Updraft: November 18, 2009 Archive

Storm pounds Pacific Northwest

Posted at 8:56 AM on November 18, 2009 by Paul Huttner

GOES IR satellite image shows potent storm heading for the Pacific Northwest coastline.

We get some pretty good storms in Minnesota, but imagine the pounding they are getting in the coastal areas of the Pacific Northwest today.

A powerful storm racing southeast from the Gulf of Alaska is crashing into the Washington and Oregon coastline. Winds gusts of 50 to as high as 80mph will slam ashore, downing trees in the process. Heavy surf is churning up along the coast, making for some excellent viewing but coming with coastal flooding. Winds along the coast will shift from easterly this morning to west and increase dramatically later today.

Numerous storm warnings are in effect including high wind warnings, winter storm warnings and even an avalanche watch in the Cascades.

Imagine trying to forecast these systems in the days before modern weather satellites allowed us to see storms from space before they reach the coast.

There is a connection between powerful Pacific Northwest storms and our weather in the Upper Midwest. Pacific storms act as huge atmospheric vacuums, sucking up milder air in the central states. This usually produces a southerly wind flow and milder than average temperatures here in Minnesota. This pattern will hold true again this time with temperatures running about 5 to 10 degrees above average through this weekend.

A piece of the Pacific storm will break off and gather in the southern states by the weekend. It may then come north, and has the potential to produce snowfall somewhere between the Twin Cities and Chicago by early next week. This could affect travel plans between the Cities and Chicago if it develops.

Stay tuned.

PH

NWS: 1" severe hail criteria goes nationwide

Posted at 4:34 PM on November 18, 2009 by Paul Huttner

Last night's Twin Cities AMS Chapter meeting featured Dr. Joe Schaefer, Director of the Storm Prediction Center (SPC). While I was unable to attend last night, my weather spies tell me he broke some news at the meeting.

You may remember last summer the NWS Central Region which includes Minnesota changed the criteria for severe hail to 1" from the previous 3/4" threshold for issuing severe thunderstorm warnings based on hail size. This move was supported by me and many other local meteorologists. It appears the change was a success. Next year, the NWS will adopt the 1" standard nationwide.

It turns out you need hail closer to 2" in diameter (golf ball size) before you really start to do serious structural damage to windows and cars. Since hailstones that size fall at nearly 100 mph, it's probably wise to stick with the 1" criteria when it comes to people outdoors. I wouldn't want to be caught out on the lake in 1" hail. This is a good move by NWS.

I'm told Joe also said SPC is very concerned and will be watchful this winter for tornado outbreaks along the Gulf Coast and in Florida. El Nino winters have a history of producing deadly winter time tornado outbreaks in the Deep South.

SPC is also talking about how to increase the alert level for killer tornadoes that occur during the overnight hours.

Delta moves NWA meteorologists to Atlanta:

Another little bird told me that Delta Airlines is completing the move of the former NWA meteorology staff to Atlanta. When complete, this marks the first time the "hometown airline" has not had a staff of trained meteorologists based in the Twin Cities in decades.

In theory this should not have an effect on the quality of weather forecasts for airline operations at MSP. However, I for one have always been a big believer in the extra "eyes on the ground" data you get from having a locally based staff of weather professionals based at MSP Airport. After all, this is one of the most challenging locations for flight operations in the world, especially in winter.

I am digging deeper into this topic.

Stay tuned.

PH