Area Forecast Discussion
Issued by NWS Elko, NV
FXUS65 KLKN 271004
Area Forecast Discussion
National Weather Service Elko NV
304 AM PDT Wed Jul 27 2016
.SYNOPSIS...A ridge of high pressure over the Great Basin Region
will continue to provide above normal temperatures across Nevada
through Friday with highs generally in the upper 90s and lower
100s. Isolated afternoon thunderstorms are possible across south
central Nevada late Thursday. Isolated afternoon showers and
thunderstorms are expected to expand across much of the state by
Saturday, then becoming confined to south central, eastern and
far northeastern Nevada by Sunday. Temperatures will cool a few
degrees over the weekend with the aid of additional cloud cover
and effects from a West Coast trough.
.SHORT TERM...Wednesday through Thursday. Hot and dry conditions
will continue through today and for most of the CWA Thursday as
an upper-level ridge remains in place over the region.
A heat advisory for above normal temperatures into the lower 100s
across a large part of central Nevada continues through Friday
afternoon. High temperatures could rise a couple of degrees more
Thursday in valley locations across mainly Humboldt county so heat
advisory may need to be expanded today to include this scenario.
Monsoon moisture appears to be more limited than the GFS has
suggested during the past few days with short term models showing
PWAT values limited to below 0.75 through Thursday across all but
northern Nye and southern White Pine counties. Oppressing ridge
will inhibit convection elsewhere so kept hybrid thunderstorm
coverage confined to mainly northern Nye and White Pine Counties
where at least some instability and moisture will exist. Winds
will remain quiescent through the next couple of days as well
with the upper-level ridge in close proximity.
.LONG TERM...Thursday night through next Tuesday. Models are in
fairly good agreement in keeping the high pressure ridge across
the southwest United States through the first half of the period,
then it will shift east during the second half. On Friday, the
position of the ridge will be across northern Arizona and southern
Utah with an upper flow from a southerly direction. It will still
be a scorcher out there, with hot temperatures in the upper 90s to
low 100s. There are some isolated dry thunderstorms possible south
of, and including, the US Highway 50 corridor. On Friday night
into Saturday, afternoon highs will remain hot, with many areas
continuing to see the upper 90s to low 100s. Models depict a
southerly flow continuing as the circulation of the upper level
high shifts towards the four-corners region, with an increasing
albeit slow, moisture push from the south. For now, have kept a
mix of wet and dry thunderstorms in the forecast for Saturday, but
will be dependent on cloud cover and how warm it will get. Current
GFS soundings show LCL heights of around 530mb. This could lead to
possible fire weather concerns.
Sunday through Tuesday, all models continue to show a gradual
eastward shift of the upper level ridge. This will bring an end to
the hot temperatures as afternoon highs cool into the upper 80s
to mid 90s through the period. It will also continue to bring a
southerly flow to the area, which will help to moisten the
atmosphere some. However, models are beginning to show an upper
trough over the Pacific Northwest states. This particular
scenario will aid in pushing residual moisture into Utah. Have
kept a mix of wet and dry storms through the weekend as a result,
and will need to keep an eye of this for fire weather concerns.
.AVIATION...VFR conditions can be anticipated at all sites
through the forecast period. With the very warm temperatures,
KELY will continue to have high density altitudes.
.FIRE WEATHER...Hot and dry conditions will continue today across
all fire zones. Thursday will be an opportunity for dry isolated
thunderstorms primarily across northern Nye and White Pine
counties Thursday afternoon. A transition from dry to wet
thunderstorms is expected Friday beginning in fire zones 457, 455
and 454 as deeper moisture is slated to advect into these zones.
The threat of dry thunderstorms moves into Humboldt and ELko
counties Saturday before moisture is pushed farther eastward early
next week by an approaching upper-level trough. Light winds for
the next several days will reduce rapid spreading of wildfires
that do start. However, outflow from thunderstorms that do develop
will have to be watched closely, especially if in the vicinity of
a newly formed or ongoing fire.
Heat Advisory until 5 PM PDT Friday for Northeastern Nye County-
Northern Lander County and Northern Eureka County-Northwestern
Nye County-Southern Lander County and Southern Eureka County-
White Pine County.