Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Reno Nevada
227 am PDT sun may 28 2017
Warm weather will remain into early next week as high pressure
settles across the region. The above average temperatures will
continue the Spring Sierra snowpack melt which will lead to cold
and swift flows near creeks, streams and rivers this Memorial Day
weekend. Chances for showers and thunderstorms will be possible
next week as a series of weak troughs drop across the region.
High pressure will continue to provide warm and above average high
temperatures into early next week. Highs across western Nevada
will reach into the the mid 80s this afternoon with upper 80s to
near 90 by Monday. Sierra valleys will warm to the mid and upper
70s. Mostly clear conditions will prevail this afternoon with some
afternoon cumulus development possible along the Sierra. Any
isolated shower activity that develops looks to mainly stay west
of the crest with a better chance of development Monday afternoon.
High pressure shifts eastward on Monday allowing for increased
instability across portions of the Sierra that are not covered by
snow. The snowpack has stabilized the boundary layer and has
largely inhibited any convective development across the Sierra.
Model runs (particularly the gfs) have been completely clueless to
this effect and have been way too aggressive with convective
development. Monday however shows a sizable enough increase in
instability to finally initiate a few showers and isolated storms
particularly across alpine and Mono counties. Still don't
anticipate any strong or widespread coverage however as forcing
is still lacking.
Southwest flow becomes better established on Tuesday which will
make for some breezy conditions with wind gusts reaching into the
30 to 40 mph range. Precipitation chances look rather meager as
dry southwest flow intensifies and instability decreases. As
such, have removed mention of thunderstorms but did maintain
isolated shower possibilities.
As a daily reminder, flows near creeks, streams and rivers remain
high, fast, and cold due to our Spring Sierra snowmelt. Please use
exercise caution and keep a safe distance from any bodies of
running water. Fuentes
not much change to the long term this morning as the models are in
reasonably good agreement with the splitting system for Wednesday.
The GFS completely splits it off while the ec is more of a weak
open wave. Both bring is some moisture with it and the instability
is modest at best. Still, see no reason to change the going
forecast of a slight chance of showers and storms. There is a
little better chance over Mono and Mineral, especially with the
GFS solution, so the higher chances look good there.
Behind this wave, it turns into a Flat Ridge with the GFS a bit
stronger than the ec. Temperatures will rise back to 5-10 degrees
above average. Winds will also be light, although there could be a
weak to moderate Zephyr depending on where the ridge axis sets up.
As far as convection, left it out for now. Temps aloft are quite
warm at -8 c at 500 mb which should keep a cap on things despite
the GFS going off every day. The GFS has been convection Happy
this Spring and the overall pattern is not a favorable one for
VFR conditions with light winds into Monday. There will be some
light east winds at less than 10 kts 21-02z this afternoon and
west around 10 kts Monday afternoon same time. Any thunderstorms
look to remain west of the Sierra crest today, with a better
chance south of ktvl to near kmmh tomorrow 22-02z.
Southwest winds increase Tuesday with gusts to 25 kts ahead of
Pacific low pressure with the best chance of any thunderstorms for