WunderBlog Archive » Category 6™
Category 6 has moved! See the latest from Dr. Jeff Masters and Bob Henson here.Dean roars towards the Yucatan; Erin's remains kill 6 in Oklahoma
Hurricane Dean is headed west towards the Yucatan, still packing Category 4 winds, with the potential to add even more punch. Dean is over waters with some of the highest heat content anywhere in the Atlantic, and could well take advantage of this energy source and become a Category 5 hurricane today. Landfall will occur late tonight or early Tuesday morning over the Yucatan Peninsula. Landfall should occur over 100 miles south of Cozumel, so the Mexican Riviera areas of Cancun and Cozumel will only experience tropical storm force winds. The region where Dean is expected to hit, just north of the border with Belize, has one large city, Chetumal. Chetumal is on a narrow bay, but the expected storm surge of up to 11 feet will have difficultly making it up the bay to flood the city. The surrounding region is sparsely populated near the coast. Damage from Dean in Mexico may be considerably higher for the storm's second landfall, if it hits the major city of Tampico in the western Gulf of Mexico.
Figure 1. Hurricane Dean close-up taken from the Space Shuttle Endeavour, Saturday August 18, 2007 at 1pm EDT. Image credit: NASA.
Jamaica
There haven't been many news reports out of Jamaica yet, but we know that electricity is still out, many roads are blocked, and numerous mudslides have been reported across the island. Wind analyses prepared by NOAA's Hurricane Research Division suggest that Category 1 and 2 hurricane conditions affected most of Jamaica, but the Category 3 and 4 winds from the eyewall stayed offshore. I expect the damage tally will reach at least $1 billion on the island, but fall well short of the $4 billion done by Hurricane Gilbert of 1988. Gilbert cut straight across Jamaica as a Category 3 hurricane with 125-130 mph winds. Kingston measured sustained winds of 116 mph during Gilbert; the top winds reported so far from Dean were in the 80-100 mph range.
Dean's impact elsewhere
Eight deaths are being blamed so far on Dean--five in the Lesser Antilles, one in the Dominican Republic, and two on Haiti. Dean missed the Cayman Islands by over 100 miles, and the top winds on Grand Cayman never exceeded tropical storm force (39 mph).
Figure 2. Radar image of Dean at its closest approach to Jamaica. Dean had two eyewalls at the time, concentric with each other. The outer eyewall just grazed the sparsely populated southern tip of Jamaica. Image credit: Cuban Meteorological Institute.
Links to follow today:
Radar from Cancun, Mexico. (Overloaded today, good luck getting an image!)
Morphed microwave animation.
Chetumal, Mexico observations.
Cozumel, Mexico observations.
Belize City observations.
New disturbance 92L to watch
There is an area of disturbed weather associated with a tropical wave a few hundred miles northeast of the Lesser Antilles Islands. NHC has labeled this system "Invest 92L" this morning. Wind shear is about 10 knots in this region, which is low enough to allow some development over the next few days. This area is moving west-northwest, and will be near the U.S. East coast late this week. The next trough of low pressure strong enough to recurve this system is not due until Saturday, so this system will definitely be a threat to the U.S. if it develops. A QuikSCAT pass from 5:25am this morning shows no signs of a surface circulation, but plenty of strong straight-line winds from the thunderstorms.
Erin finally dissipates
Tropical Storm Erin finally died this morning over Missouri. Erin dramatically re-intensified Saturday night over Oklahoma, forming a tropical storm like-vortex that brought up to 11 inches of rain to Oklahoma, and helped feed disastrous rains of up to a foot over southeastern Minnesota. At least 13 deaths are being blamed on the resulting flooding, six of them in Oklahoma. The radar presentation of Erin's remains (Figure 3) looks remarkable tropical storm-like, and such re-intensifying tropical cyclones over land, complete with calm eye and spiral bands, have been observed in Australia, where they have been dubbed "landphoons". Hurricane David of 1979 performed a similar feat, generating severe weather over Washington D.C. 27 hours after it had made landfall in Georgia. What seems to be happening in these cases is that the circulation at upper levels of the atmosphere can remain intact if there is not a lot of wind shear to tear it apart. This circulation can then reach down to the surface again during its passage far inland. I've saved a long animation of this "landphoon", and Dr. Kevin Kloesel of the University of Oklahoma provided me a plot showing that the winds in Fort Cobb, Oklahoma were sustained at tropical storm force for over 10 minutes Sunday morning, with a peak wind gust of 75 mph. Winds at Watonga, OK, blew a sustained 55 mph, with gusts to 73 mph!
