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Area forecast discussion 
National Weather Service Spokane Washington
912 PM PDT Monday may 25 2015

Synopsis...
a slow moving low pressure system will bring scattered afternoon
and evening thunderstorms to the inland northwest through
Wednesday. Locally heavy downpours, frequent lightning, and small
hail will be possible the next several days. Low pressure will
gradually depart by Thursday, bringing a decrease in precipitation
chances, but chances may increase again by early next week across
the region. Temperatures warm back above normal from Wednesday
into the end of the week, with highs pushing into 80s Thursday
Onward.



&&

Discussion...
late evening update: a closed low evident on satellite over
southern Stevens County as of 9 PM is shown by models to move east
northern Spokane and southern Pend Oreille counties overnight.
The best instability is located on the southwest side of this low
over the upper Columbia Basin around Grand Coulee and Wilbur with
quite a bit of lightning activity this evening. Brief heavy rain
has been common with these storms with as much as 0.6 inches per
hour. Overall the NAM has the best handle on the convection
currently and leaned towards the 00z NAM for the remainder of
tonight. As the low pulls east a bit overnight the area of mid
instability shifts into southern Lincoln, southern Spokane, and
northern Whitman counties. The NAM mu cape values of 500-1000 j/kg
in these areas during the overnight hours are probably
overdone...but given current convection on radar not showing any
signs of ending opted to increase pops and add a mention of
isolated thunderstorms in these areas overnight including the
Spokane area. Under the low itself...shower activity should only
be isolated over the northeast Washington mountains.
Meanwhile...with the low pulling away from the Cascades and low
level downslope flow in the Cascades...the chance of showers was
removed for the rest of tonight in this area. Jw

&&

Aviation...
00z tafs: there is good model agreement that a closed low over the
Cascades early this evening will move into the Spokane/Coeur
D'Alene area overnight and remained parked over this area through
Tuesday. This will result in a continuation of showers and
thunderstorms over the area...with the highest coverage during
peak heating (afternoon/evening). Although tonight there will
likely be more of a focus of the showers around and north of the
kgeg/ksff/kcoe taf sites with the closed low tracking into the
area. Brief heavy rain and small hail has been observed with these
storms. Jw

&&

Preliminary point temps/pops...
Spokane 51 70 52 75 54 81 / 40 60 30 30 20 20
Coeur D'Alene 48 70 48 75 51 80 / 20 60 30 40 20 20
Pullman 45 68 48 71 49 78 / 40 40 30 40 20 20
Lewiston 53 74 55 76 56 84 / 20 50 40 40 20 10
Colville 49 73 49 80 51 84 / 20 70 40 30 20 20
Sandpoint 47 68 48 75 50 78 / 30 70 40 50 30 40
Kellogg 46 67 47 71 49 78 / 30 80 50 60 30 40
Moses Lake 52 79 52 82 55 88 / 20 40 20 20 10 10
Wenatchee 57 77 58 82 60 87 / 10 40 30 20 20 10
Omak 49 76 51 83 52 86 / 40 50 40 40 20 10

&&

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

$$

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