Damaging Winds in Michigan, August 9, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
358 AM EDT TUE AUG 9 2005

.DISCUSSION...
MAIN FORECAST CONCERN IS CONVECTION TODAY AND TONIGHT ALONG WITH
POTENTIAL FOR BOTH HEAVY RAINFALL AND SEVERE WEATHER.

CURRENT WEATHER...07Z WATER VAPOR LOOP AND RUC 500MB HEIGHT ANALYSIS
SHOWED GENERALLY ZONAL FLOW ACROSS THE NORTHERN TIER OF THE U.S.
EXCLUDING IN THE PACIFIC NW WHERE A RIDGE EXTENDS NW INTO ALASKA.
AT THE SURFACE...A COLD FRONT EXTENDED FROM JAMES BAY TO WESTERN
LAKE SUPERIOR...THEN TO A LOW NEAR RAPID CITY SOUTH DAKOTA.
TEMPERATURES REMAIN WARM AHEAD OF THE FRONT WITH READINGS STILL IN
THE UPPER 60S TO LOW 70S. DEWPOINTS OVER UPPER MICHIGAN REMAIN IN
THE 60S...HOWEVER OVER WESTERN WI AND SOUTHERN MN...THEY ARE IN THE
LOW 70S. ATMOSPHERE AHEAD OF THE FRONT AT 00Z WAS QUITE CAPPED FOR
SURFACE BASED CONVECTION LOOKING AT THE MPX AND GRB SOUNDINGS.
HOWEVER...ONCE DIURNAL COOLING SET IN ALLOWING FOR THE LOW LEVEL JET
TO INCREASE...ELEVATED CONVECTION DEVELOPED ALONG THE COLD FRONT
FROM THE MPX AREA TO NORTHERN LAKE SUPERIOR. THESE STORMS OVER THE
PAST HOUR HAVE DIMINISHED DUE TO STRONGER CAPPING AND DRIER AIR OVER
THE CENTRAL U.P. NOTED ON TAMDAR SOUNDINGS. FURTHER TO THE
WEST...MORE CONVECTION WAS PRESENT ACROSS THE FARGO NORTH DAKOTA
AREA INTO NORTH CENTRAL MINNESOTA. THIS CONVECTION WAS LOCATED
WITHIN AN AREA OF 800-700MB 2-D FRONTOGENESIS AND IN THE RIGHT
ENTRANCE REGION OF A 115KT JET AT 250MB MOVING ACROSS SOUTHERN
MANITOBA. A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR THIS LINE OF
CONVECTION UNTIL 12Z.

TODAY INTO TONIGHT...

00Z GFS HAS A GOOD HANDLE ON THE CONVECTION OVER THE DAKOTAS. GFS
SHOWS THE CONVECTION PUSHING ACROSS NORTHERN MINNESOTA INTO WESTERN
LAKE SUPERIOR THIS MORNING...SUPPORTED BY THE UPPER LEVEL JET AND
800-700MB FRONTOGENESIS. THERE ARE INDICATIONS THAT THE CONVECTION
MAY DIMINISH SOMEWHAT AS IT CONTINUES ITS MARCH EAST ACROSS EASTERN
LAKE SUPERIOR. THIS APPEARS TO RELATED TO THE FRONTOGENESIS
REFOCUSING FURTHER SW INTO CENTRAL MINNESOTA. HOWEVER...WITH THE GFS
STILL SHOWING A DECENT AMOUNT OF QPF OVER EASTERN SUPERIOR...WILL
HAVE NUMEROUS SHOWERS AND THUNDERSTORMS CROSSING LAKE SUPERIOR AND
THE WESTERN U.P.. HAVE KEPT IN A CHANCE OR SLIGHT CHANCE FOR THE
REST OF THE U.P. IN THE EVENT SOME OF THE CONVECTION ENDS UP FURTHER
SOUTH.

