[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 181906
SWOMCD
SPC MCD 181905 
SDZ000-NEZ000-WYZ000-182100-

MESOSCALE DISCUSSION 2015
NWS STORM PREDICTION CENTER NORMAN OK
0206 PM CDT THU AUG 18 2005

AREAS AFFECTED...WRN SD...ERN WY AND NWRN NEB PANHANDLE

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 181905Z - 182100Z

TSTMS DEVELOPING OVER THE BLACK HILLS MAY POSE AN ISOLATED SVR
THREAT IN THE NEXT HR OR SO. ADDITIONAL TSTMS ARE EXPECTED TO
DEVELOP EITHER ALONG STATIONARY FRONTAL BOUNDARY EXTENDING E-W
ACROSS NERN/ECENTRAL WY INTO WCENTRAL SD AND/OR MOVE OUT OF CENTRAL
WY WHILE INTENSIFYING. DESPITE MODEST DEEP LAYER SHEAR...OVERALL
MARGINAL INSTABILITY SHOULD LIMIT THE SEVERE THREAT TO ISOLATED
OCCURRENCES OVER THE NEXT FEW HOURS. THUS WW ISSUANCE REMAINS
UNCERTAIN ATTM.

LATEST SATELLITE/RADAR IMAGERY INDICATE TSTMS DEVELOPING OVER THE
BLACK HILLS. ALTHOUGH LOW LEVEL WINDS REMAINS NNWLY...MODERATE
UPSLOPE COMPONENT TO LOW LEVEL FLOW ALONG WITH ADDITIONAL AIRMASS
DESTABILIZATION SHOULD SUPPORT CONTINUED DEVELOPMENT/
INTENSIFICATION OF CONVECTION OVER THE NRN BLACK HILLS AREA DURING
THE NEXT FEW HOURS. LOW LEVELS REMAIN SOMEWHAT CAPPED EAST OF THE
BLACK HILLS /LOWER ELEVATIONS/...WITH OVER 100 J/KG OF MLCINH PER
RECENT OBJECTIVE ANALYSIS. THUS CONVECTION WILL LIKELY STRUGGLE TO
MOVE OUT OF THE HIGHER TERRAIN THROUGH 21Z.  WITH 30-40 KTS OF DEEP
LAYER SHEAR AND 1000-1200 J/KG OF MUCAPE /PER RECENT FCST SOUNDINGS
AND MBW PROFILER DATA/ ISOLATED SVR HAIL MAY BE POSSIBLE WITH THE
STRONGEST STORMS. FARTHER WEST...BASED ON RAWS/ASOS REPORTS...THE
SFC FRONTAL BOUNDARY HAS BECOME STATIONARY FROM NRN NATRONA COUNTY
WY ESEWD TO DAWES COUNTY IN THE NEB PANHANDLE. SUFFICIENT
CONVERGENCE AND ADDITIONAL HEATING/MINIMAL CINH ALONG THIS BOUNDARY
SUGGESTS THAT ISOLATED TSTM DEVELOPMENT IS POSSIBLE IN THE NEXT FEW
HRS. IN ADDITION...HIGH BASED CONVECTION THAT IS OCCURRING TO THE
WEST OF THE LARAMIE MTNS MAY INTENSIFY AS IT ENCOUNTERS THE BETTER
INSTABILITY OVER ERN WY INTO THE FAR WRN NEB PANHANDLE BY MID
AFTERNOON. FCST SOUNDINGS IN ERN WY/NWRN NEB PANHANDLE BASED ON
CURRENT DEWPT FIELDS INDICATE AROUND 1200 J/KG OF MUCAPE SHOULD
EXIST BY 21Z. WITH AROUND 40 KTS OF DEEP LAYER SHEAR...THE
ENVIRONMENT WILL BE SUPPORTIVE OF AN ISOLATED SVR HAIL THREAT AS
WELL.

..CROSBIE.. 08/18/2005

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

ATTN...WFO...LBF...UNR...CYS...BYZ...RIW...

44870264 44720476 44590609 44390682 43690699 42680651
42080540 41720423 41900328 42380269 43650181 

WWWW