Hail and Damaging Wind in Wisconsin, July 16, 2008

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
802 PM CDT WED JUL 16 2008

.UPDATE...
REFINED PRECIPITATION DISTRIBUTION TONIGHT AND THURSDAY. RETAINED
AREAS OF FOG LATE TONIGHT AND PATCHY FOG EARLY THURSDAY. DECREASED
WIND AND MADE THEM A LITTLE MORE ONSHORE.

&&

.DISCUSSION...
A DOUBLE TROUGH STRUCTURE HAS SET UP...WITH ONE EAST TO WEST
TROUGH JUST SOUTH OF THE CANADIAN BORDER AND A SOUTHERN TROUGH
ALONG THE IOWA BORDER THROUGH SOUTHERN WI. ATTM THE SOUTHERN
TROUGH IS QUIET...WITH OVERRUNNING CLOUDS AND RAIN FROM DULUTH ON
NORTH. THE BACK EDGE OF THIS OVERRUNNING IS MOVING EAST THROUGH
THE IRON RANGE. VERY UNSTABLE AIR IS OVERRUNNING THE NORTHERN
TROUGH. A COUPLE OF EXTREMELY INTENSE THUNDERSTORMS SUDDENLY
DEVELOPED JUST WEST OF THE RED RIVER A SHORT TIME AGO...THESE ARE
MOVING EAST. WE WILL BE WATCHING TO SEE IF THESE HOLD TOGETHER
LONG ENOUGH TO EVENTUALLY MOVE UP THE RAINY RIVER VALLEY. WE PUT
LIKELY POPS IN THE OVERRUNNING ASSOCD WITH THE SOUTHERN TROUGH AND
MADE NO IMMEDIATE MODIFICATIONS IN OUR NORTHERN AREAS. HIGH
PRESSURE RIDGING DONW THE NORTH SHORE WILL CONTINUE TO ESTABLISH A
GRADUALLY INCREASING ONSHORE FLOW...WHICH SHOULD DEEPEN THE COOL
AIR MASS AND INHIBIT CONVECTION AS IT APPROACHES THE LAKE. HIGH
PRESSURE BUILDING EAST FROM NORTH DAKOTA SHOULD PUSH MOST OF THE
PRECIPITATION SOUTHEAST OF DULUTH ON THURSDAY.

&&

.PREV DISCUSSION... /ISSUED 318 PM CDT WED JUL 16 2008/

DISCUSSION...MAIN FORECAST CHALLENGE IS RESOLVING CONVECTIVE
CHANCES IN THE SHORT TERM. AFTERNOON SURFACE ANALYSIS SHOWS WARM
FRONT STILL SITUATED ACROSS SOUTHERN MINNESOTA INTO CENTRAL
WISCONSIN. CLOUD DEBRIS FRONT DECAYING EARLY MORNING CONVECTION
HAS HINDERED FURTHER DEVELOPMENT ACROSS THE DLH FA TODAY. MAIN
AXIS OF INSTABILITY REMAINS SOUTH OF SFC WARM FRONT AS WELL THIS
AFTERNOON IN WARM AND HUMID AIRMASS. HOWEVER...APPROACHING SHORT
WAVE CURRENTLY PUSHING THROUGH NORTH DAKOTA IS EXPECTED TO
INITIATE LATE AFTERNOON CONVECTION ALONG SFC CONVERGENCE/TROUGH
LINE IN THE EASTERN DAKOTAS. AHEAD OF THIS VORT MAX...A DEVELOPING
LOW LEVEL JET WILL AID IN RETURN MOISTURE AND ELEVATED INSTABILITY
NORTHWARD TOWARD THE SOUTHERN DLH ZONES. THE CONVECTION SHOULD
PROGRESS ESE WITH MEAN FLOW ALOFT...AND IS EXPECTED TO PARTIALLY
CROSS THE SOUTHERN ZONES LATER THIS EVENING AND TONIGHT. AIRMASS
FEEDING INTO THE CONVECTION WILL BE VERY MOIST WITH PWATS
INCREASING TO NEAR 2 INCHES. DEEP LAYER SHEAR REMAINS FAVORABLE AT
45 TO 55 KTS AS WELL. THEREFORE...WILL MAINTAIN HEAVY RAIN WORDING
WITH FORECAST ALONG THE SOUTHERN ZONES. ALSO HAVE MAINTAINED FOG
AFTER MIDNIGHT WITH INCREASING LOW LEVEL MOISTURE.

MAIN BAROCLINIC ZONE REMAINS STRETCHED ACROSS CENTRAL MN/NORTHERN WI
THURSDAY INTO FRIDAY...WITH ADDITIONAL IMPULSES TRIGGERING
CONVECTION THURSDAY AFTERNOON...MAINLY ACROSS NW WI ZONES. DRIER
AIRMASS AND HIGH PRESSURE FINALLY BUILD INTO THE REGION FOR
FRIDAY/FRIDAY NIGHT...BRINGING A BREAK IN THIS ACTIVE PATTERN.
RETURN FLOW SETS UP FOR THE WEEKEND...ALTHOUGH EXISTING DRY
AIRMASS WILL BE SLOW TO MOVE OUT.

