Severe Thunderstorm Warning 26, NWS Duluth, MN

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
305 PM CDT SUN APR 18 2004

.DISCUSSION...MAIN FOCUS IS ON SEVERE WEATHER POTENTIAL LATE THIS
AFTERNOON AND THIS EVENING.

SEVERE WEATHER HAS BEEN PROMINENT DURING THE DAY...WITH DAMAGING
WINDS INITIALLY, AND UP TO 2 INCH HAIL WITH THE LATER STORMS.
SUPERCELLS DEVELOPED IN THE LAST 3 HOURS OF THE EVENT, WITH ROTATION
EVIDENT IN MANY OF THE STORMS. NOT A GOOD VORTICITY GENERATION
POTENTIAL (VGP) SIGNAL, SO STORM RELATIVE HELICITY WAS NOT
EFFICIENTLY INGESTED INTO THE STORMS FROM THE SURFACE. THIS MIGHT
HAVE KEPT THE CIRCULATIONS FROM BECOMING SURFACE BASED.

AS FOR THE NEXT STAGE OF THE EVENT, THE CONVECTIVE INITIATION HAS
ALREADY BEGUN ACROSS CENTRAL AND SOUTHERN MN. SHEAR PROFILES, AND
INSTABILITY PARAMETERS ARE INDICATING THE STRONG POTENTIAL FOR
SUPERCELL THUNDERSTORMS THIS AFTERNOON AND EVENING, WITH TORNADOES A
STRONG THREAT. A TORNADO WATCH HAS BEEN ISSUED THROUGH 8 PM FOR MOST
OF THE CWA. THE STORM PREDICTION CENTER (SPC) DISCUSSED THE STRONG
MARINE LAYER NORTH OF THE ADVANCING WARM FRONT, AND THAT IT MAY
REDUCE THE CHANCES OF TORNADOES FARTHER INTO THE ARROWHEAD...BUT THE
TORNADO THREAT REMAINS EVERYWHERE, NONE THE LESS. THIS IMPENDING
SEVERE WEATHER EVENT IS BEING HIGHLIGHTED AS A PARTICULARLY
DANGEROUS SITUATION (PDS), BY THE SPC. STORM WILL CONTINUE
OVERNIGHT...AS THE LOW PRESSURE MOVES RAPIDLY NORTHEAST ALONG THE
WARM FRONT INTO NORTHWEST WISCONSIN BY THIS EVENING...AND ALL THE
WAY NORTH OF LAKE SUPERIOR BY MIDNIGHT. HEAVY RAINS ARE LIKELY WITH
THE STRONGEST STORMS...ALONG WITH HAIL, DAMAGING WINDS, AND
TORNADOES. RAINFALL TOTALS UP TO 2 INCHES ARE POSSIBLE. AREAS OF
DENSE FOG ARE POSSIBLE MONDAY MORNING DUE TO THE ABUNDANT SURFACE
MOISTURE FROM THIS SYSTEM.

POST FRONTAL PRECIPITATION WILL CONTINUE INTO MONDAY MORNING BEFORE
A STRONG SUBSIDENCE REGION AND HIGH PRESSURE SHUT THINGS DOWN.
CLEARING SKIES ARE EXPECTED MONDAY AFTERNOON. THE NEXT SYSTEM TO
BRING PRECIP WILL HOLD OFF UNTIL TUESDAY NIGHT...AS LOW PRESSURE
LIFTS INTO SOUTHERN MINNESOTA.

&&

.DLH...WATCHES/WARNINGS/ADVISORIES

MN...TORNADO WATCH UNTIL 8 PM FOR AREAS SOUTH AND EAST OF A LINE
FROM WALKER TO GRAND MARAIS.
WI...TORNADO WATCH UNTIL 8 PM FOR ALL OF NW WIS.

SHIMON

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DULUTH MN
730 AM CDT SUN APR 18 2004

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-191230-
ASHLAND-BAYFIELD-BURNETT-C. ST. LOUIS-CROW WING-DOUGLAS-IRON-
KOOCHICHING-N. AITKIN-N. CASS-N. ITASCA-N. LAKE/N. COOK-N. ST. LOUIS-
PINE-PRICE-S. AITKIN-S. CASS-S. COOK/LAKESHORE-S. ITASCA-
S. LAKE/LAKESHORE-S. ST. LOUIS/CARLTON-SAWYER-WASHBURN-
730 AM CDT SUN APR 18 2004

...MODERATE RISK OF SEVERE STORMS TODAY AND TONIGHT...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEASTERN MINNESOTA AND
NORTHWESTERN WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

