Another Heavy Winter Storm Targeting the Western U.S. Coast!

 

The abnormally wet pattern in the western U.S. will continue through the rest of the week. One last slug of heavy Pacific moisture will slam into California through Thursday. It will bring flooding rains to the lower elevations and dangerous blizzard conditions to the mountains.

Most of the coastal storms in the past several weeks have been affecting areas of the west coast from northern California up through Washington. The jet stream is about to shift, however, allowing this week’s storm to dip further south. Areas as far south as the L.A. Basin will see heavy precipitation with major impacts.

 

 

Lower elevations will see heavy rainfall, especially from Wednesday afternoon through Thursday morning. Rainfall amounts of 1-3 inches will be common across the region, with higher amounts of 2-5 inches likely for the coastal areas and the west to southwest-facing hills. Rainfall of this magnitude will lead to spotty flooding, life-threatening in some situations. Mudslides will lead to road closures in some areas. Gusty winds will lead to downed trees and powerlines in some areas as well, resulting in power outages.

 

 

At elevations above 6,000-7,000 feet, the precipitation will fall mainly as heavy, wet snow. Crippling accumulations of 2-4 feet will tally at those elevations. The combination of heavy snow and high winds gusting to 70 mph will lead to dangerous and prolonged blizzard conditions, including near-zero visibilities and drifts of ten feet or more. Travel will become impossible for the late week period through the high mountain passes. Lead photo courtesy Airman 1st Class Jack Sanders, USAF

Snow Drought Could Be Ending This Weekend in the Coastal Northeast U.S.

 

For snow lovers in the coastal Northeast U.S. it was a dismal holiday season. Portions of the South and Mid-Atlantic have seen plenty of the white stuff. However, the major cities along the Urban Corridor have seen little to no snow since December 1st (see table below). A major shift in the weather pattern should bring an end to the snow drought, however, starting as early as this weekend.

 

 

The upper air flow across much of the U.S. in the past 6+ weeks has been fairly zonal. There have been storm systems and plenty of rain with some snow in the mountains. However, intrusions of Arctic air have been mostly bottled up in northern Canada. Temperatures have settled down into winter-like ranges the past several days, though. Meanwhile, a more amplified jet stream pattern looks to develop later this week, often a favorable setup for snowy “Nor’Easter” storms.

 

 

The latest model guidance suggests a potent storm system will ride along a strong cold front late this week into the weekend. Significant snows could affect portions of the Midwest, the central Appalachians, and the Northeast. Which locations see how much snowfall will depend on the track and strength of the low pressure system (see map above). A stronger and/or southerly storm will mean colder air along the coast and a major snow storm! However, a more northerly and/or weaker storm will bring warmer air into the cities. In that circumstance, a wintry mix could change to rain overnight Saturday into Sunday morning. Right now the trends point to the warmer/rainier scenario. Heavy snows would threaten the interior mountains, however the Urban Corridor would be largely spared. A lot could change in the next several days, though, so play close attention to your local forecasts!

Flooding Rainfall Imminent for Northern Argentina!

 

A stationary front is hung up from northern Argentina to the Brazil-Uruguay border region. Atlantic moisture will be drawn into this area, leading to persistent storms in the mid to late week time frame. New torrential rainfall on top of already saturated soil will lead to serious flash flooding.

 

 

Northern Argentina and Uruguay have been in a rainy pattern for months. Rainfall has been three to five times normal values so far this summer (see map above). This heavy rainfall has significantly disrupted soy bean farming in this fertile region. Unfortunately, another round of torrential rainfall is on the way.

Model guidance suggests that 300-450 mm (12-18 inches) of rain could fall over northeast Argentina, especially the province of Corrientes, leading to major flooding. Rainfall of 150-300 mm (6-12 inches) will encompass a larger area of northern Argentina and areas near the Uruguay-Brazil border. The heaviest rainfall will fall from late Wednesday into early Thursday. By Thursday night into Friday morning, rains will be diminishing across this region. However, runoff could cause significant rises in the Paraná river system into next week.

 

Severe Storms To Hammer Sydney Metro Later Saturday!

A significant upper level system is sprinting eastward across southeast Australia today. It will spark the hot, humid air already in place across much of New South Wales to produce dangerous thunderstorms this afternoon and evening. These storms will develop first in the early to mid-afternoon from the interior down through the capital district. They’ll threaten Sydney after around 5-6 pm. The strongest cells will bring large hail up to 5 cm in diameter, damaging wind gusts of 80-110 kph, and locally flooding rainfall! The energy for this severe outbreak will wane in the late evening hours as the storms approach Newcastle, causing them to diminish.