Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Spokane Washington
221 am PDT Thursday Jul 31 2014

Synopsis...
it will be partly cloudy and hot with isolated thunderstorms
through the end of the week and into the weekend. No significant
relief from the hot weather is forecast through the seven-day
forecast period. However, only a few spots may reach the 100-degree
mark. Isolated thunderstorms the next several days are not
expected to be strong or severe but could bring localized heavy
downpours.




&&

Discussion...
today through Friday...hot temperatures will continue across the
region with isolated showers and thunderstorms possible across the
southeast zones today. The ridge axis will shift slightly to the
east today, but not enough to account for more than a degree or
two of cooling. Monsoonal moisture will try to push into the NE
blue mts, Camas Prairie and the central Panhandle mountains today.
This will work with a weak impulse to allow isolated to scattered
showers and thunderstorms to develop across the southeast. There
is a decent amount of cape but bulk shear is rather weak so any
thunderstorms that develop will tend to be garden variety. There
is a better push of moisture Friday that will extend into the
north Cascades as well as the Southeast. Cape will be limited to a
couple hundred j/kg for the Cascades so there is a slight risk of
thunderstorms to develop near active fires or recent burn scars.
Scattered thunderstorms will again develop across the southeast
zones. Temperatures will continue the above normal trend with
readings in the 95 to 105 degree range. The highest temperatures
will be in the Lewis-Clark Valley today where a heat advisory has
been issued. Fridays temps should be a bit cooler but just by a
couple of degrees with most valley locations in the 90s. Overnight
lows will also be well above normal. The warmest readings will be
in the mid-slope thermal belt at the top of the inversion where
readings could top out in the 70s. /Kelch

Friday night through Thursday...the inland northwest will be in
between and exiting ridge of high pressure and a deep low in the
Gulf of Alaska through Sunday. A weak upper level front will track
across the region Saturday night and Sunday. Zonal flow with weak
ridge will return Monday through the remainder of the forecast
period.

Southwest flow is expected Friday night through Saturday night or
early Sunday. The models are not necessarily in agreement but all
are showing and influx of Pacific moisture through this portion of
the forecast. Model pwats increase to 140-160 percent of normal.
Several weak waves will track through the region, with the upper
level front between 00z-12z Sunday. Model guidance is showing an
extended period of both surface based and mid level instability
through Sunday night. Isolated to scattered showers and
thunderstorms will be possible each afternoon through Sunday. The
best chance for nocturnal thunderstorms appears to be Friday night
and Saturday night. These storms may begin dry Friday night but
should become mainly wet storms Saturday and Sunday. Temperatures
will show a bit of a cooling trend with lower heights and some
cloud cover but will remain above normal.

Monday through the week the flow becomes westerly with a hint of a
ridge of high pressure at 500 mb Monday and Tuesday. The region will
lose the deep Pacific moisture tap, allowing the atmosphere to
stabilize. A few showers may be possible Monday afternoon across
the orographically favored Panhandle mountains, otherwise dry
through Thursday. Temperatures will rebound a few degrees Monday
and Tuesday under the ridge but cool off close to normal for
Wednesday and Thursday. /Tobin



&&

Aviation...
06z tafs: VFR conditions expected the next 24 hours. Cu will
develop over the mtns in the aftn with cirrus moving in from the
south through the late afternoon and evening hours. Isolated
thunderstorm development is possible from the blue mtns to Lookout
Pass thurs afternoon/evening.



&&

Preliminary point temps/pops...
Spokane 96 66 94 66 92 66 / 0 0 10 10 20 20
Coeur D'Alene 94 60 94 62 91 63 / 0 10 10 20 20 20
Pullman 94 58 93 57 92 59 / 10 10 20 20 20 20
Lewiston 101 70 99 69 97 71 / 10 10 30 30 20 20
Colville 99 56 95 59 95 58 / 0 10 10 10 20 20
Sandpoint 94 52 93 56 88 56 / 0 10 20 20 20 20
Kellogg 92 57 90 62 88 62 / 10 10 20 20 30 20
Moses Lake 101 66 98 64 97 65 / 0 10 10 10 20 20
Wenatchee 99 70 96 71 96 71 / 0 10 10 10 20 20
Omak 101 64 100 68 96 67 / 0 0 10 10 20 20

&&

Otx watches/warnings/advisories...
Idaho...heat advisory from 1 PM this afternoon to 8 PM PDT this evening
for Lewiston area.

Washington... heat advisory from 1 PM this afternoon to 8 PM PDT this evening
for lower Garfield and Asotin counties.

&&

$$

National Weather Service Glossary of Abbreviations