Severe Thunderstorm Warning 104, NWS Detroit, MI

388 
WWUS53 KDTX 292253
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
653 PM EDT Sun Aug 29 2021

MIC091-300000-
/O.CON.KDTX.SV.W.0104.000000T0000Z-210830T0000Z/
Lenawee MI-
653 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR LENAWEE COUNTY...

At 653 PM EDT, severe thunderstorms were located along a line
extending from near Onsted to near Addison to near Pioneer, moving
east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Onsted around 700 PM EDT.
  Adrian around 710 PM EDT.
  Tecumseh and Hudson around 715 PM EDT.
  Morenci and Clayton around 720 PM EDT.
  Britton around 725 PM EDT.
  Blissfield around 750 PM EDT.
  Deerfield around 755 PM EDT.

Other locations impacted by these severe thunderstorms include
Seneca, Manitou Beach-Devils Lake, Macon, Lime Creek, Munson, Ogden
Center, Canandaigua, Ridgeway, Palmyra and Tipton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4207 8435 4208 8377 4172 8377 4171 8436
TIME...MOT...LOC 2253Z 261DEG 36KT 4206 8418 4195 8425 4173 8458 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

180 
WWUS53 KDTX 292301
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
701 PM EDT Sun Aug 29 2021

MIC091-300000-
/O.CON.KDTX.SV.W.0104.000000T0000Z-210830T0000Z/
Lenawee MI-
701 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR LENAWEE COUNTY...

At 700 PM EDT, severe thunderstorms were located along a line
extending from 6 miles southwest of Manchester to near Onsted to near
Pioneer, moving east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Onsted around 705 PM EDT.
  Adrian around 710 PM EDT.
  Hudson around 715 PM EDT.
  Tecumseh and Morenci around 720 PM EDT.
  Britton and Clayton around 725 PM EDT.
  Blissfield around 750 PM EDT.
  Deerfield around 800 PM EDT.

Other locations impacted by these severe thunderstorms include
Seneca, Manitou Beach-Devils Lake, Macon, Lime Creek, Munson, Ogden
Center, Canandaigua, Ridgeway, Palmyra and Tipton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4207 8435 4208 8377 4172 8377 4171 8436
TIME...MOT...LOC 2300Z 261DEG 36KT 4207 8411 4196 8418 4174 8451 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

115 
WWUS53 KDTX 292310
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
710 PM EDT Sun Aug 29 2021

MIC091-300000-
/O.CON.KDTX.SV.W.0104.000000T0000Z-210830T0000Z/
Lenawee MI-
710 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR LENAWEE COUNTY...

At 710 PM EDT, severe thunderstorms were located along a line
extending from near Clinton to near Adrian to near Fayette, moving
east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Adrian and Tecumseh around 715 PM EDT.
  Clayton around 725 PM EDT.
  Britton around 730 PM EDT.
  Blissfield around 750 PM EDT.
  Deerfield around 800 PM EDT.

Other locations impacted by these severe thunderstorms include
Seneca, Manitou Beach-Devils Lake, Macon, Lime Creek, Munson, Ogden
Center, Canandaigua, Ridgeway, Palmyra and Tipton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4207 8435 4208 8377 4172 8377 4171 8436
TIME...MOT...LOC 2310Z 252DEG 36KT 4206 8401 4187 8404 4174 8438 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

667 
WWUS53 KDTX 292322
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
722 PM EDT Sun Aug 29 2021

MIC091-300000-
/O.CON.KDTX.SV.W.0104.000000T0000Z-210830T0000Z/
Lenawee MI-
722 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR LENAWEE COUNTY...

At 722 PM EDT, severe thunderstorms were located along a line
extending from near Britton to near Blissfield to Morenci, moving
east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Britton around 730 PM EDT.
  Deerfield around 735 PM EDT.
  Blissfield around 755 PM EDT.

