La Nina weather pattern is behind Idaho's record breaking winter

Posted at 6:19 PM, Feb 07, 2017
and last updated 2017-02-07 23:45:09-05

This winter has many people asking "What is this La Nina weather pattern that everyone's been talking about?"  Chief Meteorologist Scott Dorval said La Nina is caused when "a high pressure system pushes back out to the central part of the Pacific and as it does it shoves the jet stream to the north.  By doing that, it sends warm air up into Alaska.  They've been very warm this year, but it brings the jet stream back down and brings the colder weather back down to the northwest."

The temperatures in the Pacific Northwest have been below average by about six to 12 degrees and in some places, even 15 degrees below average.  

"The Southern jet stream is scooping up Pacific moisture from the Hawaiian Islands down here and then having it curve right back up and that's where this wetter portion is typically.  This year it was over the top wet.," Dorval said.

La Nina is also responsible for record-breaking snow fall in the Treasure Valley, avalanches in the Sierras, flooding in California and tornadoes across the south.  Moisture levels so far have been 150, 250, even 400 percent above average across this entire region.

Dorval gave a glimpse at what February holds.  "The forecast here from the Climate Prediction Center shows a good chance for above normal temperatures, in fact across the entire country.  That will mean less snow for the Treasure Valley in February."

A very moist pattern is still coming in below, blocking high pressure systems and the month will continue to be wet.

Looking out 90 days, Dorval predicts above normal temperatures and above normal precipitation for northern states, but he said there's not a connection between La Nina or El Nino and the summer months.

In answer to the question, "Will it be a hot summer?"  When looking at this year's La Nina pattern, Dorval said, "You really can't tell from this connection."