Wildfire in Idaho, July 10 to 31, 2019

Area Forecast Discussion
National Weather Service Pocatello ID
213 PM MDT Wed Jul 10 2019

.DISCUSSION...Broad southwest flow remains in place over East
Idaho, sandwiched between high pressure ridge centered near the
four-corners region and deep trough off PacNW coast. Mid level
cloud cover streaming across the central mountains this afternoon
per satellite imagery. Some instability is present, and there
continues to be enough support from the short term high resolution
runs to support a few thunderstorms this afternoon and early
evening. Most of the activity should occur over the Lemhi region
and north, so have blended precipitation chances with northern
office forecasts. Similar conditions continue on Thursday,
slightly further east with chances along and north of the Divide
east of I-15. That said, the southwest flow can be tricky at times
so would not be surprised to see a lone storm pop up elsewhere.
Additional moisture wraps around the high Friday and Saturday so
have maintained increased chances across most of the higher
elevation areas. Shortwave ejecting out of the low Sunday should
introduce drier conditions from the west for Sunday and Monday,
pushing most of the threat for convection out of the region.
Throughout much of the forecast period, temperatures stay warm.
That is until potentially Monday when the passage of the shortwave
induces a brief and very slight cooldown for the early part of
next week. DMH

&&

.AVIATION...
VFR conditions are expected through the forecast period at the TAF
sites with a fairly extensive mid and high cloud deck thinning
overnight. Winds are expected to be mainly light (12kts or less) and
terrain-driven. The next chance for convective activity arrives just
after the TAF period ends on Friday. AD

&&

.FIRE WEATHER...
The hottest and driest stretch of weather that the region has
experienced thus far this summer is kicking off today, as we reside
on the northwest fringes of a broad high pressure ridge centered
near the 4-corners region. This feature is forecast to remain
largely in place through the week. Another persistent feature
through the week will be an area of low pressure currently centered
off of the Washington coast. By next week, this low is forecast to
migrate northward towards the Alaskan Panhandle. As such, broad SW
flow will remain in place across the region through the week.
Minimum relative humidity values will be near critical values today
and Thursday across Arco Desert portions of 410 and across the Lava
Beds of zone 425. Similar, although slightly more moist (on the
order of a percent or two) min RH values are forecast for Thursday.
On Friday, some quasi-monsoonal moisture will begin to stream into
the area and this should result in isolated shower and thunderstorm
activity by afternoon across the region, with the best chances
across 476, 411 and 427. Isolated activity is possible anywhere,
however. Any shower/storm could produce gusty outflow winds. Similar
conditions are expected for Saturday and Sunday --and winds may
become a bit gusty during the afternoon across the Snake Plain and
Arco Desert, although they should remain below Red Flag thresholds.
At this time, mainly dry conditions are expected for Mon-Wed,
although a sneaky shower/storm is possible given the SW flow regime.
 will remain seasonable and RH will remain near/just
above critical values. AD

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&