Special Weather Statement, NWS Spokane, WA

Area Forecast Discussion
National Weather Service Spokane WA
208 PM PDT SAT AUG 2 2014

.SYNOPSIS...
Very warm conditions will continue, with isolated to scattered
showers and thunderstorms through Sunday. The storms may result in
some localized heavy downpours and small hail. A slight cooling
trend will occur next week but temperatures will remain above
normal.

&&

.DISCUSSION...
Tonight and Sunday...Another active afternoon of thunderstorm
activity has enveloped the region with the lion's share of storms
concentrated over the mountains ringing the Columbia Basin...but
surface based convection is blossoming over the lower Columbia
basin near the Tri Cities and some of this will likely move up
into the northern basin during the late afternoon and early
evening hours...leaving just about every location in the forecast
area under threat for a thunderstorm this evening...although for any
particular location in the basin the chance will be low. These
storms will less vicious animals than the damaging squall line of
last week. In addition to the lightning brief heavy downpours and
small hail will be the main threat...with local 30 to 40 mph gusts
possible near the cores but not common.

This activity is in response to a surge of monsoonal moisture
into a hot and unstable air mass aggravated and driven by a weak
upper level wave pushing into the Washington coast. Models are in
decent agreement in carrying this offending wave across northwest
Washington tonight. Normally convection would taper off after
sunset but the dynamic support aloft along with a continued highly
unstable mid level layer will likely promote active but somewhat
diminished convection well into the evening.

On Sunday the main difference over today's air mass will be a
shifting of deep monsoonal moisture over to the eastern and
northern reaches of the forecast area and less dynamic forcing.
The air mass will continue to be hot and unstable...but the
aforementioned factors should serve to keep the thunderstorm
activity more confined to the mountains north of the basin and the
Idaho Panhandle...with some relief for the Cascades active fire
areas which have been hit hard with storms the last two
days...although a small chance of mountain oriented storms will
continue over the north Cascades near the Canadian Border.

Thus...in short...an active evening for garden variety thunderstorms
will decrease but not end overnight. Continued hot conditions
expected on Sunday with thunderstorms still present but confined
to the mountains and the Idaho Panhandle. /Fugazzi

Sunday night through Tuesday: The Inland NW transitions to a less
active weather pattern, with hot weather. Between Sunday night and
Monday one shortwave will track out through NE WA/N ID, while
shortwave ridging builds in from the west. Shower/thunder chances
will linger across the northeast half of WA and north ID early
Sunday night. Then the loss of daytime heating shifts the primary
threat into the northern Panhandle overnight into Monday morning,
where some elevated instability lingers.

Monday afternoon the tail of the exiting shortwave will have some
renewed instability in the daytime heating to keep at least a
isolated thunder threat alive. At the same time an area of low
pressure moves up from the Desert Southwest. Energy orbiting that
low skirts southeastern Washington and the lower Panhandle late
Monday afternoon, Monday night and Tuesday. This will bring some
shower/thunderstorm chances to the Blue Mountains and Camas
Prairie into the central Panhandle Mountains. Some cannot be ruled
out over the L-C Valley and higher Palouse on Monday, residing in
the RRQ of the exiting jet streak. Overall the better precipitation
threat with the aforementioned low will remain south of our
forecast area.

For the fire weather community (and others who may be
interested), guidance suggests an increased north to northwest
drainage and gradient winds near the Cascades and Okanogan valley,
with a thermal trough positioned across the lower Columbia Basin
through east-central WA. Sunday night into Monday morning and
again late Monday night into early Tuesday morning are the prime
periods. At this time sustained speeds look less than 15 mph.

