Severe Thunderstorm Warning 20, NWS Great Falls, MT

328 
WWUS55 KTFX 130518
SVSTFX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1118 PM MDT THU JUN 12 2014

MTC013-015-099-130545-
/O.CON.KTFX.SV.W.0020.000000T0000Z-140613T0545Z/
CASCADE MT-CHOUTEAU MT-TETON MT-
1118 PM MDT THU JUN 12 2014

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT FOR EAST CENTRAL
TETON...WEST CENTRAL CHOUTEAU AND NORTH CENTRAL CASCADE COUNTIES
UNTIL 1145 PM MDT...

AT 1116 PM MDT...A SEVERE THUNDERSTORM WAS LOCATED 9 MILES SOUTHEAST
OF POWER...AND MOVING NORTHEAST AT 40 MPH.

HAZARD...GOLF BALL SIZE HAIL AND 60 MPH WIND GUSTS.

SOURCE...TRAINED WEATHER SPOTTERS.

IMPACT...PEOPLE AND ANIMALS OUTDOORS WILL BE INJURED. EXPECT HAIL
         DAMAGE TO ROOFS...SIDING...WINDOWS AND VEHICLES. EXPECT WIND
         DAMAGE TO ROOFS...SIDING AND TREES.

THE SEVERE THUNDERSTORM WILL AFFECT MAINLY RURAL AREAS OF EAST
CENTRAL TETON...NORTH CENTRAL CASCADE AND WEST CENTRAL CHOUTEAU
COUNTIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

PREPARE IMMEDIATELY FOR LARGE HAIL AND DEADLY CLOUD TO GROUND
LIGHTNING. SEEK SHELTER INSIDE A WELL-BUILT STRUCTURE. STAY AWAY FROM
WINDOWS.

&&

LAT...LON 4752 11169 4767 11179 4792 11125 4763 11098
TIME...MOT...LOC 0518Z 241DEG 34KT 4764 11153

HAIL...1.75IN
WIND...60MPH

$$

MLV

800 
WWUS55 KTFX 130541
SVSTFX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1141 PM MDT THU JUN 12 2014

MTC013-015-099-130551-
/O.EXP.KTFX.SV.W.0020.000000T0000Z-140613T0545Z/
CASCADE MT-CHOUTEAU MT-TETON MT-
1141 PM MDT THU JUN 12 2014

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL TETON...WEST
CENTRAL CHOUTEAU AND NORTH CENTRAL CASCADE COUNTIES WILL EXPIRE AT
1145 PM MDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY.
HOWEVER...SMALL HAIL IS STILL POSSIBLE WITH THIS THUNDERSTORM.

LAT...LON 4752 11169 4767 11179 4792 11125 4763 11098
TIME...MOT...LOC 0541Z 243DEG 37KT 4775 11121

$$

MLV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
1045 PM MDT Thu Jun 12 2014

UPDATED AVIATION DISCUSSION

.UPDATE...
Some minor changes to the forecast tonight. Mostly just raising
POP along the northern Rockies to reflect current radar imagery.
Showers and thunderstorms should continue to move to the north
through the night and may even continue into the morning. Overall
a showery pattern is expected with convective activity returning
Friday afternoon.

&&

.AVIATION...
UPDATED 0500Z.
Showers and thunderstorms will continue to track NE across western
portions of N-central MT throughout tonight. Some storms will bring
local/short duration MVFR conditions and mtn obscuration with small
hail/strong wind gusts possible with strongest cells.
Showers/T-storms will continue late into the night near the
KHLN-KGTF-KHVR-KCTB terminals as an upper level trough of low
pressure moves into the Northern Rockies and an associated surface
trough moves across central MT. Surface winds from the east to
southeast will shift to west and northwest Friday morning behind the
surface trough with a period of gusty winds likely and scattered to
numerous showers redeveloping over much of the area Friday
afternoon.  Hoenisch

&&

.PREV DISCUSSION...
/ISSUED 600 PM MDT Thu Jun 12 2014/

Tonight through Saturday...Upper ridge axis moves to eastern
Montana this evening in response to a strong upper trof moving
into the Pacific Northwest. This sets up increasing diffluent
Southwest flow aloft that will bring moisture and instability to
southwest Montana. Thunderstorms will develop late this afternoon
over the southwest and then move north and east. The best dynamics
for the strongest storms is likely west of Interstate 15. CAPE
values of 700-1200 J/kg are forecast for this area along with
better than 50 knots of bulk shear. It also appears storms will
likely develop between 00z and 03z. As the upper trof continues to
push further east overnight, areas of rain and isolated
thunderstorms will likely persist, By Friday, the area will be
under the influence of the trof with scattered showers and
thunderstorms continuing throughout the day and evening. Back
circulation from the upper trof as it moves east on Saturday will
continue to provide moisture and instability in the form of
scattered showers and thunderstorms. Temperatures will remain
below seasonal averages with Saturday's readings some 10 to 12
degrees below seasonal averages.

