Saturday, November 28, 2009

Super Typhoon Nida Possibly The Deepest Tropical Cyclone On Record

As Super Typhoon Nida (26W) continues to churn in the Philippine Sea northwest of the Northern Mariana Islands and south of the Volcano Islands (Iwo/Jima) with 140kt (161mph) winds, questions remain as to the exact maximum intensity of this storm. Unlike in the Atlantic Ocean where hurricane hunter aircraft send dropsondes into tropical cyclones to ascertain intensity, storms in the West Pacific must be analyzed by remote sensing technologies. One of the manners in which this is done is by using the Advanced Dvorak Technique (ADT) (more information here) According to this technique at approximately 2332Z on November 25th, Nida bottomed out at 869.3mb which would move the storm past Super Typhoon Tip as the deepest tropical cyclone on record (Tip was measured at 870mb).

It's tough to tell whether there will ever be a consensus on this as some of the same questions (apparently) were raised during the reign of Cyclone Monica north of Australia in 2006. Any way you look at it though, Nida is one hell of a storm!

Currently, the storm is a little lost. Various models and forecast agencies are taking her to the west over the next 24 hours. JTWC is recurving the storm to the northwest, though ... which is contrary to most other forecasts. I actually agree with them given the overall synoptic pattern, so we'll see. If they're right, the storm will pass between South Iwo Jima (the southernmost of the Volcano Islands) and Farallon de Pajaros (the northernmost of the Northern Mariana Islands), hopefully harmlessly. If the models/agencies are correct, then who knows! Given that the storm is fairly stationary, however, the upwelling generated by the storm should slowly weaken it.

Here is some current information on the storm:

JTWC's track

JMA's track

The storm briefly restrengthened after an eyewall replacement cycle yesterday to maximum intensity estimates of 899mb(ADT) and 150kt (JTWC). Here is a vapor image at the time:

Other archived imagery of the storm:

MODIS image from early on November 25th

... and this one just happens to be my favorite image of the storm:

Other discussion regarding the storm:
CIMSS Satellite Blog
NASA Hurricanes/Tropical Cyclones
Nida on Storm Track
Nida on Storm2K
ADT Intensity History

Finally, back here along the Footies, we enjoys above 60ºF (Thursday and Friday). It has cooled today with a weak front sweeping south along the Range. We're sitting at about 50ºF here right now and I don't expect it to get any higher. Though we may see a bit of light snow tonight and tomorrow, I'm not expecting much accumulation. What I am *not* looking forward too is the inverted air mass which should stick around for the next few days. The pattern doesn't look to allow much in the way of significant downsloping to help mix out the cold pool.

Found this image on the MODIS site today ... it's from the snow storm that moved through the Central Rockies on November 16th (image is from the 17th). Click for a larger view!


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