[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 182207
SWOMCD
SPC MCD 182206 
MNZ000-NDZ000-190030-

MESOSCALE DISCUSSION 1726
NWS STORM PREDICTION CENTER NORMAN OK
0506 PM CDT SUN JUL 18 2004

AREAS AFFECTED...ERN ND THROUGH NWRN MN

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 182206Z - 190030Z

THUNDERSTORMS ARE EXPECTED TO DEVELOP FROM PARTS OF ERN ND THROUGH
NW MN BY 23-00Z. SUPERCELLS WITH LARGE HAIL...ISOLATED TORNADOES AND
DAMAGING WIND GUSTS WILL BE THE MAIN INITIAL THREATS. WW WILL LIKELY
BE NEEDED WITHIN THE NEXT HOUR OR TWO.

THIS EVENING A SURFACE TROUGH EXTENDS FROM NERN ND SWWD TO A SURFACE
LOW IN S CNTRL ND. A BOUNDARY INDUCED BY EARLIER CLOUDS AND
PRECIPITATION OVER MN EXTENDS N-S ALONG THE ND-MN BORDER. THE
ATMOSPHERE HAS BECOME QUITE UNSTABLE ACROSS ERN ND WITH MLCAPE FROM
2500 TO 3000 J/KG. THE THETA-E GRADIENT IS SHARP E OF THE N-S
BOUNDARY INTO WRN MN WHERE MLCAPE DROPS OFF TO LESS THAN 1500 J/KG.
MODEST SWLY LOW LEVEL JET MAY INCREASE IN RESPONSE TO SHORTWAVE
TROUGH DROPPING SEWD INTO ND THIS EVENING. THIS WILL RESULT IN
DESTABILIZATION EWD WITH TIME INTO NWRN MN. STORMS MAY DEVELOP NEXT
HOUR OR TWO IN CONVERGENCE ZONE ALONG THE SURFACE TROUGH ACROSS NERN
ND. SHEAR PROFILES EXHIBIT VEERING IN THE LOW LEVELS WITH 0-1 KM
STORM RELATIVE HELICITY FROM 100 TO 150 M2/S2 AND 0-6 KM SHEAR 35 TO
40 KT...SUPPORTIVE OF SUPERCELLS. LOW LEVEL HODOGRAPHS WILL INCREASE
FURTHER AS THE LOW LEVEL JET UNDERGOES SOME STRENGTHENING THIS
EVENING. OTHER STORMS MAY DEVELOP IN ZONE OF INCREASING LOW LEVEL
WARM ADVECTION AND DESTABILIZATION OVER NWRN MN.

..DIAL.. 07/18/2004

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

ATTN...WFO...FGF...BIS...

46289800 47189921 47899828 48799738 48789633 47779553
46579603 

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