Possible Labor Day Weekend Deluge From Tropical Weather For LA/TX
After weeks and months of dry weather and drought, rainy relief looks to be on tap for Louisiana and Texas. The United States Drought Monitor currently has most of these two states in at least severe drought.
LA Drought Conditions, Image: U.S. Drought Monitor
TX Drought Conditions, Image: U.S. Drought Monitor
On the above maps, areas that are in orange are experiencing severe drought, in light red are in extreme drought, and in deep red are in exceptional drought.
That may all come to an end or at least be greatly reduced out by what is now Invest 93l in the extreme southeastern Gulf of Mexico.
Invest 93 in the Gulf of Mexico, Image: National Hurricane Center
Rain from the area of disturbed weather, at least initially, will be a good thing for the Central and Western Gulf Coast which has been dealing with wildfires, dying crops, and stifling heat all due to the recently extremely dry pattern. Unfortunately, though, it may be too much of a good thing. Not only will rain fall, heavily at times, beginning on Thursday, but it also could continue on Friday, and perhaps last through the weekend, and even possibly into early next week. Though folks in the Deep South and Texas need the rain, they don’t need it coming down in torrents and they don’t need it coming down all at once and unfortunately, it appears that’s what this batch of tropical moisture is set to do. In fact, government forecasters at NOAA’s Hydrometeorological Prediction Center are calling for over 6 inches of rain in some parts of Southeastern Louisiana through Saturday, and that’s just potentially only half-way through the event!
Rainfall Totals Through Saturday, Image: NOAA
The reason for this expected inundation of rain is due to the fact that the disturbance is going to initially move northwest toward the coast, accompanied by plenty of Gulf moisture, but then as steering currents gradually break down over the next several days, the system may meander or just plain stall somewhere south of Louisiana or Texas.
Computer Model Tracks for Invest 93, Image: Weather Underground
Another potential issue, as you can tell from several of tracks above, is the system will stay over the Gulf of Mexico for a period of time from a couple of days, with the faster models, to perhaps up to a period of nearly a week, taking into account the slower, meandering models. Even at a weaker intensity, the system will bring torrential rains, gusty winds, and possible coastal flooding to the Central Gulf Coast, but should it spend a prolonged period over the near-90-degree Gulf of Mexico, development into a tropical cyclone with more damaging effects could be possible and, in the case of the slower models, the effects could last for days. If it were to become a named system, it would be Lee.
Of course, the tracks are still in a good bit of disagreement and there is talk of some persistent wind shear over the Northern Gulf detrimental to tropical development. Therefore, nothing, by far, is written in stone, but the National Hurricane center now gives this disturbance a high chance of becoming our next tropical depression over the next 48 hours.
Check out what forecasters in New Orleans, Mobile, and Houston are saying about this possible heavy rain and tropical event and stay tuned!
Irene On Path Toward Morehead City
Irene Infrared Satellite, Image: NOAA
Irene appears to be strengthening over the open water of the Western Atlantic south of the Carolinas. The first US landfall is expected near Morehead City, North Carolina. Tonight, I’m doing a little research on major hurricanes that have shared the same path as Irene up the East Coast. I’ll publish my research tomorrow.
You can track Irene from my website at MYL’s Hurricane Tracking page. Or go to the National Hurricane Center. You can also check out the local forecast in Wilmington, North Carolina; Norfolk, Virginia; New York City, New York or Boston, Massachusetts.
Dawn Brown, FOX 8 New Orleans
Dangerous Irene Lashing Outer Bahama Islands
Irene Visible Satellite, Image: NOAA
To track Hurricane Irene, head to MYL’s Hurricane Tracking page or the National Hurricane Center website.
On Saturday, when the NHC issued its first advisory on what was then Tropical Storm Irene, the Turks and Caicos Islands were not within the National Hurricane Center track forecast. Five days later, the island chain was squarely in the most dangerous section of a major hurricane.
National Hurricane Center forecasters are emphasizing the error and uncertainty in their discussion today. Currently, the NHC is uncertain whether Irene will affect the most populous area of the United States once it starts its trek northward, turned by steering currents over the United States and the Atlantic Ocean basin. The current track has landfall on the far outer edge of the Outer Banks and then a second landfall in Montauk, New York, the most eastern point of Long Island, before moving through coastal Connecticut, Rhode Island, Massachusetts, coastal New Hampshire and then Maine. The track has been nudged farther east but hurricane forecasters aren’t confident in that forecast.