Temperatures are expected to remain above seasonal averages,
supported by 850mb temperatures lingering in the lower to mid 20s
Celsius. /J. Cote'

Tuesday night through Saturday: The longwave blocking pattern
will finally weaken and at least temporarily break down in this
time-frame. This will promote a gradual cooling trend, mostly dry
conditions, and some increased winds. A small precipitation threat
will remain across the far southeastern zones from the Blues to
southeastern Shoshone County early in the period (Tuesday evening-
Wed) as a plume of rich moisture remains entrenched over the
southeastern reaches however, any source of lift is expected to
remain either to the south or north suggested diurnal terrain
circulations/afternoon heating will be the main source of
initiation...which is not extremely favorable for much more then
an isolated cell or two. It is not until Friday when a stronger
shortwave swings through the region (remnants of the Gulf of AK
low)...BUT the air mass looks too dry to support any form of
precipitation thanks to an intrusion of very dry air Thursday.
Consequently, the main concerns/impacts Thursday through Saturday
will be dry conditions and breezy winds, especially through the
Cascade Gaps. Breezy conditions should also spread across the
Basin on Friday with the passage of the dry cold front.
Temperatures will peak Wednesday and gradually cool through the
end of the week. This will equate to high temperatures in the mid
to upper 90's Wednesday...cooling into 80's to lower 90's by the
end of the week. Looking out into next week, models in some form
or another hint at the current pattern rebounding...which if this
occurs will be another hot period. /sb

&&

.AVIATION...
18Z TAFS: A series of weather disturbances will continue to impact
the Inland NW. One is exiting through NE WA and NE ID this morning,
responsible for a few TSRA north of DEW. Afternoon heating and
revitalized instability and another disturbance moving into the
Cascades this afternoon, then across eastern WA and north ID
later tonight into Sunday morning, will bring the potential for
TSRA around TAF sites. One chance comes through afternoon 19-03Z
and again late in the evening and overnight, after 05-07Z into the
morning hours with some elevated instability. The confidence
associated isolated to scattered convection allows for VCTS,
however radar will be monitored and TAFs will be updated when more
specifics are ascertained. /J. Cote'

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        67  94  66  96  67  94 /  30  10  20  10  10  10
Coeur d'Alene  61  93  62  94  62  92 /  40  20  20  10  10  10
Pullman        58  93  58  94  58  91 /  30  10  10  20  20  10
Lewiston       70  99  71 100  71  98 /  30  10  10  20  20  10
Colville       59  96  59  98  59  97 /  40  20  30  10  10  10
Sandpoint      55  89  55  91  55  90 /  40  20  20  20  10  10
Kellogg        61  89  62  91  62  87 /  40  30  20  20  20  20
Moses Lake     65 100  66 101  66 100 /  20  10  10  10  10   0
Wenatchee      72  99  72 101  73  99 /  20  10  10  10  10  10
Omak           67  99  66 101  68 101 /  30  10  20  10  10  10

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Red Flag Warning until 11 PM PDT this evening for East
     Washington Central Cascade Mountains (Zone 682)-East
     Washington Central Cascade Valleys (Zone 677)-East
     Washington North Cascades (Zone 685)-East Washington
     Okanogan/Methow Valleys (Zone 684).

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SPOKANE WA
444 AM PDT SAT AUG 2 2014

IDZ001>004-026-027-WAZ031>038-041>044-031400-
NORTHERN PANHANDLE-COEUR D'ALENE AREA-IDAHO PALOUSE-
CENTRAL PANHANDLE MOUNTAINS-LEWISTON AREA-
LEWIS AND SOUTHERN NEZ PERCE COUNTIES-NORTHEAST BLUE MOUNTAINS-
LOWER GARFIELD AND ASOTIN COUNTIES-WASHINGTON PALOUSE-
MOSES LAKE AREA-UPPER COLUMBIA BASIN-SPOKANE AREA-
NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-WENATCHEE AREA-
EAST SLOPES NORTHERN CASCADES-OKANOGAN VALLEY-WATERVILLE PLATEAU-
444 AM PDT SAT AUG 2 2014

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH IDAHO...
NORTH CENTRAL IDAHO...CENTRAL WASHINGTON...EAST CENTRAL
WASHINGTON...NORTH CENTRAL WASHINGTON...NORTHEAST WASHINGTON AND
SOUTHEAST WASHINGTON.

