Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 011127
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
427 AM PDT SUN MAY 1 2016

.SYNOPSIS...
High pressure builds Today and Monday, resulting in a warming
trend, with temperatures climbing into the mid 70s to low 80s.
High pressure shifts east toward the middle of next week, allowing
a chance for showers and thunderstorms to return by Wednesday.
Improving conditions will begin on Friday.


&&

.DISCUSSION...
Today through Monday...High pressure will be in control of the
weather across the region. Skies are clearing across the Inland
Northwest under a building ridge, bringing dry conditions and
temperatures warming a good 10 degrees above seasonal normals. The
warming trend will continue on Monday with valley locations in the
upper 70s to low 80s. The only threat of precipitation will be
across the southeast zones Monday afternoon as some mid level
moisture tries to move up from the south and this probability is
quite low. The warm temperatures will bring on increased snow melt
which will allow some of the area creeks and streams to rise
to bankfull. /Kelch

Tuesday...One last day of quiet and warm conditions will occur on
Tuesday before a general deterioration into a cooler and more
active spring time weather regime overtakes the region. Tuesday is
shaping up to be the warmest day of the week as southerly flow
aloft pumps some warm air into the region and a weak early season
thermal trough sets up over the Columbia Basin. Moisture will be
increasing as well as the incoming Pacific trough responsible for
the southerly flow entrains a fetch of deep moisture. The Cascades
will be enveloped in this moist flow as the day wears on with an
increasing chance of showers and thunderstorms by late afternoon.
The rest of the forecast area will remain dry and warm. These
temperatures will aggravate mountain snow melt and lead to rises
on mainstem rivers draining the Cascades during the week with
several rivers expected to achieve action stage...detailed in the
River Statement issued yesterday.

Wednesday and Thursday...Latest models are in agreement in
forcing the approaching Pacific trough into the region during this
time frame. Rather than a classic progressive transit...this
trough will be digging and eventually pinching off into the Great
basin during the week...so the associated cold front and
precipitation potential will be a slow and lingering evolution
characterized by a scattered shower and thunderstorm regime
enveloping the entire forecast area Wednesday with the actual cold
front slowly dragging through the region with numerous showers
Wednesday night and Thursday. The main threat associated with this
period...particularly on Wednesday...will be the potential for
brief heavy rain producing thunderstorms rolling over recent burn
scars in the Cascades and Okanogan area. Flash Flooding on these
fresh scars is possible and will be the subject of today`s
Hazardous Weather Outlook product...with future shifts analyzing
the potential for issuing a Flash Flood Watch if the ingredients
continue to come together as depicted on current model runs.

Thursday night and Friday a general drying out period is expected
as the forecast area comes under a weak flop-over ridge/weather dead
zone north of the pinching off Great Basin upper low. Breezy north
or northeast winds will advect some drier Canadian Continental
air into the region leading to a noticeable cool down in
temperatures leading into next weekend with no further significant
storm systems identifiable from Friday through Saturday. /Fugazzi


&&

.AVIATION...
12Z TAFS: Patchy fog near sheltered mountain valleys will diminish
after sunrise. KSFF, located right next to the Spokane River, will
have occasional MVFR conditions through 14Z. Then VFR conditions
will prevail at all TAF sites under building high pressure. /EK



&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        74  49  79  52  80  53 /   0   0   0  10   0  10
Coeur d`Alene  75  45  79  48  80  50 /   0   0   0  10  10  10
Pullman        71  45  77  48  79  49 /   0   0   0  10  10  10
Lewiston       76  49  81  51  84  53 /   0   0   0  10  10  10
Colville       80  42  82  45  81  46 /   0   0   0  10  10  10
Sandpoint      73  39  78  42  78  45 /   0   0   0   0  10  10
Kellogg        71  41  79  43  78  46 /   0   0   0   0  10  10
Moses Lake     79  44  83  48  84  49 /   0   0   0  10   0  20
Wenatchee      79  51  83  54  82  54 /   0   0   0  10  10  20
Omak           78  46  82  50  83  51 /   0   0   0  10  10  20

&&

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

$$


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