Update: Hot Weather & Cold Water
The National Weather Service has extended the Heat Advisory for the Mother Lode until 11 PM Saturday.
The Heat Advisory issued for the Sierra Nevada remains in effect until 11 PM Friday.
And the Excessive Heat Warning issued for the Northern San Joaquin Valley also expires at 11 PM Friday.
High temperatures in the Central Valley will range between 103 to 112 degrees through Friday with today being the hottest day.
Overnight low temperatures in the Central Valley will be mostly in the upper seventies through Friday morning.
High temperatures in the Mother Lode will continue to be well into the 90’s to 105 degrees through Saturday.
Thermal belt areas in the Mother Lode will only be cooling into the mid 70s to lower 80s for nighttime lows.
This extended heat event will increase heat related illnesses for those who are exposed to prolonged heat, especially the elderly, children and other sensitive groups without air conditioning.
There will be heat stress to livestock with limited relief from the heat during the overnight hours.
The Sierra Nevada waterways are running very cold and fast, increasing the probability for water rescues. With record breaking heat across Central California, area rivers, lakes and streams are at very high levels due to the extensive winter snow pack melting at a very fast rate.
The National Weather Service would like to remind people of the hidden dangers of the cold snow melt waters feeding Central California waterways.
Area rivers, streams and reservoirs are directly fed from the melting snowpack on the Sierra Nevada. Even though a stream or river looks cool and inviting, the water is actually very cold ranging from 45 to 55 degrees Fahrenheit. Outdoor enthusiasts are advised to use extreme caution near rivers, streams and lakes. If possible please avoid these areas all together.
If you are planning to travel to area rivers and streams, remember that the fast flowing and very cold water is a deadly combination. Although afternoon temperatures are expected to be very hot, water temperatures are in the upper 40`s to lower 50`s. Up to fifteen minutes exposure to water this cold could lead to hypothermia, and the fast flow of the river can easily carry a rafter or swimmer quickly downstream, which can and has led to drownings.
Hypothermia is a sudden loss of body temperature that can be fatal. Warning signs include uncontrolled shivering, slurred speech, drowsiness and apparent exhaustion. Even strong swimmers can tire quickly in the cold water. When you add a strong current and underwater debris, such as rocks, limbs and sharp objects, drowning becomes more likely.
River fluctuations can and will occur without notice. River levels can change very quickly depending on upstream dam releases and debris in the rivers and streams, creating partial blocking of the water flow. If you are only near the edge of the river or stream, you could slip and fall. Don`t turn your back on the river or stream.
Central California rivers and streams are swift, cold and dangerous. Many people have already lost their lives across the Central California Interior due to drowning in area rivers and streams. Please have life vests handy and keep a close eye on children and pets near the rivers edge.
Be Safe, not a Statistic.
The heat will gradually subside over the weekend, but daytime Central Valley highs will still be hot in the upper 90s to low 100s.
A Heat Advisory means that a period of hot temperatures is expected. Very hot temperatures can create a situation in which heat illnesses are possible. Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Take extra precautions if you work or spend time outside. When possible, reschedule strenuous activities to the early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear light weight and loose fitting clothing when possible and drink plenty of water. Young children and pets should never be left unattended in vehicles under any circumstances. This is especially true during warm or hot weather when car interiors can reach lethal temperatures in a matter of minutes.