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Area forecast discussion 
National Weather Service Spokane Washington
251 PM PDT Wed Aug 24 2016

Synopsis...
light northerly winds will be in place tonight into Thursday.
This will keep smoke dispersion mainly south to southwest of
ongoing fires and 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. Seasonal
temperatures return next week with an increase chance for showers
across the northern mountains.



&&

Discussion...
today through friday: the region will remain under a northerly flow
pattern this period. Dry conditions are expected for the region
except in northern Idaho along the Canadian border. With cape
values of a couple hundred, an isolated shower could pop up in
that area and produce lightning through the early hours on
Wednesday and Thursday. Late Friday the influence of an incoming
low will switch the winds from the north to the a southwest flow.
This will also increase winds across the Columbia Basin. Winds
will be around 10 miles per hour with gusts near 15. Temperatures for the
period will mainly be in the 80s for highs and 50s for lows. /Jdc

..gusty winds and dry conditions Saturday...

Saturday: Saturday will bring the next bout of winds across the
region and elevated concerns for spreading wildfires. This has
been a consistent message amongst the forecast models and
confidence continues to increase. A shortwave trof will be
swinging through southern British Columbia and ejecting to the east late
Saturday. Look for an increase in southerly winds early Saturday
morning then becoming southwest just prior to midday as a surface
low materializes over southern Alberta. Unlike last Sunday, this
wind event will be driven more on pressure gradients than a strong
punch of cold air advection and high momentum air aloft.
Consequently, winds speeds will be not be as strong but still
problematic in regards to fire weather concerns. To give some
perspective...the air mass cooled near 10c at 850mb during the
Sunday-Monday time-frame of the last wind event. This Saturday,
the air mass is only expected to cool on the order of 5c between
Saturday and Sunday mornings. Peak wind speeds with this event
will range between 15-22 mph with gusts 25-30 mph. Looking at
humidity or dryness levels...models have trend drier with
afternoon levels and critical fire weather conditions will be
possible across the Columbia Basin, Palouse, West Plains/Spokane
area, Idaho Panhandle, and into southern reaches of the northern
mountains. Remaining areas will also experience breezy to gusty
conditions but either speeds will be lower or humidity levels will
not be as dry unless forecast parameters continue to trend toward
this direction.

Other impacts from the winds will be choppy lakes, especially
locations like Rock Lake and other SW to NE oriented water bodies
in the open basin and potential for localized blowing dust. We did
not track down any reports of blowing dust with the Sunday event
so will hold off on including it in this forecast package.

Sunday through wednesday: medium range models are in good agreement
regarding a large-scale pattern shift toward a more trough"e" pac
northwest but there remains some differences how fast this occurs and
where to place the best chances for precipitation. Saturday's
shortwave will carve out the initial trof over the pac northwest but the
main upper-level front will stall from southwest to northeast
across northern Washington and just north of the Idaho/Canadian
border. Once this boundary becomes established, several more
shortwaves reloading the trof will ride along the boundary
squeezing out periods of showers and thunderstorms with general
consensus of a decent moisture influx along the boundary. This
will not be a widespread precipitation event but rather come in a
few waves with the best shot mainly north of a line from Stevens
Pass in the Cascades to Ione in northeastern Washington. The best chance
for isolated afternoon T-storms will be north of this boundary
while dry conditions persist across the Columbia Basin and points
south. It will not be until midweek when the trof possibly digs
deeper into the northwest introducing the consideration of hit or
miss showers and T-storms in the basin and eastern mountains. Run
to run model consistency has not been stellar so overall
confidence is low. The pattern does support near to slightly above
seasonal temps until midweek and above normal odds for breezy
winds early in the work week. /Sb



&&

Aviation...
18z tafs: dry northerly winds will continue through the period.
Patchy smoke from the regions wildfires could produce some local
reduction in vis and ceilings to IFR conditions for the taf sites
kpuw and klws in the early morning hours for brief periods. But
with low confidence was left out of tafs. /Jdc



&&

Preliminary point temps/pops...
Spokane 56 81 58 83 59 86 / 0 0 0 0 0 0
Coeur D'Alene 53 80 54 81 55 85 / 0 0 0 0 0 0
Pullman 50 81 50 82 53 87 / 0 0 0 0 0 0
Lewiston 59 87 59 88 61 94 / 0 0 0 0 0 0
Colville 51 84 52 85 53 87 / 10 0 0 10 10 10
Sandpoint 49 78 50 78 50 83 / 10 0 10 10 0 10
Kellogg 50 76 50 79 52 82 / 0 0 10 10 0 0
Moses Lake 56 88 57 89 58 92 / 0 0 0 0 0 0
Wenatchee 63 88 64 89 66 87 / 0 0 0 0 0 0
Omak 57 88 59 90 59 88 / 0 0 0 0 0 10

&&

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

$$

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