Home > Products > Valid Products > AFD

000
FXUS65 KREV 052004
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
104 PM PDT THU MAY 5 2016

.SYNOPSIS...

Widespread showers with scattered thunderstorms are expected today
with storms bringing frequent lightning and copious amounts of
small hail. Unsettled weather will continue into the weekend with
locally heavy rain possible. Drier, warmer weather returns next
week.

&&

.SHORT TERM...

Forecast remains on track with few changes made. Slowly moving
area of low pressure will bring wet and stormy weather to the
Sierra, northeast California, and northwest Nevada through Sunday.
There are multiple events this weekend that could be impacted by
showers and thunderstorms including the Reno River Festival, the
Reno Sculpture Festival, the Moms on the Run Race, the Pamper
Pedal Bike Ride near Mammoth, and the Nevada State Police Memorial
Parade and Car Show in Virginia City.

Best thunderstorm coverage will be today as large scale forcing
from a south-north oriented jet combines with instability both at
the surface and aloft. These storms have had a history of
producing large amounts of small hail which can cover roadways and
make for hazardous travel conditions. In addition, expect
deadly lightning, brief heavy rainfall and wind gusts of 40 to 45
mph. Snow levels are running around 8000-8,500 feet and
accumulation has been observed on Mt Rose Highway earlier today.
Mt Rose, Carson, and Monitor Passes may all be snow covered for
brief periods of time this afternoon and overnight tonight. There
is also potential for Conway and Deadman`s Summits on Highway 395
in Mono County to be briefly snow covered as well.

The jet will be shifting eastward tonight, but there will still be
upper level diffluence present along with steepening mid and upper
level lapse rates. This will likely keep chances for thunderstorms
going through the night. As storm motions slow tonight into
Friday, the risk for heavy rain will increase with less chances
for gusty winds. Minor flooding is possible if storms train over
the same region, but of greatest concern are recent burn scars
such as the Washington Fire. These will need to be monitored as it
will take much less rain to produce debris flows than usual. River
rises are expected, but there will not be any mainstem river
flooding.

As the upper low shifts inland this weekend, deformation bands
will form on the north side of the low. This is likely to bring
additional heavy rain to portions of northeast California, the
Sierra, and northwest Nevada. At this point it is hard to pinpoint
where the exact heaviest bands will be, but some locations will
receive copious amounts of rainfall over the course of the
weekend. Snow levels will also rise this weekend as the cold core
of the low drops south and warmer air wraps around the north side
of the low. The area of low pressure will slowly shift eastward
with just lingering showers and a few thunderstorms possible on
Sunday. -Dawn


.LONG TERM...Monday through Thursday...

Models continue to show an upper low moving over the northern
Rockies for the early to middle part of next week. This is forecast
to allow some cooler air to backdoor into western Nevada and
northeast California by Tuesday, with a slow warm up by Wednesday or
Thursday as the airmass modifies and high pressure strengthens aloft.

With some residual moisture and heating each day there will be a low
chance for afternoon and evening showers near the Sierra crest,
but it will remain dry elsewhere. Snyder

&&

.AVIATION...

Thunderstorms are expected to be strongest today for much of
northeast California and western Nevada as a large-scale upper low
approaches central and southern CA. Many storms will be capable of
copious amounts of small hail (1/2 to 3/4" possible), heavy rainfall
(+TSRAGS), and wind gusts to 35-40 kts. In addition, strong storms
could be longer-lived with a much longer track than is typical for
western NV/northeast CA. Terrain obscurement and MVFR conditions
will be possible in heavier thunderstorms.

Tonight, model simulations indicate re-development of rain and
embedded thunderstorms this evening and overnight. Wherever the area
of rain forms, expect widespread higher terrain obscuration and
occasional MVFR CIGS/VIS along with isolated-scattered lightning
strikes.

For Friday, another round of showers and thunderstorms is expected
as the upper trough moves to interior/southeast CA and southern NV.
The strongest, most long-lived storms look to be generally north of
Portola and KLOL...where +TSRAGS and wind gusts to 40 kts will
continue to be a threat. Elsewhere in western NV and the eastern
Sierra, slower moving storms will be capable of heavy rain but hail
should be more isolated in nature compared to Thursday. Snyder

&&


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

$$

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





000
FXUS65 KREV 052004
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
104 PM PDT THU MAY 5 2016

.SYNOPSIS...

Widespread showers with scattered thunderstorms are expected today
with storms bringing frequent lightning and copious amounts of
small hail. Unsettled weather will continue into the weekend with
locally heavy rain possible. Drier, warmer weather returns next
week.

&&

.SHORT TERM...

Forecast remains on track with few changes made. Slowly moving
area of low pressure will bring wet and stormy weather to the
Sierra, northeast California, and northwest Nevada through Sunday.
There are multiple events this weekend that could be impacted by
showers and thunderstorms including the Reno River Festival, the
Reno Sculpture Festival, the Moms on the Run Race, the Pamper
Pedal Bike Ride near Mammoth, and the Nevada State Police Memorial
Parade and Car Show in Virginia City.

