Area forecast discussion
National Weather Service Spokane Washington
1054 am PDT Sat may 18 2013
Synopsis...
scattered showers and isolated thunderstorms will develop again
this afternoon and evening. The greatest threat of thunder will
occur over the northeast corner of Washington and much of the
Idaho Panhandle. Precipitation chances will diminish a bit on
Sunday and by Monday most locations will be dry. This drying will
come to an abrupt end by Tuesday afternoon and into Wednesday as a
a very cool and wet upper level low Parks itself over the inland
northwest. Steady, moderate precipitation will be possible
especially over northeast Washington and the northern Panhandle.
&&
Discussion...
water vapor satellite imagery shows a mid level wave tracking
across eastern Washington and north Idaho this morning. This
combined with mid level instability will continue to generate
showers this morning over the Okanogan Valley and Highlands,
northeast Washington mountains, and over north Idaho mainly north
of Lewiston. For this afternoon into the evening hours another
wave will track across the region which combined with afternoon
heating will generate more showers especially over the northern
mountains where high dew points in the upper 40s and lower 50s
exist due to the shower activity this morning. The forecast for
this morning has been updated to increase shower wording in the
valleys north of Highway 2 in Washington...and over north Idaho.
Also made some sky cover adjustments to show more cloud cover this
morning...and to increase clouds over central Washington this
afternoon as the next wave crosses the Cascades. These clouds will
keep high temperatures down more then previously expected and highs
were adjusted downward mainly areas north of a line from Omak to
Spokane to Kellogg. Jw
&&
Aviation...
18z tafs: an upper level trough and weak disturbances embedded
within will aid in generating showers especially over the
mountains. Isolated thunderstorms will also be possible mainly over
the mountains north of the Columbia Basin from 20z today through 03z
this evening. Westerly flow in the mid levels will lead to downslope
flow off the Cascades with dry conditions persisting at keat/kmwh.
Ceilings are expected to be primarily VFR...with brief MVFR conditions
possible around ksff/kcoe through 20z. Jw
&&
Preliminary point temps/pops...
Spokane 63 45 66 46 70 49 / 40 20 20 10 0 10
Coeur D'Alene 62 44 64 43 69 45 / 60 30 30 20 0 10
Pullman 62 43 63 41 69 45 / 20 20 20 10 0 10
Lewiston 69 49 70 48 76 51 / 20 20 20 10 0 10
Colville 66 44 73 43 76 44 / 70 40 30 20 10 10
Sandpoint 60 43 64 42 69 43 / 70 40 40 30 10 10
Kellogg 58 44 60 45 67 46 / 60 30 40 40 10 10
Moses Lake 72 47 76 45 79 48 / 10 10 10 0 0 10
Wenatchee 69 48 72 49 76 51 / 10 10 10 0 0 10
Omak 69 43 74 42 77 46 / 50 20 10 10 10 10
&&
Otx watches/warnings/advisories...
Idaho...none.
Washington...none.
&&
$$