THE REFOCUSED AREA OF FRONTOGENESIS IS THEN PROGGED TO MOVE INTO THE
WESTERN U.P. LATE THIS AFTERNOON. WITH AN UPPER LEVEL JET STILL
PROGGED TO BE LOCATED FROM NORTHERN LAKE SUPERIOR INTO NE ONTARIO...
UPPER DIVERGENCE WILL STILL BE OCCURRING. SO THINK THE IDEA OF
HAVING NUMEROUS SHOWERS AND THUNDERSTORMS MOVING IN AGAIN INTO
SOUTHWEST UPPER MICHIGAN THIS AFTERNOON SHOULD PAN OUT. NOTE THAT
SOME OF THE STORMS MAY ACTUALLY BE SURFACE BASED AS SUGGESTED BY
NAM/GFS SOUNDINGS...PARTICULARLY OVER THE SOUTH CENTRAL U.P.. CAPE
VALUES ARE PROGGED AT 18Z WITH A 80/66 (T/TD) VALUE AT IMT OF
2000-2500 J/KG AND LITTLE IF ANY CIN. THESE TEMPERATURES AND
DEWPOINTS SEEM REASONABLE OR COULD EVEN BE A BIT UNDERDONE GIVEN
CURRENT READINGS. 0-6KM SHEAR VALUES WITHIN THE SURFACE BASED
CONVECTION AREA ARE PROGGED BETWEEN 30-35KT...SO THESE STORMS MAY
BECOME ORGANIZED. HIGH FREEZING AND WET-BULB ZERO LEVELS SHOULD KEEP
THE THREAT OF LARGE HAIL EXCLUDING ANY STRONG ROTATING STORM.
HOWEVER...SURFACE-7000 FT DELTA THETA-E IS PROGGED TO BE BETWEEN
25-30K...DEFINITELY SUPPORTIVE OF DAMAGING WIND.

AS THE FRONTOGENESIS AND UPPER LEVEL JET PUSH EAST-SOUTHEAST
TONIGHT...SO WILL THE CONVECTION. SO HAVE PUT NUMEROUS SHOWERS AND
THUNDERSTORMS FOR THE CENTRAL AND EASTERN U.P. TONIGHT. IT IS
POSSIBLE THAT THE KEWEENAW PENINSULA MAY NOT SEE ANY RAINFALL
TONIGHT...HOWEVER HAVE MAINTAINED A 30 POP MORE FOR UNCERTAINTY OF
PLACEMENT OF THE CONVECTION.

FOR THE NON-SURFACE BASED CONVECTION...1-6KM SHEAR VALUES ARE
PROGGED TO BE AT LEAST 40 KT SO ORGANIZED STORMS DO LOOK LIKELY.
HOWEVER...BEING LOCATED BEHIND THE SURFACE COLD FRONT (LOCATED OVER
THE FAR SOUTH CENTRAL U.P. AT 21Z PER GFS/NAM)...HAIL MAY TURN INTO
BE THE MAIN HAZARD. AS STATED EARLIER...HIGH FREEZING LEVELS SHOULD
MITIGATE THE HAIL THREAT...BUT WITH SUCH HIGH SHEAR...COULD NOT RULE
IT OUT.

PRECIPITABLE WATER AROUND 1.7 INCHES ALONG WITH THE POTENTIAL FOR
TRAINING STORMS AS OBSERVED BACK IN NORTH DAKOTA AND MINNESOTA THIS
MORNING SUGGEST POTENTIAL FOR HEAVY RAIN TONIGHT. A NICE PLUME OF
MOISTURE CAN BE SEEN TOO IN THE UPPER LEVELS ON WATER VAPOR
EXTENDING FROM THE MONSOOAL MOISTURE IN THE FOUR CORNERS
AREA...ANOTHER INDICATION OF HEAVY RAINFALL POTENTIAL. WILL ALSO
HAVE THIS HAZARD MENTIONED IN THE HWO.

SWODY1 OUTLOOK HAS CWA IN SLIGHT RISK WITH PROBABILITY GRAPHICS FOR
WIND AND HAIL AT 15%. WILL BE MENTIONING BOTH THE HAIL AND WIND
HAZARDS IN HWO...MAINLY FOR THIS AFTERNOON AND EVENING.

