Area Forecast Discussion
Issued by NWS Spokane, WA

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FXUS66 KOTX 240526
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
1026 PM PDT Sat Jul 23 2016

.SYNOPSIS...
A warm and mostly dry summer pattern will arrive this weekend and
persist through next week. However there will be minor shower
and thunderstorm chances near the Canadian border, from time to
time, through Thursday. High temperatures in the 90s will be
common for nearly all towns Thursday through at least Saturday.

&&

.DISCUSSION...
Tonight through Tuesday...A zonal (westerly) flow will be over the
Inland NW through Tuesday. Moisture is limited in this flow through
Monday morning with dry air aloft supporting clearing skies this
evening after flat cumulus dissipates with the loss of daytime
heating. Flat cumulus will redevelop over the mountains Sunday
afternoon but with a warmer and drier air mass expect less
coverage of this compared to today. A weak wave then tracks into
the region Monday afternoon into Tuesday. This wave first reaches
the Cascades Monday afternoon. This combined with steep lapse
rates away from the crest may trigger scattered showers and
thunderstorms with the best chances from Lake Chelan north to the
Canadian border. Scattered showers and thunderstorms expand to
include the northern mountains on Tuesday. Surface based CAPE
values of 1000-1500 J/KG combined with a moist atmosphere with
precipitable waters increasing to near an inch will support
locally heavy rain and small hail with storms. Severe
thunderstorms are not expected with 0-6km shear values of only
10-15 kts.

A warming trend is expected through Monday as 850mb temperatures
warm to near 20C Sunday and 23C Monday. This will support high
temperatures rising into the upper 80s to mid 90s. Then a few
degrees of cooling on Tuesday as the weak wave tracks through. JW

Wednesday through Friday: The Pacific Northwest has largely
escaped hot weather so far in July. Wenatchee has only had 3 days
at or above 90 degrees, and Spokane International has only hit 90
once. The ECMWF and GFS are in good agreement that we will add
several 90 degree days to our July stats next week. The hot high
pressure ridge responsible for the oppressively hot conditions
over the central U.S. will retrograde into southern California and
the Desert Southwest Wednesday and Thursday and remain through at
least Saturday. At this time, it looks like Friday and Saturday
will be the hottest days of the week with mid to upper 90s
throughout the region. Our typical hot spots in the L-C Valley and
Columbia Basin will likely flirt with 100 Fri and Sat.

Saturday: If the medium range models verify, we can expect a cold
front next weekend. The latest GFS, ECMWF, and Canadian models
suggest that the front will arrive next Saturday or Saturday
night. At this time, it looks like a dry frontal passage. We will
be watching this closely. Breezy winds, hot temperatures, and low
humidity often raise wildfire concerns with this type of pattern
in late July. /GKoch

&&

.AVIATION...
06Z TAFS: Weak high pressure will allow VFR conditions to prevail
at all TAF sites for the next 24 hours or more. /Pelatti

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        55  86  60  91  63  89 /   0   0   0   0  10  10
Coeur d`Alene  52  86  55  91  59  89 /   0   0   0   0  10  10
Pullman        47  85  50  90  54  87 /   0   0   0   0  10  10
Lewiston       57  93  61  97  66  95 /   0   0   0   0  10  10
Colville       49  88  51  93  56  88 /   0   0   0   0  10  40
Sandpoint      47  82  49  87  52  86 /   0   0   0   0  10  20
Kellogg        49  83  52  87  54  86 /   0   0   0   0  10  10
Moses Lake     54  89  57  94  62  93 /   0   0   0   0   0  10
Wenatchee      60  89  64  93  67  90 /   0   0   0   0  10  10
Omak           57  90  60  94  65  92 /   0   0   0  10  20  10

&&

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

$$



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