Area Forecast Discussion
Issued by NWS Spokane, WA
FXUS66 KOTX 241126
Area Forecast Discussion
National Weather Service Spokane WA
426 AM PDT Wed Aug 24 2016
The winds will become northerly today and Thursday. This will
push smoke out of north Idaho and northeast Washington and push it
into the Columbia Basin and southern Idaho Panhandle. A strong
cold front is expected to bring gusty west winds Saturday and
heighten wildfire concerns once again.
Today and Tonight: The wave that moved through yesterday
afternoon/evening has moved into western Montana this morning.
There is quite a bit of drier air in the upper atmosphere moving
into central WA this morning. Some clouds this morning will mainly
impact north ID and extreme eastern WA. The winds have started to
shift to a more north or northeasterly direction. Expect the winds
to pick up later this morning across the Okanogan Valley. Once
again winds will peak in the late morning and early afternoon,
when relative humidities will be higher, which does not meet any
fire weather highlights. The winds will decrease through the
afternoon and evening. Showers and an isolated thunderstorm is
possible once again this afternoon across the north ID
Panhandle...mainly towards the Canadian border. Have extended the
chance of precip a bit further west...into Ferry county. The
threat of showers and thunderstorms will quickly diminsh by late
afternoon/early evening. Temperatures will remain near average for
this time of the year with valley temps in the in the mid to upper
70s in ID and 80s in WA. Overnight clouds will generally decrease.
Some thin cirrus may stream in from the northwest. Lows will be
average as well.
Thursday: We remain in northerly flow with about 1-3 degrees of
warming. There is a very slight chance of an afternoon shower or
thunderstorm right up along the canadian border in N ID. Winds
will generally be lighter, but still remain from the north or
Thursday night through Wednesday...Model guidance is in decent
agreement through about Sunday, then the models begin to diverge
a by quite a bit through the first part of next week.
No big changes to previous discussion of northerly flow continuing
Thursday night and slowly flattening through the day on Friday,
finally becoming westerly on Saturday as a disturbance drops south
into central B.C. The low will eject east across the Continental
divide on Saturday dragging a mainly dry cold front through the
forecast area on Saturday.
Thursday night and Friday...Conditions will be warm and dry dry
through the period. The biggest changes will be winds shifting
from the northeast to a more typical southwest as the upper level
flow becomes westerly.
Saturday...Conditions begin to change Friday night and Saturday
as the upper level low tracks across British Columbia. Pre-
frontal winds will be on the increase Friday night out of the
southwest 5-15 mph. The cold front is expected to cross the
forecast area Saturday afternoon and evening. Limited moisture
will keep the focus of any convection tied to the northern
mountains, and even this will be quite spotty. The bigger story
will be southwest-west winds increasing through the day to 15-20
mph with gusts 25-30 mph across a large portion of the forecast
area. These winds will linger well into the evening if not through
the night. Temperatures will remain on the warm side of normal and
relative humidity will be in the 20-30 percent range. This
combination of winds and relative humidity will increase fire
weather concerns for mainly fire weather zone WAZ674 (the east
Washington Palouse and Spokane area) east into fire weather zone
IDZ101 (the northern and central Panhandle).
Sunday...Southwest winds will stay somewhat elevated on Sunday
but temperatures will be down 5-10 degrees and relative humidity
up slightly. There will still be a low end chance for mountain
showers across the northern zones.
Sunday night through Wednesday...Still much uncertainty through
this portion of the forecast. All the models have some sort of low
pressure system in the vicinity of the north B.C. coast Sunday
afternoon. After that there are varying solutions. This forecast
will lean towards the slower GFS/Canadian solution which develops
a closed low Sunday night and keeps it off the coast until
Wednesday. This matches best with the ensemble members. This
solution will keep a westerly flow over southern B.C. the region.
This will result in temperatures near seasonal averages and chance
of mountain showers at times along the Canadian border. Tobin
12Z TAFS: Visibility restrictions due to smoke make the TAFs
tricky. At this time, it looks like our TAF sites may not have
much visibility reduction. Pullman and Lewiston could have smoke
advected in from the Spokane area in the morning and smoke from
western Montana by afternoon, but it is unclear how much fire
activity will occur during that time frame. With low confidence,
we chose to keep the TAFs VFR.
.PRELIMINARY POINT TEMPS/POPS...
Spokane 79 56 80 56 82 59 / 0 0 0 0 0 0
Coeur d`Alene 77 51 80 52 80 54 / 10 0 0 0 0 0
Pullman 79 50 80 49 82 52 / 0 0 0 0 0 0
Lewiston 85 57 86 58 88 60 / 0 0 0 0 0 0
Colville 82 51 84 51 84 52 / 10 10 0 0 10 10
Sandpoint 75 48 77 49 78 49 / 10 10 10 10 10 0
Kellogg 74 49 76 50 78 52 / 10 0 0 10 10 0
Moses Lake 88 56 88 55 88 57 / 0 0 0 0 0 0
Wenatchee 87 61 88 62 89 65 / 0 0 0 0 0 0
Omak 88 56 88 57 89 58 / 0 0 0 0 0 0