Note:
The expiration time in the watch graphic is amended if the watch is
replaced, cancelled or extended.
Note: Click for
Watch Status Reports.
SEL7
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 657
NWS Storm Prediction Center Norman OK
355 PM EDT Tue Aug 27 2024
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southeast Lower Michigan
Lake Huron
* Effective this Tuesday afternoon and evening from 355 PM until
900 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Isolated large hail events to 1.5 inches in diameter possible
A tornado or two possible
SUMMARY...Semi-organized cluster of storms will continue
east-southeastward across east-central and southeast Lower Michigan
through early evening.
The severe thunderstorm watch area is approximately along and 45
statute miles east and west of a line from 35 miles north of Bad Axe
MI to 10 miles southwest of Ann Arbor MI. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU7).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 656...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 550. Mean storm motion vector
29030.
...Guyer
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW7
WW 657 SEVERE TSTM MI LH 271955Z - 280100Z
AXIS..45 STATUTE MILES EAST AND WEST OF LINE..
35N BAX/BAD AXE MI/ - 10SW ARB/ANN ARBOR MI/
..AVIATION COORDS.. 40NM E/W /20ESE ASP - 24WSW DXO/
HAIL SURFACE AND ALOFT..1.5 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 550. MEAN STORM MOTION VECTOR 29030.
LAT...LON 44288208 42118301 42118477 44288390
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU7.
Watch 657 Status Report Messages:
STATUS REPORT #1 ON WW 657
VALID 272150Z - 272240Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 S AZO TO
25 SSW FNT TO 30 S BAX TO 10 ESE BAX TO 15 NNE BAX TO 25 SE APN.
..LYONS..08/27/24
ATTN...WFO...DTX...
&&
STATUS REPORT FOR WS 657
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MIC063-087-091-093-099-115-125-147-151-161-163-272240-
MI
. MICHIGAN COUNTIES INCLUDED ARE
HURON LAPEER LENAWEE
LIVINGSTON MACOMB MONROE
OAKLAND ST. CLAIR SANILAC
WASHTENAW WAYNE
$$
LCZ422-423-460-LEZ444-LHZ441-442-443-462-463-464-272240-
CW
. ADJACENT COASTAL WATERS INCLUDED ARE
ST. CLAIR RIVER
DETROIT RIVER
LAKE ST. CLAIR OPEN LAKE (U.S. PORTION)
MICHIGAN WATERS OF LAKE ERIE FROM DETROIT RIVER TO NORTH CAPE MI
PORT AUSTIN TO HARBOR BEACH MI
HARBOR BEACH TO PORT SANILAC MI
PORT SANILAC TO PORT HURON MI
LAKE HURON FROM PORT AUSTIN TO HARBOR BEACH 5NM OFF SHORE TO THE
US/CANADIAN BORDER
LAKE HURON FROM HARBOR BEACH TO PORT SANILAC 5NM OFF SHORE TO
US/CANADIAN BORDER
LAKE HURON FROM PORT SANILAC TO PORT HURON 5NM OFF SHORE TO
US/CANADIAN BORDER
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Low (20%)
|
Probability of 1 or more strong (EF2-EF5) tornadoes
|
Low (5%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (60%)
|
Probability of 1 or more wind events > 65 knots
|
Low (20%)
|
Hail
Probability of 10 or more severe hail events
|
Mod (30%)
|
Probability of 1 or more hailstones > 2 inches
|
Low (20%)
|
Combined Severe Hail/Wind
Probability of 6 or more combined severe hail/wind events
|
High (80%)
|
For each watch, probabilities for particular events inside the watch
(listed above in each table) are determined by the issuing forecaster.
The "Low" category contains probability values ranging from less than 2%
to 20% (EF2-EF5 tornadoes), less than 5% to 20% (all other probabilities),
"Moderate" from 30% to 60%, and "High" from 70% to greater than 95%.
High values are bolded and lighter in color to provide awareness of
an increased threat for a particular event.
weather.gov 
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