Severe Thunderstorm Warning 69, NWS Duluth, MN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
230 PM CDT THU SEP 18 1997

FORECAST FOCUS TONIGHT WILL BE ON PRECIPITATION CHANCES AND
SEVERE THREAT.

ETA AND NGM HANDLE SURFACE LOW SIMILARLY BUT NGM IS SLOWER WITH
H8 TROF. I BELIEVE GIVEN VICINITY OF H3 JET THAT THE FASTER
ETA IS MORE LIKELY SOLUTION.

CURRENTLY...SHOWERS MOVING ALONG FRONTAL BOUNDARY THROUGH
CENTRAL TO NORTHERN MINNESOTA. GOOD DEWPOINT BOUNDARY WITH AROUND
50 NORTH TO A POCKET OF 70 NEAR MSP. ALSO H8 THETA-E RIDGE
FROM EASTERN NEBRASKA TO NORTHEAST WI. H8 LLJ ALSO SET UP FROM
NEBRASKA TO NEAR DLH AND IS ADVECTING MOISTURE NORTHWARD. 12Z H8
ANALYSIS SHOWED A GOOD DEWPOINT GRADIENT WITH INL AT -02
AND OMA AT +14. WDL PROFILER AND DULUTH VWP BOTH SHOWING
30 KTS AT H8. SURFACE BOUNDARY PROGGED TO STAY NEARLY STATIONARY
BEFORE MOVING SE WITH H8 THETE-E RIDGE AS BLAST OF COLDER AIR
BEGINS. SURFACE BOUNDARY AND LOW IN SD TO BE FOCUS FOR PRECIPITATION.
CAPES FORECAST TO RANGE FROM 400 NEAR HIB TO 2000 IN PINE COUNTY
AT 00Z FRI. AS THE SURFACE LOW MOVES EAST I EXPECT CONVECTION TO
INCREASE AS IT ENCOUNTERS BETTER MOISTURE WITH BEST CHANCE FOR
SEVERE FROM BRD TO NORTHWEST WI AND POINTS SOUTH IN MY CWA.

ETA/NGM SIMILAR WITH DUMPING 0.50 INCHES RAIN IN NORTHERN WI BY 00Z
FRI...THIS MAY BE A BIT SOUTH GIVEN CURRENT ACTIVITY BUT BOTH MODELS
FORECASTING RAPID DEVELOPMENT.

BY 12Z FRI...SFC BOUNDARY AND H8 BOUNDARY MOVE EAST OF CWA WITH
GOOD CAA UNDERWAY. LOW TEMPERATURES TO RANGE FROM THE MIDDLE 40S
IN NORTHERN MINNESOTA TO THE MIDDLE TO UPPER 50S IN NW WI ZONES.

MELDE