Best thunderstorm coverage will be today as large scale forcing
from a south-north oriented jet combines with instability both at
the surface and aloft. These storms have had a history of
producing large amounts of small hail which can cover roadways and
make for hazardous travel conditions. In addition, expect
deadly lightning, brief heavy rainfall and wind gusts of 40 to 45
mph. Snow levels are running around 8000-8,500 feet and
accumulation has been observed on Mt Rose Highway earlier today.
Mt Rose, Carson, and Monitor Passes may all be snow covered for
brief periods of time this afternoon and overnight tonight. There
is also potential for Conway and Deadman`s Summits on Highway 395
in Mono County to be briefly snow covered as well.

The jet will be shifting eastward tonight, but there will still be
upper level diffluence present along with steepening mid and upper
level lapse rates. This will likely keep chances for thunderstorms
going through the night. As storm motions slow tonight into
Friday, the risk for heavy rain will increase with less chances
for gusty winds. Minor flooding is possible if storms train over
the same region, but of greatest concern are recent burn scars
such as the Washington Fire. These will need to be monitored as it
will take much less rain to produce debris flows than usual. River
rises are expected, but there will not be any mainstem river
flooding.

As the upper low shifts inland this weekend, deformation bands
will form on the north side of the low. This is likely to bring
additional heavy rain to portions of northeast California, the
Sierra, and northwest Nevada. At this point it is hard to pinpoint
where the exact heaviest bands will be, but some locations will
receive copious amounts of rainfall over the course of the
weekend. Snow levels will also rise this weekend as the cold core
of the low drops south and warmer air wraps around the north side
of the low. The area of low pressure will slowly shift eastward
with just lingering showers and a few thunderstorms possible on
Sunday. -Dawn


.LONG TERM...Monday through Thursday...

Models continue to show an upper low moving over the northern
Rockies for the early to middle part of next week. This is forecast
to allow some cooler air to backdoor into western Nevada and
northeast California by Tuesday, with a slow warm up by Wednesday or
Thursday as the airmass modifies and high pressure strengthens aloft.

With some residual moisture and heating each day there will be a low
chance for afternoon and evening showers near the Sierra crest,
but it will remain dry elsewhere. Snyder

&&

.AVIATION...

Thunderstorms are expected to be strongest today for much of
northeast California and western Nevada as a large-scale upper low
approaches central and southern CA. Many storms will be capable of
copious amounts of small hail (1/2 to 3/4" possible), heavy rainfall
(+TSRAGS), and wind gusts to 35-40 kts. In addition, strong storms
could be longer-lived with a much longer track than is typical for
western NV/northeast CA. Terrain obscurement and MVFR conditions
will be possible in heavier thunderstorms.

Tonight, model simulations indicate re-development of rain and
embedded thunderstorms this evening and overnight. Wherever the area
of rain forms, expect widespread higher terrain obscuration and
occasional MVFR CIGS/VIS along with isolated-scattered lightning
strikes.

For Friday, another round of showers and thunderstorms is expected
as the upper trough moves to interior/southeast CA and southern NV.
The strongest, most long-lived storms look to be generally north of
Portola and KLOL...where +TSRAGS and wind gusts to 40 kts will
continue to be a threat. Elsewhere in western NV and the eastern
Sierra, slower moving storms will be capable of heavy rain but hail
should be more isolated in nature compared to Thursday. Snyder

&&


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

$$

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





000
FXUS65 KREV 050911
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
211 AM PDT THU MAY 5 2016

.SYNOPSIS...

An increase in showers and thunderstorms is expected today as low
pressure approaches the California coast. Some of the storms
could be strong with frequent lightning and copious amounts of
small hail. Unsettled weather will continue into the weekend with
locally heavy rain possible. Drier, warmer weather returns next
week.

&&

.SHORT TERM...

Upper low moving toward the CA coast should lead to increased
instability through the day and combine with a south to north
oriented jet to produce widespread showers and scattered
thunderstorms through the day. The presence of the upper jet may
boost instability aloft well beyond that seen Wednesday when
increased cloud cover cut low level heating and limited the amount
of deep convection. The upper level diffluence is likely to aid in
the continuation of thunderstorms into the evening hours and
possibly overnight as the upper low moves slowly east toward
southern CA. Initially fast moving cells this afternoon mean the
primary threats will be small hail and gusty winds...but as the
mid level steering flow decreases into the evening hours slower
moving cells will mean the primary threat may transition to
moderate to heavy rain.

The slow movement of the low to the east will mean continued
instability Friday...but increased cloud cover and a lack of a
consolidated upper level jet support is likely to limit the
amount of thunderstorms compared to today. Still...slow moving
storms could create brief moderate to heavy rain and some
localized minor flooding.

The upper low moves east of the region Saturday...but a
deformation axis is likely to form on the back side of the low
with bands of precipitation developing across the forecast area.
For now it is difficult to pin point where any of these bands may
form. Again...cell movement appears to be fairly slow for Saturday
meaning any bands that form could produce significant rainfall
across parts of the forecast area. Extensive cloud cover and rain
could also make Saturday the coolest day of the short term period
with highs in the 50s and 60s. 20

.LONG TERM...Sunday through Wednesday...

Upper trough will finally begins its exit on Sunday with
decreasing shower and storm potential from north to south through
evening. Some stronger slow moving storms will still be capable of
small hail and heavy rainfall as the atmosphere will be unstable.
The main change to the forecast was to show a gradual decrease in
coverage across northern areas in the afternoon and central areas
by evening.

