Area Forecast Discussion
Issued by NWS Spokane, WA

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043
FXUS66 KOTX 170957
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
257 AM PDT Wed Oct 17 2018

.SYNOPSIS...
A ridge of high pressure will persist over the Inland Northwest
through the week and into the weekend. This will bring mainly
clear skies, light winds with chilly morning temperatures and
mild afternoons highs. The next chance of precipitation looks like
it could arrive by next Tuesday or Wednesday.


&&

.DISCUSSION...
Today through Thursday night...Strong upper level ridge will
remain the dominant feature through this period. All models are
showing a 582 dm 500 mb ridge centered over the eastern third of
Washington early this morning. Those heights are likely at their apex
over the Inland NW as a weak upper level front sweeps into BC
later today and tonight. As the front sweeps inland the mid-level
flow will shift from yesterdays easterly orientation to more of a
southerly one later today resulting in continued warming 850 mb.
The mid-level temperatures will climb about 1-2c vs yesterday and
should result in a subtle warming for most locations. The
exception will occur near he Cascades since there will be a little
more onshore or westerly flow compared to yesterday. For tonight
and Thursday the aforementioned disturbance continues to pass
through BC. The main impact will be some passing high clouds late
tonight and Thursday...but no threat of precipitation. It will
also cool temperatures slightly over much of the region as the
mid-level flow turns southwesterly. Expect high temperatures both
days to remain warmer than normal with highs in the 60s over all
valley locations. Meanwhile the warming aloft, combined with
generally clear skies, and light winds will allow strong
inversions to form overnight. Dewpoint values have been increasing
since yesterday and this suggests a little better chance for fog,
especially over NE Washington and N Idaho. Nonetheless fog
coverage has been rather limited lately and we don`t expect it to
blossom significantly overnight. Low temperatures in the valleys
will continue to drop into the upper 20s and 30s. fx

Friday through Tuesday: Models continue to show a strong upper
ridge through Monday for a continuation of dry weather, cool
mornings, and abundant afternoon sunshine. Highs in the 60s are
expected for most towns which is 5 to 10 degrees above normal.
Models are not showing much of the way of boundary layer moisture
so fog should be kept to a minimum despite strong night time
inversions and confined to the most favored areas near large
bodies of water in NE WA/N Idaho and possibly Lake Wenatchee
during the early morning hours. The light winds and poor mixing
associated with the ridge may result in a deterioration of air
quality. On Tuesday the ridge moves east allowing a weakening
front to move in...with latest models showing an increase threat
of rain in the Cascades late in the day or evening before shifting
east into N Idaho by Wednesday morning. JW
&&

.AVIATION...
06Z TAFS: High pressure will produce dry, VFR conditions at TAF
sites with light winds. Patchy fog may impact conditions in the
Cascade valleys and northern valleys, away from TAF sites,
overnight/early Wednesday. /Cote`


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        65  39  65  41  63  40 /   0   0   0   0   0   0
Coeur d`Alene  66  36  64  37  64  37 /   0   0   0   0   0   0
Pullman        66  37  65  40  66  41 /   0   0   0   0   0   0
Lewiston       68  41  69  44  66  43 /   0   0   0   0   0   0
Colville       66  35  65  36  66  34 /   0   0   0   0   0   0
Sandpoint      62  33  61  34  61  34 /   0   0   0   0   0   0
Kellogg        64  36  63  35  60  35 /   0   0   0   0   0   0
Moses Lake     68  32  67  35  69  34 /   0   0   0   0   0   0
Wenatchee      65  41  67  44  66  43 /   0   0   0   0   0   0
Omak           65  37  66  40  64  40 /   0   0   0   0   0   0

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.

&&

$$



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