Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

000 
FXUS66 KOTX 222325
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
425 PM PDT Thu Jun 22 2017

.SYNOPSIS...
The weather for the weekend will be quite warm. Afternoon
temperatures on Saturday will likely reach the mid 80s to low 90s.
Sunday and Monday will be even warmer with most lowland areas
reaching the 90s. A return to cooler, more average temperatures
are expected by the middle of next week, with breezy conditions
possible late Monday through Tuesday.

&&

.DISCUSSION...
Tonight through Saturday: A high pressure ridge will build in over
the next 48 hours. Strong subsidence and dry air will suppress
cloud cover with clear and sunny skies. Temperatures will see a
warming trend to above normal with widespread 80s Friday and mid
80s to low 90s by Saturday. /SVH

Saturday Night through Monday: The upper level ridge axis shifts 
east into eastern WA which will keep temperatures rising. Sunday 
valley temps will heat up to upper 80s to mid 90s, with a few 
degrees of additional warming on Monday. Monday will be the 
warmest day in the 7 day forecast. These daytime temps are 14-18 
degrees above average and overnight lows 5 to 12 degrees above 
average for this time of the year. Mostly clear skies are expected
with some cirrus streaming in Sunday and Monday. Monday afternoon
southwesterly winds start to pick up across the east slope into 
the Columbia Basin as the ridge gets pushed east. 

Monday evening and Tuesday: Lots happening these periods. The 
first is the models showing some energy moving up from the 
southwest Monday evening into Tuesday morning. Models have a very 
difficult time nailing down the specific track of these waves, but
it looks to mainly impact southeast WA and the southern ID 
Panhandle. The GFS-that shows the strongest waves-has quite a bit
of convective inhibition which would make it difficult for 
thunderstorms to get going. However given the pattern recognition 
have added thunder across extreme southeast WA and the southern ID
Panhandle with the hopes of honning in on it better as the event 
approaches and the models can see better detail of timing and 
track. 

The second weather feature to watch is a low pressure system 
moving into Canada from the Gulf of Alaska. There are some pretty 
big model differences and the confidence in this portion of the 
forecast is quite low. The GFS has been consistent in digging that
low down into our area on Tuesday while the ECMWF has been 
consistent with itself in keeping the low in northern BC and 
Alberta. Of course the models are consistent with themselves but 
totally different from each other! The Canadian seems to track the
low right in the middle of the other two models. The Canadian as 
well as the EC keep the forecast dry. Wasn't confident to take out
our slight chance showers across NE WA and north ID along the 
canadian border, but didn't increase our chance of precipitation. 

With the breakdown of the ridge and the low pressure moving 
somewhere to the north of WA, our winds will increase. Winds will 
pick up Monday evening and continue through the night and into 
Tuesday evening. They look to peak Tuesday late afternoon and 
early evening. The main area of concern is from the central east 
slopes of the Cascades east into the Columbia Basin and into the 
Palouse and Spokane area. The winds Monday will be a concern as RH
values will be in the upper teens to near 20 percent. This will 
bring fire weather concerns to the Columbia Basin. Tuesday the 
winds will be slightly stronger, but temperatures should drop 
about 10 degrees and RH values should come up a bit. 

Wednesday and Thursday: Models are having trouble with what to do
with the ridge to the west and whether or not to bring a cut off
low into the region. Temperatures will remain at or above average
for this time of the year. Low confidence on our chance of precip
across extreme NE WA and north ID. /Nisbet

&&

.AVIATION...
00Z TAFS: Dry northwest flow will bring VFR conditions to the TAF
sites through the period. Locally gusty westerly winds will taper
off early near KPUW & KLWS with light north/east winds overnight.
Light winds will continue into Friday with speeds under 10kts.
/rfox. 

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        50  82  55  87  59  91 /   0   0   0   0   0   0 
Coeur d'Alene  46  79  50  84  54  89 /   0   0   0   0   0   0 
Pullman        45  80  51  85  55  89 /   0   0   0   0   0   0 
Lewiston       53  86  56  91  59  96 /   0   0   0   0   0   0 
Colville       46  82  48  87  52  91 /   0   0   0   0   0   0 
Sandpoint      43  79  45  84  49  86 /   0   0   0   0   0   0 
Kellogg        44  78  49  83  51  88 /   0   0   0   0   0   0 
Moses Lake     50  88  55  93  56  97 /   0   0   0   0   0   0 
Wenatchee      55  87  60  92  62  96 /   0   0   0   0   0   0 
Omak           51  86  55  91  55  94 /   0   0   0   0   0   0 

&&

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

National Weather Service Glossary of Abbreviations