A SIGNIFICANT SEVERE WEATHER OUTBREAK IS SHAPING UP FOR MUCH OF THE
NORTHLAND TODAY AND TONIGHT. THE BEST CHANCE OF SEVERE WEATHER WILL
BE ACROSS EAST CENTRAL MINNESOTA AND NORTHWESTERN WISCONSIN. GOLF
BALL SIZE HAIL OR LARGER...DAMAGING WINDS IN EXCESS OF 60 MPH AND
TORRENTIAL DOWNPOURS ARE EXPECTED WITH SOME OF THE STORMS. OF
GREATEST CONCERN TODAY WILL BE THE THREAT OF TORNADOES. ALL THE
FORECAST PARAMETERS INDICATE THAT THERE IS A GOOD POSSIBILITY OF
TORNADOES...ESPECIALLY THIS AFTERNOON AND EVENING. BE SURE TO
MONITOR FOR POSSIBLE WATCHES AND WARNINGS AS THIS SEVERE WEATHER
EVENT UNFOLDS. ASIDE FROM THE SEVERE WEATHER...A SMALL CRAFT ADVISORY
IS IN EFFECT FOR THE NEAR SHORE WATERS OF WESTERN LAKE SUPERIOR.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS POSSIBLE AT ANY POINT TODAY...BUT
IT IS LIKELY THIS AFTERNOON AND EVENING.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:

HTTP://WWW.CRH.NOAA.GOV/DLH

DAP

PRELIMINARY LOCAL STORM REPORT ... CORRECTION
NATIONAL WEATHER SERVICE DULUTH MN
1137 AM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0220 AM     HAIL             4 W HINCKLEY            46.01N 93.02W
04/18/2004  0.75 INCH        PINE               MN   TRAINED SPOTTER

0224 AM     HAIL             13 E HINCKLEY           46.01N 92.67W
04/18/2004  1.50 INCH        PINE               MN   TRAINED SPOTTER

0458 AM     HAIL             LITTLE ROUND LAKE       45.97N 91.37W
04/18/2004  1.00 INCH        SAWYER             WI   AMATEUR RADIO

0510 AM     HAIL             10 E HAYWARD            46.01N 91.27W
04/18/2004  0.75 INCH        SAWYER             WI   TRAINED SPOTTER

0705 AM     HAIL             SPOONER                 45.82N 91.89W
04/18/2004  0.75 INCH        WASHBURN           WI   AMATEUR RADIO

0740 AM     HAIL             3 W SHELL LAKE          45.74N 91.96W
04/18/2004  2.00 INCH        WASHBURN           WI   AMATEUR RADIO

0747 AM     HAIL             SPOONER                 45.82N 91.89W
04/18/2004  1.00 INCH        WASHBURN           WI   TRAINED SPOTTER

0815 AM     HAIL             NORTHWOODS BEACH        45.91N 91.40W
04/18/2004  1.50 INCH        SAWYER             WI   LAW ENFORCEMENT

            THERE WERE SEVERAL REPORTS OF BROKEN WINDOWS.

0822 AM     HAIL             6 E HAYWARD             46.01N 91.36W
04/18/2004  1.00 INCH        SAWYER             WI   AMATEUR RADIO

0825 AM     HAIL             10 E HAYWARD            46.01N 91.27W
04/18/2004  0.88 INCH        SAWYER             WI   AIRPLANE PILOT

0830 AM     TSTM WND DMG     5 W PEQUOT LAKES        46.60N 94.43W
04/18/2004                   SOUTHERN CASS      MN   EMERGENCY MNGR

            POWER LINES WERE BLOWN DOWN.

0835 AM     TSTM WND GST     PEQUOT LAKES            46.60N 94.32W
04/18/2004  0 MPH            CROW WING          MN   TRAINED SPOTTER

            MANY TREES AND POWER LINES WERE BLOWN DOWN FROM PEQUOT
            LAKES TO EMILY.

0912 AM     HAIL             PARK FALLS              45.93N 90.45W
04/18/2004  1.00 INCH        PRICE              WI   TRAINED SPOTTER

0914 AM     HAIL             PARK FALLS              45.93N 90.45W
04/18/2004  1.75 INCH        PRICE              WI   TRAINED SPOTTER

0955 AM     HAIL             9 NE FLOODWOOD          47.02N 92.78W
04/18/2004  0.88 INCH        SOUTHWEST ST. LOUI MN   TRAINED SPOTTER

0955 AM     HAIL             ALBORN                  46.97N 92.58W
04/18/2004  0.88 INCH        SOUTHWEST ST. LOUI MN   TRAINED SPOTTER

1037 AM     HAIL             30 N DULUTH             47.22N 92.12W
04/18/2004  2.00 INCH        EAST CENTRAL ST. L MN   TRAINED SPOTTER

&&

CLC

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
1231 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1230 PM     HAIL             GILBERT                 47.49N 92.46W
04/18/2004  1.00 INCH        WEST CENTRAL ST. L MN   TRAINED SPOTTER

&&

SHIMON

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
1243 PM CDT SUN APR 18 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

1241 PM     HAIL             EMBARRASS               47.66N 92.20W
04/18/2004  1.75 INCH        EAST CENTRAL ST. L MN   TRAINED SPOTTER

&&

SHIMON