COLD
FRONT...LESS THAN 12 KNOTS INITIALLY. WINDS COULD BACK TO 180/170
FOR AN HOUR OR TWO THIS EVENING. FRONT ARRIVES AT KOFK BY 06Z AND
KLNK/KOMA BY 09Z WHEN WINDS SHIFT ABRUPTLY TO THE NORTHWEST AND
PICK UP TO ABOUT 14 KNOTS...WITH GUSTS UP INTO THE LOWER 20S.
GUSTS SHOULD DIMINISH BY 18Z AT KOFK...AND 21Z AT KLNK/KOMA. THERE
COULD ALSO BE MARGINAL LOW LEVEL WIND SHEAR AT ALL TAF SITES FOR
ABOUT A 3 HOUR WINDOW AROUND THE FRONTAL ARRIVAL AS WINDS SHIFT
FROM SOUTHWEST TO NORTHWEST. ISOLATED SPRINKLES WILL ALSO BE
POSSIBLE...BUT DRY AIR BELOW THE CLOUD COULD EVAPORATE ANY PRECIP
BEFORE IT HITS THE GROUND...THUS LEFT OUT OF THE FORECAST.

&&

.FIRE WEATHER...
ISSUED AT 306 PM CDT WED APR 9 2014

CRITICAL FIRE CONDITIONS WILL CONTINUE THIS EARLY THIS EVENING
WITH MOST SITES MEETING RED FLAG WARNING CRITERIA. AS TEMPERATURES
COOL RH VALUES WILL INCREASE REDUCING THE THREAT BY MID TO LATE
EVENING. BEHIND THE COLD FRONT TONIGHT WE WILL LIKELY SEE
AFTERNOON RH VALUES DROP TO AROUND 20 PERCENT AGAIN...BUT WINDS
ARE EXPECTED TO BE LIGHTER. THIS PATTERN REPEATS AGAIN FOR FRIDAY
WITH SOUTHERLY WINDS INCREASING AND AN INCREASE IN MOISTURE NOT
ARRIVING UNTIL FRIDAY NIGHT. WINDS AGAIN THOUGH LOOK TO BE A TOUCH
LOW FOR RED FLAG CONDITIONS...BUT HIGH FIRE DANGER IS LIKELY ON
BOTH DAYS.

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR NEZ011-012-
     015>018-030>034-042>045-050>053-065>068-078-088>093.

IA...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR IAZ043-055-056-
     069-079-080-090-091.

&&

$$

SHORT TERM...BOUSTEAD
LONG TERM...BOUSTEAD
AVIATION...DEWALD
FIRE WEATHER...BOUSTEAD



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