Area forecast discussion
National Weather Service Spokane Washington
1036 am PDT Tue may 21 2013
Synopsis...
the mild Spring weather will come to an end. A strong cold
front will sweep through the region today and this evening with
showers...a chance of thunderstorms and breezy winds. Cool and
showery weather will continue through much of the week, but will
improvement a bit for the Holiday weekend.
&&
Discussion...
updated the forecast to keep up on the quickly changing pattern
today. A deep upper level low is rotating to the Washington coast while a
strong cold front has slipped east of the Cascades and roughly
extends from Chelan to Hanford. Radar shows a dense line of
showers along and ahead of the front. Embedded thunderstorms were
reported early this morning which coupled with the mid level
instability, but the lightning strikes have waned in the last
hour. Local heavy downpours accompanied the thunderstorms and
Wenatchee saw 0.14" in less than an hour. The front will slowly
sweep east and take on a negative tilt through the day. Not
expected much temperature rises today in the Cascades behind the
front. Meanwhile, the Idaho Panhandle and extreme eastern Washington will
warm up into the lower 70s with rising dewpoints. Instability will
be on the rise this afternoon in this area with CAPES reaching
500-700 j/kg. This coupled with increased 0-6km speed shear and
low level directional shear ahead of the front, has the potential
for strong thunderstorms will some organization. The cons for
strong thunderstorm development will be the increase of mid and
high clouds which may cap the activity. Will continue to monitor.
/Rfox.
&&
Aviation...
18z tafs: a cold front will sweep through the taf sites today
lowering cigs, showers, a wind switch with gusty winds. The front
will push from keat to kmwh through 21z, and then March to the kgeg
vcnty, kpuw and klws toward 00z. Anticipate light high based showers
ahead of the front with the potential for thunderstorms. The best
chance for thunderstorms will be north and east of kgeg this
afternoon. Behind the front, expect cigs to continue to lower
overnight with steady light rain. Snow levels will drop to 4-5k ft
overnight. Cigs will be nearing MVFR by 12z. The rain will taper off
to shower by Wednesday morning. /Rfox.
&&
Preliminary point temps/pops...
Spokane 70 41 51 36 61 42 / 30 90 90 40 30 30
Coeur D'Alene 72 41 48 36 59 41 / 30 90 90 50 40 40
Pullman 70 38 51 35 60 41 / 20 80 80 30 40 40
Lewiston 78 44 59 41 66 46 / 40 60 70 30 30 40
Colville 74 45 55 37 66 41 / 50 90 90 60 50 40
Sandpoint 73 43 50 36 59 39 / 30 90 90 80 40 50
Kellogg 75 40 44 34 55 40 / 30 90 90 70 50 50
Moses Lake 69 43 62 40 68 44 / 70 50 30 30 30 30
Wenatchee 63 43 58 42 65 45 / 70 60 40 40 50 30
Omak 66 43 59 38 66 41 / 80 80 70 50 50 30
&&
Otx watches/warnings/advisories...
Idaho...none.
Washington...none.
&&
$$
