Tuesday, November 8, 2011

Bering Superstorm

An extraordinarily intense storm is now churning through the Bering Sea.

The central pressure is roughly 945 hPa--similar to a category three hurricane, and in fact this storm does have hurricane-force winds.  (a hPa is the same as a millibar, mb, which you may be more familiar with.  In the inches of mercury units this would be 27.9 inches).  Take a look at a recent National Weather Surface surface analysis (for 4 PM Tuesday).  943 hPa low center and the NWS folks note the hurricane-force winds (sustained winds of 64 kt or more).  That is a lot of isobars, with extraordinary pressure gradients.

It is quite unusual to have a storm this strong so far north.   This storm developed very rapidly--approximately 60 hPa in 48 h, thus putting it in the category of explosive deepeners or "meteorological bombs" as known in the weather literature. Here is an image of the storm from of the polar orbiter weather satellites...the low center is in the middle of the swirl.

This storm is far deeper and stronger than the famous "Perfect Storm" of movie fame--at its most intense that low only got down to 972 hPa...nearly 30 hPa higher pressure.  The has passed near a few weather buoys.  Here are a few samples. Buoy 46070, found in the western Bering (see map) had a minimum pressure  of 28.2 inches of Hg (954 hPa) and gust to nearly 60 kts.


 Or Buoy 46035 (to the east) with gusts to 75 knots!


Wave heights at these locations climbed above 35 ft:



The fact that the storm is moving so quickly is preventing the waves from getting catastrophic since big waves requires strong winds, large fetch, and duration to build. Coastal flooding (up to 10 feet storm surge) and blizzard conditions add to the mix.  In any case, this will be one of the great storms of the year.

Selected Peak Gusts from the NWS Hydrometeorological Prediction Center

.SELECTED PEAK WIND GUSTS IN MILES PER HOUR 

...ALASKA...
TIN CITY AFS (AWOS) 85
WALES 84
CAPE LISBURNE(AWOS) 75
KOTZEBUE/RALPH WIEN (ASOS) 73
KIVALINA ARPT 71
POINT HOPE (AWOS) 69
CAPE ROMANZOFF (AWOS) 60
ST MICHAEL 58
TELLER 58
EMMONAK 56
NOME (ASOS) 55
BETHEL AIRPORT (ASOS) 54
SAVOONGA AIRPORT 54

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