MIL-OSI USA: SPC Severe Thunderstorm Watch 502

2

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.
SEL2

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 502
NWS Storm Prediction Center Norman OK
115 PM EDT Wed Sep 15 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Western and central Maine
New Hampshire

* Effective this Wednesday afternoon and evening from 115 PM
until 800 PM EDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph likely
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible

SUMMARY…Scattered severe storms are expected to develop this
afternoon and spread west-to-east across New Hampshire into Maine.
The initial storms could be more discrete with some supercell
structures possible, though a gradual evolution into line segments
is expected. Damaging winds of 60 to 70 mph and isolated large hail
of 1 to 1.5 inch diameter will be the most common threats, though a
tornado or two may occur with embedded circulations.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 15 miles west of
Lebanon NH to 60 miles north northeast of Augusta ME. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU2).

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 501…

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 500. Mean storm motion vector
25035.

…Thompson

SEL2

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 502
NWS Storm Prediction Center Norman OK
115 PM EDT Wed Sep 15 2021

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Western and central Maine
New Hampshire

* Effective this Wednesday afternoon and evening from 115 PM
until 800 PM EDT.

* Primary threats include…
Scattered damaging wind gusts to 70 mph likely
Scattered large hail events to 1.5 inches in diameter possible
A tornado or two possible

SUMMARY…Scattered severe storms are expected to develop this
afternoon and spread west-to-east across New Hampshire into Maine.
The initial storms could be more discrete with some supercell
structures possible, though a gradual evolution into line segments
is expected. Damaging winds of 60 to 70 mph and isolated large hail
of 1 to 1.5 inch diameter will be the most common threats, though a
tornado or two may occur with embedded circulations.

The severe thunderstorm watch area is approximately along and 65
statute miles north and south of a line from 15 miles west of
Lebanon NH to 60 miles north northeast of Augusta ME. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU2).

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 501…

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 500. Mean storm motion vector
25035.

…Thompson

Note: The Aviation Watch (SAW) product is an approximation to the watch area. The actual watch is depicted by the shaded areas.
SAW2
WW 502 SEVERE TSTM ME NH 151715Z – 160000Z
AXIS..65 STATUTE MILES NORTH AND SOUTH OF LINE..
15W LEB/LEBANON NH/ – 60NNE AUG/AUGUSTA ME/
..AVIATION COORDS.. 55NM N/S /35S MPV – 26NW BGR/
HAIL SURFACE AND ALOFT..1.5 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 25035.

LAT…LON 44577260 46066933 44186933 42697260

THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU2.

Watch 502 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 (60%)

Probability of 1 or more wind events > 65 knots

Low (20%)

HailProbability of 10 or more severe hail events

Mod (40%)

Probability of 1 or more hailstones > 2 inches

Low (20%)

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

High (90%)

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.

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