Saturday night through Thursday...An interesting divergence in model
solutions for the long term as models continue to struggle with the
progression of a low pressure disturbance transitioning from the
Gulf of Alaska to the Pacific Northwest. GFS solution tries restart
the progressive zonal flow and quickly propels the disturbance out
of the area by Tuesday evening. The ECMWF and GEM both retrograde
and deepen the low over the rocky mountains and allow for it to
produce significantly more precipitation over the region through the
bulk of the long term. There is some credence for the GFS solution
as the ECMWF ensemble suite does also move the system out faster
than the operation model, but still slower than the GFS. Have leaned
towards the cooler and wetter solution of the ECMWF, however did
reduce pops slightly below model solutions due to the lack of
confidence. Regardless of the inconsistencies in the extreme long
term, this weekend does look to be unsettled as all models continue
to have diffluent flow and multiple impulses move across the area
through Tuesday. Temperatures are expected to remain near or below
seasonal averages through the extended. Suk

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  47  67  43  62 /  40  30  30  40
CTB  47  63  41  62 /  70  50  30  50
HLN  50  71  44  65 /  30  30  30  40
BZN  45  70  40  62 /  20  60  60  40
WEY  37  65  30  58 /  10  40  40  50
DLN  46  67  38  62 /  20  50  50  40
HVR  47  71  43  66 /  40  40  30  40
LWT  45  67  40  60 /  20  40  50  40

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

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SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1012 PM MDT THU JUN 12 2014

MTZ012-013-049-130515-
CASCADE MT-CHOUTEAU MT-EASTERN TETON MT-
1012 PM MDT THU JUN 12 2014

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN TETON...EXTREME
WESTERN CHOUTEAU AND NORTHWESTERN CASCADE COUNTIES UNTIL 1115 PM
MDT...

AT 1010 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A STRONG THUNDERSTORM NEAR FORT SHAW...OR 13 MILES NORTH OF
CASCADE...MOVING NORTHEAST AT 35 MPH.

HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

* LOCATIONS IMPACTED INCLUDE...
   VAUGHN...
   SUN PRAIRIE...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4767 11095 4734 11176 4762 11206 4767 11205
      4787 11180
TIME...MOT...LOC 0412Z 234DEG 38KT 4747 11172

HOENISCH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1037 PM MDT THU JUN 12 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1030 PM     HAIL             SUN PRAIRIE             47.54N 111.48W
06/12/2014  E0.88 INCH       CASCADE            MT   TRAINED SPOTTER

            PEA TO NICKEL SIZED HAIL AND VERY INTENSE LIGHTNING.

&&

HOENISCH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1055 PM MDT THU JUN 12 2014

MTZ012-130545-
CASCADE MT-
1055 PM MDT THU JUN 12 2014

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CASCADE COUNTY UNTIL
1145 PM MDT...

AT 1050 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A STRONG THUNDERSTORM 6 MILES WEST OF FORT SHAW...OR 18 MILES
NORTHWEST OF CASCADE...MOVING NORTHEAST AT 35 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

* LOCATIONS IMPACTED INCLUDE...
   FORT SHAW...
   SUN RIVER...
   VAUGHN AND  SUN PRAIRIE...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4758 11122 4736 11199 4745 11205 4752 11204
      4750 11193 4761 11191 4761 11167 4770 11166
      4770 11143
TIME...MOT...LOC 0455Z 243DEG 29KT 4750 11188

HOENISCH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
1102 PM MDT THU JUN 12 2014

MTZ013-130600-
CHOUTEAU MT-
1102 PM MDT THU JUN 12 2014

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CHOUTEAU COUNTY UNTIL
MIDNIGHT MDT...

AT 1100 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
A STRONG THUNDERSTORM 14 MILES WEST OF FORT BENTON...MOVING NORTHEAST
AT 45 MPH.

HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT
DANGEROUS LIGHTNING.

* LOCATIONS IMPACTED INCLUDE...
   FORT BENTON...
   LOMA...
   BIG SANDY...

THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4828 11003 4786 10971 4761 11103 4762 11104
      4769 11098 4770 11111 4789 11129
TIME...MOT...LOC 0502Z 241DEG 54KT 4778 11091

HOENISCH