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Area forecast discussion 
National Weather Service Spokane Washington
427 am PDT sun Jul 5 2015

Synopsis....
hot and dry weather will be featured for the remainder of the
Holiday weekend. Winds will shift from the north to the northeast
as the front moves through the region. Aside from isolated shower
chances toward the Idaho Panhandle, conditions will be dry and
warm into the first half of next week. A slight chance of showers
and thunderstorms returns late next week.




&&

Discussion...
today through Monday...the dry cold front will continue to sag south
across eastern Washington and north Idaho today bringing gusty north
to northeast winds down the northern valleys and into the Columbia
Basin. The air behind this front is very dry, keeping relative
humidity from recovering overnight. The dry and breezy conditions
continue to support a red flag warning for the Okanogan Valley and
Highlands, Waterville Plateau, Columbia Basin and northeast
Washington. There are several ongoing wildfires across the region
and numerous small brushfire starts from Independence day
celebrations. The fire weather highlights will continue through
the afternoon when winds will start to diminish. These gusty winds
could result in blowing dust across the basin. Another concern is
the slight chance of thunderstorms for portions of the northern
Panhandle as the cold front slides south today. Once the cold
front moves off to the southeast, the surface pressure gradient
will relax and winds will diminish below red flag criteria by this
afternoon. At this point, it looks like we will see a break in the
critical fire weather until the next weather system brings a
chance of thunderstorms on Tuesday.

Temperatures will continue the well above normal trend with daytime
readings in upper 80s to upper 90s. Overnight lows will also remain
quite warm, with most valley locations in the 60s with 50s for the
northern valleys. /Kelch

Monday night through Saturday...the models are in good agreement
with the overall pattern through Friday...before some differences
begin to show up. No big changes from what we have been looking at
the past few model runs. A ridge of high pressure in the eastern
Pacific will be anchored to the east by a deep low pressure system
near Hudson Bay and to the west but another deep low just inside
the date line. A few weather disturbances will move through the
pac northwest with the strongest one expected for next weekend.

The first weak wave will eject off the Hudson Bay low and wrap
all the way back to the west and clip the northeast zones on
Tuesday. Model guidance shows enough mid level moisture and
instability to support a chance of showers and thunderstorms along
the Canadian border...but mainly over the northeast Washington and
north Idaho Panhandle mountains. These storms will likely result
in brief moderate showers, occasional lighting and gusty outflow
winds. Some places in north Idaho may get up to an tenth of an
inch of rain which should bring a short respite from the very dry
conditions of late. Temperatures are not expected to cool off by
much and will remain 10 degrees warmer than normal. For the
remainder of the region the forecast will be dry.

Weak high pressure will be over the region on Wednesday for dry
and warm conditions, but by Thursday the flow flattens and
becomes westerly. While this is not expected to result in any
cooling to the temperatures it will likely inject some Pacific
moisture into the region and result in better over night relative
humidity recoveries.

Friday into the weekend is when the models start to show some
differences in an approaching upper level trough. All the models
are showing the trough moving into the eastern Pacific by Friday
afternoon. Through the weekend they all are showing slightly
different solutions on just how deep and fast(slow) to bring the
wave through. Needless to say confidence in any specifics are
lacking. However this is a good shower/thunderstorm pattern and
the southerly flow that sets up will allow deeper sub-tropical
moisture to move into the region. So timing any individual
periods of convection will be difficult. A such I chose to broad
brush the forecast for the time being and just say that there will
be a chance for afternoon and evening showers and thunderstorms
focused along the higher terrain surrounding the Columbia Basin
beginning Friday and lasting through the weekend. This deeper
wave should also result in a cooling trend and periods of
breezy/gusty winds. Tobin

&&

Aviation...
12z tafs: wind speeds 15 to 25 kts with gusts to 30 kts will be
possible, especially toward Coe and mwh this morning. Winds are
expected to slowly decrease later in the day, but gusts toward 20
to 25 kts will be possible even after 18-20z. Expect some
elevated layers of smoke from regional wildfires. All taf sites
will be dry and VFR. /Ek




&&

Preliminary point temps/pops...
Spokane 88 61 92 66 93 66 / 10 0 0 0 10 10
Coeur D'Alene 85 58 90 61 90 61 / 10 10 0 0 10 10
Pullman 89 52 90 56 92 57 / 10 10 0 0 10 10
Lewiston 98 66 97 69 99 68 / 10 10 0 0 0 10
Colville 91 57 95 62 94 60 / 10 0 0 10 20 10
Sandpoint 84 52 88 55 87 54 / 10 10 0 10 30 20
Kellogg 83 53 89 56 88 57 / 10 10 0 0 20 10
Moses Lake 96 66 99 68 101 69 / 0 0 0 0 0 0
Wenatchee 98 71 99 73 100 74 / 0 0 0 0 0 0
Omak 95 61 97 67 98 66 / 0 0 0 10 10 10

&&

Otx watches/warnings/advisories...
Idaho...none.
Washington...red flag warning until 1 PM PDT this afternoon for East
Washington northeast (zone 686).

Red flag warning until 3 PM PDT this afternoon for East
Washington northern Columbia Basin (zone 673)-East
Washington Okanogan Highlands (zone 687)-East Washington
Okanogan/Methow valleys (zone 684).

&&

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