This storm is gaining strength over the warm waters of the Bahamas and the East Coast of the United States will have to continue to monitor Irene.
Dawn Brown, FOX 8 New Orleans
How Common is the 5.8M Virginia Quake?
A 5.8 magnitude earthquake rattled metro Washington D.C., Philadelphia, New York and other East Coast cities at 1:51 EDT this Tuesday afternoon. The quake’s epicenter was located 84 miles southwest of Washington D.C.. The closest town to the epicenter was Mineral, Virginia which is 5 miles south-southwest of the epicenter. The earthquake occurred 3.7 miles beneath the earth’s surface. The last earthquake of this magnitude to occur in Virginia took place in 1897 in Blacksburg Virginia, near the Appalachian Mountain Range. The 1897 quake was felt from Georgia to Pennsylvania and from Indiana to the Atlantic Coast.
Virginia Earthquake, Image: US Geological Survey
This map from the United States Geological Survey shows the areas that experienced shaking near the epicenter. The shaking ranged from weak to very strong with moderate damage occurring. As you can see from this map, people in and around the D.C. metro area felt light to moderate shaking as a result of the quake. The US GS received close to 9000 reports from 17 cities.
Virginia Earthquake, Image: US Geological Survey
Earthquakes in Virginia are rare. However, there are fault lines in the bedrock that formed hundreds of millions of years ago from continental collisions. These collisions formed the Appalachian Mountain Range, west of the earthquake epicenter.
According to the United States Geological Survey, “Earthquakes in the central and eastern U.S., although less frequent than in the western U.S., are typically felt over a much broader region. East of the Rockies, an earthquake can be felt over an area as much as ten times larger than a similar magnitude earthquake on the west coast.”
The US GS website also states that the largest damaging earthquake (4.8M) in the Central Virginia Seismic Zone occurred in 1875. Click here for more information on Virginia’s earthquake history.
Dawn Brown, FOX 8 New Orleans
Irene Shows Eyewall, Will Strengthen Near the Bahamas
Irene Visible Satellite, Image: NOAA
Irene Infrared Satellite, Image: NOAA
Visible satellite imagery showed a better defined eye and eyewall for Hurricane Irene this afternoon. Since then, the eye has become obscured. Irene is bearing down on the Turks and Caicos with 90 mile per hour winds. In the last 24-hours, Irene’s interaction with the island of Hispaniola has had an impact on the developing storm, maximum sustained winds were at 100 miles per hour for the last 18 hours. There was also a small amount of wind shear over the island. It’s possible that wind shear has played a part in the storm not undergoing a rapid intensification.
National Hurricane Center is reporting in its latest discussion that wind shear may limit rapid intensification for the next 24-hours. Wind shear is expected to relax near the Bahamas.
The track continues to shift east. Now, the Outer Banks of North Carolina and metro areas of New Jersey and New York need to prepare for a possible landfall.
Irene 5 Day Forecast Cone, Image: NOAA
However, if you look at the latest computer tracks from Hurricane Irene, I’m starting to wonder if this storm is going to be steered away from the East Coast of the United States by a deepening trough along the East Coast.
Computer Models, Image: Colorado State University
The official track from the National Hurricane Center continues to be the outlier or the track on the edge of the computer model forecasts. Usually the National Hurricane Center track line follows the consensus of the forecast guidance from the models. The model consensus now takes the storm toward Massachusetts and New England. The storm would weaken if it moves into the far northern Atlantic because of the cooler water and interaction with the strong winds of the mid-level trough.
Dawn Brown, FOX 8 New Orleans
Irene Misses Hispaniola, Now a Category 2
Infrared Satellite, Image: NOAA
Hurricane Irene blew up into a category 2 hurricane with 100 mile per hour winds north of Hispaniola tonight. It missed the island is now poised to develop into a major (category 3 or stronger) hurricane as it makes its way toward the Bahamas.