For Mon-Wed, both the GFS/ECMWF have trended a bit cooler as
shortwave trough drops down east side of ridge, delaying the warmup
until later in the week. We cooled temperatures down a few degrees
Tue-Wed, but if some of the MOS guidance is correct, temperatures
may need to be cooled further as a northeast gradient pushes cooler
and drier air in from the northeast. Isolated showers will be
possible along the Sierra crest. Otherwise, it should remain dry
as the bulk of moisture and instability stay east. Hohmann

&&

.AVIATION...

Isolated thunderstorms across northeast CA and northwest NV will
continue through daybreak as that area remains in favorable region
of large scale forcing. Isolated showers/storms may develop farther
south toward KRNO/KCXP/KNFL early this morning, but the best
chances will be to the north.

Otherwise, showers and storms will be on the increase today as large
scale upper low moves eastward into CA/srn NV and dynamics/lift
spread across all areas. A few strong storms will be capable of
lots of small hail and moderate-heavy rainfall. Banding of
showers will be possible through Sunday with longer more
persistent periods of steady moderate rainfall and embedded
thunderstorms possible. Terrain obscurement and MVFR conditions
will be more prevalent in these bands. Hohmann

&&

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

$$

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





000
FXUS65 KREV 042136
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
236 PM PDT WED MAY 4 2016

.SYNOPSIS...

An increase in showers and thunderstorms is expected tonight and
Thursday as low pressure approaches the California coast. Some of
the storms Thursday could be strong with frequent lightning and
copious amounts of small hail. Unsettled weather will continue
into the weekend with locally heavy rain possible. Drier, warmer
weather returns next week.

&&

.SHORT TERM...

Cloud cover, no obvious forcing, and likely some capping in the
mid levels (12Z REV sounding) slowed convective development over
eastern California and western Nevada into early this afternoon.
However, of late, cumulus have begun to bubble up with isolated
showers forming over far western Nevada and northeast California.
Shower coverage is likely to trend up to scattered in the next
couple hours with peak heating. As far as thunderstorms this
evening, coverage looks isolated with fast-moving cells. Small
hail, lightning, brief heavy rain, and gusty winds to 40-45 mph
will be possible with thunderstorms into this evening.

Late tonight and Thursday morning, models have consistently shown
precipitation developing over extreme western/northwestern Nevada
and northeast California as a jet noses into the region ahead of
the potent upper low off the California coast. However, the 18Z
NAM fires up precipitation 3-6 hours later than the 12Z so the
most widespread rain may wind up being Thursday morning rather
that after midnight tonight if the NAM verifies. Upper lapse rates
increase late tonight with a few hundred joules of MUCAPE (weak
instability) so a few nocturnal storms are certainly possible into
early Thursday morning.

Thursday looks like the better day for strong thunderstorms as the
upper low nears with more divergence aloft. The divergence/cooling
aloft should erase the mid-level cap that was in place today, with
instability/CAPE increasing to up to ~800 J/kg or so, especially
north of highway 50 in northeast California and far western
Nevada. Also, the S-N upper jet is in a very favorable position
over central NV and winds aloft support some increased organization
and longevity to storms. Expect widespread showers and storms near
Reno/Tahoe up to Cedarville where instability is greatest, with at
least scattered showers/storms elsewhere by late afternoon and
early evening. Accumulating small hail (with possible brief slick
conditions on hail-covered roads) and brief heavy rains will be
the greatest threats with Thursday`s storms.

Showers and storms to continue into Thursday evening and become
less numerous. Still enough moisture and instability to continue
scattered showers overnight. Friday more showers and storms are
expected with another day of good instability as the low moves
into Southern CA. Forcing won`t be quite as strong, but still
expect some locally heavy rains and some small hail from them.

Snow level will come down somewhat late Thursday night and Friday
as the upper low moves into central and southern California. If
there is any sustained precipitation in the Sierra, higher passes
(above 8000 ft) could see a light accumulation especially if snow
falls before 9 AM Friday. Be sure to check with NDOT (for Mt Rose
Highway) or CALTRANS if traveling over higher passes Thursday
night or Friday morning.

Friday night continues to look intriguing with a deformation band
developing on the NW side of the low. The EC/GFS and less so the
NAM are hitting the Oregon border area into Lassen County. Moderate
confidence in this band location and development. Rainfall amounts
Friday night could approach 0.50" to 0.75" in this band alone.
Snyder/Wallmann

.LONG TERM...SATURDAY THROUGH WEDNESDAY...

An expansive area of low pressure will provide continued wet and
cool conditions for the remainder of the weekend. Periods of showers
and thunderstorms will continue Saturday and Sunday with conditions
drying by Sunday evening and into early next week as the low finally
departs the region.

Overall, few changes to the ongoing forecast with the upper low
remaining well behaved in deterministic and ensemble model runs. The
main forecast problems for Saturday and Sunday will be determining
the placement of a band of heavier showers and thunderstorms that is
expected to develop as a result of deformation forcing north of the
low. Currently a north-south oriented band of convergence will be
positioned just east of the Sierra mostly across far western Nevada
on Saturday and then shifting east across Pershing and Churchill
counties on Sunday. This forcing is disjointed from the best surface
based instability across far northeast California so do not think
thunderstorm activity will be as potent as earlier in the week.
Nonetheless, mid-level instability should be sufficient to still
produce periods of small hail, cloud to ground lightning strikes,
heavy rainfall, and rises on creeks and streams.

