Severe Storm Outlook Narrative (AC)
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000
ACUS11 KWNS 221939
SWOMCD
SPC MCD 221939
IAZ000-222215-

MESOSCALE DISCUSSION 1359
NWS STORM PREDICTION CENTER NORMAN OK
0239 PM CDT FRI JUL 22 2016

AREAS AFFECTED...PORTIONS OF IOWA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 221939Z - 222215Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THE AREA IS BEING MONITORED FOR A POSSIBLE INCREASE IN THE
SVR-TSTM RISK THIS AFTERNOON...AND THE ISSUANCE OF A SVR TSTM WATCH
IS POSSIBLE.

DISCUSSION...INCIPIENT CONVECTIVE TOWERS ARE BUILDING ON THE WARM
SIDE OF A W/E DIFFERENTIAL-HEATING ZONE ACROSS NRN IA. ON THE WARM
SIDE OF THIS ZONE AND FARTHER S...DEWPOINTS WELL INTO THE 70S
COMBINED WITH AMPLE SFC HEATING ARE SUPPORTING SUBSTANTIAL BUOYANCY.
LARGE-SCALE VERTICAL MOTION IS LARGELY NEUTRAL...AND LOW-LEVEL
CONVERGENCE IS WEAK. HOWEVER...VISIBLE SATELLITE TRENDS WOULD
SUGGEST THAT THE DIFFERENTIAL-HEATING-INDUCED BAROCLINICITY AMIDST
BACKGROUND CONFLUENCE IS SUFFICIENT FOR AN UPTICK IN CONVECTION.

GIVEN REPEATED CONVECTIVE ATTEMPTS AND DIURNAL MUTING OF MLCINH...IT
IS POSSIBLE THAT MORE ROBUST CONVECTION COULD DEVELOP DURING THE
NEXT FEW HOURS. IF THAT WERE TO OCCUR...THE PRESENCE OF 3000-5000
J/KG OF MLCAPE WOULD SUPPORT ROBUST UPDRAFT MASS FLUXES IN SUPPORT
OF A CONDITIONAL SVR WIND/HAIL RISK. DEEP SHEAR IS WEAK...THOUGH
10-20 KT OF WLY/NWLY FLOW AT H5 MAY BE SUFFICIENT FOR MULTICELL
CLUSTERING AS INTENSE COLD POOLS POTENTIALLY EVOLVE/MERGE AND SPREAD
GENERALLY SEWD. IF IT WERE TO APPEAR THAT A MORE CONCENTRATED
CORRIDOR OF SVR POTENTIAL WERE TO EXIST...WW ISSUANCE MAY BECOME
NECESSARY.

..COHEN/WEISS.. 07/22/2016

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

ATTN...WFO...DVN...ARX...DMX...FSD...

LAT...LON   41729439 42419608 43079584 43129435 43029230 42599110
            42049086 41529168 41729439




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