[MCD] SWOMCD

[Mesoscale Convective Discussions]

ACUS11 KWNS 052159
SWOMCD
SPC MCD 052159 
MTZ000-WYZ000-052330-

MESOSCALE DISCUSSION 0431
NWS STORM PREDICTION CENTER NORMAN OK
0459 PM CDT WED APR 05 2006

AREAS AFFECTED...NRN WY INTO S-CNTRL AND SERN MT

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 052159Z - 052330Z

POTENTIAL FOR LOCALLY STRONG WIND GUSTS AND PERHAPS ISOLATED LARGE
HAIL WILL INCREASE ACROSS AREA LATE THIS AFTERNOON INTO EVENING. 
CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE WW.

LATEST MESOANALYSIS INDICATED LOW PRESSURE S OF LND AND SW COD WITH
ATTENDANT WARM FRONT EXTENDING ENEWD ACROSS FAR SERN MT AND THEN
INTO CNTRL SD. TRAILING COLD FRONT THEN EXTENDED SWD FROM THESE LOW
PRESSURE CENTERS INTO WRN CO.  WELL-DEFINED RISE-FALL COUPLET FROM
N-CNTRL WY INTO ERN UT SUGGESTS THAT THIS LOW PRESSURE WILL CONTINUE
TO DEVELOP NEWD INTO SRN MT THIS EVENING.

MODIFICATION OF 18Z RIW SOUNDING FOR CURRENT SURFACE OBSERVATIONS
ACROSS N-CNTRL WY INDICATES STEEP LOW TO MID-LEVEL LAPSE RATES AND
SBCAPES OF AROUND 1000 J/KG.  GIVEN A DEEP AND WELL-MIXED
BOUNDARY-LAYER COUPLED WITH DCAPES OF 1000-1300 J/KG...POTENTIAL
WILL EXIST FOR LOCALLY STRONG DOWNDRAFTS WITH MOST INTENSE STORMS. 
MOREOVER...40-50 KTS OF DEEP-LAYER SHEAR ALSO SUGGESTS A THREAT OF
MARGINAL SUPERCELL STRUCTURES CAPABLE OF ISOLATED LARGE HAIL.

STRENGTHENING UPPER DIVERGENCE AHEAD OF EVOLVING UPPER LOW OVER THE
GREAT BASIN SHOULD SUPPORT AN INCREASE IN CONVECTIVE COVERAGE LATE
THIS AFTERNOON INTO EVENING ACROSS N-CNTRL/NERN WY INTO S-CNTRL AND
SERN MT.  PRIMARY QUESTION IS WHETHER THIS STRONGER FORCING FOR
ASCENT WILL SUFFICIENTLY OFFSET A COOLING BOUNDARY-LAYER AFTER
23-00Z...SUSTAINING A SEVERE THREAT THROUGH THE EVENING.

..MEAD.. 04/05/2006

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

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

43190960 44161028 45750960 46490779 46300568 44980442
43590459 42890561 42560709 

WWWW