[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 152258
SWOMCD
SPC MCD 152258 
NDZ000-SDZ000-160030-

MESOSCALE DISCUSSION 0706
NWS STORM PREDICTION CENTER NORMAN OK
0558 PM CDT SAT MAY 15 2004

AREAS AFFECTED...CENTRAL PORTIONS ND/SD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 152258Z - 160030Z

ISOLATED HAIL/DAMAGING WINDS WILL BE POSSIBLE WITH ANY DISCRETE
STORMS THAT DEVELOP DURING THE NEXT 2-3 HOURS FROM CENTRAL ND SWD
INTO CENTRAL SD.

22Z SURFACE ANALYSIS/VIS IMAGERY SHOWED A TROUGH EXTENDING GENERALLY
N-S ACROSS THE DAKOTAS FROM 60 NW DVL TO 20 NE VTN...AS A COLD FRONT
ADVANCES ESEWD ACROSS NORTH CENTRAL ND AND NWRN SD.  A NARROW AXIS
OF MARGINAL INSTABILITY EXISTS ALONG THE SURFACE TROUGH WHERE
SURFACE HEATING AND STEEPER MID-LEVEL LAPSE RATES ARE BEGINNING TO
SPREAD ACROSS THE REGION WITH THE UPPER TROUGH.  IT APPEARS THAT THE
DISCRETE STORMS THAT ARE DEVELOPING ALONG THE SURFACE TROUGH ARE
BEING FED FROM THE WSW AS THEY MOVE ESEWD ATOP A COOLER BOUNDARY
LAYER WHICH HAS BEEN INHIBITED FROM DESTABILIZATION BY CLOUDS.

DEEP LAYER SHEAR IS MORE THAN SUFFICIENT FOR SUPERCELLS WITH
ADDITIONAL DEVELOPMENT MOST LIKELY FROM ACROSS PORTIONS OF CENTRAL
SD AS LARGE SCALE ASCENT WITH THE UPPER TROUGH.  HOWEVER...AS STORMS
MOVE EWD AWAY FROM THE INSTABILITY SOURCE...THEY SHOULD WEAKEN. 
THIS WILL RESULT IN A SMALL SPATIAL/TEMPORAL WINDOW FOR SEVERE
POTENTIAL /THROUGH 01-02Z ACROSS SD/...PRIOR TO THE COLD FRONT
PASSAGE...AS HAS BEEN OBSERVED PER REGIONAL RADARS ACROSS ND.

..PETERS.. 05/15/2004

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

ATTN...WFO...FGF...FSD...ABR...BIS...UNR...

47770001 47779873 46329809 45769809 44459839 43449900
43530018 46090040 

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