Area Forecast Discussion
Issued by NWS Omaha/Valley, NE

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000
FXUS63 KOAX 080436
AFDOAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1136 PM CDT MON JUL 7 2014

.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 241 PM CDT MON JUL 7 2014

THE INITIAL FORECAST CONCERN IS POTENT SHRTWV TROUGH MOVG INTO SD
PER EARLY AFTERNOON WATER VAPOR IMAGERY. 12Z UPPER AIR ANALYSIS
INDICATED THIS SYSTEM WAS ASSOCIATED WITH 60 M H5 HEIGHT FALLS AT
KGGW AND A 85 KT H3 JET. THIS SYSTEM WILL CONT TO TRACK SEWD THRU
THE REST OF THE AFTERNOON AND INTO THE MS RVR VALLEY TONIGHT. A
COLD FRONT ASSOCIATED WITH THE SYSTEM IS FORECAST TO MOV SEWD ACRS
THE FA THIS EVENING AND OUT OF THE CWA BY 12Z ON TUE. AHEAD OF THE
COLD FRONT...A STALLED FRONTAL BOUNDARY IS FORECAST TO LIFT NWD
INTO SRN NEB BY LATE THIS AFTERNOON ALONG WITH BETTER LOW LEVEL
MOISTURE /CHARACTERIZED BY MIXING RATIOS OF 15-18 G/KG/. A
COMPLICATING FACTOR THOUGH IS THE OUTFLOW ASSOCIATED WITH THE
DECAYING MCS OVER NORTHERN NEB...BUT WE FEEL THAT WITH SOME
INSULATION ON THE COOL SIDE OF THE BOUNDARY THAT THE OUTFLOW
PROGRESS WILL SLOW AND STALL OVER SOUTHERN NEB. 12Z RAOBS
INDICATED SEASONABLE STEEP MID-LEVEL LAPSE RATES OF 7-7.5 C/KM IN
THE 700-500 MB LAYER...AND THIS COUPLED WITH THE LOW-LEVEL
MOISTURE SHOULD ALLOW FOR 1500-2500 J/KG OF MLCAPE OVER THE
SOUTHERN CWA BY LATE AFTERNOON.

LARGE-SCALE FORCING FOR ASCENT/DVPA WILL REACH THE NORTHWEST CWA
LATE THIS AFTERNOON AND QUICKLY SPREAD SEWD THROUGH THE EVENING.
ALTHOUGH CAPPING IS EXPECTED TO FURTHER INCREASE THIS AFTN THE
DEGREE OF LARGE-SCALE ASCENT APPEARS SUFFICIENT TO INITIATE SFC-
BASED TSRA LATE THIS AFTERNOON OVER CNTRL AND SRN NEB. EFFECTIVE
SHEAR OF 40-50 KT WILL CERTAINLY ALLOW FOR ORGANIZED TSRA GIVEN
THE INSTABILITY. HAIL AND WIND APPEAR TO BE THE MAIN THREATS AS
LOW-LEVEL SHEAR IS PRETTY MARGINAL EVEN ALONG THE BOUNDARY.
MORNING SOUNDINGS INDCD LIMITED DEEP MOISTURE FOR EARLY JULY
STANDARDS WITH MOST LOCATIONS INDCG AOB 1.25 PWAT VALUES. LITTLE
INCREASE IN PWATS IS EXPECTED THROUGH THE REST OF THE AFTN WITH
VALUES POTENTIALLY REACHING 1.50 INCHES BY LATE THIS AFTERNOON
OVER SE NEB AND THIS...ALONG WITH THE SEASONABLY QUICK MOVEMENT OF
THE STORMS...WILL LIMIT THE HEAVY RAIN THREAT. IF SIG RAIN DOES
MATERIALIZE IT WILL LIKELY BE RIGHT ALONG THE MO/IA BORDER AND
THUS WILL LEAVE THE WATCH IN PLACE THERE AND CANCEL FARTHER NORTH.

ONCE THE CDFNT MOVES THROUGH TONIGHT VERY PLEASANT WEATHER IS
EXPECTED FOR BOTH TUE AND WED WITH BELOW NORMAL TEMPERATURES AND
DRY WEATHER. AS THE SFC HIGH MOVES EAST RETURN FLOW WILL LEAD TO
AN INCREASE IN MOISTURE AND MAY ALLOW FOR AN ISO NOCTURNAL TSRA AS
EARLY AS WED NIGHT ACROSS THE FAR WESTERN CWA.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 241 PM CDT MON JUL 7 2014

RETURN FLOW WILL FURTHER STRENGTHEN ON THURSDAY AND INTO THURSDAY
NIGHT WITH MOISTURE QUALITY IMPROVING. THIS SHOULD LEAD TO
INCREASING CHANCES FOR SHOWERS AND STORMS ON THURSDAY NIGHT AS A
SURFACE WARM FRONT LIFTS THROUGH THE AREA. GLOBAL MODELS THEN
DIVERGE INTO NEXT WEEKEND WITH THE EC TAKING A COLD FRONT THRU THE
CWA WHILE THE GEM/GFS WOULD INDC THE FRONT REMAINING TO OUR NORTH
WITH MUCH WARMER TEMPERATURES. GIVEN THE UNCERTAINLY IN THE
PLACEMENT OF FRONTS AT THIS RANGE...AND THE LIKELYHOOD THAT ANY
FRONTAL PLACEMENT WILL BE HEAVILY INFLUENCED BY CONVECTION WE WILL
CONT WITH THE SMALL POPS INTO THE WEEKEND AND NEAR NORMAL
TEMPERATURES.

&&

.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 PM CDT MON JUL 7 2014

COLD FRONT WAS MOVING INTO SOUTHEAST NEBRASKA AT 05Z WITH ANOTHER
BATCH OF THUNDERSTORMS DEVELOPING ALONG THE KANSAS NEBRASKA BORDER
ON THE BACKSIDE OF EARLIER MCS CURRENTLY OVER NW MISSOURI. VFR
CONDITIONS ARE EXPECTED AT ALL THREE SITES THROUGH THE PERIOD AS
HIGH PRESSURE BUILDS INTO THE AREA WITH DECREASING HIGH CLOUDS AT
KOMA AND KLNK THROUGH 12Z.

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

SHORT TERM...BOUSTEAD
LONG TERM...BOUSTEAD
AVIATION...FOBERT



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