Other locations impacted by these severe thunderstorms include
Seneca, Manitou Beach-Devils Lake, Macon, Lime Creek, Munson, Ogden
Center, Canandaigua, Ridgeway, Palmyra and Tipton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4207 8435 4208 8377 4172 8377 4171 8436
TIME...MOT...LOC 2322Z 252DEG 36KT 4204 8387 4185 8390 4172 8424 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

573 
WWUS53 KDTX 292339
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
739 PM EDT Sun Aug 29 2021

MIC091-300000-
/O.CON.KDTX.SV.W.0104.000000T0000Z-210830T0000Z/
Lenawee MI-
739 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR EASTERN LENAWEE COUNTY...

At 739 PM EDT, severe thunderstorms were located along a line
extending from near Britton to near Deerfield to near Morenci, moving
east at 40 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Deerfield around 745 PM EDT.

Other locations impacted by these severe thunderstorms include
Seneca, Jasper, Macon, Weston, Ogden Center, Riga, Ridgeway, Palmyra,
Fairfield and Sand Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4208 8377 4172 8377 4171 8429 4208 8393
TIME...MOT...LOC 2339Z 252DEG 36KT 4205 8378 4186 8381 4173 8415 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

769 
WWUS53 KDTX 292347
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
747 PM EDT Sun Aug 29 2021

MIC091-300000-
/O.CON.KDTX.SV.W.0104.000000T0000Z-210830T0000Z/
Lenawee MI-
747 PM EDT Sun Aug 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM EDT
FOR SOUTHEASTERN LENAWEE COUNTY...

At 747 PM EDT, severe thunderstorms were located along a line
extending from near Ottawa Lake to near Morenci, moving east at 35
mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

These severe storms will be near...
  Blissfield and Deerfield around 755 PM EDT.

Other locations impacted by these severe thunderstorms include
Seneca, Jasper, Weston, Ogden Center, Riga, Ridgeway, Palmyra,
Fairfield, Sand Creek and Holloway.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4208 8377 4172 8377 4171 8429
TIME...MOT...LOC 2347Z 271DEG 29KT 4179 8379 4172 8412 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Behnke

068 
WWUS53 KDTX 292358
SVSDTX

Severe Weather Statement
National Weather Service Detroit/Pontiac MI
758 PM EDT Sun Aug 29 2021

MIC091-300008-
/O.EXP.KDTX.SV.W.0104.000000T0000Z-210830T0000Z/
Lenawee MI-
758 PM EDT Sun Aug 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN LENAWEE COUNTY
WILL EXPIRE AT 800 PM EDT...
    
The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire.

LAT...LON 4208 8377 4172 8377 4171 8429
TIME...MOT...LOC 2358Z 261DEG 36KT 4180 8367 4173 8400 

$$

Behnke

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
412 PM EDT Sun Aug 29 2021

.DISCUSSION...

Severe Thunderstorm Watch 473 is in effect until 7 PM EDT. Surface
based CAPE values approaching 3000 J/kg, DCAPE exceeding 1100 J/kg,
and a well mixed boundary layer brings the potential for efficient
damaging wind gust production this afternoon and evening. The main
limiting factor remains weak deep layer shear that will increase up
to 20 knots after 20Z. Multicellular storm organization with
embedded line segments brings damaging wind gusts of potentially
greater than 60 mph into play. The wind threat is expected to be
fairly scattershot and pulselike with no signal for strong cold pool
generation. Hail and tornado threats appear to be minimized for this
event. Low confidence exists in any short duration training this
evening as convective activity pushes south of the I 96 corridor.
Model signal continues to suggest that a better potential for a
multiple hour duration would be across portions of Southwest or
South Central Lower Michigan.

The deep 925-600mb cold front is forecasted to sag southward and
clear the Michigan/Ohio state line between 15-18Z Monday. A big drop
in surface dewpoints are expected with readings lowering down into
the low 60s areawide. Heat indices will reside in the lower to mid
80s which will be some 10 to 15 degrees lower than recent days.
Diurnal cumulus is anticipated at/around 5.0 kft agl but
differential cold advection in the low levels will lead to very
stable conditions.

