[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 031840
SWOMCD
SPC MCD 031840 
MNZ000-SDZ000-NDZ000-032015-

MESOSCALE DISCUSSION 2134
NWS STORM PREDICTION CENTER NORMAN OK
0140 PM CDT SAT SEP 03 2005

AREAS AFFECTED...CNTRL/SWRN MN...EXTREME SERN ND AND EXTREME NERN SD

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 031840Z - 032015Z

ELEVATED TSTMS ARE BEGINNING TO INTENSIFY ACROSS PORTIONS OF CNTRL
MN IN WAKE OF A DECAYING MCS.  IF CELLS CONTINUE TO INTENSIFY...A WW
MAY BE REQUIRED.

LATEST PROFILERS/VWP INDICATE THAT THE SWLY H95-H85 LLJ HAS REMAINED
SITUATED FROM CNTRL PLAINS TO ERN SD.  NOSE OF THIS JET WAS BLOWING
NORMAL TO A NW-SE ORIENTED OUTFLOW BOUNDARY ACROSS ERN SD AND SWRN
MN.  LATEST RUC GUIDANCE SUGGESTS THIS SCENARIO WILL PERSIST THROUGH
EARLY EVENING.

PARCELS FEEDING THE DEVELOPING TSTMS EMANATE FROM A RESERVOIR OF
MODERATE CAPES/STEEP LAPSE RATE ENVIRONMENT ACROSS ERN SD WHERE
MUCAPES WERE IN THE 1500-2500 J/KG RANGE.  AS THESE PARCELS REACH
LFC NE OF THE OUTFLOW BOUNDARY...VIGOROUS UPDRAFTS CAN BE EXPECTED. 
VERTICAL SHEAR IN THE CAPE-BEARING LAYER AOA 40 KTS WILL LIKELY
FURTHER STRENGTHEN UPDRAFTS AND LARGE HAIL WILL RESULT.

FURTHERMORE...GIVEN LLJ ORIENTATION WITH RESPECT TO THE LOW-LEVEL
THETA-E AXIS AND GENERALLY WEAK SPEED SHEAR IN THE MID-LEVELS THERE
WILL BE A TENDENCY FOR TSTMS TO BACKBUILD AND TRAIN.  PRECIPITABLE
WATER VALUES/THERMODYNAMIC PROFILES ARE SOMEWHAT LOWER THAN NORMALLY
EXPECTED FOR A WIDESPREAD HEAVY RAINFALL EVENT.  BUT...LONGEVITY OF
THE LLJ GEOMETRY W.R.T. BOUNDARIES COULD LEAD TO LOCALIZED HEAVY
RAINFALL THAT COULD PERSIST INTO THE EVENING.  THE HEAVY RAINFALL
AND SEVERE THREATS WILL LIKELY MOVE SLOWLY SWD THROUGH SWRN MN
DURING THE NEXT FEW HOURS.  UNCERTAINTY EXISTS ON HOW FAR W TSTMS
WILL DEVELOP GIVEN THE STOUT CAP ACROSS THE ERN DAKS PER 18Z TANDAR
SOUNDINGS FROM KABR.

..RACY.. 09/03/2005

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

ATTN...WFO...MPX...FGF...FSD...ABR...

44989336 44449316 44149344 43979428 44099525 44519626
45359724 45839764 46719754 46529634 

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