Dust Devil in Washington, May 1, 2019

Area Forecast Discussion
National Weather Service Pendleton OR
Issued by National Weather Service Spokane WA
257 PM PDT Wed May 1 2019

.SHORT TERM...Tonight through Saturday night: Broad northwest
flow aloft on the backside of a departing low will continue to
deliver a dry weather pattern into the weekend. There are a pair
of midlevel shortwaves swinging through; one coming through this
afternoon and a second on Thursday. The main impacts from these
waves will be a tightening pressure gradient and continuation of
breezy conditions. Wind gusts of 20-25 mph will be common with
locally stronger speeds channeling through the Columbia Gorge and
Kittitas Valley. The air mass will slowly moderate resulting in a
subtle warming trend and afternoon highs in the 50s and 60s on
Thursday toward the 70s by Saturday. /sb

.LONG TERM...Sunday through Wednesday: The large scale weather pattern
doesn't change very much for the start of the new week with
northwest flow persisting between high pressure over the Gulf of
Alaska and low pressure over the Canadian Plains. Models are in
decent agreement of a few more shortwaves dropping in from the
northwest but differ slightly on the exact timing and strength.
The first wave arriving late Sunday will usher a weak cold front
through increasing west to northwest winds. If timing
holds...Sunday should be the warmest day of the week with
afternoon highs in the 70s to lower 80s ahead of the frontal
passage. Limited moisture accompanying the front will result in
increasing clouds but little in the way of precipitation. A second
wave arrives Monday into Tuesday and will take a more north to
south trajectory as the high pressure ridge from the Gulf of
Alaska flops into British Columbia. This system will slow down
and tap into a deeper pool of moisture coming across the Northern
Rockies bringing a better chance for showers across Eastern
Oregon. Instability may deep enough to warrant a few afternoon
thunderstorms but confidence was too low to include in the
forecast at this time. Temperatures will cool into the start of
the week but generally remain above seasonal normals, topping out
in the 60s and 70s. /sb

&&

.AVIATION...18Z TAFs...VFR conditions will prevail for the next 24
hours with SCT TO BKN layers of mid and high level clouds through
the period. Winds will be light for most of the period, but breezy
conditions from the west-northwest are possible this afternoon and
evening through the eastern Columbia River Gorge, the Kittitas
Valley, and eastern foothills of the High Cascade west of RDM and
BDN. /aky

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  38  64  39  69 /   0   0   0   0
ALW  43  66  44  71 /   0   0   0   0
PSC  45  71  46  74 /   0   0   0   0
YKM  39  68  41  71 /   0   0   0   0
HRI  42  70  43  74 /   0   0   0   0
ELN  37  63  39  68 /   0   0   0   0
RDM  31  63  34  70 /   0   0   0   0
LGD  35  60  36  68 /   0   0   0   0
GCD  33  63  36  70 /   0   0   0   0
DLS  41  68  42  74 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&

99/99/