At least one computer model previously forecast Irene missing Hispaniola and developing into a major hurricane. That computer model has Irene on track toward the border of South Carolina and North Carolina between Charleston and Wilmington. Most of the computer models have developed the storm into a major hurricane off the East Coast of the United States. For at least three more days, it’s going to be in a favorable environment for intensification. There is the possibility that due to the trough developing off the eastern United States, it may weaken slightly before landfall.
Computer Models, Image: Colorado State University
This same trough is expected to draw Irene north toward the Carolinas. Computer models and the National Hurricane Center continue to shift east. If you look at the latest models, there is even a possibility that Irene could miss both North and South Carolina. This scenario is not forecast at this time by the National Hurricane Center.
The National Hurricane is urging residents along coastal United States to be aware the the forecast error for the 5-day forecast is from 200 to 250 miles. (The forecast error is how they develop the “cone of error or uncertainty) that you see in the graphic below.
Irene 5 Day Forecast, Image: NOAA
Dawn Brown, FOX 8 New Orleans
Hurricane Irene May Strengthen to Major Hurricane
Infrared Satellite, Image: NOAA
Hurricane Irene is forecast to strengthen to a category 3 hurricane packing 115 mile per hour winds before making landfall in South Carolina. That is the latest forecast from the National Hurricane Center. The landfall in South Carolina is five days from now. There may be some adjustments to that forecast track, as the hurricane center continues to edge the track farther east.
The eastward movement is now sparing Florida and a major portion of the Dominican Republic.
5 Day Forecast, Hurricane Irene, Image: NOAA
For the latest tracking information and analysis, go to MYL’s Hurricane Tracking page.
Dawn Brown, FOX 8 New Orleans
New Models and Track Posted for Tropical Storm Irene
The National Hurricane Center has shifted the track forecast slightly to the right or east of their 10am track. This shift is most likely in response to the continued shift of computer models to the east. While the shift farther northward may allow Irene to strengthen as it would not be impacted as much by Hispaniola and Cuba, it would also steer the storm farther away from Florida. However, this could also pose a greater risk to Georgia and South Carolina, which could suffer a direct hit.
National Hurricane Center Track, Image: NOAA
Computer Model Tracks, Image: Colorado State Track Model Guidance
Dawn Brown, FOX 8 New Orleans
Don’t “Tie Yourself to One Model”, Irene Threatens US
To track TS Harvey, click here. To track Irene, click here. To track 98L, click here. For an overall look at the tropics, go to MYL’s Hurricane Tracking page.
Tropical Storm Harvey, the 8th storm of the 2011 Hurricane Season, is moving through central Belize tonight. It will likely degenerate over Guatemala and Mexico, but is producing quite a bit of rainfall in and around the center of circulation.
Infrared Satellite, TS Harvey, Image: NOAA
Harvey formed in the central Caribbean and didn’t pose a threat to the United States from its inception. At the same time Harvey or TD 8 was forming, a very unimpressive tropical wave was catching our attention in New Orleans, merely based on the long-range computer models.
The models, mostly notably the GFS, or Global Forecast System, was projecting a major hurricane to form as it approached the Caribbean and making landfall somewhere along the US coastline in the end of August.
In 2006, the GFS predicted a similar occurrence about 10-15 days out.
2006 Hurricane Ernesto, Image: Unisys
It turned into Hurricane Ernesto, a category 1 hurricane, that weakened substantially over western Haiti and eastern Cuba, before hitting Florida as a tropical storm. The only reason I bring up Hurricane Ernesto is to touch on the current unreliability of long range computer models. And really what I mean by long-range, is past 3 or 4 days. As I state this, the global computer models have improved. Last year, I noticed that the GFS was doing a fairly good job of forecasting the inception of a storm, meaning in 10-15 days, the global computer models could pick up on a closed circulation (or a tropical depression) forming. I emailed an expert the National Hurricane Center about it, and they concurred, that they had made some improvements to the GFS. What the GFS could not do and still has trouble telling us, is how strong this system will be when it arrives. However, there is another global computer model that is being heavily relied on by hurricane forecasters that is doing a fairly good job in telling us which storms will strengthen and where they will go.
