Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 042116
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
216 PM PDT WED MAY 4 2016

.SYNOPSIS...
Several rounds of showers and storms will be possible across the
region tonight and into Thursday. Some storms will be capable of
heavy rainfall...hail...and gusty winds. Improving but breezy
conditions will begin on Friday, lasting through the weekend.

&&

.DISCUSSION...

Tonight through Thursday...A moist southerly flow of moisture and
energy keeps this time interval unsettled and cluttered with
showers and thunderstorms in various shape and/or form. A storm
motion from south to north at 25 mph keeps the thunderstorms
moving quickly overnight tonight. Thursday the storm motion
changes to a slower motion to the southeast at less than 5 mph
over the East Slopes of the Cascades and into parts of the
Okanogan Highlands down to part of the Columbia Basin while
further east over Extreme Eastern Washington and North Idaho the
storm motion is a bit quicker and expected to move storms
southwest to northeast at 15 to 20 mph. The instability is greater
over southeast Washington and all of the North Idaho Panhandle
Thursday which is one of the reasons it is mentioned in a Marginal
Risk of Severe Weather in the Storm Prediction Center Day 2
Outlook. Gusty wind, small hail, and brief heavy downpours are the
expected nuisance weather associated with any thunderstorms.
/Pelatti

Thursday night through Wednesday: The Inland NW dries out
and warms up before a threat of mainly mountain showers returns
early next week. Between Thursday night and Saturday a strong cut-
off low sags toward the Desert Southwest, placing our region in an
east to northeasterly flow. A weakening deformation axis and minor
impulsing rounding the north side of the low will keep a slight
risk for showers and thunderstorms across the southeast CWA
through Saturday. The remainder of the CWA will be dry. However
winds will be a concern with a tight northeast to southwest
gradient. Winds should be breezy both Friday and Saturday. Yet
winds look strongest on Friday with speeds in the 15-20 mph range
and gusts to 30 mph, before they start to slacken going into
Saturday.

From Sunday into Wednesday the next long-wave trough (now moving
into the Gulf of AK) migrates into western Canada and then into
the northern Rockies. Sunday moisture starts to creep up from the
south again, bolstering shower chances near the southeast CWA.
Other chances return to the northern mountains. Sunday night into
Wednesday the jet streams sags into the Inland Northwest, carrying
shortwaves and the threat of showers in. However the threat will
be somewhat limited by the fact not a lot of deep moisture or
instability comes into the region. What does exists appears best
across northern WA and ID Panhandle mountains and so is where the
best shower threat will be. Expect breezy conditions between
Sunday and Monday with the incoming trough too. Temperatures
undergo a warming trend through Sunday, with highs some 10-15
degrees above normal, before the trough pushes values back down to
maybe 5 degrees above normal. /J. Cote`

&&

.AVIATION...
18Z TAFS: A south to north flow of moisture will allow for showers
and thunderstorms to move up from south to north with a storm
motion of 30 mph and bring MVFR ceilings and visibilities to the
aviation area. Currently some light elevated convective showers
are moving north at 30 mph through the aviation area but those
should diminish during the day. The expectation is more
thunderstorms will develop and primarily in the time interval
between 23Z Wednesday through 12Z Thursday. Heavy rain, small
hail, and gusty wind will be the primary nuisance associated with
these thunderstorms. /Pelatti

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  73  52  76  54  81 /  50  60  50  10  10   0
Coeur d`Alene  52  74  49  74  50  81 /  50  60  50  10  10  10
Pullman        51  70  48  74  49  79 /  50  50  50  10  10  10
Lewiston       56  76  52  79  54  84 /  40  40  50  20  10  10
Colville       50  71  45  79  47  85 /  40  70  50  10  10   0
Sandpoint      50  72  45  72  44  79 /  30  60  50  20  10   0
Kellogg        49  74  44  72  44  79 /  30  50  50  30  20  10
Moses Lake     53  75  49  81  53  87 /  60  40  20  10   0   0
Wenatchee      55  74  53  81  57  87 /  60  40  20  10  10   0
Omak           54  72  48  80  53  85 /  50  60  30  10   0   0

&&

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

$$


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