Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.
By: Dr. Jeff Masters , 4:29 PM GMT on September 27, 2008
Tropical Storm Kyle has intensified to a 70 mph tropical storm in the face of about 20 knots of hostile wind shear. However, visible satellite loops show little change in the appearance of Kyle today, and for now the shear is keeping the storm just below hurricane strength. The latest Hurricane Hunter mission's center fix at 10:37 am EDT found that the pressure had risen to 999 mb, which is quite high for a strong tropical storm. Top surface winds measured by the SFMR instrument were in the 60-70 mph range.
Figure 1. Current satellite image of Kyle.
Wind shear is forecast to increase to 25 knots today and remain at least 25 knots for the remainder of Kyle's life. That is high shear, but the upper-level winds over Kyle creating this shear will also be spreading out horizontally as they pass over the storm. When upper-level winds diverge like this, it creates a suction effect that acts to intensify the updrafts in the thunderstorms beneath. Thus, this "upper-level divergence" will act to intensify Kyle. It remains to be seen whether the upper-level divergence will be strong enough to overcome the shear and allow Kyle to intensify into a Category 1 hurricane, as the GFDL, HWRF, and SHIPS intensity models have consistently been predicting. Given the storm's current struggle to organize, I doubt Kyle will ever attain hurricane strength.
Kyle's storm surge
Storm surge should not be a major issue with Kyle. If it makes landfall in the Maine/New Brunswick region as a Category 1 hurricane, it would likely generate a storm surge in the 3-5 foot range, according to NOAA's SLOSH model. Given that the range between low tide and high tide is at least 12 feet in the region, Kyle would have to hit very close to high tide to cause any storm surge flooding. Kyle's likely impact as a tropical storm makes surge flooding problems improbable. Hurricane Edna of 1954, which hit just west of Eastport, Maine, as a Category 1 hurricane with 90 mph winds, generated a storm surge of just 3.4 feet at Eastport. If Kyle hits Nova Scotia as a Category 1 hurricane or tropical storm, a storm surge of 1-3 feet is likely. Hurricane Juan of 2003, which hit Halifax, Nova Scotia as a Category 2 hurricane with 100 mph winds, generated a storm surge of 4.9 feet in Halifax.
Kyle's cone of uncertainty covers the eastern coast of Maine and the western half of the coast of Nova Scotia. Recent model runs have trended to take Kyle a little more to the west, near the Maine/New Brunswick border. given the tendency of the models in recent runs to flip-flop, it wouldn't be a surprise to see the forecast track shift back to Nova Scotia in future runs. This province will probably get Kyle's worst winds and rain, since wind shear is keeping Kyle's heaviest thunderstorms on the east side of the storm. My best guess is a landfall in western Nova Scotia as a tropical storm with 45-55 mph winds. The latest runs of the GFDL and HWRF models bring tropical storm-force winds of 40 mph to Cape Cod, Nantucket, and the entire Maine coast, as well as western Nova Scotia and eastern New Brunswick. The strongest Kyle is likely to be at landfall is a 65 mph tropical storm, as forecast by the GFDL model.
Kyle's main threat is heavy rain. Kyle's rains will primarily affect Nova Scotia and New Brunswick at landfall on Monday morning. However, Kyle should pull copious amounts of tropical moisture and the remains of the unnamed storm that hit South Carolina Thursday northwards into Canada and northern New England. This will create potential flooding problems early next week in the region. NOAA is forecasting up to five inches of rain could fall in New England over the next five days (Figure 2).
Figure 2. Forecast rain amounts for the 5-day period ending 8 am Thursday 10/2/08. Image credit: NOAA/HPC.
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Yucatan disturbance may threaten western Florida next week
A 1008 mb low pressure system in the Western Caribbean, just east of Belize and Mexico's Yucatan Peninsula, has the potential for some slow development over the next few days. Visible satellite images show a modest-sized area of heavy thunderstorms that is currently not increasing in size. QuikSCAT from this morning showed top winds near 45 mph offshore of Belize in the heaviest thunderstorm activity, but no sign of a surface circulation. Wind shear is about 10-20 knots over the region, which is low enough to allow some slow development. NHC is giving this system a low (<20% chance) of developing into a tropical depression by Monday. Most of the models predict the low will start to develop over the next few days, although interaction with the landmass of the Yucatan Peninsula will be a problem for it. The low should lift northeastwards beginning Monday, and the west coast of Florida can anticipate heavy rains from this system by Wednesday. NOAA is predicting up to four inches of rain may fall over southern Florida (Figure 2). Due to the very high wind shear over the northern Gulf of Mexico, this storm will not be a threat to the Gulf Coast from the Florida Panhandle westward.
Figure 3. Super Typhoon Jangmi at 3:30 am EDT Saturday, 9/27/08. Image credit: NOAA.
Super Typhoon Jangmi takes aim at Taiwan
Super Typhoon Jangmi put on an impressive burst of rapid intensification yesterday, and now stands as an extremely dangerous Category 4 Super Typhoon with 155 mph winds. Jangmi is expected to hit Taiwan Sunday as a Category 4 typhoon. Jangmi is tied with May's Super Typhoon Rammasun as the strongest tropical cyclone on the planet this year. There have not yet been any Category 5 storms anywhere on Earth this year, which is unusual.
The Hurricane Ike relief effort continues
Thanks to everyone who has contributed to the portlight.org charity! We raised enough money to send another truck with relief supplies to Winnie and Bridge City, Texas, where traditional relief efforts have fallen short. Wunderground member Presslord (AKA Paul Timmons, Jr.), who is coordinating this effort along with Patrap and StormJunkie, has announced that if we raise an additional $10,000 mark, he will pose in a dress for our wunderphoto gallery. We're up to $4800 so far. The effort has raised a grand total of $25,000 so far. Great work, everyone!
Figure 3. The town of Bridge City was inundated with a massive storm surge even though it was far displaced from Ike's landfall point. This speaks to just how massive Ike was. The people of Bridge City, Winnie, and other small towns in Ike's path will need help for a long time to come: www.portlight.org. Image credit: Storm Junkie.
You can read more about the effort at at stormjunkie's blog.
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