UPDATE FOR THE 06Z NAM...NAM INDICATING THAT THE PRECIP TONIGHT MAY
GO A LITTLE FURTHER SOUTH THAN SHOWN IN THE 00Z GFS/NAM RUNS. HAVE
TRIMMED THE NUMEROUS COVERAGE AREA A LITTLE SOUTHEAST FROM WHERE IT
WAS GOING TO BE PLACED.

LASTLY...AS FOR TEMPERATURES...TODAY IS TRICKY DUE TO CONVECTION...
SKY COVER...WIND DIRECTION AND 850MB TEMPS STILL IN THE 14-18C RANGE
(WARMEST SOUTH). HAVE FOLLOWED A BLEND OF THE PREVIOUS FORECAST AND
LATEST GUIDANCE...BUT DEFINITELY LOOKS LIKE THE LAKE MICHIGAN
COUNTIES WILL BE ABLE TO GET QUITE WARM AGAIN. HAVE PUT READINGS
NEAR 90 FOR MENOMINEE AS WEST WINDS AHEAD OF THE COLD FRONT DROP
SOUTH DOWNSLOPE. LOWS WILL BE COOLER TONIGHT DUE TO RAINFALL AND
NORTHERLY WINDS. CURRENT LOWS LOOK GOOD.

WEDNESDAY...SOME CONVECTION MAY STILL BE GOING ALONG THE LAKE
MICHIGAN COUNTIES IN THE MORNING...BUT THIS SHOULD BE PUSHING
EAST-SOUTHEAST PRETTY QUICKLY. BY AFTERNOON...THE GFS/NAM SHOW SOME
STRONG DRYING...HELPING TO TURN SKIES AT A MINIMUM PARTLY SUNNY OR
PERHAPS EVEN MOSTLY SUNNY. 850MB TEMPS OF 12-14C SUGGEST READINGS IN
THE UPPER 70S TO LOW 80S...WITH SLIGHTLY COOLER READINGS ALONG LAKE
SUPERIOR DUE TO ONSHORE WINDS.

WEDNESDAY NIGHT INTO THURSDAY...GFS/NAM INDICATE SOME 800-700MB
FRONTOGENESIS OCCURRING AGAIN OVER NORTH DAKOTA ON WEDNESDAY
AFTERNOON IN THE ZONAL FLOW ALOFT. THIS FRONTOGENESIS AREA IS
PROGGED TO MOVE INTO THE WESTERN U.P. THURSDAY MORNING AND EXIT THE
U.P. THURSDAY EVENING. GFS DOES PRODUCE QPF OUT OF THIS WHEREAS THE
NAM DOES NOT. GIVEN THE EVENT THAT IS EXPECTED TO OCCUR
TONIGHT...COULD NOT RULE OUT ANOTHER LIGHTER EVENT LIKE THE GFS
SHOWS. THEREFORE HAVE INTRODUCED A CHANCE OF SHOWERS AND
THUNDERSTORMS WITH THE FRONTOGENESIS. GFS ALSO SHOWS POTENTIAL FOR
SOME UPPER LEVEL DIVERGENCE FROM AN UPPER JET MOVING ACROSS THE
NORTHERN PART OF LAKE SUPERIOR...ASSISTING IN THE -TSRA PRODUCTION.
OTHERWISE...THE REST OF THE TIME LOOKS PARTLY CLOUDY. MIN TEMPS MAY
NEED TO BE WATCHED A BIT FOR WEDNESDAY NIGHT AS LIGHT WINDS AND THE
PARTLY CLOUDY SKIES MAY ALLOW TEMPERATURES TO DROP QUITE A BIT.
GUIDANCE HAD LOWS INTO THE UPPER 40S IN SOME PLACES IN THE CENTRAL
U.P.. FOR NOW HAVE DROPPED LOWS INTO THE LOW 50S FOR THOSE SPOTS.
THURSDAY READINGS EXPECTED TO BE CLOSE TO NORMAL.

NO CHANGES BEYOND THURSDAY...HOWEVER THE 00Z GFS RUN DOES INDICATE
POTENTIAL FOR SOME RAIN SATURDAY NIGHT ASSOCIATED WITH MORE
FRONTOGENESIS AND UPPER LEVEL DIVERGENCE. WILL PASS ALONG TO DAY
SHIFT TO LOOK FURTHER.

