Fred On a Downward Spiral… Heavy Rain in the Gulf

Hurricane Fred has now weakened to a category 2 hurricane, and will further weaken in the next few days.  Yesterday, I was talking about the wind shear the storm was headed into, and it has already weakened the southern portion of the storm. The storm was never a threat to the US mainland, but now it looks like it will decay faster than expected.

There is a lot of curiosity about some showers and thunderstorms in the western Gulf of Mexico. In the next couple of days, watchful eyes across the Gulf will be on this area of rain and thunderstorms to see if a low level circulation develops.  Watch this forecaster from Houston on the developing low.

No matter if it becomes tropical or not, Texas and Louisiana will get soaked Saturday into Sunday. Ever since Humberto and Claudette’s rapid development in the Gulf, forecasters keep a close eye on these persistent areas of showers and thunderstorms so we’re not caught off guard if it develops into a tropical system, especially since it’s so close to land. In the Gulf of Mexico there’s plenty of warm water, so if a low does develop, it can rapidly. At the same time, the computer models don’t have a great handle on this system.

If you really want a techy explanation of the different computer model solutions, check out Crown Weather’s blog today.

Also, both Max Mayfield, former NHC director, and Jeff Masters from Weather Underground have some interesting statistics on this year’s hurricane season if you want to check out their blogs.

I’ll talk to you later!

-Dawn Brown

Tropical Storm Fred

UPDATE:  Tropical Storm Fred is on the verge of hurricane status, and may increase in intensity overnight. Reliable computer models continue to keep it in the middle of the Atlantic, far from the US mainland, and at some point degenerating in the 5-day forecast.

Tropical Storm Fred is currently in a healthy environment for growth, and may end up being the next major hurricane of the 2009 season in the next couple of days. Upper air steering currents are expected to keep the storm in the middle of the Atlantic Ocean Basin well away from the United States. This year, upper level troughs traveling across the continental United States have dominated the tropical weather pattern on the East Coast, forcing these storms on a more northerly path once the storm comes close to the US mainland. Most of the models agree on this track for Fred. Click here to track Fred.

While we like to see these upper level troughs send these storms to the middle of the Atlantic, there is another variable that these troughs and associate cold fronts produce. Once the tail end of the cold front moves into the Gulf of Mexico or off the East Coast, often the front stalls and a circulation can develop along the decaying front. This circulation can allow a tropical system to develop. At this time of year, when a cold front stalls over the Gulf or Atlantic near the coastline, meteorologists watch it closely for possible development. At least one model suggests this may happen in the Western Gulf of Mexico in the next 10 days. We will be watching for that. If you are interested in discussing Fred, check out the MYL Forums.

Also, I have Jeff Masters Weather Undergound blog in my left hand menu bar under HURRICANE BLOGS.  In the next few weeks, he’s introducing a series of blogs on storm surge.  Storm surge has been one of the least understood components of a hurricane’s landfall, but it can be the most destructive component along the Gulf of Mexico. More and more researchers are trying to introduce computer models to give viewers an idea of how storm surge will effect their community during a landfalling hurricane. Storm surge is very localized, meaning the impact is different depending on the terrain where you live. Last year, during Hurricane Gustav, meteorologist Mike Koziara at the National Weather Service in New Orleans briefed me on the storm surge model they run. Koziara explained that terrain factors such as railroads, levees, canals, and the  coastline underwater were all included in the storm surge model. If the storm moves 100 miles to the east or west, this model won’t work, because the terrain is completely different. So, it is an exciting prospect that researchers are tackling this aspect of forecasting a landfalling hurricane.

I just got back from a dive trip on San Clemente island in California. What a great experience! Since Fred is alive and well in the Atlantic, I’ll have another update later tonight.

-Dawn Brown

Tracking Hurricanes

Okay… I don’t want to overwhelm you with hurricane weather pages. You can visit a million pages, and still come up with the same result—the hurricane is headed in your direction. However, in this day and age, you can track a hurricane as often as the satellite captures its image. I have a few descriptions of these web pages to help you wade through.

Basic Hurricane Data

National Hurricane Center (Has the latest storms, 5-day track forecasts, satellite imagery, analysis and frequently asked questions. It does NOT have computer models-see below.)

Weather Underground Hurricane Page (Dr. Jeff Masters has compiled such a thorough page, it has latest storms, tracks, computer models, and a dozen websites to help you analyze a storm.)

Storm Pulse (Very pretty website with easy to understand track plots of current storms.)

Guide To Hurricanes (Cool website from Scientific American that explains why hurricanes occur.)

Central Florida Hurricane Center (Good website with lots of data.)

Skeetobite Weather ( I like skeetobite’s dropdown menus, easy to find info.)

Crown Weather Services (Crown has a useful blog about the storms’ as well.)

Millennium Weather (Kind of a techy website, not easy to use.)

Unisys Weather Hurricane Page ( I mainly use this for historical information.)

Hurricane Computer Models – for the Weather Expert (and Geek too)

Florida State University Experimental Tropical Cyclone Genesis Page (Forecasters like this one because it shows frame by frame the possible track, and possible intensification.)

Weather Underground’s GFS Model ( I like this one… it shows the Atlantic basin, and has easy to read color contours)

National Weather Service Hurricane Models (NCEP) (Provided by the National Center for Environmental Prediction, this shows the computer models put out by the National Weather Service-most importantly the GFDL (GHM), GFS and HWRF.)

Canadian Model (I look at the GEM to see if it’s in line with the other forecasts.)

ECMWF – European Centre for Medium-Range Weather Forecasts Model (The ECMWF is one model that the NHC watches to see if it diverges from computer models sponsored by the United States. It’s relied on heavily during hurricane season. If you read the NHC discussions on storms, it will often say ECMWF.)

Colorado State Track Model Guidance (A lot of people like this track model guidance, because it shows you a dozen computer model tracks, and shows whether there is an agreement or disagreement among the hurricane computer models. Take note: it shows some unsophisticated models.)

MIT’s Track & Intensity Guidance (This page isn’t “pretty” but it’s pretty easy to understand. There’s a graph to show the computer model for intensity forecast, and the forecast model tracks.)

WX Forecaster’s Hurricane Page (This is a website put together by a forecaster for forecasters… gotta love this guy!)

The Navy’s Weather Forecasting Website (During hurricane season, everyone wants to know which is better the NOGAPS or the GFDL, especially if they disagree. Both are global models, the GFDL is run and researched by the NHC. As far as statistics, the National Hurricane Center track “bests” all models at most forecast times.)

Explanation of Computer Models

Dr. Jeff Master’s Explanation of Hurricane Models (Dr. Jeff Masters, the Director of Meteorology for Weather Underground has a more detailed description of the hurricane computer models is you would like something else to refer to.)

Table Listing Computer Models and Summaries by NHC (This link has a summary of the hurricane computer models. You can find out the actual name of the model—it lists the name as well as abbreviation. For example, the GFDL is the Geophysical Fluid Dynamics Laboratory model, and also has a technical description for you.)

National Hurricane Center FAQ’s – Hurricane Models (And for one more explanation, you can go to the NHC’s Frequently Asked Questions website.)

Interpretation of Hurricane Forecasts (This is a GREAT website to thoroughly understand what the TV weather anchors are talking about when they show you the CONE OF UNCERTAINTY.)

Hurricane Formation – for the Weather Geek!

NOAA Hurricane Formation

NCEP Cyclogenesis Tracking Page