Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Spokane Washington
427 am PDT Sat Jul 4 2015
hot and dry weather will be featured for the Independence day
weekend. Today winds will shift to the north and increase as a
front sags in from Canada. Breezy conditions continue on Sunday.
It is still looking dry and warm into the beginning of next week.
today through Sunday...a dry cold front will sag south across the
inland northwest later today, bringing increasing northerly winds
to the Okanogan Valley late this morning that will spill out into
the Waterville Plateau and western Columbia Basin by around noon.
Winds will continue to increase during the afternoon and early
evening hours with sustained winds of 15 to 25 mph and gusts to 35
mph. This will combine with very low relative humidity to produce
critical fire weather conditions. The red flag warning remains in
effect for these areas, fwz673, 684 and 687, through 10 PM. The
northeast Washington fire districts will see lighter winds during peak
daytime heating (and minimum rh) so the decision was made to not
expand the warning to fwz686. It will still be hot and dry, but
winds will be less of a concern. There will be almost no
precipitation with this front so temperatures will remain hot.
Expect readings a few degrees cooler than friday's numbers, which
will still be well above seasonal normals.
As the front pivots through the forecast area tonight, the focus
will shift to northeast Washington and the northern Panhandle of
Idaho. There may even be an isolated thunderstorm or two for the
northern Panhandle mountains early Sunday morning but confidence
is low. The winds continue to be the main concern. Northeast winds
will be channeled down the Purcell Trench into the West Plains.
Fortunately, the winds will be increasing during the overnight
hours while relative humidity is recovering. There is a low
probability of critical winds and low relative humidity for Sunday afternoon but
for now it looks like rhs will recover a bit behind the front as
slightly cooler air arrives from the north. Temperatures will cool
a bit with some of the northern valley locations in the 80s. We
will continue to re-evaluate expected fire weather conditions with
the next forecast package. /Kelch
Sunday night through Saturday...the models are in decent agreement
handling the current weather pattern(s). Deep low pressure
centers anchor the end points in the Gulf of Alaska and in the
vicinity of Hudson Bay. In between high pressure will build in the
eastern Pacific. This will put the inland northwest in a northwest
to northerly flow through about Wednesday, depending on what model
you like. A weather disturbance moving through the northerly flow
will clip the northeast zones Tuesday and Tuesday night. Behind
that disturbance high pressure will build back into the pac northwest
through Thursday in response to the Gulf of Alaska low moving into
the eastern Pacific. By Friday night/Saturday the models are
hinting that the Gulf of Alaska low will move into position just
off the coast.
Sunday night to Monday night expect a slight rebound of the
temperatures and a continued dry forecast gusty winds from Sunday
will decrease and remain out of the northwest.
Tuesday and Tuesday night...increased moisture with the aforementioned
short wave will tap into both surface based and mid level
instability and result in a chance for showers and thunderstorms.
These storms will be focused along the northeast Washington
mountains and the north Idaho Panhandle. The convection should be
isolated at best, but any lightning after this extended period of
dry weather will result in potential fire starts. The remainder of
the region will remain dry with temperatures 8-12 degrees above
normal. Another thing we will need to keep an eye on will be
increased winds down the Okanogan Valley Tuesday. At this time it
doesn't look like a strong front but winds will be on the
Wednesday and Thursday another transient ridge axis will track
across the area for a period of very warm and dry conditions.
Friday and Saturday things may get interesting. All of the model
guidance is indicating the upper low will move to just off the
Washington coast in some form or other. This is the a very good
pattern east of the Cascades for a convective outbreak as
southerly flow will tap into fairly deep sub-tropical moisture. If
this pattern verifies there will be a chance for thunderstorms
both Friday ad Saturday. Thunderstorms possibly starting off high
in the atmosphere for virga, little precipitation, and gusty
outflow winds on Friday and Friday night...then becoming much
wetter Saturday. Tobin
12z tafs: a dry airmass will allow for VFR conditions at all taf
sites. Winds at keat will remain occasionally breezy through
this afternoon. Elevated smoke layers from area wildfires will
appear as thin mid level clouds but surface visibility will not be
affected. Northerly winds will pick up aft 00z along the Canadian
border and push south through the evening hours towards kgeg kcoe
and kmwh. /Ek
Preliminary point temps/pops...
Spokane 98 67 89 61 91 67 / 0 10 10 0 0 0
Coeur D'Alene 95 62 85 57 89 61 / 0 10 10 0 0 0
Pullman 94 59 89 53 90 56 / 0 0 10 0 0 0
Lewiston 103 71 98 65 98 68 / 0 0 0 0 0 0
Colville 100 61 92 57 94 62 / 0 10 10 0 0 10
Sandpoint 94 54 83 49 88 54 / 0 10 10 0 0 10
Kellogg 94 61 83 52 88 57 / 0 10 10 0 0 0
Moses Lake 102 71 97 66 98 68 / 0 0 0 0 0 0
Wenatchee 103 75 98 72 99 72 / 0 0 0 0 0 0
Omak 100 66 96 63 97 65 / 0 0 0 0 0 10
Washington...red flag warning from noon today to 10 PM PDT this evening for
East Washington northern Columbia Basin (zone 673)-East
Washington Okanogan Highlands (zone 687)-East Washington
Okanogan/Methow valleys (zone 684).