[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 122241
SWOMCD
SPC MCD 122241 
IAZ000-NEZ000-SDZ000-130045-

MESOSCALE DISCUSSION 1635
NWS STORM PREDICTION CENTER NORMAN OK
0541 PM CDT MON JUL 12 2004

AREAS AFFECTED...SE SD...NE NEB...NW IA

CONCERNING...TORNADO WATCH 612...

VALID 122241Z - 130045Z

CONTINUE WW.  CONVECTIVE TRENDS ARE BEING MONITORED ACROSS PARTS OF
CENTRAL NEBRASKA FOR POSSIBILITY OF INCREASING SEVERE THREAT.

INTENSE CONVECTIVE DEVELOPMENT CONTINUES...WITH A SLOW INCREASE IN
COVERAGE... JUST EAST OF WEAK SURFACE LOW NEAR O'NEILL NEB.  THIS IS
BEING SUPPORTED BY STRONGER LOW-LEVEL WARM ADVECTION REGIME
ASSOCIATED WITH VIGOROUS SHORT WAVE TROUGH NOW BEGINNING TO DIG
ACROSS THE FAR NORTHERN PLAINS/UPPER MISSISSIPPI VALLEY.  STRONGER
LOW-LEVEL CONVERGENCE IS ALSO FOCUSED ACROSS THIS REGION...AND THIS
SHOULD INCREASE ON NOSE OF NOCTURNALLY STRENGTHENING CENTRAL PLAINS
SOUTHERLY LOW-LEVEL JET BY THE 02-03Z TIME FRAME.

UNTIL UPSCALE EVOLUTION INTO MESOSCALE CONVECTIVE SYSTEM OCCURS
LATER THIS EVENING...ISOLATED SUPERCELLS WITH VERY LARGE
HAIL/DAMAGING WIND GUSTS...PERHAPS AN ISOLATED TORNADO...WILL REMAIN
POSSIBLE ACROSS NORTHEAST NEBRASKA.  MEAN MIXED LAYER CAPE IS NOW UP
TO AROUND 4000 J/KG...AND DESPITE RELATIVE WEAK LOW/MID-LEVEL
FLOW...VEERING WINDS WITH HEIGHT BENEATH STRENGTHENING NORTHWESTERLY
MID-LEVEL FLOW ARE CONTRIBUTING TO STRONG VERTICAL SHEAR.

CONVECTIVE DEVELOPMENT HAS ALSO BEEN APPARENT SOUTHWESTWARD FROM LOW
ALONG LOW-LEVEL THERMAL RIDGE AXIS/SURFACE TROUGH INTO AREAS WEST OF
BROKEN BOW/NORTHEAST OF NORTH PLATTE.  ALTHOUGH AN ISOLATED SEVERE
STORM MAY EVENTUALLY DEVELOP WITHIN THE NEXT HOUR OR TWO...ACTIVITY
ACROSS THIS AREA SHOULD BE RELATIVELY SHORT LIVED DUE TO STRONG
CAP...WHICH WILL STRENGTHEN FURTHER WITH ONSET OF RADIATIONAL
COOLING AROUND SUNSET.

..KERR.. 07/12/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FSD...OAX...GID...LBF...

41360057 41769984 42099916 42509906 42989873 42959784
42679685 42289619 41839638 41579693 41549745 41539815
41309885 41039969 40990025 41130056 

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