COORDINATED WITH APX...THANKS.

&&

.MQT...WATCHES/WARNINGS/ADVISORIES...NONE.

&&

AJ

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MARQUETTE MI
506 AM EDT TUE AUG 9 2005

MIZ001>007-009>014-084-085-101200-
ALGER-BARAGA-DELTA-DICKINSON-GOGEBIC-IRON-KEWEENAW-LUCE-MARQUETTE-
MENOMINEE-NORTHERN HOUGHTON-NORTHERN SCHOOLCRAFT-ONTONAGON-
SOUTHERN HOUGHTON-SOUTHERN SCHOOLCRAFT-
506 AM EDT TUE AUG 9 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL UPPER
MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO MOVE INTO WESTERN LAKE SUPERIOR AND
FAR WESTERN UPPER MICHIGAN THIS MORNING...THEN ACROSS THE REST OF
LAKE SUPERIOR AND THE KEWEENAW PENINSULA LATE THIS MORNING INTO THIS
AFTERNOON. HEAVY RAINFALL WILL BE THE MAIN HAZARD FROM THESE STORMS.

THUNDERSTORMS ARE ALSO EXPECTED TO DEVELOP EARLY THIS AFTERNOON
ALONG THE WISCONSIN BORDER AND SPREAD NORTHEAST. HEAVY RAINFALL AND
FREQUENT LIGHTNING ARE LIKELY WITH THESE STORMS...HOWEVER THERE IS
ALSO A SLIGHT RISK THAT THESE STORMS COULD PRODUCE DAMAGING
WINDS AND LARGE HAIL.

THUNDERSTORMS WILL CONTINUE THIS EVENING ACROSS MUCH OF CENTRAL
UPPER MICHIGAN...THEN DIMINISH FROM NORTHWEST TO SOUTHEAST OVERNIGHT
AS THE STORMS MOVE SOUTHEAST. THERE IS A SLIGHT RISK THAT THESE
STORMS COULD PRODUCE LARGE HAIL IN THE EVENING...THOUGH HEAVY
RAINFALL AND FREQUENT LIGHTNING APPEAR TO BE THE MAIN HAZARDS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS ARE EXPECTED TO DIMINISH EARLY WEDNESDAY MORNING ALONG
LAKE MICHIGAN.

THERE IS ALSO A CHANCE FOR THUNDERSTORMS ACROSS WEST AND CENTRAL
UPPER MICHIGAN ON THURSDAY...AND FOR CENTRAL UPPER MICHIGAN
THURSDAY EVENING. ANOTHER CHANCE FOR THUNDERSTORMS EXISTS FRIDAY
AFTERNOON ACROSS WESTERN UPPER MICHIGAN...THEN OVER WEST AND CENTRAL
UPPER MICHIGAN ON FRIDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND EVENING.

ADDITIONAL WEATHER INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:

HTTP://WWW.WEATHER.GOV/MQT (ALL LOWER CASE)

AJ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MARQUETTE MI
803 AM EDT TUE AUG 9 2005

MIZ002-009-091415-
ONTONAGON-GOGEBIC-
INCLUDING THE CITIES OF...ONTONAGON...IRONWOOD
703 AM CDT TUE AUG 9 2005 /803 AM EDT TUE AUG 9 2005/

...STRONG THUNDERSTORMS APPROACHING WESTERN UPPER MICHIGAN...
...SEVERE THUNDERSTORM WATCH IS IN EFFECT UNTIL 11 AM CDT...

A CLUSTER OF STRONG THUNDERSTORMS IS MOVING ACROSS NORTHWEST WISCONSIN
AND WILL REACH IRONWOOD BETWEEN 730 AM AND 800 AM CDT...AND MARENISCO
AND ONTONAGON BY 830 AM CDT. EXPECT WIND GUSTS TO 50 MPH...HAIL TO
A HALF INCH IN DIAMETER...AND FREQUENT CLOUD TO GROUND LIGHTNING
AS THESE STORMS MOVE THROUGH. IT IS POSSIBLE THAT THESE STORMS MAY
STRENGTHEN AND FUTURE WARNINGS MAY BE NEEDED.

JLA