Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 300021
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
521 PM PDT FRI APR 29 2016

.SYNOPSIS...
Showers will linger over the region into Saturday with isolated
thunderstorms possible mainly over the Idaho Panhandle for the
afternoon. High pressure will build in Sunday resulting in a
warming trend heading into next week. Temperatures will climb to
above normal once again early next week...with highs mainly in
the mid 70s to lower 80s. High pressure will move east for the
middle of next week allowing increased moisture to move in from
the south...resulting in a chance for showers and thunderstorms.

&&

.DISCUSSION...
Tonight through Saturday night: An upper level low pressure
circulation will hang around the southern Panhandle, but also fill
in over the next 24 hours. Moisture will continue to wrap around
this low into the region with showers pushing from north to south.
The best axis of moisture along a weak deformation band will
generally be across the extreme eastern portion of WA. This band
will generally remain stationary or shift slightly eastward
through tonight, but models are in general agreement that rainfall
will be becoming less and less overnight. Skies should begin to
clear from west to east as this band slowly does shift further
east. This is expected to result in enough radiational cooling for
fog to develop in the Okanogan Highlands and into portions of the
Northeast Mtns for early Saturday morning.

The eastern third of the region will remain conditionally unstable
for Saturday afternoon. Dew points across the Northeast Mtns and
over into the ID Panhandle will be in the low 40s. I expect this
will result in enough surface based CAPE for the possibility of
isolated thunderstorms during peak heating hours. Temperatures
will warmer on Saturday closer to average for late April or early
May with highs warming into the 60s to low 70s. /SVH

Sunday through Tuesday night...Models are in good agreement that the
building ridge poised off the Washington coast will fold over the
Inland NW by Sunday and then slowly migrate eastward through the
remainder of this period. For Sunday and Monday this will equate
to a substantial warming and drying trend with little threat of
precipitation. High temperatures will climb into the 70s on Sunday
for valley locations and then into the mid 70s to lower 80s on
Monday. Average highs for this period are generally in the 60s.

The ridge is expect to continue to amplify through Tuesday and
Tuesday night while moving into western Montana. This will result
in additional warming and highs in the upper 70s to mid 80s.
This latest round of warm weather will take another bite out of
the existing snowpack which will lead to a renewed round of river
rises. None are expected to flood during this time period but
minor flooding could develop later in the week. More noteworthy
will be an influx of moisture on the back side of the ridge.
Precipitable water values will near 0.80 inches near the Cascades
in the southerly flow and diurnal heating could produce just
enough instability for some showers and even a thunderstorm. The
greatest risk will be near the Cascades as the remainder of the
forecast area will be too stable with relatively warm air aloft.
fx

Wednesday through Friday: Models are showing this to be a very
active period. A low off the Oregon Coast will push a series of
shortwaves through the region. Currently, the instability
associated with these shortwaves is expected to produce
thunderstorms for the Inland Northwest. The expected impacts will
brief heavy downpours, small hail, and gusty winds. High
temperatures will range from the mid 70s to low 80s. Lows will
range from the mid 40s to low 50s. /JDC

&&

.AVIATION...
00Z TAFS: Light rain wrapping around a weakening low near Missoula
MT will linger through Saturday morning over the Idaho Panhandle
and eastern third of Washington. The low will drift southward
through the night, but the moisture left behind will linger into
Saturday. Low stratus is expected to develop at Spokane, Coeur
D`Alene, Pullman, and possibly Lewiston. The high sun angle on the
last day of April should lift and disperse any stratus that
develops by late morning. /GKoch

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        45  65  46  73  50  76 /  50  30  10   0   0   0
Coeur d`Alene  42  65  43  74  46  76 /  60  40  10   0   0   0
Pullman        42  61  42  71  46  74 /  70  50  10   0   0   0
Lewiston       45  67  46  76  49  79 /  60  40  10   0   0   0
Colville       43  69  42  78  45  79 /  70  20  10   0   0   0
Sandpoint      42  64  39  72  43  75 /  60  40  10   0   0   0
Kellogg        40  62  40  70  43  74 /  70  40  20   0   0   0
Moses Lake     44  73  44  79  48  82 /  30  10   0   0   0   0
Wenatchee      47  75  49  78  51  80 /  10  10   0   0   0   0
Omak           42  73  45  78  49  79 /  30  10   0   0   0   0

&&

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

$$


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