Area Forecast Discussion
Issued by NWS Boise, ID

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FXUS65 KBOI 190808

Area Forecast Discussion
National Weather Service Boise ID
208 AM MDT Fri Apr 19 2019

.SHORT TERM...Today through Monday...Southwest flow aloft ahead
of an approaching trough will advect warmer and more unstable air
into the region today. Showers and thunderstorms will develop
this afternoon in or near our northwest forecast area, generally
in or near Baker County. Temps will warm today to their warmest
readings of 2019 so far, with upper 70s to lower 80s in the lower
elevations, and 60s and 70s in the mountains. The approaching
system will bring a cold front through the area tonight, and as it
moves from northwest to southeast, the chance for showers and
thunderstorms will spread southeast with it. Thunderstorms should
end by around midnight, but showers will continue overnight. By
Saturday morning, the chance for precipitation will be seen area-
wide. With daytime heating, the chance for thunderstorms returns
Saturday afternoon and evening, with the best chance over the
southeast part of the forecast area, generally south and east of
Boise. Temps will cool significantly on Saturday behind the cold
front, with readings down around 15 degrees from today`s highs.
Sunday will be a little warmer than Saturday, and most of the
precipitation will move off to the east as the upper level trough
departs in that direction. Monday will be dry and warmer, with
temps around 5 degrees above normal. There may be enough
precipitation in Harney County to put the Silvies River into minor
flooding Sunday, but confidence is not high enough at this time
to issue a flood warning. We will analyze additional data later
today, so watch for later statements.

.LONG TERM...Monday night through Thursday...A weak upper ridge
moves across the area Monday Night and early Tuesday, but flattens
by late Tuesday, and a shower in the northern mountains late
Tuesday is not out of the question. Better chances for precip on
Wednesday and Thursday as the storm track sags slightly further
south, and some weak shortwaves brush by to the north. None of
these waves look particularly strong, and timing is fairly
different among models. Thus, kept precip chances fairly low, and
concentrated over the mountains, with a slight chance of
thunderstorms in the afternoon on Wed/Thu. Temperatures should
warm slightly from about 5 degrees above normal on Monday, to 5-10
degrees above normal by Thursday. Models seem to agree that a
weak trough will start to move in by Friday, so started
temperatures trending slightly downward for Friday.


.AVIATION...VFR. Showers and isolated thunderstorms associated
with a cold front moving into KBKE area by late afternoon, then
spreading into KBNO-KMYL line late evening and overnight. Surface
winds: SE 10- 15 kts in Snake River plain, elsewhere SW 5-15 kts
by late afternoon. Shifting to NW 15-25 behind front in the
evening, with higher gusts near thunderstorms. Winds aloft near 10
KFT MSL: SW 10- 20 kts.

Weekend outlook: Cloudy, with showers and isolated thunderstorms,
mainly over terrain. Mountains obscured. Clearing from the west
Sunday afternoon. Breezy northwest winds developing behind the
cold front, with occasional gusts to 25 kts in the valleys.





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