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Area forecast discussion 
National Weather Service Spokane Washington
1031 PM PDT sun may 24 2015

Synopsis...
low pressure moves into the inland northwest through mid-week,
providing scattered showers and thunderstorms each afternoon and
smaller chances in the morning and night. Locally heavy rain,
small hail and gusty winds will be possible in storms. Some chance
of showers continues into the second part of the week into next
weekend, especially in the mountains. Next weekend also looks to
warm with Summer-like temperatures in the mid 80s to low 90s.

&&

Discussion...
satellite imagery this evening indicates a closed low over
southern British Columbia slowly moving south. Earlier today afternoon heating
helped destabilize the atmosphere leading to the development of
showers and thunderstorms over the northern Cascades, Okanogan
Valley and Highlands, extending south into the upper Columbia
Basin and Waterville Plateau this evening. Meanwhile a secondary
area of showers and thunderstorms was found over the central
Panhandle mountains.

While surface based instability is on the decrease this evening...plenty
of mid level moisture and instability is present across northeast
Washington and north Idaho. The main area of shower and
thunderstorm activity stretching from the upper Columbia Basin and
NE Washington mountains is shown by the GFS, hrrr, and NAM to
swing towards north Idaho through the overnight hours. Convection
between Coeur D'Alene and Shoshone County will also get drawn
north with the approaching low. Thus...pop's were increased in
these areas. Models also show a general increase in showers across
the Spokane area possibly extending into the Palouse late this
evening and overnight. Areas along and north of I-90 over NE
Washington and north Idaho will have the best opportunity for
nocturnal thunderstorms with MUCAPE values of 300-600 j/kg during
the overnight hours. Cloudy skies will result in mild overnight
lows in the mid 50s for NE Washington and north Idaho and low temps were
increased. Jw

&&

Aviation...
06z tafs: a closed low in southern British Columbia will drop south into
northern Washington through Monday. This will result in showers and
scattered thunderstorms especially for the northern mountains and
Idaho Panhandle given the cold pool aloft with the low over the
area. The highest coverage of thunderstorm activity will be during
peak heating (20z Mon-02z tue) but isolated nocturnal
thunderstorms will continue overnight into Monday morning with mid
level instability in place over northeast Washington and north
Idaho. Jw

&&

Preliminary point temps/pops...
Spokane 55 71 51 73 52 77 / 60 50 40 60 40 30
Coeur D'Alene 55 70 49 73 50 75 / 70 70 40 60 40 40
Pullman 49 69 45 71 47 73 / 20 20 10 40 30 40
Lewiston 55 77 52 78 55 79 / 10 20 10 20 20 30
Colville 55 74 50 76 50 81 / 90 90 60 70 40 30
Sandpoint 54 70 48 72 49 74 / 80 70 60 60 50 40
Kellogg 53 70 46 72 47 73 / 60 80 50 60 50 50
Moses Lake 54 79 54 80 53 84 / 10 10 20 20 20 20
Wenatchee 56 78 56 79 59 84 / 0 20 20 40 30 20
Omak 50 77 50 78 51 84 / 20 50 50 60 40 20

&&

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

$$

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