Snow levels will remain quite high through the weekend mainly from
8,500 feet on Saturday rising to near 10,000 feet by Sunday. As
such, any problems from snow will only impact the highest passes
during periods more intense convective cells. Anyone planning
outdoor activities should prepare now for a very active weather
pattern which will include the possibility of lightning and small
hail.

The low will finally pull away for the beginning of next week which
should largely provide warmer and drier conditions aside from a few
lingering showers across the Sierra.  After a cool weekend,
temperatures will warm quickly next week with high temperatures
warming into the upper 70s and near 80 by midweek across western
Nevada. Fuentes

&&

.AVIATION...

Showers and thunderstorms will be on the increase this evening and
Thursday. Expecting showers and storms to increase after 06z as
forcing from an upper level low and jet arrive across the northern
Sierra. This widespread coverage will continue into Thursday.

Storms will be capable of lots of small hail and heavy rain,
especially Thursday when forcing/instability will be strongest.
Since this is a wetter system, potential for severe outflow winds
looks less probable with more impacts expected from heavy rain,
decreased visibility, and abundant small hail.

Potential for continued periods of showers and thunderstorms will
remain through Sunday as the low will be slow to depart the region.
Precipitation will diminish by Sunday evening as the low departs
with drier conditions expected by early next week. Fuentes

&&

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

$$

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





000
FXUS65 KREV 041612
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
912 AM PDT WED MAY 4 2016

.UPDATE...

Tweaked today`s forecast to delay onset of thunderstorms,
especially for the Sierra south of Tahoe and western Nevada south
of Gerlach. The morning sounding in Reno indicated that there was
a fairly stout cap at around 425 mb which should, when combined
with cloud cover, hold back most thunderstorms until at least mid
afternoon for western Nevada (although there is sufficient
instability for some showers earlier).

As far as the forecast through evening, GFS soundings hold the
capping in all day while the NAM erodes it by late afternoon. With
no major upper forcing apparent until tonight, I am not sure why
the NAM erodes the capping so fast. With the model differences,
the NAM fires up convection in a more widespread manner than the
GFS today. I would tend to side with the GFS but have not delved
into tonight`s forecast yet so POP remains unchanged for tonight.
Snyder

&&

.SYNOPSIS...
Showers and a few thunderstorms are expected this afternoon and
evening as low pressure moves onshore. An increase in showers and
thunderstorms is expected Thursday with some of the storms being
strong. Unsettled weather will continue into the weekend with
locally heavy rain possible. Drier, warmer weather returns early
next week.

&&

.PREVIOUS DISCUSSION... /Issued 242 AM PDT WED MAY 4 2016/

SHORT TERM... Made a few changes to the forecast, mainly to lower
the rain chances a bit into Thursday. We are still expecting a
good event and while most areas will see rain each day, it is
showery so not everyone will get hit.

The upper low that will be the main weather player into the
weekend will approach the coast today with moisture increasing.
A few showers are present this morning across Western Lassen
County and are fairly light. Expect these to increase today as the
low moves in. The models have continued the trend of backing off
on the instability and this looks reasonable. There is still quite
a bit of cloud cover, so expect more showers than thunderstorms.
With the best forcing not expected to arrive until evening, also
do not believe the thunderstorms will be that strong today. Still
could expect some brief heavy rains and small hail.

The jet moves north tonight as the upper low continues its slow
east trek. The dynamics are better, so showers will continue
overnight north of South Lake Tahoe/Minden with an isolated storm
or two.

Thursday looks like the better day for strong thunderstorms.
Instability increases with CAPE up to 1000 J/kg, and the S-N
upper jet is in a very favorable position over central NV. Expect
widespread showers and storms near Reno/Tahoe up to Cedarville
where instability is greatest with at least scattered
showers/storms everywhere else. Larger hail and brief heavy rains
will be the greatest threats.

Showers and storms to continue into Thursday evening and become
less numerous. Still enough moisture and instability to continue
scattered showers overnight. Friday more showers and storms are
expected with another day of good instability as the low moves
into Southern CA. Forcing won`t be quite as strong, but still
expect some locally heavy rains from them.

Friday night continues to look intriguing with a deformation band
developing on the NW side of the low. The models are coming into
better agreement with the location, the EC/GFS/NAM hitting the
Oregon border area into Lassen County. Moderate confidence in
this band location and development. Rainfall amounts Friday night
could approach 1" in this band alone. Wallmann

LONG TERM...Saturday through Tuesday...

Upper low will be centered just south of Las Vegas Saturday with
the Sierra and western NV remaining in a favorable location for
additional showers and thunderstorms, some with locally heavy
rain. Aforementioned band of showers/storms over northeast CA and
northwest NV will be winding down Saturday morning as a second
shortwave feature rotates around upper low into western NV. Models
have been showing this Sat-Sat night band for several days now,
although there have been some slight variations in where heaviest
precipitation bands will set up as well as exact timing. It
appears this band will set up Sat afternoon as shortwave
approaches and instability increases across the Basin and Range.
The GFS is a bit farther north than the ECMWF, but generally south
of where the Friday night band sets up. This would focus heavier
rains on the Tahoe Basin and Sierra Front. Confidence is only
medium and this location could change. But most areas will see
showers and thunderstorms Sat-Sat night nonetheless. Some model
solutions keep this band going into Sunday morning.

