Winter in noord Amerika 2023/2024

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Severe flash flooding hits Southern California, millions under Flood Watch

Southern California is under a dangerous flood threat with heavy rainfall impacting Los Angeles and San Diego areas, and moving eastward. Flood Watch is in effect for more than 20 million people from Southern California to central Arizona.

As the storms continue on Friday, December 22, 2023, Southern California is grappling with a severe flood threat that has been persisting throughout the week. The Los Angeles and San Diego areas have been particularly impacted, with the severe weather conditions expected to move eastward.

Over 20 million residents across Southern California and central Arizona remain under Flood Watch as cumulative rainfall totals have surpassed 250 mm (10 inches) in several mountain areas as of December 22 — Rocky Butte, for example, registered a total of 408.2 mm (16.07 inches) in 5 days, while Ventura County experienced a month’s worth of rain in just an hour.

The NOAA’s Weather Prediction Center (WPC) has classified a swath of Southern California in a Level 3 out of 4 risk zone for flash flooding due to the overall rainfall amounts and potential for bursts of thunderstorm-triggered heavier rain, especially over recent wildfire burn-scar areas.

For many communities, this period marks the heaviest rainfall event since the remnants of Hurricane “Hilary” impacted the region in August.

Significant flash flooding has occurred in the Oxnard area, the largest city in Ventura County, after 80.8 mm (3.18 inches) of rain fell in one hour on December 21.

The city’s overall storm totals approached 152.4 mm (6 inches) at the city’s civic center by Thursday evening, December 21. Local residents have been severely affected, with about 60 homes flooded and emergency evacuations, including from a senior living center.

The Ventura County Fire Department reported a significant increase in emergency calls during the peak of the storm, with approximately 275 calls received within five hours.

By the end of the week, forecasters anticipate that between 125 to 200 mm (5 and 8 inches) of rain will have fallen in several areas, with some places potentially experiencing even higher amounts.

This continued precipitation keeps the risk of flash and urban flooding high.

The storm system is not only bringing heavy rains but also heavy snow over the Sierra Nevada Mountains and impacting other areas like the Washington and Oregon Cascades and parts of Idaho and Nevada.

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Op vrijdag 5 januari 2024 14:13 schreef Frutsel het volgende:
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Powerful East Coast storm leaves 5 fatalities, nearly 1 million power outages, U.S.

A severe storm system struck the Eastern U.S. on January 9 and 10, 2024, resulting in coastal flooding, damaging winds, nearly a million power outages from New England to the mid-Atlantic states, and the tragic loss of at least five lives.

As of 15:20 UTC on January 10, the storm has claimed at least five lives, with nearly 400 000 customers still without power. The worst affected state is currently New York with 140 000 customers without power, followed by Pennsylvania with 95 000, New Jersey with 55 000, Michigan with 52 000 and North Carolina with 48 000.

Despite the end of rain in the Northeast, rising river levels now pose a major flooding threat, particularly along the Pawtuxet River in Rhode Island and the Pompton and Passaic rivers in New Jersey.

Wisconsin and Michigan reported fatal car crashes due to adverse weather conditions, while in Cottonwood, Alabama, an 81-year-old woman tragically died in a tornado-related incident. Severe weather also claimed lives in Claremont, North Carolina, and Jonesboro, Georgia.

Since January 8, at least 23 tornadoes have been reported across Texas, Alabama, Georgia, Florida, South Carolina, and North Carolina. The Midwest experienced up to 38 cm (15 inches) of snow, while the Northeast saw winds reaching 105 km/h (65 mph).

lorida witnessed several injuries, and over 2 000 people in Brooklyn, New York City, were evacuated from tent shelters. The storm led to significant travel disruptions, with at least 1 465 flights canceled on January 9 and 9 135 delayed.

In Connecticut, the emergency management in New London County reported a potential dam failure at Fitchville Pond along the Yantic River, triggering life-threatening flash flooding warnings in downstream areas, including Fitchville. The Delaware River in Philadelphia broke its all-time record crest, previously set during Superstorm Sandy.

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Winter storms cause over 40 deaths across nine US states

Since January 12, 2024, a series of winter storms and an outbreak of cold air have led to at least 40 deaths across nine US states. The severe weather has caused significant disruptions, including power outages affecting over 85 000 homes and businesses in Oregon, hazardous travel conditions, and extensive road closures. The latest forecasts indicate another round of extreme cold and heavy snowfall across the central and eastern US.

