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fxus66 kotx 160930 
afdotx

Area forecast discussion
National Weather Service Spokane Washington
230 am PDT Mon Sep 16 2019

Synopsis...
cool, wet Fall weather will persist through mid week as a pair of
weather systems slowly make their way across the inland northwest.
The wetter storm will be moving in Tuesday with widespread rain and
continued unsettled weather Wednesday into Thursday. Drier, breezy
and more seasonal weather is expected Friday with a return of some
mountain showers into the weekend.

&&

Discussion...
today and tonight: a slow moving front with moisture in southerly
flow aloft will bring some light rain as it transitions from
East-Central
Washington into the Idaho Panhandle. Post frontal showers
later today are expected to pop up especially in the Washington
mountains. There are some isolated thunderstorms forecast
for the northern Cascades and The Blues later this afternoon
however they will quickly fade with the setting sun early this
evening. It will be a cooler day as cloud cover will be slow
to move out. Today will be nearly 15 degrees cooler than Sunday
hovering around the 60 degree mark in the Spokane/Coeur D'Alene
area with mid 60s farther south in the Central Basin. Tonight
there will be some late night clearing ahead of the next weather
system so patchy fog is expected in the northern valleys on
down toward the Palouse country.

Tuesday into Tuesday night: the next, more potent weather system
will move in more rapidly Tuesday morning spreading rain from
the Cascades into Idaho by Tuesday afternoon. By Tuesday night a
fair portion of the inland northwest could get up to .25 or more
precipitation with somewhat less going south to the Washington/Oregon
border. Higher mountains will could get close to a half inch of rain
with snow levels just above 6000 feet and light accumulations of high
elevation snow. Post frontal showers once again will keep precipitation
going especially near the Cascades into Tuesday night with a slight
chance of thunderstorms. Latest guidance Marks Tuesday as an even cooler day with
with widespread temperatures 55-60 degrees. Tc

Wednesday through thursday: unsettled weather will continue into
Wednesday as the upper low very slowly traverses across the
region. Widespread showers appear likely, and given the cold pool
aloft a few thunderstorms can't be ruled out. One area to pay
attention to may be extreme southeast Washington into the central Idaho
Panhandle, where ensemble guidance suggests highly anomalous
precipitable water values, and could cause impacts if convection
forms. Precipitation should move south and eastward Wednesday
night into Thursday. Given the recent rainfall and potential for
clearing skies, fog may form in some of the northeast valleys
early Thursday morning.

Friday through saturday: generally drier and warmer weather is
expected across the region as high pressure builds over the
eastern Pacific, then slides into the pacnw. A bit of moisture may
still creep into the region, with the best chance of any showery
activity over the high Cascades and across the Idaho Panhandle.
Look for high temperatures to rebound into the upper 60s to mid
70s...still a few degrees cooler than normal.

Sunday through monday: the general consensus among deterministic
and ensemble models is for the upper ridge to quickly move
eastward, and a shortwave trough to bring a chance of
precipitation early next week. The timing and strength of this
system is poorly handled though, and confidence in the forecast is
low from Sunday Onward.
Dang

&&

Aviation...
06z tafs: cold front is moving very slowly to the east. Rain band
currently between keat and kmwh won't reach Spokane until midday
Monday. Kmwh may have some MVFR cigs in the morning, but
confidence is too low to put in the taf forecast at this point.
The potential for lower cigs at kgeg/ksff/kcoe doesn't look quite
as good. The rain for these locations should wait until after 18z
when it would be harder to form lower ceilings. That said, the
front is expected to strengthen a bit over extreme eastern Washington so
this could lead to lower cigs before any rain occurs. All sites
should clear out by late afternoon or evening as the front finally
pushes through. Rj




&&

Preliminary point temps/pops...
Spokane 59 44 63 46 61 43 / 60 10 40 80 60 30
Coeur D'Alene 58 44 63 47 61 43 / 40 20 20 70 60 30
Pullman 56 40 64 44 61 41 / 50 40 30 80 60 40
Lewiston 67 49 71 53 66 51 / 50 50 20 70 60 40
Colville 62 38 65 40 66 36 / 50 30 50 80 70 30
Sandpoint 60 44 60 44 60 41 / 30 30 30 70 70 40
Kellogg 61 47 60 49 59 45 / 30 40 40 70 70 40
Moses Lake 69 43 65 44 68 43 / 60 0 80 60 40 20
Wenatchee 68 50 61 51 66 50 / 20 0 90 60 40 10
Omak 67 45 62 48 65 45 / 40 10 80 80 40 10

&&

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

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