As upper low slowly pulls out of the region Sunday, another day of
scattered showers and thunderstorms is expected although coverage
should begin to decrease. Favored areas will be south of I-80. By
Monday, a ridge will work into the west coast with a few showers
lingering mainly along the Sierra. After a cool weekend,
temperatures will warm quickly next week with some model
simulations indicating low-mid 80s for western NV Tue-Wed.
Hohmann

AVIATION...

Showers and thunderstorms will be on the increase today and
Thursday with coverage of lightning generally isolated today,
increasing to scattered on Thursday. Storms will be capable of
lots of small hail and heavy rain, especially Thursday when
forcing/instability will be strongest. There will not be much
break overnight with a few storms possible.

As far as timing, showers/storms will develop along the Sierra
this afternoon and remain mostly locked to the terrain until late
afternoon/this evening when upper forcing shifts into western NV.
Hohmann

&&

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

$$

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





000
FXUS65 KREV 040942
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
242 AM PDT WED MAY 4 2016

.SYNOPSIS...
Showers and a few thunderstorms are expected this afternoon and
evening as low pressure moves onshore. An increase in showers and
thunderstorms is expected Thursday with some of the storms being
strong. Unsettled weather will continue into the weekend with
locally heavy rain possible. Drier, warmer weather returns early
next week.

&&

.SHORT TERM...
Made a few changes to the forecast, mainly to lower the rain
chances a bit into Thursday. We are still expecting a good event
and while most areas will see rain each day, it is showery so not
everyone will get hit.

The upper low that will be the main weather player into the
weekend will approach the coast today with moisture increasing.
A few showers are present this morning across Western Lassen
County and are fairly light. Expect these to increase today as the
low moves in. The models have continued the trend of backing off
on the instability and this looks reasonable. There is still quite
a bit of cloud cover, so expect more showers than thunderstorms.
With the best forcing not expected to arrive until evening, also
do not believe the thunderstorms will be that strong today. Still
could expect some brief heavy rains and small hail.

The jet moves north tonight as the upper low continues its slow
east trek. The dynamics are better, so showers will continue
overnight north of South Lake Tahoe/Minden with an isolated storm
or two.

Thursday looks like the better day for strong thunderstorms.
Instability increases with CAPE up to 1000 J/kg, and the S-N
upper jet is in a very favorable position over central NV. Expect
widespread showers and storms near Reno/Tahoe up to Cedarville
where instability is greatest with at least scattered
showers/storms everywhere else. Larger hail and brief heavy rains
will be the greatest threats.

Showers and storms to continue into Thursday evening and become
less numerous. Still enough moisture and instability to continue
scattered showers overnight. Friday more showers and storms are
expected with another day of good instability as the low moves
into Southern CA. Forcing won`t be quite as strong, but still
expect some locally heavy rains from them.

Friday night continues to look intriguing with a deformation band
developing on the NW side of the low. The models are coming into
better agreement with the location, the EC/GFS/NAM hitting the
Oregon border area into Lassen County. Moderate confidence in
this band location and development. Rainfall amounts Friday night
could approach 1" in this band alone. Wallmann

.LONG TERM...Saturday through Tuesday...

Upper low will be centered just south of Las Vegas Saturday with
the Sierra and western NV remaining in a favorable location for
additional showers and thunderstorms, some with locally heavy
rain. Aforementioned band of showers/storms over northeast CA and
northwest NV will be winding down Saturday morning as a second
shortwave feature rotates around upper low into western NV. Models
have been showing this Sat-Sat night band for several days now,
although there have been some slight variations in where heaviest
precipitation bands will set up as well as exact timing. It
appears this band will set up Sat afternoon as shortwave
approaches and instability increases across the Basin and Range.
The GFS is a bit farther north than the ECMWF, but generally south
of where the Friday night band sets up. This would focus heavier
rains on the Tahoe Basin and Sierra Front. Confidence is only
medium and this location could change. But most areas will see
showers and thunderstorms Sat-Sat night nonetheless. Some model
solutions keep this band going into Sunday morning.

As upper low slowly pulls out of the region Sunday, another day of
scattered showers and thunderstorms is expected although coverage
should begin to decrease. Favored areas will be south of I-80. By
Monday, a ridge will work into the west coast with a few showers
lingering mainly along the Sierra. After a cool weekend,
temperatures will warm quickly next week with some model
simulations indicating low-mid 80s for western NV Tue-Wed.
Hohmann

&&

.AVIATION...

Showers and thunderstorms will be on the increase today and
Thursday with coverage of lightning generally isolated today,
increasing to scattered on Thursday. Storms will be capable of
lots of small hail and heavy rain, especially Thursday when
forcing/instability will be strongest. There will not be much
break overnight with a few storms possible.

