Weather Service Report


085 
FXUS66 KOTX 281122
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
422 AM PDT MON JUL 28 2014

.SYNOPSIS...
Hot temperatures and dry weather will continue through midweek.
Thunderstorms chances will increase during the latter portion of
the work week as monsoonal moisture overspreads the Inland
Northwest.

&&

.DISCUSSION...
Today to Tuesday: Dry, hot conditions prevail. A high-amplitude
ridge is anchored over the Rockies and the Inland NW will be in a
southwest flow on its west side. Mid-level disturbances in the
flow skirt eastern WA and north ID, but aside from some clouds
they aren't expected to generate much of a precipitation threat.
One disturbance, a mid-level shortwave, was tracking into WA early
this morning and all guidance brings it into Montana around
midday. The available instability (HLTT, elevated CAPE, negative
dtheta/dz lapse rates) looks too weak to generate much of
precipitation or thunder threat. In addition, much of the moisture
is above ~12,000 feet and this moisture shifts east-northeast
through the morning. There have been a few returns on radar, but
at most I might expect a few sprinkles. A secondary disturbance
follows on its heels and passes by southeast WA and the lower ID
Panhandle. But it appears to weaken as it transits the area. Any
SBCAPE that develops through the day looks well capped. So that
secondary disturbance also does not appear to bring much of a
threat of precipitation this afternoon. Models do generate some
precipitation near the Clearwaters into northeast Oregon, but this
is expected to stay here. In general look for decreasing clouds
through this morning. Tuesday looks relatively quiet and
disturbance-free, though one shortwave starts to approach late in
the day. Look for a few more high clouds to enter then. Models
once again generate some showers around the Clearwaters into
northeast Oregon. But these are not expected to reach into our
area. Temperatures are expected to be hot today and Tuesday. Under
the ridge and southwest flow, 850mb temperatures warm about 3 to 5
degrees C over Sunday. This supports highs well above normal. This
means many areas reaching the middle to upper 90s and some areas
pushing into the lower 100s. A heat advisory remains in place
across the Columbia Basin, Palouse and L-C valley. It is a
borderline event, meaning forecast highs skirt advisory criteria.
But either way expect noticeable summertime heat. /J. Cote'

Tuesday night through Sunday...Models are in good agreement in
maintaining a strong ridge pattern over the forecast area through
the next week with a stubborn surface thermal trough over the
Columbia Basin. As yet neither the GFS or ECMWF advertise a return
to a more progressive Pacific flow regime within the confidently
foreseeable future...at least the next 5 to 7 days. This argues
strongly for a continued hot forecast. Less confidence concerns
the threat of monsoonal moisture fed thunderstorm activity...which
if history is any guide should eventually come to fruition under
this pattern. The latest guidance is converging on a common
solution in bringing a moisture surge and short wave impulse
up from the south and clipping across the southeastern zones and
Idaho Panhandle Wednesday afternoon and Wednesday night. This is
the highest confidence thunderstorm forecast in the extended
period. Beyond Wednesday some more moisture surges are
probable...possibly encompassing more of the region than the
Panhandle...but the models are somewhat nebulous and out of
agreement regarding details and timing these thunder fuel
injections. Thus...a small mention of thunderstorms across mainly
the eastern half of the forecast area each day is warranted...but
no sure bets for any particular day being especially active at
this time. /Fugazzi 


&&

.AVIATION...
12Z TAFS: Mid/high level clouds will move over the area Monday
morning, decreasing after 15-18Z. A sprinkle is possible over
eastern WA and north ID before 16Z. Otherwise weather will remain
VFR for the next 24 hours. /J. Cote'


&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        97  67  99  69  94  67 /   0   0   0   0  10  10 
Coeur d'Alene  95  61  97  64  91  62 /   0   0   0   0  10  20 
Pullman        97  57  97  61  90  61 /   0   0   0  10  20  20 
Lewiston      103  69 103  72  97  68 /   0   0   0  10  20  20 
Colville       98  57 100  60  98  59 /   0   0   0   0  10  10 
Sandpoint      92  54  94  57  91  57 /   0   0   0   0  10  20 
Kellogg        92  61  93  62  88  60 /   0   0   0   0  20  20 
Moses Lake    102  64 103  67  98  67 /   0   0   0   0  10  10 
Wenatchee     102  71 102  71  98  70 /   0   0   0   0  10  10 
Omak          101  65 103  66 101  66 /   0   0   0   0  10  10 

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Heat Advisory from 1 PM this afternoon to 8 PM PDT Tuesday for 
     Lewiston Area.

WA...Heat Advisory from 1 PM this afternoon to 8 PM PDT Tuesday for 
     Lower Garfield and Asotin Counties-Moses Lake Area-Upper 
     Columbia Basin-Washington Palouse.

&&

$$


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