Area Forecast Discussion
Issued by NWS Reno, NV
FXUS65 KREV 282113
Area Forecast Discussion
National Weather Service Reno NV
213 PM PDT TUE JUN 28 2016
Highs around 100 degrees are expected for lower elevations of
western Nevada through Friday as high pressure remains over the
Great Basin. A few thunderstorms are possible south of Highway 50
each afternoon through Friday. There could be a few thunderstorms
just north of Highway 50 along the eastern Sierra Friday
afternoon, but this is highly uncertain for now. For the holiday
weekend, dry conditions are expected with temperatures remaining
The primary changes to the forecast today involve trying to
better refine the areas where convection may develop through
The GFS...NAM and HRRR all have development starting closer to
the Sierra crest in Mono County this afternoon...then move this
development farther north and east into southern Lyon and Mineral
counties by this evening. There is a bit less movement to the east
for Wednesday afternoon and evening but we also see stronger late
afternoon and early evening westerly flow that would aid in
developing convection north along the Pine Nut Mountains and
possibly as far north as the southern Virginia Range.
Overall...the instability is not overwhelming either day...but
the very hot temperatures and a weak short wave in the mid levels
is providing just enough lift to aid the development of storms.
Dry sub-cloud layers today should begin to moisten just a bit by
Wednesday. Dry storms today should give way to hybrid storms by
Wednesday and slow storm motions will also help produce some brief
moderate to heavy downpours in the strongest storms. Gusty outflow
winds of up to 50 mph along with dry lightning strikes outside of
the rain cores are also possible.
Storms redevelop Thursday...but this development could be just a
bit farther east initially. Slow storm motions should again help
produce rain in the strongest storms...even with dry air near the
surface. By Friday the model guidance begins to diverge as the GFS
is a bit more progressive with southwest flow aloft shearing most
of the moisture to the east while the NAM is digging a trough
toward California that is producing backing flow in the mid
levels. That allows more moisture to be drawn north and initiates
convection along the Sierra and into northeast California. While
the ECMWF has a little development in far northern California it
mostly supports the GFS. So for now we will leave the higher pops
out of the forecast for Friday.
Well above normal high temperatures continue into Friday with a
few records possible Wednesday and Thursday. Highs reach the
98-103 range in the lower valleys with upper 80s to lower 90s in
the Sierra valleys.
.LONG TERM...Saturday through Tuesday...
Only minimal changes were made to the extended forecast. The GFS
is still trying to maintain or rebuild the ridge through Tuesday
while the latest ECMWF shows more of an elongated trough along
the CA coast. The ECMWF would provide slightly cooler temperatures
but the chance for stronger winds. The GFS solution supports
higher temperatures and the possibility of weak convection in the
favored convergence zones...especially Mono County...each day.
The GEFS ensemble members show a variety of solutions with no
operational model favored over any other. Thus...we will maintain
a dry forecast with slightly above average temperatures through
the extended period. Bear in mind this forecast remains highly
uncertain and confidence is moderate at best that the current
forecast will play out as stated.
Thunderstorms are possible each afternoon and evening south of
Highway 50 from near the Sierra crest east to about Highway 95
through Friday. There is an outside chance storms could develop
farther north along the eastern side of the Sierra late Friday
afternoon...but there is great uncertainty in this solution for
Typical zephyr winds are likely each day through Friday with gusts
in the 20-25 knot range immediately east of the Sierra. Lighter
gusts are expected east of Highway 95 except in the vicinity of
thunderstorms. VFR conditions are also likely each day through
Friday except in the vicinity of thunderstorms. XX
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