SPC Severe Thunderstorm Watch 390

Source: US National Oceanic and Atmospheric Administration

Note:  The expiration time in the watch graphic is amended if the watch is replaced, cancelled or extended.Note: Click for Watch Status Reports.
SEL0

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 390
NWS Storm Prediction Center Norman OK
315 PM EDT Sat Jul 24 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Central and Southern Lower Michigan
Lake Huron

* Effective this Saturday afternoon and evening from 315 PM until
1000 PM EDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
A tornado or two possible

SUMMARY…Multiple lines and clusters of thunderstorms will move
across the watch area this afternoon and early evening, posing a
risk of locally damaging wind gusts and isolated hail. A tornado or
two cannot be ruled out.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 40 miles east of Oscoda
MI to 35 miles west of Grand Rapids MI. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU0).

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.

&&

AVIATION…A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
28030.

…Hart

SEL0

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 390
NWS Storm Prediction Center Norman OK
315 PM EDT Sat Jul 24 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Central and Southern Lower Michigan
Lake Huron

* Effective this Saturday afternoon and evening from 315 PM until
1000 PM EDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
A tornado or two possible

SUMMARY…Multiple lines and clusters of thunderstorms will move
across the watch area this afternoon and early evening, posing a
risk of locally damaging wind gusts and isolated hail. A tornado or
two cannot be ruled out.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 40 miles east of Oscoda
MI to 35 miles west of Grand Rapids MI. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU0).

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.

&&

AVIATION…A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
28030.

…Hart

Note: The Aviation Watch (SAW) product is an approximation to the watch area. The actual watch is depicted by the shaded areas.
SAW0
WW 390 SEVERE TSTM MI LH 241915Z – 250200Z
AXIS..65 STATUTE MILES NORTH AND SOUTH OF LINE..
40E OSC/OSCODA MI/ – 35W GRR/GRAND RAPIDS MI/
..AVIATION COORDS.. 55NM N/S /34E ASP – 19SSW MKG/
HAIL SURFACE AND ALOFT..1 INCH. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 28030.

LAT…LON 43518259 41948621 43828621 45398259

THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU0.

Watch 390 Status Report Message has not been issued yet.

Note:  Click for Complete Product Text.TornadoesProbability of 2 or more tornadoes

Low (20%)

Probability of 1 or more strong (EF2-EF5) tornadoes

Low (5%)

WindProbability of 10 or more severe wind events

Mod (40%)

Probability of 1 or more wind events > 65 knots

Low (20%)

HailProbability of 10 or more severe hail events

Low (20%)

Probability of 1 or more hailstones > 2 inches

Low (10%)

Combined Severe Hail/WindProbability of 6 or more combined severe hail/wind events

Mod (60%)

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.