Thursday, January 24, 2013

Superstorm in the Atlantic

Although my attention is generally on the Pacific Ocean, I can't help note the weather event that many meteorologists are talking about the last few days:  the development of an extraordinarily intense cyclone in the north Atlantic, a storm much deeper than Hurricane Sandy.

The central pressure of Hurricane Sandy dropped to approximately 940 hPa and was huge in size.  The storm that will be revving up tomorrow is forecast to hit roughly 924 hPa by Saturday morning (4 AM PST).   The is one intense storm.   Here is this morning's forecast of the European Center model made  for 4 AM PST on Saturday.   More isobars (lines of constant pressure) than you can make out.  The shading shows sustained winds at roughly 5000 ft in meters per second (double to get knots).  A large area of greater than 80 kts.  I am pretty sure this is close to what will happen....a wide range of models are giving the same solution and the forecasts have been quite stable.

 Again, our models gave good warning way into the future.  Here is the 120 hr forecast--you can hardly tell the difference from the 48h forecasts shown above.
Just to give you some perspective on this storm, the strongest north Atlantic cyclone on record got down to 913 hPa near Scotland, and getting into the 940s is not unusual in the Gulf of Alaska.

Here is the sustained wind field near this storm when it is predicted to be near its height (note gusts are much stronger than sustained, or average, winds.)  Large area of 50-60 knot winds (shown by shading).  The white lines are streamlines that are parallel to the wind direction.  Huge storm.


The waves produced by this event will be immense.  Here is the latest National Weather Service WaveWatch3 forecast for Saturday afternoon.   Waves off the chart (more than 15 meters-49 ft).  I bet the container ships will avoid this area!

There is an important point here for everyone, including those of us in the Northwest.  Modern numerical weather prediction is now gaining the capability to predict even highly unusual, extreme events days to a week ahead of time.   Time enough for folks and governments to prepare...and in this case for container ships to get out of the way.  It wasn't that long ago that transoceanic shipping would be hit by the big storms, with damage and loss of life.  For example, there is the famous QEII storm (Sept 9-10, 1978(, where the great ocean liner found itself in the middle of an intense storm.

The forecast for the Northwest U.S. will be boring, benign and normal for the next several days.  No more inversions, fog, and crazy temperature variations through this weekend into early next week.  We will get another ridge of high pressure next week...but the US model is suggesting the potential for a lowland snow event...a modest one...next Thursday.  Too early to say much.


9 comments:

Super said...

Boring and benign are the best descriptors of this winter. What a yawner.

Super said...

Boring and benign are the best descriptors of this winter. What a yawner.

Vizarch said...

Several sailboats racing the the Vendee Globe single-hand around the world race are currently in the vicinity of the Azores and heading for the finish line in SW France, could a dangerous situation for them

Lance said...

Hopefully a lowland snow event develops late next week! I'll be waiting...

Ansel said...

Cliff, I never thought I'd hear you admit the East has more exciting weather... this morning on KPLU. But yes- I agree. They do.

Ansel

Kevin Purcell said...

It's a good job there's a decent blocking ridge over the UK and Ireland right now (they've been having snow and cold over the past couple of weeks). It's stopping the storm from coming onshore anywhere.

I also presume that the big north/south temperature gradient is what's powering this storm?

Any sign of this storm coming ashore?

windlover said...

I'm agree with Lance. I would love for it to snow next week...but not holding my breath! This has been one of the most boring winters ever for the lowlands!

Unknown said...

doing a half marathon Saturday in Redmond called "The Rain Run" - sounds like it will probably live up to it's name... might be nice to get a little snow this winter but I'm glad it's not happening right now!

Sean said...

Reading a book called 'Fastnet Force 10' about a 1979 yacht racing tragedy. Chart looked similar to this, except it went west, right up the channel between Ireland and UK. Back then the BBC provided four weather updates a day. The storm originated in the US Midwest. Nobody knew it was coming. Boats sank and people died.