Figure 3. The remains of Tropical Storm Erin re-intensified into a remarkably tropical storm-like cyclone Sunday morning.
I'll have a short update this afternoon at about 4pm EDT, and full update Tuesday morning at about 10am EDT.
Jeff Masters
Figure 1. Hurricane Dean close-up taken from the Space Shuttle Endeavour, Saturday August 18, 2007 at 1pm EDT. Image credit: NASA.
Jamaica
There haven't been many news reports out of Jamaica yet, but we know that electricity is still out, many roads are blocked, and numerous mudslides have been reported across the island. Wind analyses prepared by NOAA's Hurricane Research Division suggest that Category 1 and 2 hurricane conditions affected most of Jamaica, but the Category 3 and 4 winds from the eyewall stayed offshore. I expect the damage tally will reach at least $1 billion on the island, but fall well short of the $4 billion done by Hurricane Gilbert of 1988. Gilbert cut straight across Jamaica as a Category 3 hurricane with 125-130 mph winds. Kingston measured sustained winds of 116 mph during Gilbert; the top winds reported so far from Dean were in the 80-100 mph range.
Dean's impact elsewhere
Eight deaths are being blamed so far on Dean--five in the Lesser Antilles, one in the Dominican Republic, and two on Haiti. Dean missed the Cayman Islands by over 100 miles, and the top winds on Grand Cayman never exceeded tropical storm force (39 mph).
Figure 2. Radar image of Dean at its closest approach to Jamaica. Dean had two eyewalls at the time, concentric with each other. The outer eyewall just grazed the sparsely populated southern tip of Jamaica. Image credit: Cuban Meteorological Institute.
Links to follow today:
Radar from Cancun, Mexico. (Overloaded today, good luck getting an image!)
Morphed microwave animation.
Chetumal, Mexico observations.
Cozumel, Mexico observations.
Belize City observations.
New disturbance 92L to watch
There is an area of disturbed weather associated with a tropical wave a few hundred miles northeast of the Lesser Antilles Islands. NHC has labeled this system "Invest 92L" this morning. Wind shear is about 10 knots in this region, which is low enough to allow some development over the next few days. This area is moving west-northwest, and will be near the U.S. East coast late this week. The next trough of low pressure strong enough to recurve this system is not due until Saturday, so this system will definitely be a threat to the U.S. if it develops. A QuikSCAT pass from 5:25am this morning shows no signs of a surface circulation, but plenty of strong straight-line winds from the thunderstorms.
Erin finally dissipates
Tropical Storm Erin finally died this morning over Missouri. Erin dramatically re-intensified Saturday night over Oklahoma, forming a tropical storm like-vortex that brought up to 11 inches of rain to Oklahoma, and helped feed disastrous rains of up to a foot over southeastern Minnesota. At least 13 deaths are being blamed on the resulting flooding, six of them in Oklahoma. The radar presentation of Erin's remains (Figure 3) looks remarkable tropical storm-like, and such re-intensifying tropical cyclones over land, complete with calm eye and spiral bands, have been observed in Australia, where they have been dubbed "landphoons". Hurricane David of 1979 performed a similar feat, generating severe weather over Washington D.C. 27 hours after it had made landfall in Georgia. What seems to be happening in these cases is that the circulation at upper levels of the atmosphere can remain intact if there is not a lot of wind shear to tear it apart. This circulation can then reach down to the surface again during its passage far inland. I've saved a long animation of this "landphoon", and Dr. Kevin Kloesel of the University of Oklahoma provided me a plot showing that the winds in Fort Cobb, Oklahoma were sustained at tropical storm force for over 10 minutes Sunday morning, with a peak wind gust of 75 mph. Winds at Watonga, OK, blew a sustained 55 mph, with gusts to 73 mph!
Figure 3. The remains of Tropical Storm Erin re-intensified into a remarkably tropical storm-like cyclone Sunday morning.
I'll have a short update this afternoon at about 4pm EDT, and full update Tuesday morning at about 10am EDT.
Jeff Masters
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.