[MCD] SWOMCD

Fri Jul 28 22:55:33 UTC 2006

ACUS11 KWNS 282257
SWOMCD
SPC MCD 282256 
MNZ000-NDZ000-SDZ000-290030-

MESOSCALE DISCUSSION 1654
NWS STORM PREDICTION CENTER NORMAN OK
0556 PM CDT FRI JUL 28 2006

AREAS AFFECTED...NWRN SD INTO ERN ND

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 282256Z - 290030Z

THE POTENTIAL FOR ISOLATED SEVERE STORMS /INCLUDING HIGH-BASED
SUPERCELLS/ IS INCREASING OVER NWRN SD INTO SWRN ND.  A POTENTIALLY
MORE ORGANIZED SEVERE WEATHER THREAT IS EXPECTED TO DEVELOP LATER
THIS EVENING FROM S-CNTRL INTO ERN ND. CONVECTIVE TRENDS WILL BE
MONITORED FOR A WW.

LATEST MESOANALYSIS INDICATES SURFACE LOW PRESSURE OVER FAR SWRN MT
WITH AN ATTENDANT QUASI-STATIONARY BOUNDARY STRETCHED EWD NEAR THE
SD/ND BORDER...AND A PRESSURE TROUGH TRAILING THIS LOW INTO NERN WY.
STRONG DIABATIC HEATING HAS ALLOWED TEMPERATURES TO WARM TO 100-110F
S OF THIS LOW AND FRONTAL ZONE ACROSS WRN AND CNTRL SD...WHICH IS
LARGELY CONTRIBUTING TO DEEPENING CUMULUS/EARLY TSTM DEVELOPMENT
OVER HARDING COUNTY SD INTO BOWMAN COUNTY ND.  PROXIMITY RUC
FORECAST SOUNDINGS INDICATE THE PRESENCE OF A DEEPLY-MIXED BOUNDARY
LAYER NEAR THIS BOUNDARY TO NEAR 600 MB WITH STEEP LOW/MID-LEVEL
LAPSE RATES WHICH ARE CONTRIBUTING TO SBCAPES OF 500-1000 J/KG.  

GLANCING INFLUENCE OF SHORT WAVE TROUGH MOVING THROUGH ERN MT/WRN ND
COUPLED WITH THIS HEATING MAY BE SUFFICIENT TO SUSTAIN A FEW SEVERE
STORMS THIS EVENING INVOF FRONTAL ZONE FROM NEAR AND N OF 2WX EWD TO
N OF MBG.  STRONG LOW-LEVEL DIRECTIONAL SHEAR AND 40-45 KTS OF
MID-LEVEL WLY FLOW ARE RESULTING IN SHEAR PROFILES SUPPORTIVE OF
SUPERCELLS CAPABLE OF LOCALLY DAMAGING WINDS AND PERHAPS SOME HAIL.

A POTENTIALLY MORE ORGANIZED SEVERE THREAT IS EXPECTED TO DEVELOP
AFTER 29/03Z N OF FRONTAL ZONE FROM S-CNTRL INTO ERN ND WITHIN
LOW-LEVEL WAA ZONE ASSOCIATED WITH INTENSIFYING LLJ.  HERE...RUC
FORECAST SOUNDINGS INDICATE THAT STORMS SHOULD BE SLIGHTLY ELEVATED
ABOVE INCREASING NEAR SURFACE INVERSION/CAP WITHIN ENVIRONMENT OF
STEEP MID-LEVEL LAPSE RATES AND 1500-2500 J/KG MUCAPES.  HERE
TOO...VERTICAL SHEAR WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF
LARGE HAIL AND DAMAGING WINDS.

..MEAD.. 07/28/2006

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

ATTN...WFO...FGF...ABR...BIS...UNR...BYZ...

45930404 46250367 46740267 47410062 47739934 47999717
47359663 46249681 45829877 45560093 45520355 

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