AVIATION...MAINLY VFR CONDITIONS WILL PREVAIL LATE THIS
AFTERNOON...WITH GENERALLY BROKEN MID LEVEL CLOUDS. AS A SHORT WAVE
FROM THE DAKOTAS PUSHES EAST INTO WESTERN MINNESOTA...AND A WARM
FRONT LIFTS NORTH TOWARD EVENING...INCREASING LOW LEVEL MOISTURE
COMBINED WITH A STRENGTHENING LOW LEVEL JET...WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE WESTERN PORTION OF
THE AREA AS EARLY AS 22Z...BEFORE AFFECTING THE REST OF THE REGION
AFTER 00-01Z. A BAND OF MORE ORGANIZED CONVECTION AND LOCALLY HEAVY
RAINFALL MAY IMPACT AREAS FROM KBRD...TO KRZN...TO KHYR BETWEEN
02Z-09Z. CONSIDERABLE LOW LEVEL MOISTURE NORTH OF AND ALONG THE WARM
FRONT WILL RESULT IN THE DEVELOPMENT OF FOG LATE THIS EVENING AND
DURING THE OVERNIGHT HOURS...WITH LOCAL IFR CEILINGS AND
VISIBILITIES...WITH THE POOREST CONDITIONS EXPECTED AT KDLH AND
KHIB. FOG WILL SLOWLY LIFT BETWEEN 12Z AND 14Z THURSDAY...WITH VFR
CONDITIONS RETURNING AFTER 14Z.

&&

POINT TEMPS/POPS...
DLH  59  76  55  77 /  70  30  30  10
INL  56  75  53  77 /  40  20  10  10
BRD  62  79  58  80 /  70  40  20  10
HYR  62  81  58  82 /  70  50  40  10
ASX  60  77  58  77 /  70  50  30  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...

MN...NONE.
WI...NONE.
LS...NONE.

EOM/TL

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
345 PM CDT WED JUL 16 2008

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-171030-
KOOCHICHING-NORTHERN ST. LOUIS-NORTHERN COOK/NORTHERN LAKE-
NORTHERN ITASCA-CENTRAL ST. LOUIS-SOUTHERN LAKE/LAKESHORE-
SOUTHERN COOK/LAKESHORE-NORTHERN CASS-SOUTHERN ITASCA-
SOUTHERN CASS-CROW WING-NORTHERN AITKIN-SOUTHERN AITKIN-
CARLTON/SOUTHERN ST. LOUIS-PINE-DOUGLAS-BAYFIELD-ASHLAND-IRON-
BURNETT-WASHBURN-SAWYER-PRICE-
345 PM CDT WED JUL 16 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING AND
TONIGHT GENERALLY SOUTH OF AN APOSTLE ISLANDS TO SILVER BAY TO
VIRGINIA TO BIG FORK MINNESOTA LINE. THE PRIMARY THREAT WILL BE
DAMAGING WINDS AND HAIL.

LOCALLY HEAVY RAIN MAY INCREASE OVERNIGHT IN THE SOUTHERN PART OF
THE REGION...MAINLY FROM SOUTHEAST OF BRAINERD TO ASKOV IN
MINNESOTA...AND SOUTH OF A DAIRYLAND TO PHILLIPS LINE IN NORTHWEST
WISCONSIN.

LOCALLY DENSE FOG IS POSSIBLE...ESPECIALLY AFTER MIDNIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

 LOCALLY HEAVY RAIN IS POSSIBLE OVER SAWYER AND PRICE COUNTIES IN
WISCONSIN EARLY THURSDAY.

THUNDERSTORMS MAY RETURN TO THE REGION DURING THE WEEKEND. AT THIS
TIME IT IS DIFFICULT TO DETERMINE IF THE STORMS WILL BE SEVERE.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON AND
TONIGHT.

LSZ121-140>148-171030-
BAYFIELD TO OAK POINT WI-GRAND PORTAGE TO GRAND MARAIS MN-
GRAND MARAIS TO TACONITE HARBOR MN-
TACONITE HARBOR TO SILVER BAY HARBOR MN-
SILVER BAY HARBOR TO TWO HARBORS MN-TWO HARBORS TO DULUTH MN-
DULUTH MN TO PORT WING WI-PORT WING TO SAND ISLAND WI-
SAND ISLAND TO BAYFIELD WI-OAK POINT TO SAXON HARBOR WI-
345 PM CDT WED JUL 16 2008

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NEARSHORE WATERS OF
WESTERN LAKE SUPERIOR.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING
TONIGHT SOUTH OF A LINE FROM SILVER BAY MINNESOTA TO OUTER ISLAND
WISCONSIN. THE PRIMARY THREAT WILL BE DAMAGING WINDS AND HAIL.

ONSHORE WINDS MAY POSE AN ENHANCED RISK OF RIP CURRENTS THIS
AFTERNOON AND TONIGHT FROM THE BEACHES AROUND THE TWIN
PORTS...EAST ALONG THE SOUTH SHORE.

LOCALLY DENSE FOG IS POSSIBLE OVERNIGHT OVER THE LAKE.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THUNDERSTORMS MAY RETURN TO THE REGION DURING THE WEEKEND. AT
THIS TIME IT IS DIFFICULT TO DETERMINE IF THE STORMS WILL BE
SEVERE.

LILES