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 398
NWS Storm Prediction Center Norman OK
245 PM MDT Thu Jul 23 2020
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southwest and Central Montana
* Effective this Thursday afternoon and evening from 245 PM until
900 PM MDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Scattered large hail events to 1.5 inches in diameter possible
SUMMARY...Thunderstorms have developed over the mountains of
southwest Montana. These storms will spread northeastward this
afternoon across the watch area, posing a risk of damaging winds and
hail.
The severe thunderstorm watch area is approximately along and 65
statute miles east and west of a line from 50 miles northeast of
Great Falls MT to 50 miles east southeast of Dillon MT. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 395...WW 396...WW 397...
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
25030.
...Hart
SEL8
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 398
NWS Storm Prediction Center Norman OK
245 PM MDT Thu Jul 23 2020
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Southwest and Central Montana
* Effective this Thursday afternoon and evening from 245 PM until
900 PM MDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Scattered large hail events to 1.5 inches in diameter possible
SUMMARY...Thunderstorms have developed over the mountains of
southwest Montana. These storms will spread northeastward this
afternoon across the watch area, posing a risk of damaging winds and
hail.
The severe thunderstorm watch area is approximately along and 65
statute miles east and west of a line from 50 miles northeast of
Great Falls MT to 50 miles east southeast of Dillon MT. 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.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 395...WW 396...WW 397...
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
25030.
...Hart
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW8
WW 398 SEVERE TSTM MT 232045Z - 240300Z
AXIS..65 STATUTE MILES EAST AND WEST OF LINE..
50NE GTF/GREAT FALLS MT/ - 50ESE DLN/DILLON MT/
..AVIATION COORDS.. 55NM E/W /46NE GTF - 43ESE DLN/
HAIL SURFACE AND ALOFT..1.5 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 25030.
LAT...LON 47980920 44961028 44961293 47981201
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU8.
Watch 398 Status Report Messages:
STATUS REPORT #3 ON WW 398
VALID 240000Z - 240140Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 50 NNW COD
TO 15 WSW LWT TO 55 NNE GTF.
..BROYLES..07/23/20
ATTN...WFO...TFX...BYZ...
&&
STATUS REPORT FOR WS 398
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC015-037-095-240140-
MT
. MONTANA COUNTIES INCLUDED ARE
CHOUTEAU GOLDEN VALLEY STILLWATER
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #2 ON WW 398
VALID 232305Z - 240040Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 ENE WEY
TO 15 W 3HT TO 5 NE GTF TO 45 ESE CTB.
..BROYLES..07/23/20
ATTN...WFO...TFX...BYZ...
&&
STATUS REPORT FOR WS 398
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC015-037-045-095-097-107-240040-
MT
. MONTANA COUNTIES INCLUDED ARE
CHOUTEAU GOLDEN VALLEY JUDITH BASIN
STILLWATER SWEET GRASS WHEATLAND
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 398
VALID 232135Z - 232240Z
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
..BROYLES..07/23/20
ATTN...WFO...TFX...BYZ...
&&
STATUS REPORT FOR WS 398
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC001-007-013-015-031-037-045-049-057-059-067-095-097-099-107-
232240-
MT
. MONTANA COUNTIES INCLUDED ARE
BEAVERHEAD BROADWATER CASCADE
CHOUTEAU GALLATIN GOLDEN VALLEY
JUDITH BASIN LEWIS AND CLARK MADISON
MEAGHER PARK STILLWATER
SWEET GRASS TETON WHEATLAND
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Low (<5%)
|
Probability of 1 or more strong (EF2-EF5) tornadoes
|
Low (<2%)
|
Wind
Probability of 10 or more severe wind events
|
Mod (40%)
|
Probability of 1 or more wind events > 65 knots
|
Low (20%)
|
Hail
Probability of 10 or more severe hail events
|
Mod (40%)
|
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 (70%)
|
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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