FXUS65 KLKN 211139 CCA
Area Forecast Discussion
National Weather Service Elko NV...CORRECTED
313 AM PDT Mon Aug 21 2017
Added eclipse information
.SYNOPSIS...A few showers and thunderstorms are expected over
central Nevada this afternoon. Showers and thunderstorm chances
increase Tuesday and expand northward continuing into Wednesday.
Hotter and drier weather return by the end of the week with
above normal temperatures expected.
.SHORT TERM...Today through Tuesday.
A band of mid to upper level clouds is shifting southeastward into
northwestern Nevada this morning. However, satellite shows these
clouds dissipating as they move farther south and east. High
resolution computer models are showing most of the cloud cover
absent around the time of the eclipse around 1027 AM later this
morning so the vast majority of northern Nevada will have great
eclipse viewing conditions besides some haze in the region.
Satellite imagery also shows dissipating cloud cover south of I-80,
leftover from convection yesterday. Typical late morning to
afternoon cloud development across central Nevada will largely occur
after 1100 AM so eclipse viewing south of I-80 will be near optimal
as well. Central Nye county including Tonopah could see a bit of
higher clouds filtering in from the south this morning but will
likely emerge as a thin veil of cirrus having only a minor impact on
Northward transport of monsoon moisture by distant upper low off CA
coast will remain lackluster today with only a spattering of pulsed
convection across the higher terrain of central and east central NV.
Reduced insolation by solar eclipse will delay boundary layer
destabilization just a bit across the state, more so farther
north so convection initiation should be a little later this
Upper low becomes better positioned for monsoon moisture
advection into the Great Basin late tonight and Tuesday with
widespread convection under slightly more favorable southwest flow
aloft. Main threat will be brief downpours, lighting and outflow
winds as shear profile remains rather weak. Storm mode is expected
to be mainly wet as PWATs rise in the range of 0.80" to 0.90"
across much of the state.
.LONG TERM...Tuesday night through next Monday
Latest model runs reflect current grids very well so few changes
or adjustments to the long term forecast were necessary.
The upper low off of the southern California coast opens up on
Tuesday night, though still hangs around socal for a couple more
days. Moist atmosphere exists on Tuesday night and nocturnal
showers still look like a good bet. On Wednesday, best upper level
divergence and moisture and instability looks to be in Northern
Nevada, though convection will be possible throughout the state.
On Thursday, a front from a low centered in northwest Canada
drapes through northern Nevada. Upper level jet is progged to be
in Northern Nevada, so storms will probably be closer to the
Nevada/Idaho border. The jet hangs around on Friday, but moisture
availability will have retreated except for in northeast Elko
county where a few afternoon thunderstorms may develop.
By Saturday, strong upper ridging builds into the western conus
with global models still in agreement for heights in Nevada
593-595 dm (which equals much above normal temperatures). Some
guidance indicates upper 90's to lower 100's for Elko and WMC for
next Sunday. I bumped highs up a bit for next weekend, but not
ready to fully commit to those numbers 7 days out. However, if
guidance is correct, record highs would be in reach. Regardless,
it looks like the above average temperatures will likely set up
shop well into the following week.
.AVIATION...VCSH KTPH late afternoon. TS chances to low to put in
TAF as cap looks like it may remain in place. VCSH KELY as well
although the better chances, including TS, south and west of the
station. Very low chance of an evening shower in KEKO. KWMC dry.
.FIRE WEATHER...Isolated showers and thunderstorms over central
Nevada mountains are expected this afternoon with development
more favorable along ridgelines. Some rain is expected but will
not be wetting and will be short lived. On Tuesday, the threat of
storms increases across the central and expands northward. Storms
will be slow movers and should produce wetting rains in some
locations, but again, storms will be brief. Some gusty outflow
winds can be expected during the late afternoon and early evening
hours. There is a potential for flash flooding over recent burn
scars Tuesday and perhaps Wednesday.
With increased moisture expected Tuesday relative humidity
recoveries will improve Tuesday night in the 55-70% range for
most of the state. Hotter and drier conditions for the end of the
week will bring back critical daytime RH values below 15% by
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