[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 192026
SWOMCD
SPC MCD 192026 
ILZ000-WIZ000-IAZ000-192230-

MESOSCALE DISCUSSION 1734
NWS STORM PREDICTION CENTER NORMAN OK
0326 PM CDT MON JUL 19 2004

AREAS AFFECTED...ERN IA...SWRN WI AND NWRN IL

CONCERNING...TORNADO WATCH 655...

VALID 192026Z - 192230Z

THE SEVERE THREAT CONTINUES TO INCREASE ACROSS THE TORNADO WATCH.

ORIGINAL ELEVATED SUPERCELL THAT GAVE TWO-INCH HAILSTONES AT THE LA
CROSSE WEATHER OFFICE WEAKENED...BUT OTHER TSTMS HAVE FORMED ALONG
ITS WRN FLANK. CHARACTER OF RAPIDLY COOLING CLOUD TOPS AND
EXPANDING ANVILS SUGGEST THIS NEW ACTIVITY IS MORE THAN LIKELY
SURFACE BASED. RECENT MESOANALYSIS DEPICTS A THERMAL RIDGE /UPPER
80S/ ACROSS ERN IA AND A RUC40 PROXIMITY SOUNDING SUGGEST LITTLE IF
ANY INHIBITION REMAINING.

STRONGEST MASS CONVERGENCE WILL LIKELY FOCUS ALONG WRN PERIPHERY OF
THE CURRENT TSTMS FROM NERN IA SWD TO ALONG/WEST OF THE MS RVR FOR
THE NEXT FEW HOURS.  VSBL SATELLITE SHOWS A SHARP WRN EDGE TO THE
BOUNDARY LAYER CU FIELD ALONG INTERSTATE 35 AND THIS LIKELY DENOTES
ERN EDGE OF THE STRONGER CAP.  EAST OF THE MS RIVER...TSTM BLOWOFF
HAS AFFECTED BOUNDARY LAYER HEATING AND THUS CONVECTIVE INITIATION
POTENTIAL.  WILL MAINTAIN THE WATCH ACROSS NWRN IL...BUT HIGHER
PROBABILITIES OF DEEP MOIST CONVECTION WILL LIKELY BE ACROSS
ERN/CNTRL IA THROUGH THE EVENING.

GIVEN THE SSWLY LOW LEVEL WINDS BENEATH MODEST AND SHARPLY VEERING
MIDLEVEL FLOW...SUBSTANTIAL DEEP LAYER SHEAR EXISTS ACROSS THE
WEATHER WATCH FOR SUPERCELLS.  THIS COMBINED WITH THE STEEP MIDLEVEL
LAPSE RATES IN PLACE SUGGEST THAT HAIL UP TO THE SIZE OF BASEBALLS
AND DAMAGING WIND GUSTS WILL BE THE PRIMARY THREATS.  ISOLD
TORNADOES CANNOT BE RULED OUT AS WELL GIVEN SUBSTANTIAL LOW LEVEL
VEERING AND MAGNITUDE OF INSTABILITY.

..RACY.. 07/19/2004

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

ATTN...WFO...ILX...MKX...DVN...ARX...DMX...

40689218 43439274 43409000 40718976 

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