Severe Thunderstorm Warning 21, NWS Sacramento, CA

737 
WWUS56 KSTO 102236
SVSSTO

Severe Weather Statement
National Weather Service Sacramento CA
336 PM PDT Sat Jun 10 2023

CAC007-063-103-102245-
/O.EXP.KSTO.SV.W.0021.000000T0000Z-230610T2245Z/
Plumas CA-Tehama CA-Butte CA-
336 PM PDT Sat Jun 10 2023

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN PLUMAS...
NORTHEASTERN TEHAMA AND NORTH CENTRAL BUTTE COUNTIES WILL EXPIRE AT
345 PM PDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However hail and 
heavy rain are still possible with this thunderstorm.

LAT...LON 4040 12138 4014 12135 4008 12173 4042 12178
TIME...MOT...LOC 2235Z 063DEG 15KT 4019 12168 

$$

kh

Area Forecast Discussion
National Weather Service Sacramento CA
1240 PM PDT Sat Jun 10 2023

.SYNOPSIS...
Afternoon and evening thunderstorms through at least mid week,
with the most widespread chances on Sunday. Temperatures will
remain below normal then start increasing to near to slightly
above normal by end of next week.

&&

.DISCUSSION...
Current radar shows some showers and thunderstorms developing
across portions of interior northern California early this
Saturday afternoon. The counter-clockwise spinning low can be seen
currently on GOES-West satellite imagery. Ensembles project that
the upper level low will slowly work it's way down the California
coastline today before moving inland over southern California on
Sunday.

Thunderstorms will continue to be the main weather element of
concern over the next several days, as the National Blend of
Models (NBM) displays generally a 25 to 50 percent probability of
thunderstorm development in the mountains and foothills, and a 10
to 20 percent probability in portions of the Valley for the
afternoon and evening hours. The better chances for thunderstorms
will be in the Sierra and southern Cascades today, but become more
widespread Sunday to include the Coastal Range, and much of the
Sacramento Valley.

The main threats with any thunderstorms that develop will be heavy
rain, gusty winds, frequent lightning, and hail. The latest high-
resolution model guidance shows generally a 20 to 55 percent
probability of rain rates greater than a half inch per hour, and a
10 to 25 percent probability of rain rates greater than an inch
per hour for today, mainly over the Sierra and southern Cascades.
Those probabilities increase slightly on Sunday, as the PWATs
increase across the area. There is the potential for rain rates to
reach burn scar debris flow criteria with any strong, slower
moving storms. Additionally, localized flooding, ponding of water
on roadways and increased travel times are certainly possible due
to locally heavy rain. People should stay weather aware this
weekend, especially if they have outdoor plans in the afternoon
and evening hours.

Temperatures will remain near to below normal in the short-term,
with minor heatrisk in the Valley and foothills. Unsettled weather
will continue early next week, however the thunderstorm potential
will mainly be confined to the higher elevations of the Sierra
Nevada and southern Cascades by Tuesday.

&&

.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)...
Ensemble guidance and cluster analysis support troughing pattern
to continue to influence the region for mid to late week with high
pressure building off to the west over the Pacific Ocean. This
will result in continued afternoon and evening thunderstorm
potential over the mountains. The best chances will be along the
Sierra Crest, mainly south of Interstate-80 (10 to 25 percent
probability of thunderstorm development). Temperatures will trend
warmer throughout the week. The National Blend of Models (NBM)
advertises a 40 to 85 percent probability of reaching 90 degrees
for the daytime high temperature over the extended forecast period
for most of the Valley, excluding the immediate vicinity of the
Delta. Even with the warming temperatures, widespread minor
heatrisk remains over interior NorCal as those temperatures will
be rising only to near to slightly above normal for this time of
year, however with the large spread in temperatures in the models
we could see some patches of moderate heatrisk by Friday/Saturday
if things trend warmer.

&&

.AVIATION...
Mostly VFR conditions expected over the next 24 hours in the
valley. Isolated to scattered thunderstorms over the Sierra
Nevada, southern Cascades, and Coastal Range mainly 19Z through
03Z Sunday (30-60% probability) and isolated into the northern
Sacramento Valley (15-25% probability) resulting in local IFR
conditions. Scattered showers through Sunday will result in mainly
areas of MVFR conditions over the mountains. The main threats for
thunderstorms are gusty and erratic winds, lightning, brief heavy
rain and small hail. Winds away from thunderstorms generally less
than 12 kt, except southwesterly up to 25 kts in the vicinity of
the Delta.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.

&&

Special Weather Statement
National Weather Service Sacramento CA
139 PM PDT Sat Jun 10 2023

CAZ068-069-102130-
West Slope Northern Sierra Nevada CA-
Western Plumas County/Lassen Park CA-
139 PM PDT Sat Jun 10 2023

...A strong thunderstorm will impact portions of south central
Plumas, northwestern Sierra and northeastern Yuba Counties through
230 PM PDT...

At 138 PM PDT, Doppler radar was tracking a strong thunderstorm over
Downieville, moving northwest at 10 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Downieville, American House, La Porte and Little Grass Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

If on or near a lake, get out of the water and move indoors or
inside a vehicle. Remember, lightning can strike out to 10 miles
from the parent thunderstorm. If you can hear thunder, you are close
enough to be struck by lightning. Move to safe shelter now! Do not
be caught on the water in a thunderstorm.

&&

LAT...LON 3950 12074 3954 12107 3975 12100 3968 12073
TIME...MOT...LOC 2038Z 125DEG 10KT 3959 12084

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

Baruffaldi

Special Weather Statement
National Weather Service Sacramento CA
204 PM PDT Sat Jun 10 2023

CAZ066-068-102145-
Northeast Foothills/Sacramento Valley CA-
Western Plumas County/Lassen Park CA-
204 PM PDT Sat Jun 10 2023

...A strong thunderstorm will impact portions of eastern Tehama and
north central Butte Counties through 245 PM PDT...

At 204 PM PDT, Doppler radar was tracking a strong thunderstorm near
Butte Meadows, or 17 miles northwest of Pulga, moving northwest at 5
mph.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will remain over mainly rural areas of eastern Tehama and
north central Butte Counties.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4003 12155 3998 12160 4002 12174 4010 12166
TIME...MOT...LOC 2104Z 129DEG 5KT 4003 12162

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

Baruffaldi

Special Weather Statement
National Weather Service Sacramento CA
227 PM PDT Sat Jun 10 2023

CAZ068-102200-
Western Plumas County/Lassen Park CA-
227 PM PDT Sat Jun 10 2023

...A strong thunderstorm will impact portions of central Plumas
County through 300 PM PDT...

At 227 PM PDT, Doppler radar was tracking a strong thunderstorm over
Bucks Lake, or 11 miles east of Pulga. This storm was nearly
stationary.

HAZARD...Winds in excess of 40 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Bucks Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3986 12118 3981 12123 3985 12128 3989 12123
TIME...MOT...LOC 2127Z 099DEG 1KT 3985 12123

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

Baruffaldi