[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 210953
SWOMCD
SPC MCD 210952 
MNZ000-NDZ000-SDZ000-211115-

MESOSCALE DISCUSSION 0948
NWS STORM PREDICTION CENTER NORMAN OK
0452 AM CDT SAT MAY 21 2005

AREAS AFFECTED...CNTRL/ERN ND

CONCERNING...SEVERE THUNDERSTORM WATCH 309...

VALID 210952Z - 211115Z

THROUGH 12Z...GREATEST SEVERE WEATHER THREAT WILL BE FROM NEAR BIS
NEWD TO THE RED RIVER N OF FAR.

OVER THE PAST COUPLE OF HOURS...REGIONAL RADAR IMAGERY HAS SHOWN THE
DEVELOPMENT OF A MESOSCALE CONVECTIVE VORTEX /MCV/ WITH THE CENTER
OF CIRCULATION JUST E OF THE MO RIVER APPROXIMATELY 60 MILES N OF
BIS AS OF 0936Z. WITH THE EXCEPTION OF A BOWING STRUCTURE OVER
WELLS...EDDY AND BENSON COUNTIES...AND A MORE ISOLATED STORM OVER
MORTON COUNTY...IT APPEARS THAT A STRONG CAP IS SUPPRESSING MORE
INTENSE CONVECTIVE DEVELOPMENT AHEAD OF SURFACE LOW AND COLD FRONT.

THROUGH 12Z...THE GREATEST SEVERE WEATHER THREAT WILL EXIST FROM
VICINITY OF SURFACE LOW NEAR BIS NEWD TOWARD THE RED RIVER N OF FAR.
HERE...CAP MAY BE SUFFICIENTLY ERODED TO SUSTAIN SEVERE CONVECTION
OWING TO PRESENCE OF DEEP-LAYER FORCING FOR ASCENT ARISING FROM
COUPLING OF: 1) STRONG LOW-LEVEL WAA ALONG LLJ AXIS...AND 2) REGION
OF MESOSCALE ASCENT IMMEDIATELY DOWNSTREAM FROM MCV. AMBIENT WIND
FIELDS REMAIN QUITE SUPPORTIVE OF SUPERCELLS AND BOWING STRUCTURES
WITH LARGE HAIL AND DAMAGING WINDS BEING THE PRIMARY SEVERE WEATHER
THREATS.

..MEAD.. 05/21/2005

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

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

47510224 48899562 46549568 45210201 

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