Area Forecast Discussion
Issued by NWS Elko, NV
FXUS65 KLKN 292356
Area Forecast Discussion
National Weather Service Elko NV
456 PM PDT Fri Jul 29 2016
.SYNOPSIS...Increased monsoon moisture combined with strong daytime
heating under a high pressure ridge over the region will produce
afternoon showers and thunderstorms across central Nevada
today...then expand northward into northern Nevada over the weekend.
Dry thunderstorms that occur have the potential to spark wildfires.
Gusty winds could accompany thunderstorms that develop through the
weekend. Temperatures will cool down a few degrees next week but
still remain hot and slightly above normal.
.UPDATE...Allowed heat advisory to expire. With the clouds, temps
.PREV DISCUSSION... /ISSUED AT 250 PM /
SHORT TERM...Tonight through Sunday. most of Nevada sits between the
monsoonal wet eastern Great Basin and the dry western Great Basin.
Thunderstorms are kicking off on the central Nevada highlands at
this time and drifting off the east at very...slow...speeds...if
they`re moving at all. Result of forming under the ridge axis. The
change in the weather from blue dry skies to active thunderstorms is
due to weak increase in monsoonal flow, very hot temps, and a bit of
cooling aloft. Adequate but not outstanding instability exists over
central and eastern Nevada. PW`s are in the 0.6 to 0.7" range and
will increase slightly through the weekend, especially along the
Utah border. In addition to steering winds being slow, surface winds
are on the lighter side and fairly disorganized with drainage
influences dominating the gradient. Hence, storm movement will
remain fairly slow. This will contribute to a more hybrid wet/dry
pattern. Still...one meteorologist reported brief heavy rain at his
house in a tiny rain core....with lightning striking the grass all
around the storms. This will be typical.
Temps will remain above normal..but will cool off a bit by Saturday
and Sunday. Will allow the Heat Advisory to expire, normally, and
update forecast as needed.
LONG TERM...Sunday night through next Friday. The models seem to
be in good agreement showing daily variance of a monsoon flow all
next week. The main plume of moisture with tropical origin will
flow east of Nevada. The eastern half of the LKN HSA will have
thunderstorms develop nearly each day. Being on the western fringe
of the moisture core, thunderstorms will likely be mainly dry
mixed with some wetter storms closer to the Utah border. One
reason for the sporadic surging of the moisture and associated
convection is an upper low that will move onshore across
Washington State Monday night then track along the CONUS/Canadian
border during the week. As this low feature moves across Montana
and North Dakota, low temperatures in northern Elko County will
dip to around 40 degrees, possibly into the 30s in some spots,
Tuesday and Wednesday nights. High temperatures will continue to
make it into the 90s each day for the most part.
AVIATION...VFR conditions are expected through Saturday
afternoon. Thunderstorms today and tomorrow will have little
rainfall however gusty outflow winds to 45kts could affect KELY
and KTPH today then all four TAF sites on Saturday.
FIRE WEATHER...Bottom line: it`s a dry-ish pattern with enough
moisture to produce mostly dry thunderstorms in central and eastern
Nevada today and into tonight. RH recovery will still be on the poor
side. Monsoon moisture is strongest in the east along the Utah line,
and especially over zone 455. It grows weaker further north and
west. Through Sunday the wet flow will increase and storms will
gradually change from mostly dry to wet/dry mix to mostly wet. Low
level winds are weak and so drainage/upslope winds will dominate.
Upper level winds are also weak so storm movement will be on the slow
Storms will therefore produce more rain than typically dry storms,
but likely not enough to warrant the wet status. One meteorologist
in western Nevada reported a quick 0.25" of rain at his house with
lightning in the grass all around the storm. These storms will have
tight rain cores and might dump briefly, but in a very small spot
and lightning will still affect dry area around the storm. If you
get rain, you win the lottery.
Confidence in this forecast and the fire products is average. There
will be dry/wet storms which will change to mostly wet, but exactly
where and how fast is tough. Just FYI.
Last, the fire weather watch is cancelled and a Red Flag Warning
will be in effect for zones 454, 455, and 457 from 5 pm PDT Friday
through 5 am PDT Saturday. This will cover the thunderstorms and dry
virga outflows along with poor RH recovery.
Another Red Flag Warning will be in effect for zones 468, 469, and
470 from 5 am Saturday through 11 pm Saturday for lightning.
The reasons for these RFW, despite some wettish storms is that
fuels are dry, temperatures have been very much above normal, RH`s
Red Flag Warning from 5 AM to 11 PM PDT Saturday for Eastern
Elko County-Eastern Humboldt County and Northwestern Elko County-
Southwestern and Central Elko County.
Red Flag Warning until 5 AM PDT Saturday for Central Lander and
Eureka Counties-Northern Nye County/Lander and Eureka Counties
South of Highway 50-White Pine County.