Since January 12, 2024, a series of winter storms and a cold air outbreak have wreaked havoc across several states in the United States, resulting in over 40 fatalities. These weather-related deaths have been reported in nine states, including Arkansas, Illinois, Kansas, Mississippi, New York, Oregon, Pennsylvania, Tennessee, and Wisconsin.

Tennessee has been particularly hard hit, with 14 weather-related deaths, including a tragic incident where a box truck driver lost control on a snowy highway in Knoxville.

In Pennsylvania, a snow-covered Interstate 81 was the site of a fatal minivan accident that claimed five lives, according to the coroner’s office in Lackawanna County.

On January 13 and 14, as the cold airmass moved south, sub-zero air temperatures enveloped Montana and the Dakotas. In Billings, Montana, the National Weather Service station recorded a temperature of -34 °C (-30 °F) on January 13, marking the lowest temperature at this site since its establishment in 1999.

The wind chill factor, which measures how cold it feels to human skin when wind is considered, reached extreme lows in both states, dropping to as much as -51 °C (-60 °F).

In the Pacific Northwest, Oregon experienced significant power outages, with more than 85 000 homes and businesses losing power amid freezing temperatures. As of 09:17 UTC on January 18, there were 42 000 customers still without power in Oregon and another 12 000 in California.

Travel remained treacherous due to icy roadways, downed trees, and power lines. A critical stretch of Interstate 84 was closed, and as of Wednesday evening, it remained shut down due to unsafe conditions.

New York City experienced its first significant snowfall in almost two years. On Tuesday morning, January 16, Manhattan’s Central Park was blanketed with 3.6 cm (1.4 inches) of snow, marking the end of a notable “snow drought” that lasted 701 days, during which the city had not seen more than 2.5 cm (1 inch) of snow.

10 to 13 cm (4 to 5 inches) of snow was recorded in Washington, D.C., and 5 to 8 cm (2 to 3 inches) in Baltimore and Philadelphia.

Buffalo, New York, received 30 – 91 cm (1 to 3 feet) of lake-effect snow overnight Tuesday. That’s on top of 91 cm (3 feet) that fell over the weekend.

Snowfall extended to the Appalachians and Western North Carolina, while Southern states faced unexpected cold conditions.

In Texas and Louisiana, temperatures dropped into the teens on January 15 and 16. On January 16, the airport in Houston, Texas, registered -7 °C (19 °F), setting a new all-time low for that date.

Nashville, Tennessee, a city not typically accustomed to heavy snow, received from 15 to 20 cm (6 to 8 inches) while residents of Mobile, Alabama experienced rare freezing rain and temperatures dropping to -0.5 °C (31 °F).

The weather forecast indicates that the situation is far from over. Another round of freezing rain and heavy mountain snowfall is expected to hit the Pacific Northwest. This new storm system is anticipated to bring up to 13 mm (0.5 inches) of ice in some areas, exacerbating the already challenging conditions. In the Cascades, snowfall rates could exceed 2.5 cm (1 inch) per hour, leading to total snowfall of 30 to 90 cm (1 – 3 feet) by Saturday, January 20.

The immediate coastline in northwest Oregon and Washington will experience rain, which poses a risk of localized flash flooding. Northern California is also bracing for isolated flash flooding. Meanwhile, lake effect snow bands will continue to affect areas downwind of the Great Lakes.

The Mid-Mississippi Valley is now the focus of the next winter weather system, with snow expected to spread to the Midwest, Lower Great Lakes, and Mid-Atlantic by Friday. The Southern Plains and Gulf Coast will experience a brief respite from the cold, with temperatures in the range of 16 – 27 °C (60s and 70s °F).

However, another Arctic airmass is set to bring a sharp drop in temperatures across the eastern half of the US, with daytime highs predicted to be 11 – 17 °C (20 – 30 °F) below normal in some areas. This will also bring low-temperature records and harsh wind chills.

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Powerful atmospheric river triggers state of emergency in Southern California, rare Level 4 of 4 risk of excessive rainfall

An intense atmospheric river event hit California on Sunday, February 4, 2024, prompting Gov. Gavin Newsom to declare a state of emergency in eight counties due to the potential for “life-threatening” flooding, mudslides, and widespread power outages. The National Weather Service warns of significant rainfall, powerful winds, and heavy snowfall continuing over the next few days.

An intense, slow-moving atmospheric river that arrived in California on Sunday, February 4, 2024, has unleashed a series of severe weather phenomena across the state, including “life-threatening” flooding, mudslides, and widespread power outages.