Modest upper level confluence will become increasingly more
organized over the central Great Lakes region Monday and Tuesday.
Dynamic forcing aloft will then be bolstered by differential
geopotential height increases to result in strong surface ridge axis
expanding down into Lower Michigan. The surface ridging will be non-
trivial as high confidence exists that Ida remnants will be blocked
and turned sharply to the east on Wednesday. Expectations are for
the precipitation to miss Southeast Michigan with increase in
northerly geostrophic flow Wednesday afternoon and Wednesday night. A
secondary cold front is expected to release through the area Tuesday
night. The biggest effect will be on low temperatures with morning
readings in the 50s and perhaps the upper 40s Thursday morning.
Models do show an upper level jet arriving for the end of the week.
Lower confidence exists on how exactly the sensible weather effects
could play out because of possible anticyclonic shear dominating the
region.

&&

.MARINE...

One more day of unsettled weather will exist across the local waters
as a very warm and humid airmass promotes another round of
thunderstorms through this evening ahead of a passing cold front.
Any thunderstorm will have the potential to produce strong winds in
excess of 34 knots and locally erratic waves. Outside of
thunderstorms, moderate southwesterly winds gusting 20-25 knots at
times will eventually veer northwesterly behind the cold front
passage as drier air begins to filter into the central Great Lakes.
Moderate north to northwesterly flow will then prevail through
midweek as broad high pressure settles over the region.

&&

.HYDROLOGY...

Scattered to numerous thunderstorms develop this afternoon and
continue into the evening as a cold front moves in from the Midwest.
Locally heavy rainfall remains possible with this activity although
flooding potential is reduced slightly by fast motion of the line.
Conditions will be monitored for any west to east positioning of
storms which would be more capable of flooding. Basin-average
rainfall totals are expected to range from 0.25 to 0.50 inches, but
localized areas could receive upwards of 1 to 2 inches as rainfall
rates will likely exceed 1 inch per hour. This may result in
flooding of susceptible areas, particularly if repeated storms occur
over urban areas before the line moves south and east of the region
toward midnight.

&&

.PREV DISCUSSION...
Issued at 141 PM EDT Sun Aug 29 2021

AVIATION...

Main aviation concern today will be the threat of scattered to
numerous showers and thunderstorms along several lines moving
through southeast Michigan from west to east along and ahead of a
cold front between 19Z and 02Z. Storms will produce periods of
downpours along with the potential for strong to severe winds
resulting in brief periods of MVFR to possible IFR conditions. Prior
to arrival of convection will be SCT to BKN diurnal cumulus with
bases around 4 to 5 kft. Southwest winds will be elevated this
afternoon with gusts to 20 to 25 knots ahead of the thunderstorm
activity. Winds will begin to decrease after 00Z as activity pushes
east. Frontal passage occurs late tonight with potential for lower
VFR to MVFR conditions right along the front before drier air arrives
behind the front for Monday.

For DTW...SCT to BKN ceilings will hover around 4 to 5 kft through
this afternoon ahead of showers and thunderstorms, which are
anticipated to arrive at during the 22 to 02Z window. After showers
and thunderstorms move east, the frontal passage after 06Z will
carry another chance for low VFR/MVFR ceilings/fog before drier air
arrives Monday after 12Z.

DTW THRESHOLD PROBABILITIES...

* Moderate for ceilings at or below 5 kft into tonight.

* Moderate for thunderstorms from late afternoon to early evening.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&

DISCUSSION...CB
MARINE.......IRL
HYDROLOGY....BT
AVIATION.....AA

You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

Hazardous Weather Outlook
National Weather Service Detroit/Pontiac MI
1053 AM EDT Sun Aug 29 2021

MIZ047>049-053>055-060>063-068>070-075-076-082-083-301500-
Midland-Bay-Huron-Saginaw-Tuscola-Sanilac-Shiawassee-Genesee-Lapeer-
St. Clair-Livingston-Oakland-Macomb-Washtenaw-Wayne-Lenawee-Monroe-
1053 AM EDT Sun Aug 29 2021

This hazardous weather outlook is for portions of southeast
Michigan.

.DAY ONE...Today and Tonight

Scattered to numerous thunderstorms develop this afternoon as a cold
front moves in from the Midwest. There is a SLIGHT risk for severe
storm intensity mainly in the 2 PM to 10 PM time window with
damaging wind gusts of 60 mph or greater being the primary hazard.
Hail to around 1 inch and localized flooding are also possible as
storms move west to east at 35 mph.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight.