As far as timing, showers/storms will develop along the Sierra
this afternoon and remain mostly locked to the terrain until late
afternoon/this evening when upper forcing shifts into western NV.
Hohmann

&&

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

$$

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





000
FXUS65 KREV 032315 CCA
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
415 PM PDT TUE MAY 3 2016

.SYNOPSIS...
A few showers and thunderstorms are possible this afternoon and
evening, then thunderstorm chances increase Wednesday with a few
strong storms possible. More widespread rain and high elevation
snow, with possible thunderstorms will continue Thursday and into
the weekend as low pressure remains over the region.

&&

.SHORT TERM...

Low pressure moving into CA/NV over the next couple days will
bring increasing chances of showers and thunderstorms to the
region. There is a high forecaster confidence in an unsettled,
wet pattern for the rest of the week and into the weekend. A few
showers and isolated thunderstorms are possible through this
evening before convective activity really ramps up tomorrow. No
major changes in the forecast reasoning today, as models have been
fairly stable over the last few days. However, with increasing
confidence we have continued to increase PoPs to categorical for
many locations, especially in the Sierra and western NV Sierra
Front.

The low starts to move inland on Wednesday with an associated
100kt jet max, increasing instability and moisture over the
Sierra and western NV by Wednesday afternoon. Models have
continued to trend slightly slower and further west with the low
pressure, so we have trimmed back chances of showers and
thunderstorms for the areas east of Highway 95. Thunderstorms may
be capable of producing heavy rainfall and small hail during the
late afternoon and evening hours. By Wednesday night into Thursday
morning, we will see continued widespread shower activity with a
few nocturnal elevated thunderstorms mixed in as the forcing from
the jet moves over our area. Snow levels will remain generally
around the 8000-9000 foot range with only the highest Sierra
passes being impacted by snow over the next few days. Heavier
convection may bring down snow levels briefly to around 7000 feet,
although little to no accumulations expected for elevations below
8000 feet.

Instability increases on Thursday again, especially during the
afternoon with cooler temperatures aloft and diffluent flow aloft.
We have continued to raise the pops for Thursday as well as we
have a high confidence of showers and thunderstorms. Thunderstorms
may produce heavy rainfall with models showing a bullseye for
low- level convergence and precipitation around the Reno- Tahoe
area on Thursday afternoon and evening. Hoon

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

A slow moving upper low will continue to provide cool and unsettled
weather this weekend with numerous showers and likely afternoon
thunderstorm development. Shower and storm activity is expected to
be widespread this weekend but being on the north side of the low,
do expect a favored banded region of heavier precipitation. Friday
and Saturday should have the best chances for this heavier banded
precipitation with the most favored region existing mainly north of
Interstate 80. Have trended precipitation chances higher across this
region as a result. This band will shift eastward mainly across
western Nevada by Sunday as the low slowly departs the region, with
only lingering showers by Monday.

Precipitation totals overall continue to look impressive and some
rises on streams and creeks can be expected. Snow levels will remain
rather high (generally above 8,000 feet) through Saturday before
rising more on Sunday. Snow impacts should remain confined to the
highest passes during this event. What seems more impactful would be
thunderstorms producing abundant amounts of accumulating small hail
on roadways especially across higher elevations. Overall, anyone
traveling or planning outdoor recreation this weekend should be
prepared for very active weather with rapidly changing conditions in
and near showers and storms. Those on the lake waters and with other
outdoor recreation plans will be subject to lightning, small hail,
and heavy rain through Sunday. Fuentes

&&

.AVIATION...

Scattered showers and isolated thunderstorms are possible this
afternoon and evening along and just east of the Sierra although
probability of a thunderstorm will be low. An approaching low
pressure system will increase the chances for showers and
thunderstorms beginning Wednesday with widespread activity expected
by Thursday and Friday.

Confidence is increasing that these showers and storms will be
better organized and stronger particularly on Thursday. These storms
will have the potential of producing gusty of outflow winds,
abundant small hail, lightning, and rapid reductions in visibility
in and near storms. Fuentes

&&

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

$$

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





000
FXUS65 KREV 032315 CCA
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
415 PM PDT TUE MAY 3 2016

.SYNOPSIS...
A few showers and thunderstorms are possible this afternoon and
evening, then thunderstorm chances increase Wednesday with a few
strong storms possible. More widespread rain and high elevation
snow, with possible thunderstorms will continue Thursday and into
the weekend as low pressure remains over the region.

&&

.SHORT TERM...

Low pressure moving into CA/NV over the next couple days will
bring increasing chances of showers and thunderstorms to the
region. There is a high forecaster confidence in an unsettled,
wet pattern for the rest of the week and into the weekend. A few
showers and isolated thunderstorms are possible through this
evening before convective activity really ramps up tomorrow. No
major changes in the forecast reasoning today, as models have been
fairly stable over the last few days. However, with increasing
confidence we have continued to increase PoPs to categorical for
many locations, especially in the Sierra and western NV Sierra
Front.

The low starts to move inland on Wednesday with an associated
100kt jet max, increasing instability and moisture over the
Sierra and western NV by Wednesday afternoon. Models have
continued to trend slightly slower and further west with the low
pressure, so we have trimmed back chances of showers and
thunderstorms for the areas east of Highway 95. Thunderstorms may
be capable of producing heavy rainfall and small hail during the
late afternoon and evening hours. By Wednesday night into Thursday
morning, we will see continued widespread shower activity with a
few nocturnal elevated thunderstorms mixed in as the forcing from
the jet moves over our area. Snow levels will remain generally
around the 8000-9000 foot range with only the highest Sierra
passes being impacted by snow over the next few days. Heavier
convection may bring down snow levels briefly to around 7000 feet,
although little to no accumulations expected for elevations below
8000 feet.

