MIL-OSI USA: SPC Severe Thunderstorm Watch 268

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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.
SEL8

URGENT – IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 268
NWS Storm Prediction Center Norman OK
555 PM MDT Mon Jul 9 2018

The NWS Storm Prediction Center has issued a

* Severe Thunderstorm Watch for portions of
Northeast Montana
Northwest and Central North Dakota

* Effective this Monday afternoon from 555 PM until Midnight MDT.

* Primary threats include…
Scattered damaging winds and isolated significant gusts to 75
mph possible
Scattered large hail and isolated very large hail events to 2.5
inches in diameter possible
A tornado or two possible

SUMMARY…The severe threat is expected to increase across northeast
Montana and northwest into central North Dakota. Moderate
instability and strong deep-layer shear along with steep mid-level
lapse rates will be favorable for supercells with large hail. Some
significant hail greater than 2 inches in diameter and wind damage
will be possible. An isolated tornado threat will also accompany the
stronger supercells.

The severe thunderstorm watch area is approximately along and 40
statute miles north and south of a line from 60 miles west northwest
of Williston ND to 20 miles north northeast of Garrison ND. For a
complete depiction of the watch see the associated watch outline
update (WOUS64 KWNS WOU8).

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
2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
29035.

…Broyles

Note: The Aviation Watch (SAW) product is an approximation to the watch area. The actual watch is depicted by the shaded areas.
SAW8
WW 268 SEVERE TSTM MT ND 092355Z – 100600Z
AXIS..40 STATUTE MILES NORTH AND SOUTH OF LINE..
60WNW ISN/WILLISTON ND/ – 20NNE N60/GARRISON ND/
..AVIATION COORDS.. 35NM N/S /52WNW ISN – 21S MOT/
HAIL SURFACE AND ALOFT..2.5 INCHES. WIND GUSTS..65 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 29035.

LAT…LON 49080483 48500126 47340126 47930483

THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU8.

Watch 268 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 (F2-F5) tornadoes

Low ( 65 knots

Mod (30%)

HailProbability of 10 or more severe hail events

Mod (40%)

Probability of 1 or more hailstones > 2 inches

Mod (40%)

Combined Severe Hail/WindProbability 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% (F2-F5 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.

MIL OSI USA News

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