Severe Thunderstorm Warning 9, NWS Boise, ID

Area Forecast Discussion
National Weather Service Boise ID
242 PM MDT Mon Oct 24 2016

.SHORT TERM...Tonight through Wednesday...A strong area of low
pressure parked off the Washington and Oregon coast continues to
send a broad swath of moisture over the region. The cold front
associated with the low is finally making eastward progress across
Washington and Oregon. This front is expected to stall over southeast
Oregon and southwest Idaho this evening and overnight. Showers and
isolated thunderstorms have developed and will continue to develop
along and just ahead of the front. These showers and isolated
thunderstorms will be most prevalent during the evening hours
while weak instability lasts. While the best chance for thunder
exists over the higher terrain, generally south of the Snake River
Plain, some strikes and rumbles may make their way northward
across the valley into the central mountains this evening.

Near term models are in good agreement that the front will stall
and weaken over the area tomorrow as the Pacific low tracks north
and mid and upper-level ridging attempts to build over the
intermountain west. This remnant front will serve as the impetus
for shower activity tomorrow into tomorrow evening before lifting
northward as a resurgent warm front ahead of the next Pacific low
tomorrow night into Wednesday. As the front lifts northward the
area will see a drying and warming trend for the remainder of the
day Wednesday with shower activity confined to northern areas and
higher terrain.

.LONG TERM...Wednesday night through Saturday...A moist
southwesterly flow aloft will keep a threat of showers over
southeast Oregon and Idaho's West Central Mountains through
Thursday. As early as Friday morning, a stronger shortwave will
pull out of the southwest and transition across the region,
bringing widespread showers to the whole region. This shortwave
looks to have enough jet support and instability to produce
thunderstorms Friday, but have left this aspect out of the
forecast for now as there are still a few discrepancies between
the models that need to be worked out. Precipitation totals with
any initiated convection could become a concern over the
mountains. Saturday will continue the trend of moist
southwesterly flow aloft, with a threat of showers forecasted
over much of the region. Temperatures will remain above the
seasonal norm through the period under this pattern. Expecting
snow levels between 8500-9500 ft.

Saturday night through Monday...An active pattern through this
period with an upper low sitting off the California coastline
Saturday night advecting moisture into our area with the
southwesterly flow aloft. Chances of precipitation are greatest for
the higher elevations in both SE Oregon and SW Idaho through Sunday
evening. This low slowly tracks northeastward Sunday into early
Monday morning increasing chances of precipitation for valley
locations. Temperatures remain above normal during this time
period.

&&

.AVIATION...VFR. BKN-OVC mid-high level ceilings. Areas of
MVFR and mountain obscuration under lower cloud heights and in rain
showers. Scattered showers across the region with isolated afternoon
thunderstorms over southern southeast Oregon and central and
southwest Idaho, mainly east and south of KBOI 18-00Z. Scattered
showers again Tuesday. Surface winds: generally south to southeast
10-20 kts, with 15-30 kts expected across SE OR and in the Treasure
Valley between KBOI and KMUO, diminishing around 06Z. Winds aloft up
through 10KFT MSL: SE 20-30 kts, becoming 40-50 kts 03-09Z over SE
OR.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

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SHORT TERM...MC
LONG TERM....AB/JC
AVIATION.....AB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BOISE ID
451 PM MDT MON OCT 24 2016

IDZ014-015-242330-
UPPER TREASURE VALLEY ID-SOUTHWEST HIGHLANDS ID-
451 PM MDT MON OCT 24 2016

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL ELMORE AND EAST
CENTRAL OWYHEE COUNTIES UNTIL 530 PM MDT...

AT 450 PM MDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
TWIN BUTTE...OR 38 MILES SOUTHWEST OF GLENNS FERRY...MOVING NORTHEAST
AT 35 MPH.

DIME SIZE HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH THIS
STORM.

THIS STRONG THUNDERSTORM WILL BE NEAR...
  LOOKOUT BUTTE AROUND 510 PM MDT.
  WINTER CAMP BUTTE AND POT HOLE BUTTE AROUND 520 PM MDT.
  CROWS NEST BUTTE AROUND 530 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN SAFE TO DO SO...PLEASE RELAY STORM REPORTS TO THE NATIONAL
WEATHER SERVICE IN BOISE VIA LOCAL LAW ENFORCEMENT...OR NATIONAL
WEATHER SERVICE BOISE FACEBOOK AND TWITTER ACCOUNTS.

&&

LAT...LON 4238 11588 4256 11594 4284 11531 4254 11517
TIME...MOT...LOC 2250Z 243DEG 30KT 4252 11579

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BOISE ID
502 PM MDT MON OCT 24 2016

IDZ014-016-242345-
UPPER TREASURE VALLEY ID-WESTERN MAGIC VALLEY ID-
502 PM MDT MON OCT 24 2016

...SIGNIFICANT WEATHER ADVISORY FOR GOODING...NORTHWESTERN TWIN FALLS
AND SOUTHEASTERN ELMORE COUNTIES UNTIL 545 PM MDT...

AT 501 PM MDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
HAGERMAN...OR 14 MILES SOUTHWEST OF GOODING...MOVING EAST AT 25 MPH.

DIME SIZE HAIL AND WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH THIS
STORM.

THIS STRONG THUNDERSTORM WILL BE NEAR...
  GOODING AND FLAT TOP BUTTE AROUND 540 PM MDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

WHEN SAFE TO DO SO...PLEASE RELAY STORM REPORTS TO THE NATIONAL
WEATHER SERVICE IN BOISE VIA LOCAL LAW ENFORCEMENT...OR NATIONAL
WEATHER SERVICE BOISE FACEBOOK AND TWITTER ACCOUNTS.

&&

LAT...LON 4274 11501 4290 11510 4320 11463 4320 11461
      4317 11459 4286 11460 4285 11459 4285 11446
TIME...MOT...LOC 2301Z 248DEG 22KT 4285 11497

JC