[MCD] SWOMCD

Wed Aug 23 02:15:46 UTC 2006

ACUS11 KWNS 230001
SWOMCD
SPC MCD 230000 
MNZ000-SDZ000-NDZ000-230200-

MESOSCALE DISCUSSION 1854
NWS STORM PREDICTION CENTER NORMAN OK
0700 PM CDT TUE AUG 22 2006

AREAS AFFECTED...DAKOTAS...MN

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 230000Z - 230200Z

TRENDS ARE BEING MONITORED FOR AN INCREASE IN SEVERE POTENTIAL...
BUT THIS MAY STILL BE SEVERAL HOURS AWAY.

LOW-LEVEL MOISTENING IS UNDERWAY ACROSS PARTS OF THE CENTRAL/
EASTERN DAKOTAS.  THIS IS OCCURRING IN A RELATIVELY NARROW ZONE OF
ASCENT...ASSOCIATED WITH LOW-LEVEL WARM ADVECTION...NORTH OF A
SURFACE FRONT WHICH EXTENDS SOUTHWEST OF SIOUX FALLS AND MOBRIDGE SD
INTO SOUTHWESTERN NORTH DAKOTA.  HOWEVER...STRONG WARMING ABOVE THIS
LAYER...EAST OF THE NORTH CENTRAL ROCKIES THROUGH MUCH OF THE
NORTHERN PLAINS...IS CONTRIBUTING TO SUBSTANTIAL INHIBITION...WHICH
APPEARS LIKELY TO STRENGTHEN FURTHER THROUGH THE EVENING.  THIS
IS...AND SHOULD CONTINUE TO...SUPPRESS ONGOING CONVECTIVE
DEVELOPMENT OFF THE BLACK HILLS...PARTICULARLY WITH ONSET OF SURFACE
COOLING DURING THE NEXT COUPLE OF HOURS.

AN INCREASE IN MID-LEVEL CONVECTION...PROBABLY BASED AROUND 700 MB
...IS EVIDENT ALONG EDGE OF STRONGER CAP NORTH/NORTHEAST OF
JAMESTOWN AND FARGO ND.  THIS MAY PERSIST/INCREASE THROUGH THE
EVENING...WITH PERHAPS ADDITIONAL DEVELOPMENT SOUTHEASTWARD ALONG
MID-LEVEL BAROCLINIC ZONE THROUGH WEST CENTRAL/CENTRAL MINNESOTA. 
EVEN WITH RELATIVELY STEEP MID-LEVEL LAPSE RATES...MOST UNSTABLE
CAPE FOR THIS ACTIVITY APPEARS LIKELY TO REMAIN AT OR BELOW 1000
J/KG.  THIS IS EXPECTED TO LIMIT HAIL POTENTIAL WELL INTO THE
EVENING HOURS. 

TOWARD THE 04-05Z TIME FRAME...MODELS DO SUGGEST VEERING AND
STRENGTHENING OF SOUTHERLY LOW-LEVEL JET WILL OCCUR IN RESPONSE TO
AN IMPULSE PROGRESSING THROUGH THE CREST OF UPPER RIDGE.  AS THIS
OCCURS...NORTHEASTWARD ADVECTION OF BETTER LOW-LEVEL MOISTURE
BENEATH EDGE OF STRONGER CAP IS FORECAST TO CONTRIBUTE TO MORE
SIZABLE CAPE...POSSIBLY IN EXCESS OF 2000 J/KG.  IF THIS
OCCURS...POTENTIAL FOR LARGE HAIL IN FAVORABLY SHEARED ENVIRONMENT
WILL INCREASE. BEST CHANCE FOR THIS SEEMS NEAR/EAST OF FARGO INTO
ALEXANDRIA/BRAINERD AREAS.

..KERR.. 08/23/2006

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

ATTN...WFO...DLH...MPX...FGF...ABR...BIS...

47489895 47969841 48039725 47159526 45949367 45139343
44849456 45599598 45999693 46389843 46859900 