Karl near hurricane strength; Igor intensifying again
Tropical Storm Karl is back over water after popping off the coast of Mexico's Yucatan Peninsula early this morning. Despite being a small storm, Karl managed to keep a remarkable degree of organization during its crossing of the Yucatan. Karl has already regained all of its lost strength, and is near hurricane intensity. A Hurricane Hunter aircraft is currently in Karl, and at 8:47am EDT found winds at 5,000 feet of 85 mph, which suggest winds near 65 - 70 mph were occurring at the surface. The aircraft noted that Karl had built an eyewall that was open on the north-northeast side. The eye is now apparent in both visible and infrared satellite imagery. Mexican radar out of Alvarado shows the outer spirals bands of Karl are approaching the coast near Veracruz, and heavy rains of 2 - 4 inches can be expected today along much of Mexico's Bay of Campeche coast.
Figure 1. Image from NASA's Terra satellite taken at 12:40pm EDT Wednesday September 15, 2010 of Tropical Storm Karl over the Yucatan Peninsula. Image credit: NASA.
Forecast for Karl
Conditions for intensification are ideal in the Gulf of Mexico's Bay of Campeche, with wind shear expected to be low, 5 - 10 knots, SSTs warm, 29°C - 30°C, and the atmosphere very moist. These conditions, combined with the topography of the surrounding coast which tends to enhance counter-clockwise flow, should allow Karl to intensify into a Category 2 hurricane before making landfall between Tampico and Vercruz, Mexico Friday morning. NHC is giving Karl a 7% chance of reaching Category 3 strength, but the recent data from the Hurricane Hunters suggest that these odds are higher, perhaps 30%. The 06Z (2 am EDT) run of the GFDL model makes Karl a strong Category 2 hurricane with 105 - 110 mph winds at landfall Friday, and this is a reasonable forecast. Karl is a small storm, and is unlikely to bring any rain or wind to Texas.
Figure 2. Forecast swath of maximum winds from Karl, as predicted by the GFDL model on its 2am EDT (6Z) run this morning. The GFDL is predicting a 50-mile wide stretch of the Mexican coast will receive Category 1 (yellow colors, 64+ knots) or Category 2 (orange colors, 83+ knots) winds. Image credit: Morris Bender, NOAA/GFDL.
Igor
Hurricane Igor completed an eyewall replacement cycle early this morning, and has been intensifying. Igor is headed west-northwest to northwest at 7 mph, and this motion will carry the core of the hurricane close to NOAA buoy 41044 between 9 - 11 pm EDT tonight. Top winds at the buoy so far today have been 52 mph, gusting to 65, with a significant wave height of 32 feet (the significant wave height is the average height of the highest 1/3 of the waves.) The Hurricane Hunters are scheduled to make their first flight into Igor this afternoon, and we will see then exactly how strong Igor is. Satellite imagery shows that Igor looks a bit ragged on its north side, but the northern eyewall is getting stronger, and the eye is clearing out and contracting--signs of strengthening.
Figure 3. Morning satellite image of Igor.
Intensity forecast for Igor
Wind shear is low to moderate, 5 - 15 knots, and is expected to remain in this range through Saturday morning. Waters are warm, 29°C, and will remain 29°C through Saturday morning. Igor is well armored against any intrusions of dry air for at least the next two days. These conditions should allow Igor to remain at major hurricane status through Saturday afternoon. It is possible the hurricane will undergo another eyewall replacement cycle on Friday or Saturday, where the eyewall collapses and a new eyewall forms from an outer spiral band. This will weaken the hurricane by 10 - 20 mph if it occurs, but Igor may regain its lost intensity once the cycle is over, as it has done after the two eyewall replacement cycles it has already undergone. By Saturday morning, 36 hours before the core of Igor is expected to pass Bermuda's latitude, the trough of low pressure steering Igor northwestwards should bring moderate wind shear of 10 - 20 knots to the storm, potentially weakening Igor. The SHIPS models predicts shear will not rise to the high range, 20 - 30 knots, until after the hurricane reaches the island. Igor will also be tracking over cooler 28°C waters during this period, and substantial weakening by perhaps 20 - 30 mph can be expected about the time Igor arrives at Bermuda. Igor will still probably be at least a Category 2 hurricane on its closest pass by Bermuda on Sunday night, and perhaps a Category 3 storm. NHC is giving Bermuda a 21% chance of experiencing hurricane force winds from Igor, but this probability is likely too low. The Bermuda Weather Service is calling for Category 1 or 2 hurricane conditions for the island on Sunday, with 20 - 30 foot waves in the offshore waters.