.DAY ONE...TODAY AND TONIGHT

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
202 PM PDT SAT AUG 2 2014

WAZ038-022130-
OKANOGAN HIGHLANDS-
202 PM PDT SAT AUG 2 2014

...A STRONG THUNDERSTORM WILL AFFECT OKANOGAN HIGHLANDS...

AT 200 PM PDT...A STRONG THUNDERSTORM WAS 15 MILES WEST OF SHERMAN
PASS...OR ALONG THE FERRY...OKANOGAN COUNTY BORDER OVER HIGHWAY
20...MOVING NORTHEAST AT 25 MPH.

WINDS IN EXCESS OF 40 MPH AND HALF INCH HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
REPUBLIC AND CURLEW LAKE STATE PARK.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

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 4861 11887 4865 11892 4880 11877 4872 11853
TIME...MOT...LOC 2100Z 236DEG 20KT 4867 11881

SB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
207 PM PDT SAT AUG 2 2014

WAZ042-022145-
EAST SLOPES NORTHERN CASCADES-
207 PM PDT SAT AUG 2 2014

...A STRONG THUNDERSTORM WILL AFFECT EAST SLOPES NORTHERN CASCADES...

AT 206 PM PDT...A STRONG THUNDERSTORM WAS 17 MILES EAST OF
STEHEKIN...OR 5 MILES WEST OF TWISP...MOVING NORTH AT 25 MPH.

WINDS IN EXCESS OF 30 MPH AND NICKEL SIZE HAIL ARE POSSIBLE WITH THIS
STORM.

LOCATIONS IMPACTED INCLUDE...
WINTHROP...BLACK PINE LAKE CAMPGROUND...MEMORIAL CAMPGROUND...NICE
CAMPGROUND...FLAT CAMPGROUND...FALLS CREEK CAMPGROUND AND WAR CREEK
CAMPGROUND.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

LAT...LON 4830 12025 4835 12047 4869 12031 4860 11997
TIME...MOT...LOC 2106Z 201DEG 25KT 4840 12031

FLIEHMAN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
224 PM PDT SAT AUG 2 2014

WAZ038-022200-
OKANOGAN HIGHLANDS-
224 PM PDT SAT AUG 2 2014

...A STRONG THUNDERSTORM WILL AFFECT OKANOGAN HIGHLANDS...

AT 223 PM PDT...A STRONG THUNDERSTORM WAS 15 MILES NORTH OF SHERMAN
PASS...OR OVER MALO...MOVING NORTHEAST AT 30 MPH.

WINDS IN EXCESS OF 35 MPH AND HALF TO THREE QUARTER INCH HAIL ARE
POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
MALO.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY CAUSE
LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

LAT...LON 4893 11822 4891 11820 4890 11820 4889 11821
      4876 11864 4881 11869 4897 11832
TIME...MOT...LOC 2123Z 242DEG 26KT 4884 11847

SB

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SPOKANE WA
231 PM PDT SAT AUG 2 2014

WAZ042-043-022230-
EAST SLOPES NORTHERN CASCADES WA-OKANOGAN VALLEY WA-
231 PM PDT SAT AUG 2 2014

...SIGNIFICANT WEATHER ADVISORY FOR NORTH CENTRAL OKANOGAN COUNTY
UNTIL 330 PM PDT...

AT 229 PM PDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 20
MILES NORTHWEST OF OMAK... MOVING NORTHEAST AT 20 MPH.

NICKEL SIZE HAIL AND WINDS IN EXCESS OF 30 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
SALMON MEADOWS CAMPGROUND...ALDER CAMPGROUND AND LOOMIS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 4858 11974 4866 11987 4900 11961 4883 11936
TIME...MOT...LOC 2129Z 230DEG 17KT 4868 11970

COTE