Weather Service Report


641 
FXUS66 KOTX 022114
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
214 PM PDT THU JUL 2 2015

.SYNOPSIS....
Hot and dry weather will be featured into the Independence Day
weekend. Hottest days will likely be today and Friday with many
valley sites topping the century mark. Breezes will be kicking up
as weather systems move across the strong upper level ridge.
Friday and Saturday winds are potentially looking more substantial
as a cool front tries to sag in from Canada eventually forcing
winds more from the north. It is still looking dry and warm even
into the beginning of next week.




&&

.DISCUSSION...
Tonight though Saturday evening: Hot and dry conditions will
continue across the Inland Northwest courtesy of a ridge of high
pressure. As of 2PM...several locations across the lower Columbia
Basin were already recording triple digit temperatures and the air
mass is only going to warm into Friday. The ridge however will
begin to weaken by the evening and this will allow a local
increase in winds and elevate the threat for wildfire spread. Our
first concern will be near the Cascade Gaps starting around late
afternoon and evening on Friday. Confidence is higher that winds
will materialized in Ellensburg and red flag warnings have been
hoisted. Confidence is lower for the Wenatchee River Valley where
model consensus is only indicating winds 8-14 mph between 5-8PM.
There is an isolated run of the higher res NMM that would support
a low-end red flag but given the lack of support from MOS, will
hold off on upgrade at this point and let the next 2 shifts
examine the incoming 00z model guidance.

As the ridge deflates Saturday, we will look for increasing northerly 
pressure gradients and eventually a dry cold front passage Saturday
afternoon and evening. Temperatures will remain warm but do come
down some from Friday. A bigger impact will be increasing
northerly winds which will be squeezing through the Okanogan
Valley and spilling into the Western Columbia Basin. We should see
gusty winds in the Okanogan Highlands as well and red flag
warnings have been issued to address the concern for low humidity
and winds. We will also see an increase of north winds in Stevens
and Pend Oreille Counties as well as the West Plains toward the
Hwy 2 corridor. At this time, these winds look to be a bit weaker
in a sustained standpoint but will have the potential to produce
gusts 20-30 mph, especially along exposed ridge-tops.

Temperatures during the 4th of July festivities will be quite comfortable 
but winds will raise concern for wildfire starts. Even if humidities
climb out of critical thresholds by dark. Please be advised that
fuels around the region are generally as dry as they are by late
August and this will elevate the risk for wildfire ignitions
around fireworks whether there is a red flag warning or not. /sb

Saturday evening through Thursday...Northerly flow between the
edge of a ridge with axis over the Gulf of Alaska with departing
trof in Northern Montana keeps some breezy conditions going
through the evening in some locations. This northerly flow has a
nice influence on temperatures for Sunday as they are about 10
degrees cooler in comparison to Friday's high temps, yet they are
still above normal for this time of year given this ridge. The
ridge axis remains off the coast for the remainder of the forecast
which means there is potential for more weather disturbances to
drop down along the east edge of the ridge in a northwest to
southeast trajectory through Wednesday. The GFS and the ECMWF
suggest the best potential for such a scenario in the Tuesday and
Wednesday time intervals and limits the measurable precipitation
generated in the form of showers and thunderstorms to the extreme
Northeast Portion of Washington and the Northeast edges of the
North Idaho Panhandle. By Thursday models suggest the ridge is
undercut by westerly flow and leaves Eastern Washington and
Northern Idaho somewhat of a split flow with the jet stream and
active weather associated with it well to the north and a closed
low over Central California that has nuisance mesoscale
disturbances rotating around it well to our south. /Pelatti

&&

.AVIATION... 18Z TAFS: A dry and stable airmass will remain over
the aviation area allowing for VFR conditions at all TAF sites
through 18Z Friday with the exception of a small chance of
thunderstorms up in North Idaho near the Canadian Border. /Pelatti 


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        69 100  67  96  64  89 /   0   0   0   0   0   0 
Coeur d'Alene  63  97  63  94  61  85 /   0   0   0   0   0   0 
Pullman        58  97  58  93  56  90 /   0   0   0   0   0   0 
Lewiston       70 105  70 101  68  97 /   0   0   0   0   0   0 
Colville       63 102  62  98  59  93 /   0   0   0   0   0   0 
Sandpoint      59  96  55  93  54  85 /   0   0   0  10  10   0 
Kellogg        60  97  61  92  58  86 /   0   0   0   0   0   0 
Moses Lake     69 107  67 101  69  96 /   0   0   0   0   0   0 
Wenatchee      75 105  72 101  72  98 /   0   0   0   0   0   0 
Omak           70 104  68  98  64  96 /   0   0   0   0   0   0 

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Heat Advisory until 9 PM PDT Friday for Lewis and Southern Nez 
     Perce Counties-Lewiston Area.

WA...Heat Advisory until 9 PM PDT Friday for Lower Garfield and 
     Asotin Counties-Moses Lake Area-Okanogan Valley-Upper 
     Columbia Basin-Washington Palouse-Wenatchee Area.

     FIRE Weather Watch from Friday afternoon through Friday evening 
     for East Washington Central Cascade Valleys (Zone 677).

     Red Flag Warning from Noon to 10 PM PDT Saturday for East 
     Washington Northern Columbia Basin (Zone 673)-East 
     Washington Okanogan Highlands (Zone 687)-East Washington 
     Okanogan/Methow Valleys (Zone 684).

     Red Flag Warning from 3 PM to 9 PM PDT Friday for East 
     Washington South Central Cascade Valleys (Zone 676).

&&

$$

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Western Regional Climate Center, wrcc@dri.edu