Instability increases on Thursday again, especially during the
afternoon with cooler temperatures aloft and diffluent flow aloft.
We have continued to raise the pops for Thursday as well as we
have a high confidence of showers and thunderstorms. Thunderstorms
may produce heavy rainfall with models showing a bullseye for
low- level convergence and precipitation around the Reno- Tahoe
area on Thursday afternoon and evening. Hoon

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

A slow moving upper low will continue to provide cool and unsettled
weather this weekend with numerous showers and likely afternoon
thunderstorm development. Shower and storm activity is expected to
be widespread this weekend but being on the north side of the low,
do expect a favored banded region of heavier precipitation. Friday
and Saturday should have the best chances for this heavier banded
precipitation with the most favored region existing mainly north of
Interstate 80. Have trended precipitation chances higher across this
region as a result. This band will shift eastward mainly across
western Nevada by Sunday as the low slowly departs the region, with
only lingering showers by Monday.

Precipitation totals overall continue to look impressive and some
rises on streams and creeks can be expected. Snow levels will remain
rather high (generally above 8,000 feet) through Saturday before
rising more on Sunday. Snow impacts should remain confined to the
highest passes during this event. What seems more impactful would be
thunderstorms producing abundant amounts of accumulating small hail
on roadways especially across higher elevations. Overall, anyone
traveling or planning outdoor recreation this weekend should be
prepared for very active weather with rapidly changing conditions in
and near showers and storms. Those on the lake waters and with other
outdoor recreation plans will be subject to lightning, small hail,
and heavy rain through Sunday. Fuentes

&&

.AVIATION...

Scattered showers and isolated thunderstorms are possible this
afternoon and evening along and just east of the Sierra although
probability of a thunderstorm will be low. An approaching low
pressure system will increase the chances for showers and
thunderstorms beginning Wednesday with widespread activity expected
by Thursday and Friday.

Confidence is increasing that these showers and storms will be
better organized and stronger particularly on Thursday. These storms
will have the potential of producing gusty of outflow winds,
abundant small hail, lightning, and rapid reductions in visibility
in and near storms. Fuentes

&&

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

$$

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





000
FXUS65 KREV 032145
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
245 PM PDT TUE MAY 3 2016

.UPDATE...
A few showers and thunderstorms are possible this afternoon and
evening, then thunderstorm chances increase Wednesday with a few
strong storms possible. More widespread rain and high elevation
snow, with possible thunderstorms will continue Thursday and into
the weekend as low pressure remains over the region.

&&

.SHORT TERM...

Low pressure moving into CA/NV over the next couple days will
bring increasing chances of showers and thunderstorms to the
region. There is a high forecaster confidence in an unsettled,
wet pattern for the rest of the week and into the weekend. A few
showers and isolated thunderstorms are possible through this
evening before convective activity really ramps up tomorrow. No
major changes in the forecast reasoning today, as models have been
fairly stable over the last few days. However, with increasing
confidence we have continued to increase PoPs to categorical for
many locations, especially in the Sierra and western NV Sierra
Front.

The low starts to move inland on Wednesday with an associated
100kt jet max, increasing instability and moisture over the
Sierra and western NV by Wednesday afternoon. Models have
continued to trend slightly slower and further west with the low
pressure, so we have trimmed back chances of showers and
thunderstorms for the areas east of Highway 95. Thunderstorms may
be capable of producing heavy rainfall and small hail during the
late afternoon and evening hours. By Wednesday night into Thursday
morning, we will see continued widespread shower activity with a
few nocturnal elevated thunderstorms mixed in as the forcing from
the jet moves over our area. Snow levels will remain generally
around the 8000-9000 foot range with only the highest Sierra
passes being impacted by snow over the next few days. Heavier
convection may bring down snow levels briefly to around 7000 feet,
although little to no accumulations expected for elevations below
8000 feet.

Instability increases on Thursday again, especially during the
afternoon with cooler temperatures aloft and diffluent flow aloft.
We have continued to raise the pops for Thursday as well as we
have a high confidence of showers and thunderstorms. Thunderstorms
may produce heavy rainfall with models showing a bullseye for
low- level convergence and precipitation around the Reno- Tahoe
area on Thursday afternoon and evening. Hoon

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

A slow moving upper low will continue to provide cool and unsettled
weather this weekend with numerous showers and likely afternoon
thunderstorm development. Shower and storm activity is expected to
be widespread this weekend but being on the north side of the low,
do expect a favored banded region of heavier precipitation. Friday
and Saturday should have the best chances for this heavier banded
precipitation with the most favored region existing mainly north of
Interstate 80. Have trended precipitation chances higher across this
region as a result. This band will shift eastward mainly across
western Nevada by Sunday as the low slowly departs the region, with
only lingering showers by Monday.

