[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 171840
SWOMCD
SPC MCD 171839 
NEZ000-SDZ000-172115-

MESOSCALE DISCUSSION 0574
NWS STORM PREDICTION CENTER NORMAN OK
0139 PM CDT SUN APR 17 2005

AREAS AFFECTED...WRN/CENTRAL SD...NCENTRAL NEB

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 171839Z - 172115Z

ISOLATED SVR THUNDERSTORMS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING
WINDS MAY DEVELOP IN THE 21-23Z TIME FRAME FROM NWRN/NCENTRAL SD SWD
INTO NCENTRAL NEB.  A WW MAY BE NEEDED LATER THIS AFTERNOON IF LATER
TRENDS INDICATE MORE THAN AN ISOLATED THREAT.

RECENT SFC ANALYSIS AND RADAR IMAGERY INDICATES A DRYLINE/LEE TROUGH
HAS MOVED INTO FAR WRN SD/NWRN NEB PANHANDLE. A WARM FRONT EXTENDED
ESEWD FROM A SFC LOW OVER SERN MT TO PIERRE TO YANKTON SD.
WARM/MOIST AREA BENEATH STEEP MID LEVEL LAPSE RATES HAS ALREADY LED
TO OVER 1000 J/KG OF MLCAPE OBSERVED IN THE AREA. SELY LOW LEVEL
FLOW IN THE WARM SECTOR COMBINED WITH 20-25 KTS OF MID LEVEL FLOW
PER REGIONAL PROFILERS WILL SUPPORT 30-35 KTS OF 0-6 KM SHEAR
SUFFICIENT FOR AN ORGANIZED SVR THREAT...IF STORMS DEVELOP. MODIFIED
15Z RUC FORECAST SOUNDINGS INDICATE THAT TEMPERATURES WILL NEED TO
WARM ANOTHER 5-10 DEGREES /MID 80S/ BEFORE CINH WEAKENS SUFFICIENTLY
TO SUPPORT CONVECTIVE DEVELOPMENT ALONG THE DRYLINE AND/OR WARM
FRONT. THE STRENGTH OF THE CURRENT CINH IS ALSO EVIDENT GIVEN LACK
OF CUMULUS FIELD OVER THE AREA. GIVEN THE CURRENT TRENDS IN
TEMPERATURES/DEWPTS...ISOLATED CONVECTION MAY INITIATE IN THE 21-23Z
TIME FRAME. THE MOST LIKELY LOCATION FOR ISOLATED STORM INITIATION
WILL BE WHERE THE DRYLINE/WARM FRONT INTERSECTION ENHANCES
CONVERGENCE. GIVEN THE SLOW MOTION OF THE DRYLINE...THIS IS
ANTICIPATED TO BE OVER PORTIONS OF WCENTRAL SD...TO THE NE OF THE
RAP AREA.

..CROSBIE.. 04/17/2005

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

ATTN...WFO...FSD...ABR...LBF...UNR...

42369917 44019943 45610115 45390224 44670261 43490267
42430253 42270098 

WWWW