United States

The stormy, snowy weather pattern underway in the West will culminate with a mid- to late-week freeze over California's San Joaquin Valley, home to many orange groves.

Temperatures over the lower part of the valley, where most of the groves are located, will dip into the middle 20s at the core of the cold air.

The cold will challenge record low temperatures in the region which are generally in the upper 20s to near 30 degrees. Lows this time of the year tend to average near 40 degrees.

The lowest temperatures are forecast to occur late Wednesday night into Thanksgiving Day morning, when several hours of below-freezing temperatures can occur in areas between Porterville and Bakersfield.

Oranges are still maturing over the southern San Joaquin Valley and are far from harvest as of late November 2010.

According to Agricultural Meteorologist Dale Mohler, "Low temperatures in some of the groves may dip as low as 24 degrees Thursday morning."

"Temperatures could also dip into the upper 20s for a few hours late Thursday night into Friday morning," Mohler added.

While near-freezing temperatures are also forecast for the lower San Joaquin Valley Monday night and Tuesday night, it would only be for a very brief time and damage is not expected.

The magnitude of the cold air is very unusual so early in the season.

"You are much more likely to see a freeze like this late in December, rather than late November," Mohler said.

The groves in the region are known for their table oranges, but also a small amount of juice oranges are grown in the area as well.

"Lemons, grown farther south in California, will also be hit with freezing temperatures for a few hours late in the week," according to Western Weather Expert Ken Clark.

Clark added, "These areas are likely to experience low temperatures in the upper 20s Thursday morning and again Friday morning."

Interests in the orange and lemon grove regions are advised to take protective measures or risk damage.

Meteorologist John Feerick pointed out "The cold wave will deliver the lowest temperatures of the year so far to the Deserts, including Las Vegas and Phoenix."

"Temperatures have not yet reached freezing this year in Las Vegas and the temperature has not dipped below 40 thus far in Phoenix," Feerick added.

Lows for 2010 thus far have been 33 and 41 degrees respectively.