597 
FXUS66 KOTX 132212
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
312 PM PDT Mon Sep 13 2021

.SYNOPSIS...
After a quiet start to the week, late Tuesday into Wednesday, 
another weather system may bring slight precipitation chances in 
the mountains along with breezy winds. Warmest temperatures will
be on Tuesday, then temperatures will cool to below average highs
in the 60s and low 70s by the end of the week. Nighttime lows will 
be cool Thursday morning for a patchy frost potential. Another 
round of very wet and active weather is expected Friday into the 
weekend with widespread rain, some high mountain snow showers and 
breezy winds.


&&

.DISCUSSION...
Tonight through Tuesday night: This will be the quietest period 
of the week overall as high pressure lingers through Tuesday 
afternoon. Nighttime lows will bin the 40s to lower 50s in the 
lower elevations. There are some colder pockets around such as 
near Republic that will be 35 to 40 degrees. Tuesday will be the 
warmest day of the week with widespread 70s. A persistent south 
wind 10 mph will increase in the afternoon across eastern 
Washington ahead of a cold front moving in from the northwest. The
Clouds will start moving into the region in the afternoon Tuesday
especially near the Cascades. By late afternoon, the northern 
Cascades may see some light rain followed by areas along the 
Canadian Border to the north Idaho Panhandle Tuesday evening but
that will be the extent of the light rain potential for the 
evening.

Wednesday into Wednesday night: A cold front moves across the 
Inland northwest increasing wind gusts to 25-35 mph potentially 
across the Basin, Palouse and even into the central Idaho 
Panhandle midday into Wednesday afternoon. It seems the Okanogan 
valley will be breezy as well with gusty north winds down the 
valley. Overall the winds have been increased from the previous
forecast due to MOS guidance insisting on the stronger wind. The
wind will also bring in much drier air. As winds calm overnight
Wednesday there could be some more widespread pockets of frost 
again in the mountain valleys at the very least.

Thursday: This will be the last dry day before the next, wetter
storm moves into the region. TC

Friday through Sunday: A cooling, wet period begins Friday and 
will continue through the weekend. Prior to the arrival of a large
trough, a warm front will pass through the region bringing light 
to moderate rain and the potential for light snow in the ridge 
tops. Accumulations continue to vary by model, but there is high 
confidence that Friday will be a widespread wet day. The greatest 
rainfall rates look like they will be in the afternoon and early 
evening. Winds pick up in the afternoon as well, with the 
potential for widespread gusts to reach 20 - 30 mph. 

As the trough axis approaches, the incoming cold front will continue 
to bring precipitation and breezy conditions through the weekend. 
With a tight pressure gradient on Saturday, winds will pick up in 
the afternoon with possible gusts up to 20 - 30 mph in the Basin and 
Palouse. The winds will weaken overnight and remain light for the 
remainder of the weekend. Precipitation looks lighter over the 
weekend than the forecast shows for Friday. However, it looks like 
it will be a light wetting rain, especially for the Cascades and ID 
Panhandle. Low confidence, but with the current model guidance, 
northeastern WA and northern ID Panhandle may have some embedded 
thunderstorms with the showers on Saturday. Temperatures will 
continue to cool by day, with below-normal highs dropping into the 
upper 50s and mid-60s by Sunday. JS

&&

.AVIATION...
18Z TAFS: The northern valleys are expected to burn off any patchy
fog and valley stratus by 19Z Monday. Northern valleys near the ID
Panhandle and Canadian border will have some isolated afternoon
showers.  Otherwise, TAF sites are expected to have VFR 
conditions through the period as high pressure keeps dry air over 
the region. Expect increasing high clouds early Tuesday as 
another weather system and cold front begins to move into the 
Pacific Northwest. /TC




&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        46  75  52  71  40  67 /   0   0  10   0   0   0 
Coeur d'Alene  46  74  52  71  40  67 /   0   0  10   0   0   0 
Pullman        41  74  49  68  37  65 /   0   0   0  10   0   0 
Lewiston       50  81  58  78  48  73 /   0   0   0   0   0   0 
Colville       40  75  42  68  32  67 /   0   0  20   0   0   0 
Sandpoint      43  71  49  66  35  64 /   0   0  20  10   0   0 
Kellogg        48  73  55  67  43  65 /   0   0  10  20   0   0 
Moses Lake     45  77  52  72  39  68 /   0   0  10   0   0   0 
Wenatchee      52  78  56  71  46  68 /   0   0  10   0   0   0 
Omak           50  78  52  72  42  70 /   0   0  10   0   0   0 

&&

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

&&

$$