Area Forecast Discussion
Issued by NWS Reno, NV

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

000
FXUS65 KREV 262115
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
215 PM PDT Fri May 26 2017

.SYNOPSIS...

High elevation Sierra snowpack melt will continue to produce minor
flooding near some creeks, streams and rivers through the Memorial
Day weekend and into most of next week. High temperatures this
afternoon are near average, but temperatures will begin a warming
trend to well above average temperatures by early next week. A
few showers and thunderstorms will be possible over the Sierra in
Mono county by Sunday and Monday with better chances by midweek.

&&

.SHORT TERM...

A building ridge of high pressure will bring tranquil weather
conditions for the Memorial Day weekend with warming temperatures
and generally light winds. Today will be the coldest day of the
weekend with high temperatures warming 10-15 degrees by Monday. The
warming temperatures will bring an increase in snowmelt rates, with
flows only expected to increase on creeks, streams, and rivers from
where they currently are. Rivers are extremely dangerous right now
and you could easily be pulled under with the current as
hypothermia quickly sets in. Stay away from waterways the next
several weeks! Be extra careful while recreating in the back
country as the snow may not be a solid bank with running water
beneath, allowing hikers to fall through. In addition, many lakes
and reservoirs are rising rapidly, with anywhere from a couple
inches to over a foot of rise per day. Use caution when setting up
camp this holiday weekend -- if you set your tent up next to the
water, you may wake up to a cold, wet surprise.

Overall, the forecast looks dry with just cumulus buildups
anticipated. Will maintain the slight chances for thunderstorms
along the Sierra Sunday and Monday afternoons as we are not
completely capped and the above normal temperatures can help to
generate surface instability. However, expect any storms that do
develop to be few and far between. Overall flow is light, so storms
should mainly be confined to the higher terrain. -Dawn

.LONG TERM...Tuesday through Friday...

Ridge axis continues to slide east for early next week and begins to
breakdown as a trough sets up in the northeastern Pacific. Although
there is pretty good agreement between the models that high pressure
will be on its way out of the West, the models are only starting to
come in agreement with how the pattern materializes.

With ridge breakdowns there is typically a pretty good chance of
thunderstorms developing as the atmosphere destabilizes, especially
with the warm spring temperatures and sufficient moisture. The GFS
continues to bring a closed cutoff low across the eastern Sierra and
western Nevada by Wednesday which would provide more than sufficient
instability and divergence aloft for thunderstorm development.
Cutoff lows such as this can also meander over an area for a
couple of days, so that will be something to monitor over the
coming week. The ECMWF is looking more similar to the GFS with
respect to Wednesday, so we are looking at an increased risk for
thunderstorm development possibly early Wednesday into Wednesday
evening.

So while we are fairly certain that the ridge will be breaking down
and moving east by midweek next week, there is still some
uncertainty with when and where the most thunderstorm coverage will
occur. Otherwise, we can say with some certainty that we will be
seeing another cooldown in the temperatures as the ridge moves out
of the region. -Edan

&&

.AVIATION...

Widespread VFR conditions with scattered cumulus clouds this
afternoon becoming clear overnight. Generally north to northwest
winds around 10 kts today will become light northeasterly overnight,
then light easterly flow will continue through the weekend. There is
a 15-20% chance for isolated thunderstorms Sunday through Tuesday
afternoons along the Sierra mainly south of Lake Tahoe. -Dawn

&&

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

$$

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.