Precipitation totals overall continue to look impressive and some
rises on streams and creeks can be expected. Snow levels will remain
rather high (generally above 8,000 feet) through Saturday before
rising more on Sunday. Snow impacts should remain confined to the
highest passes during this event. What seems more impactful would be
thunderstorms producing abundant amounts of accumulating small hail
on roadways especially across higher elevations. Overall, anyone
traveling or planning outdoor recreation this weekend should be
prepared for very active weather with rapidly changing conditions in
and near showers and storms. Those on the lake waters and with other
outdoor recreation plans will be subject to lightning, small hail,
and heavy rain through Sunday. Fuentes

&&

.AVIATION...

Scattered showers and isolated thunderstorms are possible this
afternoon and evening along and just east of the Sierra although
probability of a thunderstorm will be low. An approaching low
pressure system will increase the chances for showers and
thunderstorms beginning Wednesday with widespread activity expected
by Thursday and Friday.

Confidence is increasing that these showers and storms will be
better organized and stronger particularly on Thursday. These storms
will have the potential of producing gusty of outflow winds,
abundant small hail, lightning, and rapid reductions in visibility
in and near storms. Fuentes

&&

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

$$

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





000
FXUS65 KREV 030939
AFDREV

Area Forecast Discussion
National Weather Service Reno NV
239 AM PDT TUE MAY 3 2016

.SYNOPSIS...
A few showers and thunderstorms are possible this afternoon and
evening, then thunderstorm chances increase Wednesday with a few
strong storms possible. More widespread rain and high elevation
snow, with possible thunderstorms will continue Thursday and into
the weekend as low pressure remains over the region.

&&

.SHORT TERM...
Made a few changes to the details, but the overall idea of the
transition to a wet pattern remains on track. High confidence in
a wet week, especially as we get to Wednesday and Thursday. The
main changes were to decrease the thunderstorm potential into
Wednesday and also trim back pops near/east of Highway 95. The
system is moving in slightly slower so snow levels look to remain
above 8-9000 feet at least through the short term.

The upper low that will affect the region into the weekend is near
135W and slowly making its way toward the coast. Moisture begins
to increase today in the Sierra and extreme Western NV. However,
cloud cover increases and there is a nice stable layer around 450
mb. There is enough instability for some showers near the 395
corridor north of Bridgeport, but any thunderstorms look to be
isolated at best. Showers also will not be that heavy today,
although localized amounts up to 1/4" are possible.

The upper low is expected to near the coast Wednesday afternoon.
Instability and moisture increase with the best instability once
again near the 395 corridor. However, compared to previous runs,
it appears less than before. In addition, the upper jet streak is
slower to move east of the Sierra so the forcing does not look
quite as good. Factor in the cloud cover, and we may not see as
many thunderstorms, nor be as strong as it looked yesterday. I
kept the chances of showers near the 395 corridor high, but
trimmed them east of highway 95 where there is less moisture and
instability. I also cut back the thunderstorm potential to
scattered. This is still a decent number, but if the cloud cover
is too much it could be less.

The jet then does move east Wednesday night and the forcing is
better. Loss of heating may limit thunderstorm potential to
isolated, but showers should be quite numerous at least near and
east of the Sierra.

Thursday could be a potentially very active day as instability and
moisture increase even more. In addition, the upper forcing
remains favorable with the jet in a good location and diffluence
in the flow aloft. Kept showers likely for much of the area with a
chance of thunder. Some of these could be rather heavy if the
models are correct with the instability and forcing. The best
chances for these heavy showers continue to be centered on the
Reno-Tahoe area. Wallmann

.LONG TERM...Friday through Monday...

Expansive upper low will be centered over southern CA to begin
period, and move only slowly eastward through the weekend. This
will keep the cool and unsettled weather pattern going with
numerous showers and isolated-scattered thunderstorms. Being on
the north-northwest side of upper low, heavier and more persistent
bands of precipitation are likely to occur although confidence in
exact location/timing remains low-medium. Deterministic runs of
the GFS/ECMWF show two distinct periods where such heavier bands
could develop, late Friday into Saturday morning and again by
Saturday night/Sunday morning. However, these smaller scale
features are difficult to pinpoint so far out. Precipitation
totals overall continue to look impressive and some rises on
streams and creeks can be expected. Snow levels have trended a bit
higher from previous model runs but should still generally be
7000-8000 feet Fri-Sat before rising Sunday. So snow impacts
should remain confined to the highest passes during this event.
Anyone traveling or planning outdoor activities should prepare now
for a very active weather pattern which will include the
possibility of lightning and small hail.

The upper low is forecast to finally depart Monday with decreasing
showers and warmer temperatures. After highs in the 50s and 60s
Friday-Saturday, readings will rise into the 60s and 70s Sunday-
Monday. Model simulations are pointing to even warmer conditions
beyond Monday. Hohmann

&&

.AVIATION...

Scattered showers and isolated thunderstorms are possible this
afternoon and evening along and just east of the Sierra although
probability of a thunderstorm will be low. Showers and
thunderstorms will increase Wednesday through the weekend with
storms capable of heavy rain and small hail. Hohmann

&&

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

$$

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





    US Dept of Commerce
    National Oceanic and Atmospheric Administration
    National Weather Service
    1325 East West Highway
    Silver Spring, MD 20910
    Page Author: NWS Internet Services Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities