San Jose, CA Weather Alerts

Excessive Heat Warning issued July 9 at 9:22PM PDT until July 12 at 8:00PM PDT

Alert Icon Weather Alerts

* WHAT...Dangerously hot conditions with temperatures up to 110
with limited overnight cooling in higher elevations expected.

* WHERE...North Bay Interior Mountains, East Bay Interior
Valleys, Santa Clara Valley, including San Jose, Eastern Santa
Clara Hills and East Bay Hills.

* WHEN...From 11 AM Wednesday to 8 PM PDT Friday.

* IMPACTS...Most individuals will be at risk for heat-related
illnesses without effective cooling or adequate hydration,
especially with prolonged outdoor exposure. Without effective
cooling and/or adequate hydration, heat-related illnesses
including heat stroke will be a risk to everyone. Overnight
lows will warm as well leading to poor relief from the heat
specifically in elevated terrain and interior areas.

* ADDITIONAL DETAILS...An exceptionally dangerous situation will
unfold over the next couple of days we move through this
deadly heat event for inland areas. Another couple days of
temperatures well above normal will lead to compounding
effects among people and infrastructure, with the possibility
of numerous heat related fatalities.

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3 days ago

Excessive Heat Warning issued July 3 at 12:26PM PDT until July 10 at 11:00PM PDT

Alert Icon Weather Alerts

* WHAT...Dangerously hot conditions with temperatures in the
upper 90's to 115F expected. Limited overnight relief with low
temperatures in the mid 60s to low 80s. Resultant widespread
Major HeatRisk, with areas of Extreme HeatRisk.

* WHERE...Marin Coastal Range, Sonoma Coastal Range, North Bay
Interior Mountains, North Bay Interior Valleys, East Bay
Interior Valleys, Santa Cruz Mountains, Santa Clara Valley,
Eastern Santa Clara Hills, East Bay Hills, Southern Salinas
Valley, Santa Lucia Mountains and Los Padres National Forest,
and Mountains of San Benito and Interior Monterey.

* WHEN...Until 11 PM PDT Wednesday.

* IMPACTS...Most individuals will be at risk for heat-related
illnesses without effective cooling or adequate hydration,
especially with prolonged outdoor exposure. Without effective
cooling and/or adequate hydration, heat-related illnesses
including heat stroke will be a risk to everyone. Overnight
lows will warm as well leading to poor relief from the heat
specifically in elevated terrain and interior areas.

* ADDITIONAL DETAILS...An exceptionally dangerous situation is
expected to unfold during this potentially historic and deadly
heat event. Several days of temperatures well above normal
will lead to compounding effects among people and
infrastructure, with the possibility of numerous heat related
fatalities. It cannot be stressed enough that while one day at
these temperatures may be manageable for some, an event of
this scale, magnitude, and longevity will likely rival
anything we've seen in the last 18 years. Heat is the number
one weather related killer in the United States. By this
weekend, it is VERY LIKELY that we add to that statistic if
preparations are not taken seriously.

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10 days ago

Excessive Heat Warning issued June 30 at 1:19AM PDT until July 5 at 11:00PM PDT

Alert Icon Weather Alerts

* WHAT...Dangerously hot conditions with temperatures in the upper
90's to 110F expected. Limited overnight relief with low
temperatures in the mid 60s to low 80s. Resultant widespread
Major HeatRisk, with areas of Extreme HeatRisk.

* WHERE...Marin Coastal Range, Sonoma Coastal Range, North Bay
Interior Mountains, North Bay Interior Valleys, East Bay
Interior Valleys, Santa Cruz Mountains, Santa Clara Valley,
Eastern Santa Clara Hills, East Bay Hills, Southern Salinas
Valley, Santa Lucia Mountains and Los Padres National Forest,
and Mountains of San Benito and Interior Monterey.

* WHEN...From 11 AM Tuesday to 11 PM PDT Friday.

* IMPACTS...Most individuals will be at risk for heat-related
illnesses without effective cooling or adequate hydration,
especially with prolonged outdoor exposure. Without effective
cooling and/or adequate hydration, heat-related illnesses
including heat stroke will be a risk to everyone. Overnight lows
will warm as well leading to poor relief from the heat
specifically in elevated terrain and interior areas.

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13 days ago

Excessive Heat Watch issued June 29 at 2:52AM PDT until July 5 at 11:00PM PDT

Alert Icon Weather Alerts

* WHAT...Dangerously hot, well above average temperatures with
limited overnight cooling.

* WHERE...Areas away from the immediate coast in the Bay Area and
Central Coast.

* WHEN...From Tuesday morning through Friday evening.

* IMPACTS...Most individuals will be at risk for heat-related
illnesses without effective cooling or adequate hydration,
especially with prolonged outdoor exposure. Without effective
cooling and/or adequate hydration, heat-related illnesses
including heat stroke will be a risk to everyone. Overnight lows
will warm as well leading to poor relief from the heat
specifically in elevated terrain and interior areas.

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15 days ago

Heat Advisory issued June 22 at 9:39PM PDT until June 22 at 10:00PM PDT

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With cooler conditions forecast to set in through the night, the
Heat advisory will be allowed to expire on time at 10 PM PDT.

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21 days ago

Frost Advisory issued April 5 at 8:22PM PDT until April 6 at 9:00AM PDT

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* WHAT...Temperatures as low as 33 will result in frost formation.

* WHERE...Central to Southern parts of the Santa Clara Valley,the
Santa Cruz Mountains, Southern Salinas Valley, and Carmel Valley.

* WHEN...From 1 AM to 9 AM PDT Saturday.

* IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive
outdoor plants may be killed if left uncovered.

* ADDITIONAL DETAILS...These temperatures will be hazardous to
sensitive populations such as unhoused individuals.

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3months ago

Hydrologic Outlook issued February 15 at 12:13PM PST

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ESFMTR

* WHAT...A series of storms forecasted to move through the region
this weekend and into the first half of next week will bring the
potential for moderate to rapid rises along area creeks, streams,
and rivers across the region. Soil moisture remains high from
previous storms earlier this month and will reach saturation this
weekend as the first of three cold fronts moves through the area.
Once saturated, additional rainfall will runoff resulting in
moderate to rapid rises on our creeks, streams, and rivers, as
well as lead to nuisance and/or minor flooding. Latest river
forecasts from the CNRFC depict an initial rise on area creeks,
streams, and rivers on Saturday and Saturday night with a larger
rise on Monday and Tuesday. The latest update from CNRFC lowered
the probabilities of reaching flood stage for most of the rivers.
The current ensemble guidance from the CNRFC indicates the Russian
River at Guerneville, the San Lorenzo River at Big Trees and the
Carmel River at Robles del Rio have a 20% chance of reaching flood
stage in the next 5 day while the Salinas River at Spreckels and
Pajaro River at Chittenden which will be slower to crest will have
a 20% chance of reaching flood stage in the next 10 days. Although
most sites are forecast to remain below flood stage, some
locations may reach monitor stage or minor flood stage.

Model guidance suggests greatest accumulation of precipitation
will be observed along the coastal ranges. Rainfall totals remain
consistent with 1 to 3 inches expected across most areas with 3-6
inches expected over favored peaks and higher terrain of the
coastal hills and mountains.

USGS instrumentation throughout the San Francisco Bay Area
indicates that shallow soils on steep hillsides are approaching
saturation. This coupled with the forecasted precipitation means
shallow landslides are possible.

* WHERE...For the entire forecast area from Napa and Sonoma
Counties and south through Monterey and San Benito Counties.
Although the current forecast shows these creeks and rivers
remaining below flood stage, some locations may reach monitor
stage.

* WHEN...Saturday through Wednesday.

* ADDITIONAL DETAILS...Localized ponding of water in low-lying or
poorly drained areas, such as freeway offramps.

Details regarding this storm will likely change as the system
nears. Therefore, stay tuned to the latest forecast for the most
up to date weather information. Confidence is high that we will
receive rainfall from this system. However, confidence is
moderate with respect to location and total rainfall amounts.

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4months ago

Flood Watch issued January 29 at 12:41PM PST until February 2 at 4:00AM PST

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Model guidance continues to suggests greatest accumulation of
precipitation will be observed across the North Bay and along
the coastal ranges. Rainfall totals remain consistent with
1.5 to 3 inches expected across most areas with 3-5 inches
expected over the North Bay. Locally up to 6 to 8 inches over
favored peaks and higher terrain of the the North Bay and up to
4 to 6 inches in the Santa Cruz and Santa Lucia Mountains.

* WHAT...Flooding caused by excessive rainfall is possible.

* WHERE...Entire San Francisco Bay Area and Central Coast including
Monterey and San Benito Counties.

* WHEN...From late Tuesday night through late Thursday night.

* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
Flooding may occur in poor drainage and urban areas. Low-water
crossings may be flooded. Storm drains and ditches may become
clogged with debris.

* ADDITIONAL DETAILS...
- Periods of moderate to heavy rainfall will bring the
potential for moderate to rapid rises along area rivers,
streams, and creeks across the region. This could result in
nuisance as well as minor flooding. Although many sites are
forecast to remain below flood stage, several locations may
reach and exceed flood stage across the region.

Ensemble guidance shows a greater than 50 percent chance of
reaching flood stage on numerous rivers and creeks across the
North Bay and monitor stage on the San Lorenzo River at Big
Trees and numerous other locations across the San Francisco
and Monterey Bay Area by Thursday.
- http://www.weather.gov/safety/flood

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5months ago

Flood Advisory issued January 22 at 7:24AM PST until January 22 at 8:30AM PST

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* WHAT...Flooding caused by excessive rainfall continues.

* WHERE...A portion of northern California, including the following
county, Santa Clara.

* WHEN...Until 830 AM PST.

* IMPACTS...Minor flooding in low-lying and poor drainage areas.
Ponding of water in urban or other areas is occurring or is
imminent.

* ADDITIONAL DETAILS...
- At 724 AM PST, Doppler radar indicated heavy rain.
Overflowing poor drainage areas will cause minor flooding in
the advisory area. Between 0.7 and 1 inch of rain has fallen.
- Additional rainfall amounts up to 0.1 inches are expected
over the area. This additional rain will result in minor
flooding.
- Some locations that will experience flooding include...
San Jose, Mt. Hamilton and Seven Trees.
- http://www.weather.gov/safety/flood

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5months ago

Hydrologic Outlook issued January 18 at 11:46AM PST

Alert Icon Weather Alerts

ESFMTR

* WHAT...Periods of moderate to heavy rainfall will bring the
potential for moderate to rapid rises along area rivers,
streams, and creeks across the region. This could result in
nuisance as well as minor flooding. Although most sites are
forecast to remain below flood stage, some locations may reach
monitor stage, especially in Sonoma County. Ensemble guidance
shows a greater than 20% chance of reaching flood stage on the
Russian River at Guerneville by late Monday night.

Model guidance continues to suggests greatest accumulation of
precipitation will be observed across the North Bay and along
the coastal ranges. Rainfall totals remain consistent with
1.5 to 3 inches expected across most areas with 3-5 inches
expected over the North Bay. Locally up to 5 to 7 inches over
favored peaks and higher terrain of the the North Bay and up to
4 to 6 inches in the Santa Cruz and Santa Lucia Mountains.

USGS instrumentation throughout the San Francisco Bay Area
indicates that shallow soils on steep hillslopes are
approaching saturation. This coupled with the forecasted
precipitation means widespread shallow landslides are likely.

* WHERE...For the entire forecast area from Napa and Sonoma
Counties and south through Monterey and San Benito Counties.
Although the current forecast shows these creeks and rivers
remaining below flood stage, some locations may reach monitor
stage. The creeks that are most likely to see rapid rises are
located within Sonoma County such as Mark West, Green Valley,
and Laguna De Santa Rosa. However, rapid rises could also occur
along the San Francisquito Creek and San Lorenzo River.

* WHEN...Friday through Monday.

* ADDITIONAL DETAILS...Localized ponding of water in low-lying or
poorly drained areas, such as freeway offramps.

Details regarding this storm will likely change as the system
nears. Therefore, stay tuned to the latest forecast for the most
up to date weather information. Confidence is high that we will
receive rainfall from this system. However, confidence is moderate
with respect to location and total rainfall amounts.

User Icon WikiXM Admin
5months ago