30 December 2005

Tropical Storm Zeta forms...

Go ahead, re-read the subject; it did NOT say "Winter Storm Update 
12/30".  Continuing an unprecedented tropical season (and post-season), 
the 27th named storm, Zeta, has formed today in the eastern Atlantic, 
south of the Azores.  Satellite-estimated intensity is 45kts and 1003mb.
It's located at 25.0N 36.9W and tracking NW at 7kts.  It has healthy 
deep convection centralized over the core, and several banding features.  
It's in about 20kts of westerly shear and is over 23C water.

The forecast is bleak for the storm, possibly strengthening briefly in 
the next 24 hours, then rapidly dissipating in increasingly hostile 
conditions as it turns toward the west.

The formation of Zeta brings the season's NTC up to 268% (an average 
season is defined to be 100%)

Please visit my tropical Atlantic headquarters.

07 December 2005

Yet another record for the 2005 hurricane season

From Phil Klotzbach:

According to the monthly data that I have since 1950, December 2005 has now posted the highest NTC of any December on record with 8.8%.  It broke the old record of 7.7% set in 1984.  December 2005 also has the record for most named storm days (7) and hurricane days (5.25) ever in a December.  

Please visit my tropical Atlantic headquarters.

06 December 2005

Epsilon... and what lies ahead?

At 15Z, Epsilon was still a hurricane, much to the dismay of enervated 
forecasters at NHC.  It's located at 31.9N 33.8W and now moving S at 
8kts.  Satellite-estimated intensity is 65kts and 987mb.  Although it 
still has deep convection wrapped around the center, the circulation is 
beginning to elongate.  It's forecast to weaken in the face of increasing 
shear and head southwest toward the tropics over the next 5 days.  While 
the track has been fairly easy to forecast, the intensity has not, so at 
this point, take the intensity forecast with a grain of salt... Epsilon 
has not cooperated with our typical understanding of tropical systems!

Bill Gray and Phil Klotzbach (also here at CSU) have released their 
forecast for the 2006 hurricane season (this is the 23rd seasonal 
forecast made at CSU, by far the most experienced team!).  As expected, 
it calls for another very active season, with 17 Named Storms, 9 
Hurricanes, and 5 Intense Hurricanes, or about twice the average.  With 
this heightened activity, US landfall probabilities are also higher than 
average again.  To the first order, activity in the Atlantic undergoes a 
40-60 year oscillation, and for the past 10 years we have been in the 
active phase of this oscillation, and probably will be for another 10-15 
years before it slows down.  A period very similar to this was seen in 
the 1940s through mid 1960s, then from the mid 60s through mid 90s, the 
basin was relatively dormant.
For full details of the forecast and the six long lead-time predictors 
used, visit http://hurricane.atmos.colostate.edu/Forecasts/2005/dec2005/

To bring you up-to-date on the NTC, it's now 264.5%.

Please visit my tropical Atlantic headquarters.

05 December 2005

Tenacious Epsilon still a hurricane...

Epsilon has now been a named storm for as long as the mighty Katrina, 
and could still have a few days left, at least!  Despite cold SSTs (21C) 
and strong vertical shear (35kts), the hurricane maintains a beautiful 
large eye and persistent deep convection in the eyewall... baffling 
forecasters.  This is truly the season that does not want to end.

The latest position is 33.6N 35.1W, or about 7 degress southwest of the 
Azores.  Satellite-based intensity estimates are 70kts and 982mb.  Going 
with persistence, one would expect it to maintain this intensity.  Going 
with physical reasoning, one would expect it to weaken rapidly.  When in 
doubt, go with persistence!  It's currently moving ESE at 7kts.

The future is very questionable, as evident by the poor intensity 
forecasts.  Models and forecasts alike have been predicting weakening, 
but it refuses to lose hurricane status.  Forecasts made as recently as 
Sunday said that by this time, it would be a 35-40kt remnant low or 
extratropical cyclone... instead, it's a healthy CAT1 hurricane!  The 
official intensity forecast still calls for weakening, but they admit 
that forecast has almost no certainty.  The forecast track is very 
interesting: it's expected to cease eastward movement and turn back to 
the southwest toward the tropics.  This storm could be around for many 
more days, extending the already-extended record-smashing hurricane 

As of 15Z today, the NTC stands at 263.4%, and is rising at a rate of 
1.1% per day while Epsilon is a hurricane.

Please visit my tropical Atlantic headquarters.

02 December 2005

Epsilon upgraded to a hurricane...

Although the official hurricane season ended two days ago, at 15Z today, 
Epsilon was upgraded to a hurricane, making it the 14th of the year (the 
"average" number is 6).  The previous record for number of hurricanes in 
a season was 12.  Epsilon became somewhat less organized yesterday, but 
today looks much better... more symmetric, more convection, more 
outflow.  It once again has an eye.  It's in about 20kts of westerly 
shear and the SST is about 24C.

Satellite-estimated intensity is 65kts and 987mb, and it's moving NE at 
12kts.  Current location is way out at 33.7N 48.2W, safely in the north 
central part of the basin between the Azores and Bermuda.  It is forecast 
to gradually weaken and continue a northeast motion.  Over much colder 
water, it should decay to a fossil cyclone in a couple days.

This now brings the seasonal Net Tropical Cyclone activity up to 261%, 
meaning that 2005 has been about 2.6 times more active than an average 

Please visit my tropical Atlantic headquarters.