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Area forecast discussion 
National Weather Service Spokane Washington
429 PM PDT Wed Jul 27 2016

Synopsis...
dry and hot weather is expected Thursday and Friday. A cold front
arrives this weekend, bringing breezy conditions and cooler
weather for the start of next week.

&&

Discussion...

Evening update: T-storms have been trimmed back for much of the
region. The boundary layer is very warm and moist but there looks
to be too much cin and not enough forcing to break this stable
layer. If we do see any storms, they will be isolated in nature.

My only concern will be if 1-2 storms do fire, outflow boundaries
could work against my reasoning but for the time being, hi-res
modeling, satellite, and lack of radar returns suggest most
T-storm activity will skirt far NE Washington and north Idaho.

The main threats with any storms will be heavy rainfall but a few
stronger cells may strengthen enough for small hail and gusty
winds near 35 mph. Any activity will wane near sunset with mostly
clear skies, light winds, and mild temperatures overnight. /Sb

Thursday through Saturday night...weak and rather flat dirty
ridging shows some amplification to allow for a continued general
warming and drying trend that peaks on Friday and has a tendency
to keep the storm track pushed up north to within close proximity
of the southern British Columbia. This changes as a cold front
passes through late Friday night into Saturday allowing for breezy
conditions and cooling apparent in the cooler daytime highs
forecast for Saturday.

Sunday through wednesday: the upper level low and associated cold
front will continue on the southeastward track out of British Columbia on
Sunday. Models are in good agreement on the timing, but the European model (ecmwf)
amplifies the trough a bit more giving better precip chances for
the north. The main story with this low's passage will be the
winds, though, as moisture will be lacking by the weekend. Pwats
drop by nearly half from a few days prior under increasingly dry
westerly mid level flow, leaving very little from which we will
see any precip. One region which could see some convection will be
along the mountains of our northern border, where enough moisture
and instability will exist to see some scattered showers and even
a thunderstorm during the day Sunday. Potential for elevated fire
conditions exists Sunday as winds will be breezy following the
cold frontal passage, combined with borderline relative humidity levels, it will
be something to watch in the coming days.

Monday brings a brief respite as a weak ridge builds in,
sandwiched between two quick moving troughs, but doesn't stick
around long before a second upper low swings through sometime late
Monday into Tuesday. Models aren't in good agreement on the timing
yet but the late Monday into early Tuesday time frame looks most
likely. The 500mb cold pool moves over and destabilizes the
northern part of the region and by the afternoon, returning the
chance of showers and thunderstorms to the northern mountains.
Winds will be gusty on Tuesday as well with the frontal passage,
meaning enhanced fire conditions will be possible. Temperatures
Sunday through the early week will be significantly cooler than
the 90s of this week, only reaching the upper 70s to mid 80s.
/Bwilliams

&&

Aviation...
00z tafs: overall a quieter evening in store compared to last
night. A couple mountain showers are expected with a slight chance
of thunderstorms. These will die down around sunset with the loss
of daytime heating. For Thursday afternoon cumulus may build up
into an isolated thunderstorm mainly for the mountains surrounding
the Methow Valley. For the taf sites...expect clear to mostly
clear skies and VFR conditions through Thursday afternoon. Jw

&&

Preliminary point temps/pops...
Spokane 65 93 68 94 64 89 / 10 0 0 0 0 0
Coeur D'Alene 63 92 63 93 61 88 / 10 10 0 0 0 0
Pullman 56 92 57 93 57 88 / 0 0 0 0 0 0
Lewiston 72 99 69 100 67 97 / 0 0 0 0 0 0
Colville 58 95 60 95 55 91 / 10 10 0 0 0 0
Sandpoint 57 88 57 89 55 85 / 20 10 0 0 0 0
Kellogg 58 89 57 90 57 85 / 20 10 0 0 0 0
Moses Lake 65 98 66 99 61 92 / 0 0 0 0 0 0
Wenatchee 70 98 70 98 66 89 / 0 0 0 0 0 0
Omak 65 97 68 98 64 92 / 10 10 0 0 0 0

&&

Otx watches/warnings/advisories...
Idaho...none.
Washington...none.
&&

$$

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