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.

Dual Cyclones Threaten the South Pacific Tropical Basin!

 

We’re approaching the middle of summer in the Southern Hemisphere and the tropics are starting to heat up. Cyclone Penny has redeveloped over the central Coral Sea after dropping torrential rain over northeastern Australia around New Year’s. Meanwhile, the ninth cyclone of the season (unnamed) has spun up over the South Pacific. Both of these storms could bring significant hazards to portions of the region in the next several days.

 

 

Cyclone Penny first developed over the extremely warm waters of the Gulf of Carpentaria in northern Australia on New Year’s Eve. The cyclone was originally part of an active monsoonal flow enhanced by an upper level trough. This combination of factors has been dumping flooding rains over northern Queensland for the past few weeks. Penny also produced localized wind gusts to 90 kph. It weakened to a tropical low as it crossed the peninsula through 1-2 January, however it has regained strength over the open, warm waters of the Coral Sea. Penny will likely turn south and southwest over the next several days. By late this weekend or early next week, the cyclone could be threatening another landfall in coastal Queensland (see map below). Conditions don’t favor rapid, sustained intensification, however gusty winds and very heavy rainfall are likely threats wherever the cyclone moves.

 

 

Cyclone Nine developed overnight north of Fiji (see map below). Warm water and a favorable upper level wind pattern support continued intensification as the system moves south. The Fijian archipelago will likely see stormy weather this weekend, including high winds and heavy rains. The system will weaken as it moves south away from the islands next week. Lead photo courtesy Wikipedia contributor Firth McEachern.