Severe Thunderstorm Warning 24, NWS Great Falls, MT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
549 PM MDT Thu Jul 3 2014

.DISCUSSION...
Thursday through Saturday...Potential for strong and severe
thunderstorms Thursday Afternoon remains on track as a weak
disturbance and associated jet streak moves across the area.
Soundings appear to show a dry lower layer of the atmosphere and
moisture mid and upper levels conducive to an enhanced wind
threat from storms...while the lapse rates are steep through the
dry layers...modest moist lapse rates above limit cape through
the best sections of the hail growth zone. Therefore the best
chance for severe threats will be due to damaging winds through
the evening hours. The best chance for convection generally
remains in area south of a line from Great Falls to
Havre...including Southwest Montana. Dry and relatively quiet
conditions are expected for Friday and Saturday with temperatures
climbing to near 90 in some locations. Convective based storms
will be possible but should be isolated to the mountains. Suk

Saturday night through Thursday...The forecast models during this
timeframe are in good agreement with the large scale features, but
there are some minor differences in the details. Have therefore
avoided going with major temperature swings (as the ECMWF model is
indicating) and have gone with more of a trend forecast at this
time. In the wake of a weak shortwave trough, the upper level high
pressure ridge will rebuild into the area, but its axis will remain
over the Pacific Northwest. This will put the area under a
west-northwesterly flow aloft through the period, which will cause
minor cooling across the area. However, high temperatures will
mostly remain in the 80s at most lower elevations with lows in the
mid to upper 50s. The warmest temperatures will be at the beginning
of the period. A weak disturbance will bring a slight chance of
showers/thunderstorms to the Canadian border area for Sunday into
Sunday night. As the flow aloft becomes more northwesterly, a series
of disturbances with associated weak moisture will move over the
state. Have therefore kept at least a slight chance of
showers/thunderstorms over most of the area through the remainder of
the period. Because this is a less unstable pattern than a more
southwesterly flow aloft, am not expecting the storms to become
strong/severe at this time.
Coulston

&&

.AVIATION...
UPDATED 2347Z.
The air mass over Central Montana will remain unsettled as a low
pressure system over the Eastern Pacific slowly moves east.
Showers and thunderstorms will diminish this evening as a shortwave
moves east of the region. The airmass will become unstable again
Friday afternoon and afternoon showers and thunderstorms will
develop. Local MVFR conditions are possible near thunderstorms along
with strong...erratic gusts. Elsewhere, VFR conditions will prevail
through the next 24 hours.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  60  90  60  90 /  40  10  20  10
CTB  56  86  58  83 /  20  10  10  10
HLN  60  91  62  91 /  40  20  20  10
BZN  54  90  56  92 /  40  10  10  10
WEY  43  81  45  83 /  50  20  10  10
DLN  53  87  55  87 /  30  10  10  10
HVR  60  92  59  91 /  40  10  10  10
LWT  57  88  58  88 /  70  20  20  20

&&

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

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PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
524 PM MDT THU JUL 03 2014

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

0345 PM     HAIL             TOWNSEND                46.32N 111.52W
07/03/2014  E0.70 INCH       BROADWATER         MT   PUBLIC

&&

UTTECH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
528 PM MDT THU JUL 03 2014

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

0300 PM     HAIL             5 SE HOBSON             46.95N 109.80W
07/03/2014  E0.50 INCH       JUDITH BASIN       MT   TRAINED SPOTTER

&&

UTTECH

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
539 PM MDT THU JUL 3 2014

MTZ015-052-053-055-040045-
BROADWATER MT-GALLATIN MT-JEFFERSON MT-MADISON MT-
539 PM MDT THU JUL 3 2014

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN GALLATIN...NORTHERN
MADISON...SOUTHEASTERN JEFFERSON AND SOUTHWESTERN BROADWATER COUNTIES
UNTIL 645 PM MDT...

AT 536 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 11 MILES EAST OF WHITEHALL...OR 27 MILES
SOUTHEAST OF BOULDER...MOVING EAST AT 25 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...
   THREE FORKS...
   TRIDENT...

IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.

LAT...LON 4603 11182 4616 11142 4592 11133 4570 11212
      4590 11218
TIME...MOT...LOC 2339Z 251DEG 22KT 4590 11184

UTTECH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
658 PM MDT THU JUL 03 2014

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

0545 PM     FLASH FLOOD      3 E WHITEHALL           45.87N 112.03W
07/03/2014                   JEFFERSON          MT   LAW ENFORCEMENT

            STANDING WATER WAS REPORTED ON HIGHWAY 69 WHERE I-90
            CROSSES OVERHEAD...THE FLOODING WAS ESTIMATED TO BE
            AFFECTING A 20 FOOT SPAN OF THE HIGHWAY

&&

UTTECH

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