[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 210345
SWOMCD
SPC MCD 210345 
NDZ000-MTZ000-WYZ000-210545-

MESOSCALE DISCUSSION 0945
NWS STORM PREDICTION CENTER NORMAN OK
1045 PM CDT FRI MAY 20 2005

AREAS AFFECTED...ERN MT AND WRN ND

CONCERNING...SEVERE THUNDERSTORM WATCH 303...307...

VALID 210345Z - 210545Z

NUMEROUS SEVERE TSTMS/SUPERCELLS CONTINUE LATE THIS EVENING FROM
ROSEBUD AND CUSTER COUNTIES...EAST TO DAWSON COUNTY IN ERN MT AS
STRONG UPPER IMPULSE DRIVES LOW LEVEL CYCLOGENESIS AND INTENSE WARM
AIR ADVECTION ACROSS THE NRN HIGH PLAINS. ENVIRONMENT IS EXPECTED TO
REMAIN FAVORABLE FOR LARGE HAIL AND HIGH WINDS WITH STORMS LIKELY
EVOLVING INTO A LARGER SCALE MCS OVER ND IN THE NEXT FEW HOURS.

LATEST MESOANALYSIS PLACES SFC LOW OVER NCNTRL WY AND THIS FEATURE
HAS MOVED LITTLE IN THE PAST FEW HOURS. A WARM FRONT EXTENDS EWD
FROM THE LOW TO ND/SD BORDER AREA. MEANWHILE...COLD FRONT AND
ASSOCIATED MID LEVEL IMPULSE HAVE CROSSED THE HIGHER TERRAIN OF WRN
MT/WY WITH STORMS ON THIS BOUNDARY MOVING INTO WRN PORTION OF WATCH
303. DEEPENING SFC LOW AND INCREASING ISENTROPIC ASCENT ACROSS THE
WARM FRONT WILL CONTINUE TO TRANSPORT STRONG INSTABILITY NWWD OVER
ERN MT AND WRN ND OVER THE NEXT FEW HOURS. GIVEN VERY STRONG
DIRECTIONAL AND DEEP LAYER SPEED SHEAR... STORMS IN THIS REGIME WILL
PERSIST AND ROTATE WITH LARGE HAIL AND OCCASIONAL STRONG DOWNBURSTS.

LATEST IR SATELLITE AND RADAR TRENDS APPEAR TO CONFIRM SHORT TERM
MODEL DATA THAT A LARGE COMPLEX OF DEEP CONVECTION WITH EMBEDDED
SEVERE STORMS WILL SPREAD INTO NWRN ND THROUGH LATE TONIGHT.

..CARBIN.. 05/21/2005

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

ATTN...WFO...BIS...UNR...BYZ...GGW...RIW...TFX...

47240263 46790505 44920434 44890945 46871060 46920707
47890674 48710261 

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