Monday, May 31, 2010

Tropical Storm Agatha: May 31, 2010 - a potential Pacific Interloper!

Beep beep beep, the sirens have gone off: we have a Pacific interloper in the Caribbean! I don't think this one counts for Atlantic storms (yet), but I'll mention it anyway.

A system looks like it might be re-developing just off the coast of Belize, in the Caribbean. Tropical Storm Agatha was the first tropical storm of the Eastern Pacific hurricane season, lasted for about 12 hours, hit Guatamala yesterday(ish) and resulted in numerous deaths (from heavy rains etc).

The Guatamalans have had a busy week as far as natural disasters. The Pacaya Volcano erupted on May 27 covering the capital, Guatamala City, with something like 8cm of ash, resulting in some loss of life, and shutting down airspace. Also, whilst I'm rambling about rumblings, less than a day later the Tungurahua Volcano in Ecuador also erupted, spewing out rocks and ash and stuff (that's technical jargon for er... stuff). Both have calmed down a bit now (I think). Back to tropical storms (these other pesky natural disasters just keep getting in the way!).

So, Tropical Storm Agatha - although there is some circulation, she doesn't look too healthy because the whole system is still interacting with the central American landmass. But there is considerable convection developing over the portion of the system that is over the rather warm (30 deg C and higher) Caribbean waters.

Storms that cross from one basin to another are called... (drum-roll please)... "crossover storms" (are you surprised? ;-)). There have been about 8 or 9 that have sneaked into the Atlantic from the Eastern Pacific, and 12 or so from the Atlantic to the Eastern Pacific (the most recent in 2008). Those numbers aren't definite because many of them were before we had good observations. If a storm retains it's structure as it crosses, it keeps its name. But if it falls apart during the crossing and then re-develops in the other basin, it gets re-named to the next storm in the new basin.

I won't mention Agatha again unless she decides she wants to completely cross-over and become Alex (first name for the Atlantic system). :-)

I'll send out a proper 'welcome to the Atlantic Hurricane Season' message tomorrow. It might be entertaining. It might not. ;-)

Hasta Manana!

These remarks are just what I think/see regarding tropical storms - not the opinion of any organization I represent. If you are making an evacuation decision, please heed your local emergency management and the National Hurricane Center's official forecast and the National Weather Service announcements. This is not an official forecast. If I was there and planning to "run away, run away" (Monty Python), I'll let you know.

Wednesday, May 12, 2010

Volcanic Ash Special

Hello my friends :-)

Don't Panic! (phew, got that Douglas Adams quote in early this year). No tropical storms. Yet. ;-)

But, alas, I had to come out of hibernation a little early. Too many other things are going on. Yawwwnnn. Cuppa tea anyone?

For a start, Iceland decided they would like to have a larger role in global events. They've already played their "Financial melt-down" card and handed it over to Greece. So now we have the "Volcanic eruption/glacial meltdown" card AND, to really show us what's what, they picked a volcano with a name that Prince would be proud of. The-Volcano-In-Iceland, formerly known as Eyjafjallajokull, began rumbling a few months ago, resulting in a minor eruption in March. So minor in fact that most of the planet payed absolutely no attention. Deciding it didn't like being ignored, it had another go on April 14 and by April 15 a large ash plume was heading towards the rest of Europe, causing some minor (!) problems here and there (or so I heard). It was idyllic being stuck in the UK during that time - contrail-free blue(ish) skies, warm weather, birds tweeting, cows mooing, flowers blooming, and the slight coating of some metallic and bitter tasting stuff on my skin didn't do me any long term damage (well, none that anyone could detect anyway ;-)) .

So, just in case you are silly enough to want to fly across the Atlantic any time in the next 2 years (says she, who flew across about 5 days ago), I thought you'd like to know where to look for forecasts and what the volcano is doing.

But first the REALLY important stuff... "How to look good and impress your friends: A phonetic guide to Eyjafjallajokull":
From Iceland's embassy in Washington, via NPR, this is how you say Eyjafjallajokull: "AY-yah-fyah-lah-YOH-kuul."
( There's a little audio clip on there too, so you can hear someone saying it (warning: you'll be saying it with a proper Icelandic accent if you listen to it too much). With 3 weeks of practice, I can now pronounce it correctly after 1.5 glasses of wine. Of course no-one else knows what I'm saying, they are just impressed I have the approximate number of syllables. ;-)

For volcanic ash forecasting the world is divided into regions with a Volcanic Ash Advisory Centre (or Center ;-); VAAC) per region. Each VAAC is responsible for providing the official global forecast for ash from any misbehaving volcano in it's region (see website below). The London VAAC covers Iceland and is based in the UK Met Office: This website has the latest Volcanic Ash advisory information. Click on "London VAA: Issued graphics" text( There's a looong list of numbers (PFXD...) next to a date and time stamp (the time is GMT), click on the top one which is the latest forecast, and you'll see four maps. Each map is a forecast for a different time. The top left map is the first in the series and has the year, the month (05), the date/time (Z stands for Zulu time, which is GMT). The red line shows ash location in the lower levels of the atmosphere (SFC-FL200), the green dotted line (FL200/FL350) is ash location at cruising altitude for many flights. FL stands for Flight Level in this case, not Florida :-), so FL350 is a cruising altitude of 35,000 ft.

For a ROUGH idea of concentration charts (I say rough because these are not an official product in the same sense as the plots above), go back to the VAAC homepage ( and click on "London VAAC NWP Volcanic Ash Concentration Charts: Latest charts" (there's a disclaimer at the top). Scroll down, you'll see the time and date stamp in bold above each chart for different flight levels. Each chart that has a red and possibly black area indicates ash concentration for that time and level. Black areas are bad: these are where ash exceeds the plane engine manufacturer tolerence level.

To read about what the volcano is doing, I go to the Icelandic Met Office: They update this at least daily. An eruption plume of 4-5km or higher (13,000 - 16, 400 ft) indicates that it's still quite active.

So there we have it for this "Special". If you have any questions about this, let me know and as with tropical storms, I'll make up an answer for you or find someone who knows about these things. ;-)

Stay tuned... if I have time I'll be doing another "special" before the season really begins on June 1. And then I'll have a nap. ;-)

Toodle Pip!

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DISCLAIMER: These remarks are just what I think/see regarding volcanic eruptions in Iceland - not the opinion of any organization I represent. If you are making an evacuation decision (o.k.... so this disclaimer I cut and paste from the old one, so if you are in Iceland this bit might apply), please heed your local emergency management announcements. This is not an official forecast. If I "run away, run away" (Monty Python), I'll let you know. Hee hee.