This event has prompted Governor Gavin Newsom to declare a state of emergency in Los Angeles, Orange, Riverside, San Bernardino, San Diego, San Luis Obispo, Santa Barbara, and Ventura counties.

The National Weather Service (NWS) in Oxnard has highlighted the situation as one of the most dramatic weather days in recent memory, with a rare Level 4 of 4 risk of excessive rainfall announced for parts of Southern California, including Los Angeles, Santa Barbara, and Oxnard. This warning predicts rainfall rates of up to 25 mm (1 inch) per hour, resulting in total rainfall amounts of 76 to 152 mm (3 to 6 inches) across the affected areas.

The situation has led to significant disruptions, including the closure of Santa Barbara Airport due to flooding and the rescue of 19 people off Long Beach after their boat’s mast broke in high winds.

In Northern California, fallen trees and power lines have caused injuries and power outages, with over 800 000 customers currently without electricity.

The weather conditions have also impacted travel, with the NWS issuing its first-ever hurricane-force wind warning for San Francisco, forecasting winds of 64 to 97 km/h (40 to 60 mph) with gusts up to 153 km/h (95 mph) in the foothills and mountains. This has made travel in the mountains, particularly above elevations of 1 500 to 1 800 meters (5 000 to 6 000 feet), near impossible due to heavy snowfall and whiteout conditions.

CAT 5 Atmospheric River Event in Southern California

02-04-2024 Ventura, CA-Swift water rescue, firefighters rescue man from river

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Significant winter storm set to impact the West, bringing heavy snow, U.S.

An impending winter storm, driven by an upper-level trough and strong cold front from the northeastern Pacific and western Canada, is forecasted to deliver significant snowfall and strong gusty winds to much of the West in the coming days. Heavy snow is expected in the Central Rockies and Cascades through Monday, extending to the Sierra and the Northern Rockies/Great Basin by Tuesday, with over a foot of snow possible in many areas.

The strong cold front will move into the Northwest Sunday evening, progress southeastward on Monday into the Northern Rockies, and then into the Central Rockies by Tuesday.
Snowfall rates of 25 – 50 mm (1 – 2 inches) per hour are expected over the Cascades and Northern Rockies through Monday, before spreading into the Great Basin and Central Rockies Tuesday. These snow rates combined with winds gusting to 80 – 105 km/h (50 – 65 mph) will produce near-blizzard conditions with significantly reduced visibility and snow-covered roads leading to dangerous travel.
More than 60 cm (2 feet) of snow is expected (>80% chance) in the Cascades through Tuesday, with locally as much as 120 cm (4 feet) possible in the highest terrain. Elsewhere across the Intermountain West, there is a high chance (>70%) of more than 30 cm (1 foot) of snow in the higher elevations. Lowering snow levels will also produce some accumulations on the valley floors.
Snow squalls are expected to develop along the path of the cold front Monday and Tuesday. Where snow squalls occur, intense snow rates will produce rapid drops in visibility and a flash freeze, resulting in dangerous travel.
Temperatures will fall into the teens and single digits (°F) by Tuesday morning along and east of the Rockies.
A strong cold front moving southward from the northeastern Pacific and western Canada is forecast to trigger a major winter storm across the West, affecting areas from the Central Rockies to the Great Basin in the next couple of days.

This system will draw increased moisture from the Pacific, resulting in heavy snowfall across higher elevations and mountainous regions.

The Central Rockies and Cascades are expected to see significant snow accumulations through Monday, with the Sierra and Northern Rockies/Great Basin experiencing similar conditions by Tuesday. Most locations within these areas are predicted to receive at least 30 cm (1 foot) of snow through Tuesday evening, February 27.

n addition to the snow, the region is forecasted to experience widespread, strong, and gusty winds, with numerous high wind-related watches and warnings already in effect across the Intermountain West and adjacent High Plains.

Wind gusts may reach up to 120 km/h (75 mph), which, combined with heavy snowfall rates of 2.5 – 5 cm (1 – 2 inches) per hour, could lead to significant blowing and drifting snow, dramatically reducing visibility.

The forecast also highlights the likelihood of snow squalls across the northern Great Basin and Rockies on Monday, potentially leading to sudden drops in visibility and flash freezes on roads, which would create dangerous travel conditions.

“As this storm system over the West continues eastward into the Plains/Midwest Tuesday, moist southerly flow ahead of the cold front will bring increasing shower and thunderstorm chances to the Midwest/Great Lakes,” NWS forecaster Putnam said.