000
FXUS66 KOTX 151144
AFDOTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
444 AM PDT Sat Jun 15 2013

.SYNOPSIS...
Drier, warmer weather can be expected this weekend. The next
weather system arrives Monday, bring showery and cooler weather,
that lingers for much of the upcoming work week.

&&

.DISCUSSION...
Today and tonight: Low pressure will continue to take hold of the
northeast Pacific, while mid-level high pressure promotes mild and
mostly dry conditions across the Inland Northwest. WV/IR satellite
shows a shortwave disturbance pivoting around the offshore low.
This relatively weak feature is progged to slip toward the
Cascades late today into this evening and north into southern B.C.
overnight. The Cascades also come under some mid-level diffluence
as the mid-level ridge axis shifts toward the Idaho Panhandle. For
the most part the shortwave disturbance will lead to increased
middle to higher level clouds through the next 24 hours, especially
closer to the Cascades. Low-grade CAPE (100-200 J/kg or so) near
the Cascade crest later this afternoon and evening will carry a
threat of isolated showers and thunderstorms as well, before
dissipating into the overnight. Guidance shows 850mb temperatures
about 5 degrees milder today as compared to Friday. Given this
factor and the increasing subsidence and modest amount of sunshine,
afternoon temperatures are expected to be near or slightly above
normal. /J. Cote`

Sunday and Sunday night: Temperatures in the region will be higher
than Saturday with some locations in the L-C Valley reaching into
the low 90s. The Cascades will be the best area for any rain
showers as moisture being pushed into the region from the Low in
the Pacific will be pushed over the mountains. A small chance of
thunder is associated with these showers. With the Low moving onto
the land on Sunday night, southerly wind flow will push moisture
from the South increase the chance for precip through most of the
Columbia Basin. A slight increase int he instability in the region
could produce an isolated thunderstorm in the overnight
period. /JDC

Monday through Tuesday...Good and consistent model agreement
suggests the forecast area will experience moist southerly flow
above a surface thermal trough as the next upper low draws nearer
to the forecast area. This is a thundery pattern for the
region...and while models at present do not indicate any
especially strong disturbances in this flow which would be
necessary to kick off any serious convective episodes...the
moisture and at least elevated instability will be increasing
through the period with an increasing chance of afternoon and
evening thunderstorms just about anywhere in the forecast
area...and even a small chance of nocturnal elevated thunderstorms
depending if any sub-synoptic waves or disturbances migrate
through during the overnight periods. By no means will this be a
truly wet pattern (yet) with many locations probably being missed
altogether by prowling showers and storms...but precipitable
water values in the 0.8 to 1.0 inch range will bring the
possibility of brief heavy downpours under the core of some of
these storms as they pass through any particular location.
temperatures will remain well above normal on Monday...but begin
retrograding back to near normal on Tuesday as the incoming low
shifts the thermal trough eastward into Montana.

Tuesday night through Friday...Latest EC and GFS models continue
to forecast the passage of the upper low directly across the
region mainly Wednesday and Thursday. Also both models are coming
into agreement of a deformation precipitation band setting up over
the eastern and northern reaches of the forecast area on Wednesday
and possibly lasting well into Thursday...with some drying
possible by Friday. Thus...confidence is becoming quite high of a
wet and cool period around mid-week for most of the forecast area.
While Monday and Tuesday look to be a hit-and-miss
shower/thunderstorm regime...Wednesday and Thursday appear to be
a downright wet regime featuring dense shower activity everywhere
except the deep basin where merely scattered showers will exist.
Embedded thunder is still possible but will be subdued in favor
of regular and frequent rain showers. Even on Friday models
continue to hint at wrap-around moisture continuing to advect into
the region. Thus...there is high confidence that Wednesday through
Friday will be cool and wet fro most of the region. /Fugazzi

&&

.AVIATION...
12Z TAFS: A ridge of high pressure will bring mostly clear, dry
conditions at most TAF sites for the next 24 hours. The exception
will be near the Cascades. An approaching low will bring thickening
middle and higher clouds into the western TAFs (KEAT/KMWH) late
this afternoon into tonight. A few showers/thunderstorms are
possible within the Cascades later this afternoon and evening as
well. /J. Cote`

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        77  53  84  56  80  54 /   0   0   0  20  10  20
Coeur d`Alene  77  48  84  54  82  52 /   0   0   0  10  20  20
Pullman        78  46  84  49  80  48 /   0   0   0  10  10  30
Lewiston       86  54  90  58  88  56 /   0   0   0  10  10  20
Colville       82  49  87  52  85  50 /   0   0  10  20  40  30
Sandpoint      76  43  82  50  84  48 /   0   0  10  10  20  30
Kellogg        73  48  81  55  81  52 /   0   0   0  10  20  30
Moses Lake     85  56  91  60  86  58 /   0   0   0  10  20  20
Wenatchee      85  61  88  62  84  61 /   0   0  10  20  20  30
Omak           83  53  88  54  84  53 /   0  10  20  20  20  30

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&

$$