National Hurricane Center
Last year, while attending the annual Broadcaster’s Conference of the American Meteorological Society in Miami, attendees were privileged to meet, not only the entire staff of hurricane forecasters from the National Hurricane Center, but we also got every insight they could offer to how they put together the forecast. One of the forecasters/researchers also told us the ECMWF, the forecast put other by the European Centre for Medium Range Weather Forecasts had been beating their track forecast for the past couple of years. The percentage was small, but somehow, their global forecasting model was able to beat forecasters with 20-30 years of experience. This may get some guffaws from readers, but keep in mind that the official track by the National Hurricane Center was statistically better than all of the other computer models out there. That means—don’t tie yourself to one model.
Ever since they told me that, I can’t help it. I rely on the “European”.
But then, last year, I noticed the GFDL, the United States’ global hurricane model, nailing the forecast track as well. I was hopeful, proud. I’m not sure why, but I guess it bothered me a little bit that Europe, which is barely affected by hurricanes, could forecast them better than us! Then the GFDL started really performing well on the track and intensity.
That was last year. This year, I’m back to the European. I don’t know what happened to the GFS and GFDL, but this hurricane season, it’s been having some wild swings when it comes to storm tracks. It also ratchets some storms into a major hurricanes 10-15 days out like it did back in 2006. The European only goes out 8 days, but in the last few years, I felt confident telling my viewers which way the storm was headed and relatively how strong the storm was going to be when it got there. This year, it’s been guiding me through Arlene, Bret, Cindy, Don and Emily. It forecast Emily forming briefly, dying somewhere north of Hispaniola and then possibly reforming as a weak system before getting carried northeast with a trough of low pressure off the East Coast. Guess what happened? Exactly that. Now, the GFS did eventually forecast a similar scenario. And, it’s much easier to be confident with a forecast when more of the computer models are in alignment.
And the European only guides me in track and possible strength. It doesn’t give particulars, what’s causing the weakening/strengthening, how weak/strong will the storm be, what areas could suffer torrential downpours or high winds. It’s merely guidance. We still have to do all of our own analysis of the wind shear, upper air pattern, the water vapor (these tropical systems really struggle with dry air), the Saharan Air Layer, everything that tells us what kind of storm we’ll be dealing with. But, it gives me confidence to let me know if I need to be gearing up for a 5-day stretch of spending the night in the weather center. (Technically I got to go home during Gustav—I lived 3 blocks from the station!)
Infrared Satellite, Invest 97L, Image: NOAA
In terms of Invest 97L, it’s been undergoing some interaction with dry air and wind shear that has kept it from developing into Tropical Depression # 9 or Tropical Storm Irene. It looks like it’s going to be a tropical storm in the next 24-hours. It also looks like despite dry air still to its north and west and its possible interaction with Hispaniola and Cuba, it will most likely hit Florida as a tropical storm or possibly even category 1 hurricane.
It looks like the persistent trough off the East Coast will keep it from affecting the northern Gulf Coast states.
I say this in confidence at this point because of my faith in the European. Also-because the other computer models are lining up with a similar forecast.
But… since I live along the Gulf Coast and not along the beaches of the Mediterranean, I still keep my hurricane plan in place until October 15th.
Dawn Brown, FOX 8 New Orleans
P.S. This is my anecdotal account of forecasting with models, Wunderblogger Jeff Masters has a much more studious approach to explaining the performance of models in his blog, click here.
Arlene to Drench Drought Stricken Mexico
The Latin American Herald Tribune is reporting today that Mexico is experiencing its worst drought in 70 years.
Tropical Storm Arlene may alleviate some of the drought, although many mountainous regions may experience flash floods because of the amount of rainfall associated with the tropical storm.
Tropical Storm Arlene, Image: NOAA
The satellite presentation became much more impressive in the overnight hours, most likely due to the lack of wind shear in the southwestern Gulf of Mexico. Thunderstorms started sprouting up in the southern and eastern section of the storm early this morning. It’s possible Arlene could reach just below hurricane strength before making landfall between Tampico and Poza Rico. The topography in this section of Mexico makes it susceptible to flooding rains.
Although Arlene doesn’t have much time to strengthen, it could be just below hurricane strength before making landfall between Tampico and Poza Rica. For complete tropical storm coverage, visit TV stations in coastal towns of Texas like Houston and Corpus Christi.
Dawn Brown, FOX 8 New Orleans