LCZ460-LEZ444-LHZ361>363-421-422-441>443-462>464-301500-
Lake St Clair-
Michigan Waters of Lake Erie from Detroit River to North Cape MI-
Lake Huron from 5NM east of Mackinac Bridge to Presque Isle Lt
beyond 5 NM off shore-
Lake Huron from Presque Isle Light to Sturgeon Point MI beyond 5NM
off shore-
Lake Huron from Sturgeon Point to Alabaster MI beyond 5NM off shore-
Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw
Bay-Inner Saginaw Bay SW of Point Au Gres to Bay Port MI-
Port Austin to Harbor Beach MI-Harbor Beach to Port Sanilac MI-
Port Sanilac to Port Huron MI-
Lake Huron from Port Austin to Harbor Beach beyond 5NM Off Shore-
Lake Huron from Harbor Beach to Port Sanilac beyond 5NM Off Shore-
Lake Huron from Port Sanilac to Port Huron beyond 5NM Off Shore-
1053 AM EDT Sun Aug 29 2021

This hazardous weather outlook is for portions of Lake Erie, Lake
Huron and Lake St Clair.

.DAY ONE...Today and Tonight

Scattered to numerous thunderstorms develop this afternoon as a cold
front moves in from the Midwest. There is a SLIGHT risk for severe
storm intensity mainly in the 2 PM to 10 PM time window with
damaging wind gusts of 60 mph or greater being the primary hazard.
Hail to around 1 inch and localized flooding are also possible as
storms move west to east at 35 mph.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight.

You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

CB

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
619 PM EDT SUN AUG 29 2021

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

0520 PM     TSTM WND DMG     3 WSW PERRY             42.81N 84.29W
08/29/2021                   SHIAWASSEE         MI   911 CALL CENTER

            TREES DOWN. TIME ESTIMATED BY RADAR.

0533 PM     TSTM WND DMG     2 S BYRON               42.79N 83.94W
08/29/2021                   SHIAWASSEE         MI   911 CALL CENTER

            TREES DOWN INCLUDING A TREE DOWN ON A VEHICLE. TIME
            ESTIMATED BY RADAR.

&&

IRL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
624 PM EDT SUN AUG 29 2021

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

0601 PM     TSTM WND DMG     2 NW EAST DAYTON        43.43N 83.31W
08/29/2021                   TUSCOLA            MI   911 CALL CENTER

            TREES DOWN OVER THE ROAD NEAR THE INTERSECTION OF M-46
            AND PHILLIPS ROAD.

&&

ANDREW.ARNOLD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
628 PM EDT SUN AUG 29 2021

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

0700 PM     TSTM WND DMG     2 ENE CASEVILLE         43.96N 83.24W
08/28/2021                   HURON              MI   PUBLIC

            MULTIPLE TREES DOWN.

&&

IRL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
629 PM EDT SUN AUG 29 2021

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

0510 PM     TSTM WND DMG     2 ENE CASEVILLE         43.96N 83.24W
08/29/2021                   HURON              MI   PUBLIC

            TREES DOWN. TIME ESTIMATED FROM RADAR.

&&

IRL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
632 PM EDT SUN AUG 29 2021

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

0532 PM     TSTM WND DMG     3 SW VASSAR             43.34N 83.62W
08/29/2021                   TUSCOLA            MI   911 CALL CENTER

            TREES AND WIRES REPORTED DOWN ALONG PINKERTON ROAD. TIME
            ESTIMATED BASED ON RADAR.

&&

ANDREW.ARNOLD

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
639 PM EDT SUN AUG 29 2021

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

0450 PM     MARINE TSTM WIND 8 ESE AU GRES           44.02N 83.54W
08/29/2021  M41 MPH          LHZ421             MI   BUOY

            A MARINE THUNDERSTORM WIND GUST OF 41 MPH, 36 KNOTS,
            MEASURED AT GRAVELLY SHOAL LIGHT.

&&

IRL