Posts Tagged ‘channeled winds’

Sea breezes: an Alaskan spring-summer staple

Friday, May 30th, 2014

You’ve heard it said…Alaska has sooo much coastline… We do, about 34,000 miles (54,700 km) worth, and we have the perfect weather phenomenon to go with it: the sea breeze. The sea breeze is a local wind blowing from water to land arising from the relative warmth of the land vs. the water. Warmer land leads to rising and/or expanding air and lowers the surface pressure, drawing in the cool  air off the water. It is not unique to Alaska–It is found (more…)

Alaska weather on a roller coaster

Tuesday, February 11th, 2014

Wind-blown dust in Haines and other places.

forecast-map

Red flag wildfire danger for the Mat Valley.

Strong pressure gradient along coast.

Back into the freezer

The strong “January thaw” that pushed well into the interior and tied the all time January record for Alaska is being pushed toward the back of our memories by seasonal and colder weather. Boy, it feels colder after a long warm spell! Wind chills here in northern Southeast Alaska are bouncing down to 5 to 15F below zero (-20C to -26C) at times. (more…)

Flying through the JAWS of Southeast Alaska Weather

Thursday, May 2nd, 2013

While waiting to board my Alaska Airlines flight from Juneau to Seattle April 9, the all-to-common announcement came over the PA about a likely weather delay. As I happened to have my laptop handy with Internet access available, I quickly checked the Juneau airport weather observations. I did not see any weather issue that would keep the 737 on the ground. The ceiling and visibility were way above minimums. The wind was strong, but pretty well aligned with the runway…not too bad. Here are the observations in METAR format (click here for help in reading them).

PAJN 091353Z 12021G36KT 10SM -RA FEW018 BKN036 OVC050 06/02 A2918 RMK AO2
     PK WND 12036/1349 PRESFR SLP880 P0001 T00560022
PAJN 091453Z 13028G37KT 7SM -RA FEW013 BKN032 OVC045 05/03 A2914 RMK AO2 
     PK WND 13041/1431 SLP867 VIS LWR S-SW P0000 60004 T00500028 58048 

PAJN 091553Z 12022G33KT 3SM -RA FEW013 BKN032 OVC045 05/03 A2912 RMK AO2 
     PK WND 12036/1501 SLP859 P0004 T00500033

What was I missing? Before I could dig deeper, one of the pilots got on the PA and re-educated me, and the whole crowd–mostly seasoned Alaskan flyers with way more weather and aviation savvy than you’d find at a typical airport down south. (more…)

Two kinds of cold in Alaska

Friday, February 1st, 2013

Dry cold, wet cold?   no.

Winter cold and summer cold?  no. Bitterly cold vs extremely cold?  no. Calm vs windy cold? close.

All these would make good blog subjects, but what I’m thinking about today is domestic cold vs imported cold. Seriously.

I have a good recent example. (more…)

The highly channeled winds of coastal Alaska

Friday, January 20th, 2012

Alaska is a big place, and the weather system affecting our state right now is even bigger, but I’m going to show you that is it the small scale that counts when it comes to winds of the south and southeast coasts. As I write this, virtually the whole state is under the influence of the strong pressure gradient between a large, deep low in the Northeast Pacific and strong but gradually weakening high pressure in Siberia and the Alaska interior. (The high was up to a crushing 1060 mb a few days ago, compared to the still hefty 1040 mb on this map) Here is the surface map from 3 pm/00z this afternoon from the GFS model (It’s the 12 hr forecast which is about as good as an analysis):

GFS40_Pacific_t85slp_20120120_1200_F012

You probably know that where the isobars are drawn with the closest spacing is where the gradient is the strongest and therefore where the wind is supposed to be the strongest. (more…)