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 618
NWS STORM PREDICTION CENTER NORMAN OK
245 PM MDT FRI JUL 24 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF
WESTERN MONTANA
EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 245 PM UNTIL
1000 PM MDT.
HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.
THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65
STATUTE MILES EAST AND WEST OF A LINE FROM 45 MILES NORTH OF
KALISPELL MONTANA TO 20 MILES SOUTHEAST OF DILLON MONTANA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU8).
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 616...WW 617...
DISCUSSION...UPPER LOW OVER ERN WA WAS RESULTING IN STRONGLY
DIFFLUENT FLOW ALOFT ACROSS WRN MT. THE STORMS ARE EXPECTED TO
DEVELOP NWWD AND ALSO INTENSIFY THROUGH THE EVENING HOURS. ALTHOUGH
INSTABILITY IS NOT PARTICULARLY STRONG...MLCAPES AROUND 1000
J/KG...DEEP LAYER SHEAR NEAR 40 KT AND THE STRONG FORCING SHOULD
SUPPORT A FEW SUPERCELLS WITH THE POTENTIAL FOR LARGE HAIL AND ALSO
DAMAGING WINDS.
AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. MEAN STORM
MOTION VECTOR 24020.
...IMY
Note:
The Aviation Watch (SAW) product is an approximation to the watch area.
The actual watch is depicted by the shaded areas.
SAW8
WW 618 SEVERE TSTM MT 242045Z - 250400Z
AXIS..65 STATUTE MILES EAST AND WEST OF LINE..
45N GPI/KALISPELL MT/ - 20SE DLN/DILLON MT/
..AVIATION COORDS.. 55NM E/W /46N FCA - 17SE DLN/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 450. MEAN STORM MOTION VECTOR 24020.
LAT...LON 48951281 45041093 45041358 48951568
THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU8.
Watch 618 Status Report Messages:
STATUS REPORT #3 ON WW 618
VALID 250025Z - 250140Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 N SMN TO
45 WNW GTF.
..SMITH..07/25/09
ATTN...WFO...TFX...MSO...
&&
STATUS REPORT FOR WS 618
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC001-007-013-023-031-039-043-045-049-057-059-077-093-250140-
MT
. MONTANA COUNTIES INCLUDED ARE
BEAVERHEAD BROADWATER CASCADE
DEER LODGE GALLATIN GRANITE
JEFFERSON JUDITH BASIN LEWIS AND CLARK
MADISON MEAGHER POWELL
SILVER BOW
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #2 ON WW 618
VALID 242335Z - 250040Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 N SMN TO
30 NE MSO TO 35 SSW GPI TO 30 NNE 3TH.
..SMITH..07/24/09
ATTN...WFO...TFX...MSO...
&&
STATUS REPORT FOR WS 618
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC001-007-013-023-029-031-035-039-043-045-047-049-053-057-059-
073-077-093-099-250040-
MT
. MONTANA COUNTIES INCLUDED ARE
BEAVERHEAD BROADWATER CASCADE
DEER LODGE FLATHEAD GALLATIN
GLACIER GRANITE JEFFERSON
JUDITH BASIN LAKE LEWIS AND CLARK
LINCOLN MADISON MEAGHER
PONDERA POWELL SILVER BOW
TETON
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
STATUS REPORT #1 ON WW 618
VALID 242250Z - 242340Z
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N SMN TO
30 NE MSO TO 35 SSW GPI TO 30 NNE 3TH.
..SMITH..07/24/09
ATTN...WFO...TFX...MSO...
&&
STATUS REPORT FOR WS 618
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MTC001-007-013-023-029-031-035-039-043-045-047-049-053-057-059-
073-077-093-099-242340-
MT
. MONTANA COUNTIES INCLUDED ARE
BEAVERHEAD BROADWATER CASCADE
DEER LODGE FLATHEAD GALLATIN
GLACIER GRANITE JEFFERSON
JUDITH BASIN LAKE LEWIS AND CLARK
LINCOLN MADISON MEAGHER
PONDERA POWELL SILVER BOW
TETON
$$
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
$$
Note:
Click for Complete Product Text.
Tornadoes
Probability of 2 or more tornadoes
|
Low (20%)
|
Probability of 1 or more strong (F2-F5) tornadoes
|
Low (5%)
|
Wind
Probability of 10 or more severe wind events
|
Low (20%)
|
Probability of 1 or more wind events > 65 knots
|
Mod (30%)
|
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 (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.
weather.gov 
