Love Quiet Mondays
Texas Rainfall (courtesy NWS)
Texas and Louisiana will begin to dry out after a weeks worth of storms dumped more than 10″ of rain in portions of Central Texas and Southern Louisiana. The area of low pressure generating those storms is slowly moving to the Northeast, and the Dallas-Fort Worth area is still getting hit this Monday. Coastal areas are beginning to see a break, but northern Mississippi and Alabama will be the latest victims of this slow moving system before it finally loses steam.
Grey skies across Southern California as a cold front sweeps through. Although beachgoers may not like it, the cooler temperatures are a welcome weather treat this time of year, at a time when wildfires, driven by Santa Ana winds are fed by the hot temperatures in September and October.
It is a quiet Monday across the country, and silent in the tropics as well. We can ease into the workweek.
For a couple of days now, I’ve been meaning to show you an article I saw on Smart Money magazine online. It’s about the fallacy of the 7-day forecast. The author of the article seems to be “revealing” to people that extended forecasts aren’t very good, but I don’t think any forecaster, including the ones he interviews, argues that they are! Television weathercasters give you the 7-day forecast because the computer models go out 10 days. After about three days, the forecast tends toward climatology. But, sometimes, climatology is correct. What I like about this article is the meteorologists give you the limitations of todays forecasting. What I don’t like about the article is the innuendo that weather forecasters “won’t tell you” the limitations of their forecasting, when he has several meteorologists in the interview giving him the “inside information”. Oh, and the Doppler radar does do a good job during a storm of helping the on-air meteorologist forecast the immediate weather event for the next couple of hours. It also helps the forecaster determine whether a storm is severe, and if the public needs to be warned. Here’s the link to the article:
-Dawn Brown
Fred On a Downward Spiral… Heavy Rain in the Gulf
Fred Satellite Image ( Courtesy NOAA)
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
Tips for the Gulf South TV Forecaster
Moving to a new TV market is tough. I’m putting together some of the most important websites you’ll need to hit the ground running. Good Luck! Since the Gulf South is driven in a large part by the tropics during the summertime, you will have many days of frustation before you begin to learn the patterns and the different small scale boundaries that can develop. Severe weather develops rapidly, especially in the fall, winter and spring. Even a summertime thunderstorm can cause flooding in the streets. Of course snow is not a common occurence, but if you get all the right ingredients, you will have a miracle snow day during a cold winter.
Looking at the radar and satellite, (if your shop doesn’t have what you need, go to the National Weather Service Eastern Region Headquarters and Aviation Weather) to get a general idea of the weather pattern.
Use your synoptic scale models (large scale models) to get storm placement, flow patterns, and 850 mb temperatures, and precipitation amounts (this is available at Unisys Weather), and make a short-term forecast. Look at atmospheric forecast soundings site, especially if thunderstorms are expected, to determine severity. Make sure you visit the Storm Prediction Center to see if you are in a risk category for thunderstorms.
Generally, your local NWS office can give you the risk of inland flooding due to repeated storms, but here’s a link to the Hydrometeorological Prediction Center – Inland Flooding in case that is a concern during repeated storm events or a tropical storm has moved inland.
Tides are extremely important for coastal communities, here’s a link to Tide Predictions for Gulf States. Marine and boating forecasters also generally use buoy data. NOAA Buoys Gulf of Mexico
Make an extended 7-day forecast using the latest and most complete suite of extended model runs (e.g. the GFS), available at NCEP Model Analyses and Forecasts.
Also, you’ll need a temperature forecast to compare all of your graphical data against for a highs/lows forecast. The best place to find MOS (Model Output Statistics) is Current NWS MOS Forecast Products.
When it comes to tropical weather, which can also often be a player, things can get even more interesting, here’s a link to my blog on Tracking Hurricanes.
Oh! One added note, sea fog can develop in the wintertime along the Gulf South. The NWS Office in New Orleans has a decision tree Sea Fog Forecasting to help you forecast a sea fog event in the wintertime. It’s fascinating!