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ACUS11 KWNS 230021
SWOMCD
SPC MCD 230021
SDZ000-NDZ000-MTZ000-WYZ000-230215-

MESOSCALE DISCUSSION 1435
NWS STORM PREDICTION CENTER NORMAN OK
0721 PM CDT TUE JUL 22 2014

AREAS AFFECTED...PORTIONS WRN SD...NERN WY...SWRN ND...EXTREME SERN
MT.

CONCERNING...SEVERE THUNDERSTORM WATCH 430...

VALID 230021Z - 230215Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 430
CONTINUES.

SUMMARY...SCATTERED TSTMS...INCLUDING A FEW SUPERCELLS WILL CONTINUE
TO POSE SVR HAIL/GUST THREAT WHILE MOVING OVER DISCUSSION AREA
WITHIN ERN/SRN PARTS OF ORIGINAL WW.  AIR MASS BEHIND CONVECTION
OVER E-CENTRAL MT HAS STABILIZED...HOWEVER INSTABILITY/CONVECTIVE
TRENDS WILL NEED TO BE MONITORED FOR POSSIBILITY OF ISOLATED STG-SVR
CONVECTION OVER S-CENTRAL MT INTERACTING WITH OUTFLOW BOUNDARY AND
ENTERING WW THIS EVENING.

DISCUSSION...00Z SFC CHART INDICATED MOIST AXIS FROM ERN NEB NWWD TO
JUST E OF IEN-RAP-2WX LINE...AHEAD OF ONGOING TSTMS THAT OCCUPY
SWATH FROM GOLDEN VALLEY/BILLINGS COUNTIES ND SWD TO EXTREME WRN
PENNINGTON COUNTY SD AND NRN WESTON COUNTY WY.  SFC ANALYSIS ALSO
SHOWS RELATIVELY DRY POCKETS OVER NWRN ND...S-CENTRAL ND...AND
CENTRAL SD WHERE RR-BASED OBJECTIVE ANALYSES DEPICT RELATIVE MINS IN
CAPE...MAXIMA IN CINH OR BOTH.  THAT SHOULD LIMIT EWD EXTENT OF
SUBSTANTIAL CONVECTIVE/SVR THREAT...GIVEN EXPECTED PERSISTENCE OF
LIGHT ELY/NELY SFC WINDS AND RELATED NEUTRAL MOIST-ADVECTION FIELDS.
 EXISTING ACTIVITY SHOULD MAINTAIN ORGANIZED SVR POTENTIAL AS IT
MOVES SEWD ACROSS MOIST AXIS...WHERE PRECONVECTIVE MLCAPE 1500-2000
J/KG SHOULD PERSIST FOR A FEW MORE HOURS.  EFFECTIVE-SHEAR
MAGNITUDES 35-50 KT ARE COMMON OVER THIS CORRIDOR BASED ON UNR RAOB
AND MODIFIED MODEL SOUNDINGS.  AT LEAST MRGLLY UNSTABLE AIR MASS
EXTENDS WWD ACROSS ERN MT INVOF OUTFLOW BOUNDARY...SO IT MAY BE TOO
SOON YET TO CLEAR SOME SERN MT/NERN WY COUNTIES FROM WW AHEAD OF
CONVECTION STILL LOCATED W/SW BIL.

..EDWARDS.. 07/23/2014

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

ATTN...WFO...ABR...BIS...UNR...CYS...BYZ...

LAT...LON   43090395 43570496 43890527 44200463 44570533 44840604
            45070633 45700620 45700502 45890459 46060424 46440404
            46750394 46930360 46930325 46720277 46320232 45840190
            44430191 43250206 43020296 43090395

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