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Area forecast discussion 
National Weather Service Spokane Washington
233 am PDT Thursday Sep 18 2014

Synopsis...
a weak cold front will move through Washington and Idaho today.
The front will push temperatures closer to normal and bring the
potential for widely scattered showers. A strong high pressure
ridge will return Friday and promote warm and dry weather through
the weekend. High temperatures Sunday should be ten degrees above
normal. The breakdown of this ridge...and a return to cooler
conditions...will begin Monday. However...precipitation is not
expected until late Tuesday or Wednesday for most towns.

&&

Discussion...
today and tonight...scattered showers will develop across the
inland northwest today as moisture continues to stream into the
region from the southwest. So far the light radar returns on
regional radar mosaic have not resulted in any precipitation
reports from observation sites across the forecast area. The dry
lower levels of the atmosphere, as seen on 00z otx sounding, will
take a while to moisten up. The best chance of showers across the
area will be this afternoon as the cold front and shortwave trough
slide across the region. Modest instability may allow isolated
thunderstorms to develop across extreme eastern Washington and the
Panhandle of Idaho. As daytime instability increases this
afternoon, bulk shear decreases substantially so organized storm
cells are not anticipated. Winds will increase behind the cold
front, with gusts of 25 to 30 mph common from the Cascade Gap
valleys, across the basin and into the Palouse and West Plains.
Daytime temperatures will be somewhat cooler for the western zones
but pretty close to wednesday's readings for extreme eastern Washington
and north Idaho. Overnight temperatures tonight will remain above
normal thanks to gusty winds behind the front. /Kelch

Fri through Mon nt: with a rapidly building upper ridge Fri
through the weekend, we're not expecting any pcpn as large-scale
subsidence/warming aloft accompanies clear skies and light winds.
Fri morning should be the coolest morning, with some NE WA and north
Idaho valleys seeing some patchy fog. The warmest day should be
Sunday with high temps generally in the 80s... 10 degrees warmer
than normal for a number of towns. The breakdown of the
ridge...and the approach of a strong ern Pacific trough...still
looks to be on track for the Mon through Tue time frame. Based on
trends in model guidance, the lack of sufficient instability, and
a deep sub-cloud dry lyr, the first minor wave that ejects from
the offshore trough tues morning is not expected to produce any
pcpn outside of the mtns across the east slopes of the Cascades.Bz

Tuesday through thursday: a cold front will be pushing through the
region during this period bringing a small taste of autumn along
with it. Poor consistency among the models is keeping the exact
timing of the front a little unclear. It is expected to a chance
of precip to the entire inland northwest and temperatures will
decrease around 10 degrees from the beginning of the period. /Jdc

&&

Aviation...
06z tafs: a moist southwest flow and incoming cold front/upper
trough impact the inland NW, providing increased cloud cover and
the threat of a few showers. The best shower chances will be near
the Cascades, including eat, and over the northeast mountains
going into later tonight into Thursday. A threat will come up
through the Blue Mountain and toward the central Panhandle of Idaho
late overnight into Thursday morning, potentially near lws and puw
between 09-15z. Other chances will be found in the vcnty of geg to
Coe in the afternoon with the passing front. There is also the
slight risk for -tsra across the mountains of far eastern Washington and north
Idaho. Expect increased winds Thursday afternoon, with gusts in the
20 to 25kt range, locally higher near eat. Winds will gradually
abate after Thursday evening (after 02-04z). /J. Cote'




&&

Preliminary point temps/pops...
Spokane 80 55 76 48 81 52 / 20 10 0 0 0 0
Coeur D'Alene 79 54 76 46 80 49 / 30 20 10 0 0 0
Pullman 81 53 76 45 81 49 / 20 10 0 0 0 0
Lewiston 86 60 82 53 86 55 / 20 10 0 0 0 0
Colville 83 52 80 45 84 47 / 40 20 10 0 0 0
Sandpoint 75 47 74 39 78 44 / 40 30 10 10 0 0
Kellogg 77 53 73 46 78 46 / 30 20 10 0 0 0
Moses Lake 85 57 84 49 85 53 / 10 0 0 0 0 0
Wenatchee 82 61 83 54 84 55 / 20 10 0 0 0 0
Omak 82 55 82 48 85 49 / 30 10 0 0 0 0

&&

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

$$

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