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fxus66 kotx 060951 
afdotx 


Area forecast discussion 
National Weather Service Spokane Washington 
251 am PDT sun Jul 6 2008 


Synopsis...closer to normal temperatures and a dry forecast 
through the rest of the Holiday weekend can be expected as the 
weather pattern transitions to a more stable regime. Temperatures 
will begin a warming trend Monday...peaking by Wednesday. Its not 
until Thursday and Friday that a cold front moves off the Pacific 
and through the Pacific northwest...increasing the threat of 
showers and ushering in a cooler air mass for the weekend. 


&& 


Discussion... 
today and tonight...we've begun the transition to a dry and warmer 
forecast as what's left of the short-wave trough over the Pacific northwest at this time 
moves east into Montana and Alberta and falls apart in the increasingly 
split steering flow. Drying aloft behind this wave has already 
nosed into eastern Washington and will continue to do so the next 24 hours. 
Forecast soundings show this dry and relatively warm layer aloft playing 
a big role in limiting the amount and depth of the SBCAPE layer...so 
much so that it's unlikely we would be able to get a simple shower 
over the NE Washington and north Idaho mountains under full sun and westerly orographic 
ascent. The best chance of isolated rain showers would be along the British Columbia/Idaho 
border. Forecast local/cloud condensation level heights do favor mountain cumulus with bases higher than 
Sat. A few wind gusts are also expected today under nearly 
unidirectional S/SW flow. For tonight...broad short-wave 
riding...clearing skies and weakening pressure gradients will lead 
to overnight lows slightly below normal. Forecast low temperatures were cooled 
somewhat from the previous forecast. Bz 


Monday through Wednesday...model solutions for this time period 
still are all trending toward the entrance and gradual slight 
amplification of a ridge over the County Warning Area through Wednesday. While 
this ridge is not forecast to be nearly as strong as the ridge of 
a week ago...heights still rise to near 585 dam by Wednesday on 
most guidance...and all global guidance has been relatively 
consistent in suggesting the ridge axis should be over the County Warning Area by 
Wednesday. Additionally...the models are all rather consistent 
with the long wave pattern progression through Wednesday...and 
they have all indicated ridging to be more subdued than in recent 
weeks...with any embedded short wave troughs in the flow lacking 
significant amplification or dynamics in a rather dry atmosphere. 
The forecast because of all this features no chances of 
precipitation with days warming to about a dozen degrees above 
normal by Wednesday as 850 mb temperatures jump toward 23c on the 
European model (ecmwf)...24c on the GFS...and a gefs mean of 23c. 
Additionally...with clear skies...overnight thermal belts develop 
and strengthen through Wednesday night...with relative humidity values falling 
through middle-week as well. 


Beyond Wednesday...the models shift the ridge axis to the east 
Thursday...and at varying forward phase speeds all track a trough 
axis over the area by Friday. The results are cooling temperatures 
likely below normal for a day or two the end of the week...and 
higher relative humidity values. While dynamics are rather weak...a slight chance 
of showers skirting the mountains along the Canadian border region 
and in north Idaho probably maximizes about Friday...however with 
model solutions lacking consistent timing...this could change. The 
big story for this portion of the forecast likely will be falling 
temperatures. /Fries 


&& 


Aviation... 
VFR conditions expected at all taf sites through 12z Monday. Afternoon 
sounding indicates only a shallow layer of potential convective 
growth from 09-15k feet but strong capping above the layer will 
limit any showers over taf sites. Bz 


&& 


Preliminary point temps/pops... 
Spokane 79 52 84 57 89 59 / 0 0 0 0 0 0 
Coeur D'Alene 79 51 83 54 88 57 / 0 0 0 0 0 0 
Pullman 79 47 82 51 88 53 / 0 0 0 0 0 0 
Lewiston 86 56 91 59 94 62 / 0 0 0 0 0 0 
Colville 84 49 87 52 92 55 / 0 0 0 0 0 0 
Sandpoint 76 50 80 49 85 51 / 0 0 0 0 0 0 
Kellogg 75 49 82 51 86 58 / 0 0 0 0 0 0 
Moses Lake 86 52 90 59 94 62 / 0 0 0 0 0 0 
Wenatchee 84 57 90 62 93 65 / 0 0 0 0 0 0 
Omak 86 53 90 55 94 58 / 0 0 0 0 0 0 


&& 


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


$$