Jeffs713's Tomball & Tropical Weather

The 2009 Atlantic Hurricane Season

By: jeffs713, 4:28 AM GMT on June 01, 2009

Hello all!

Well, the 2009 Atlantic basin hurricane season is officially upon us now. So far, it has been fairly quiet officially, with just 2 invests, and one official TD. Lets start by going over whats happened so far:

90L - almost Sub-Tropical Depression (May 18 - May 23):
This system started out of a thunderstorm complex in the triangle between Cuba, Haiti, and Jamaica, and slowly moved NNW, towards Florida, before fizzling out, and the energy being absorbed by a new system. The new system, near the Florida keys, slowly developed a LLC, but never fully got going tropically (it remained a cold-core low), until it was very close to the Alabama coast. By that time, there simply was not enough time for the system to organize into anything fully tropical (or really even subtropical), and earn a name from the NHC.
That said, the system still had a very significant impact, dumping incredible amounts of rain on Florida. Rain totals from this system easily exceeded 20 inches in some areas, unfortunately causing some significant flooding. Volusia county in Florida was very hard hit, and our friends at Portlight Strategies are stepping in to help those most in need. Please check out their WU blog and website for more information as to how you can help.

91L - later TD 1 (May 27-28):
91L formed as a mid-latitude cyclone off the NC coast, and started pulling off to the NE, pulling out to sea. After getting several hundred miles off the coast, it evolved into TD 1, but never sustained enough convection around the center before running into colder water.

Personally, I think June will be fairly quiet. Looking at the SAL (Saharan Air Layer - layer of dust in the atmosphere from the Saharan Desert), and also the shear maps, the Atlantic basin is looking pretty hostile right now.

Figure 1: SAL Map

Figure 2: Wind Shear

On the other side, SSTs (Sea Surface Temps) and TCHP (Tropical Cyclone Heat Potential) is roughly normal for the time of year in the GOM and Caribbnean, but the Atlantic is still a bit slow to warm up.

Figure 3: TCHP for the Atlantic Basin

Figure 4: SSTs for the Atlantic Basin

Overall, I think we might get a few TD, and maybe a full Tropical Storm in June, but I doubt a hurricane, as anything forming is likely to start up near a coastline, and not have a friendly enough environment to get rolling.

Recently, I decided to become more involved in Portlight Strategies, Inc., and give back to my community a bit. For those that don't know, Portlight is a charitable organization led by a few of our own WU bloggers (namely Presslord, Patrap, and Stormjunkie), and nationally sponsored by Weather Underground. After Hurricane Ike devastated the upper Texas coast, Portlight stepped up in a HUGE way, donating over $500,000 worth of relief supplies to areas and populations most in need. With the 2009 season officially here, Portlight needs your help. Please check out the link below to see how you can help.

Also, Portlight will be organizing a Houston-area event at Dionysus Theatre on June 21. There will be a post-show party immediately after the performance of The Pirates of Penzance, and all attendees of the post-show party will receive a commemorative Portlight t-shirt. Please check out the Portlight Houston Event page for details, or contact either myself, EmmyRose, or smmcdavid for details.

To wrap this all up.. Are YOU prepared for Hurricane Season? If you haven't already, now is the time to get your hurricane kit together. The National Hurricane Center has put together an excellent list of what needs to go into a hurricane kit... are you prepared?
NHC's Hurricane Supply List


Also... here is the link to the 2009 WU prognostication spreadsheet.
Link to Excel 2003 spreadsheet(the charts may not look right)

WU's 2009 Storm Predictions

By: jeffs713, 6:30 PM GMT on May 17, 2009

A few weeks ago, several of our members (led by Ossqss) decided to gather the blogger's predictions as to how the 2009 Atlantic hurricane season would pan out. As part of this project, I volunteered to put this info info a graphical format, and also do a little analysis on it. So, without further ado, here is all the goodies.

We had 57 entries, with a wide range of guesses as to how the season would turn out. Overall, the numbers show that we predict a slightly above average season. The WU bloggers predicted, on average, 14 named storms, 8 hurricanes, 4 intense (Category 3+) hurricanes, and one Category 5 hurricane this year in the Atlantic Basin.

Figure 1: Number of Tropical Storms and Hurricanes Predicted

Figure 2: Number of Intense (Cat 3+) and Category 5 Hurricanes Predicted

Generally, all of the data follows a general bell curve, with the most responses near the middle. Of some interest is the drop-off of entries for 13 tropical storms, especially considering the spike at 12 tropical storms.

Figure 3: Minimum/Maximum number of Hurricanes

Generally, WU bloggers predicted slightly over 50% of the tropical storms this year would transition into hurricanes, and the variance overall around this ratio was surprisingly small (except in 2 isolated cases at 14 and 18 tropical storms).

Figure 4: Minimum/Maxiumum number of Intense Hurricanes (Category 3+)

When comparing WU blogger's predictions for intense hurricanes, it was difficult to find a general trend, as they predicted anywhere from 15% of tropical storms all the way to 40% of tropical storms would go all the way to major hurricane status.


The WU tropical storm blogging community has a surprisingly similar predictive ability in comparison to the major storm prediction groups, namely Colorado State University's Dr. Gray and Klotzbach, and also Tropical Storm Risk's forecast.

Figure 5: WU prediction compared to CSU's and TSR's.

As is evident in the graph above, the WU community is slightly less "bullish" on the total number of storms as compared to TSR's prediction (predicting one less tropical storm). The WU community is decidedly more bullish than the CSU team, predicting 2 more intense hurricanes.


As a tie-breaker for the contest, everyone who entered was asked to predict when the first tropical system of 2009 will be named. The dates ranged over 2 months, and none of the dates had more than 3 entries. (the dates with 3 entries were May 26, June 3, and June 16) Since this data was so spread out, it was hard to find any trends looking at individual dates, but some general trends were evident when the data was broken down to a week-by-week basis.

Figure 6: Date of First Named Tropical System

As you can see in the chart above, roughly half the WU blogging community sampled believe that there will be a named tropical system in the Atlantic basin by mid-June. The predictions drop off dramatically after June 22nd. (so, it looks like we will have an early start to the season)

As a reminder to everyone, how many storms form this year has absolutely zero impact to the degree of damage and suffering caused by tropical systems. We could have a very active season with few landfalls, and we could also have a very slow season, with one or two major landfalls. It only takes one storm. The best bet is to be prepared if a storm comes your way, and also to be mindful of others' plight if they are hit by a storm.

Many organizations exist to help those most in need after a hurricane strike, but few have quite the attachment to the WU community as Portlight Strategies ( Portlight is organized by several of our very active members, and also maintains a running blog here on WU (Portlight's WunderBlog). Please check them out, and do what you are able to assist them in their cause.


As a note, I will be posting the raw data (on an Excel spreadsheet) in the coming days.

The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.

Jeffs713's Tomball & Tropical Weather

About jeffs713

I live near Tomball, Texas (30 miles NW of Houston), and will write about whatever comes to mind. You've been warned.