Area Forecast Discussion
Issued by NWS Boise, ID

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FXUS65 KBOI 260943

Area Forecast Discussion
National Weather Service Boise ID
343 AM MDT Tue May 26 2020

.SHORT TERM...Today through Thursday night...Zonal flow will
continue to bring in a stream of moisture into the Pacific NW
through the short term, keeping a threat of showers across the
area at times. Models have not handled the showers very well
earlier this evening. Upper level dynamics with this feature is
almost non existent compared to the amount of moisture associated
with the system. Precipitable water values are in the 95th
percentile for this time of year lasting now through Wednesday
evening. Surface dewpoints are in the mid 50s to low 60s! The
hires models have a shortwave moving across the region late
tonight into early Wednesday morning, and it shouldn`t take much
forcing to get showers going, given the amount of moisture in the
ATM to work with. A moisture gradient will set up along the Nevada
border, which may help trigger thunderstorms this afternoon and
again on Wednesday afternoon. The moisture tap will shut off on
Wednesday evening as the flow shifts to the southwest as warmer
and drier air moves into the area. Temperatures will be around 5
degrees above normal today, warming to around 15 degrees above
normal by Thursday. A weak shortwave combined with strong surface
heating may trigger some thunderstorms in eastern OR Thursday
evening, particularly in Harney and Baker County.

.LONG TERM...Friday through Tuesday...Ridging continues on Friday,
with hot temperatures expected. Weak moisture within the ridge will
generate a few higher elevation showers and thunderstorms through
the evening hours. An area of low pressure will move north along
the California coast on Saturday, sending additional surges of
moisture into the forecast area during the afternoon. Despite the
presence of this system, temperatures will continue to warm on
Saturday ahead of the system`s arrival. Sunday will see relief from
the hot temperatures in response to the passage of the low pressure
system on Saturday. Temperatures will be 10 to 15 degrees cooler
compared to values experienced on Saturday, with values
continuing to cool through Tuesday. Periods of unstable conditions
continue through Tuesday with additional disturbances impacting
the area.


.AVIATION...VFR. A few mountain obscurations remain possible this
morning with lingering shower activity. Activity will linger over
the higher elevations through the evening hours. Surface winds:
Light and variable, becoming northerly 5-10 kts after 27/00z.
Gusty wind possible near any storm activity. Winds aloft near 10k
feet MSL: West 20-35 kts.





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