Area Forecast Discussion
Issued by NWS Reno, NV

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FXUS65 KREV 310324 AAA
AFDREV

Area Forecast Discussion...UPDATED
National Weather Service Reno NV
824 PM PDT SAT JUL 30 2016

.UPDATE...

Showers and thunderstorms were diminishing and moving out of the
area this evening and we have updated to remove them from the
forecast for the night. Latest web cams show smoke/haze getting
fairly widespread including the Tahoe Basin, so we expanded the
mention to a few more areas. Based on recent radar images, the
fire activity from the Tule and Anderson fires continues to be
quite active and smoke will likely continue to push eastward
across Pyramid Lake into the Basin and Range for the next several
hours as the zephyr winds continue to act on the dry airmass to
push the fires. Winds will gradually diminish from west to east
through 2 am with mostly light and variable winds for most valleys
and midslopes by daybreak. Hohmann

&&

.PREVIOUS DISCUSSION... /Issued 208 PM PDT SAT JUL 30 2016/

SYNOPSIS...

Moisture and afternoon instability will keep chances of thunderstorms
in the forecast into early next week until a drier and slightly
cooler flow pattern develops. However, much of the convection will
be limited to south of Highway 50. Expect an increase in afternoon
winds by early next week across northeast California and western
Nevada.

SHORT TERM...

Convection is developing over portions of Mono/Mineral/Lyon
counties today as lingering moisture and instability are maximized
south of Highway 50. Additional development early this evening
could extend north along the Pine Nut and Virginia ranges as
typical late afternoon/early evening westerly flow develops east
of the Sierra and provides a focus for storms. Brief moderate to
heavy rain is possible...but precipitable water values are a
little less than yesterday. Small hail and gusty outflow winds to
near 50 mph are also possible in the stronger cells.

Beyond tonight...westerly flow begins to increase over the far
northern forecast area as a longwave trough moves into the Pac NW.
The flow will not be strong enough to scour all of the moisture
out the region...especially south of Highway 50...so we will leave
a slight chance for thunderstorms in the forecast south of Highway
50 for Sunday and across far southern Mono County for Monday where
sufficient instability and light flow aloft will allow for a few
storms to develop. A couple of isolated cells are not completely
out of the question over far northern areas Sunday where mid level
convergence will be maximized...but the moisture is limited so we
will not include them at this time.

Temperatures will cool slightly the next few days as the southern
edge of the trough gets closer to the region...lowering highs to
about 4-7 degrees above normal. Also...the presence of this
trough will result in slightly stronger winds for Monday and
Tuesday from I-80 northward. Gusts may briefly exceed 30 mph in
isolated locations Monday and increase to near 35 mph by Tuesday.
We are monitoring the situation for possible critical fire weather
conditions...but right now the coverage and duration of the
strongest winds appears to be a bit too limited for issuing any
watches. These gusty winds could hamper ongoing fire fighting
efforts on the recent lightning-caused fires.

LONG TERM...Wednesday through Saturday...

There is an increase in west-southwest flow aloft over the
northern half of the forecast area in the extended period...but
light flow in the mid levels and a bit of lingering moisture could
lead to isolated storms again Wednesday over far southern Mono
County and the southern half of Mineral County. The medium range
model guidance also shows a weak trough moving into the area from
the west late Thursday into early Friday. The timing is not
perfect with this trough...but it could aid in some deeper cloud
development late Thursday night and early Friday morning. The best
instability associated with this feature is east of the forecast
area into central Nevada...so we will not add thunderstorms just
yet.

Temperatures still look to range in the near to slightly above
normal range for early August. Both average highs and lows start
to drop a degree or two from their peaks in late July. We can
expect highs in the western Nevada valleys in the 95-100 range
with northeast California valleys in the 92-98 range. For Sierra
valleys, highs should be in the lower to mid 80s. XX

AVIATION...

Expect isolated thunderstorms this afternoon/evening from MMH
northward along the high terrain to east of RNO/CXP and points east
(NFL/HTH). Westerly zephyr wind will keep any convection east of the
Tahoe basin (TVL/TRK) and likely east of RNO/CXP. While not directly
impacting these airports, storms could send in strong easterly
outflows if they can overcome the zephyr. We are still seeing about
a 10-20% chance of a direct thunderstorm hit at MMH/NFL/HTH.

Drier airmass works in for Sunday-Monday with weak to moderate
westerly afternoon winds. Airmass from MMH-HTH-TPH remains slightly
unstable so we can`t rule out isolated storms impacting those
locations. -Jon/Chris

&&

.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&

$$

For more information from the National Weather Service visit...
http://weather.gov/reno



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