Igor's impact on Bermuda
The track forecast for Igor remains unchanged. Igor is moving west-northwest, in response to the steering influence of a broad trough of low pressure moving across the Western Atlantic. This trough will steer Igor to the northwest and north over the next three days, bringing the core of the storm very close to Bermuda late Sunday night. Igor is a huge storm, and tropical storm force winds extend out 270 miles to the north of its center. As the hurricane moves north, it will expand in size, as it takes advantage of the extra spin available at higher latitudes due to Earth's rotation. By Saturday night, Igor's tropical storm force winds are expected to extend outwards 310 miles from the center. Igor will be moving at about 11 - 13 mph during the final 24 hours of its approach to Bermuda, so that island can expect a period of 39+ mph tropical storm force winds to begin near midnight Saturday night--a full 24 hours before the core of Igor arrives. Igor will speed up to about 15 mph as it passes Bermuda near midnight Sunday night. Hurricane force winds will probably extend out about 60 miles from the center then, and the island can expect to be pounded by hurricane force winds for up to 6 - 8 hours if the core of the hurricane tracks over the island. In all, Bermuda is likely to suffer a remarkably long 36-hour period of tropical storm force winds, with the potential for many hours of hurricane force winds. Long-duration poundings like this are very stressful for buildings, and there is the potential for significant damage on Bermuda.
Igor's impact on the rest of the Atlantic
The models have been in substantial agreement over multiple runs that Igor will miss the U.S. and Canadian coasts--with the possible exception of southeast Newfoundland, which the ECMWF model predicts could see a close pass by Igor. The chief danger to the U.S. and Canada will come in the form of high waves. Large swells from Igor have arrived in the Northern Lesser Antilles Islands and Puerto Rico, and will spread westwards over the next few days. By Saturday, much of the East Coast from northern Florida to Cape Cod Massachusetts can expect waves of 3 - 4 meters (10 - 13 feet), causing dangerous rip currents and significant beach erosion. These waves will continue through Sunday then gradually die down. The latest NOAA marine forecast for Cape Hatteras, North Carolina calls for 7 - 10 foot waves on Saturday, and 9 - 13 foot waves on Sunday.
Julia
Hurricane Julia put on a remarkable and unexpected burst of intensification yesterday morning to become the season's fourth Category 4 storm, but is now on a long steadily decline in intensity. The hurricane is currently over waters right at the lower limit for maintaining a hurricane, 26.5°C (80°F), and is undergoing high shear of 20 - 25 knots. While the shear will abate tonight and the water will warm some, Julia is headed towards some very hostile upper-level winds beginning on Friday. These strong winds, courtesy of the upper level outflow from Hurricane Igor, will bring 30 - 45 knots of wind shear to Julia Friday night through Sunday. The high shear should be enough to rapidly weaken Julia over the weekend. Julia is not expected to threaten any land areas.
Elsewhere in the tropics
The ECMWF model develops a new tropical depression a few hundred miles off the coast of Africa 2 - 4 days from now. The GFS and NOGAPS models are suggesting the eastern Caribbean could see a strong tropical disturbance form 6 - 7 days from now.
I'll have an update this afternoon.
Jeff Masters
Reader Comments
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There is still some westerly shear that is impacting Igor, which has resulted in some deterioration of the western side of the eye and on the western quadrant in general.
NHC discussion 5p.m.
THE EXTENSION OF AN
UPPER-LEVEL TROUGH PASSING NORTH OF IGOR IS STILL PRODUCING ABOUT
15 KT OF WESTERLY SHEAR OVER THE CYCLONE...ACCORDING TO THE LATEST
UW-CIMSS ANALYSES. THE SHIPS MODEL OUTPUT SHOWS A REDUCTION IN THE
SHEAR WITHIN THE NEXT 12 HOURS AS THIS FEATURE MOVES AWAY...WHICH
COULD ALLOW AN OPPORTUNITY FOR SOME RE-INTENSIFICATION IN THE
SHORT-TERM. THE GUIDANCE INDICATES THAT IGOR WILL BE MOVING INTO AN
ENVIRONMENT OF GRADUALLY INCREASING SOUTHERLY TO SOUTH-
SOUTHWESTERLY SHEAR IN ABOUT TWO DAYS...AND OVER COOLER WATERS BY
THE END OF THE FORECAST PERIOD.
CLICK FOR LARGER IMAGE
And a twofer:
CLICK FOR LARGER IMAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112010
500 PM AST THU SEP 16 2010
...HURRICANE HUNTER AIRCRAFT REACHES IGOR...
SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...21.7N 58.1W
ABOUT 405 MI...650 KM NE OF THE NORTHERN LEEWARD ISLANDS
ABOUT 840 MI...1350 KM SSE OF BERMUDA
MAXIMUM SUSTAINED WINDS...125 MPH...205 KM/HR
PRESENT MOVEMENT...NW OR 310 DEGREES AT 8 MPH...13 KM/HR
MINIMUM CENTRAL PRESSURE...940 MB...27.76 INCHES
IMO it is ridiculous for people to even comment about something may or may not happen 10 days out.
That and having to process all that flagging.
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM AST THU SEP 08 2005
...MARIA STILL A HURRICANE...
AT 5 PM AST...2100Z...THE CENTER OF HURRICANE MARIA WAS LOCATED NEAR
LATITUDE 39.5 NORTH... LONGITUDE 46.8 WEST OR ABOUT 590 MILES...
950 KM... SOUTHEAST OF CAPE RACE NEWFOUNDLAND AND ABOUT 1070
MILES...1720 KM...WEST-NORTHWEST OF THE AZORES.
HURRICANE NATE ADVISORY NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT THU SEP 08 2005
...NATE MOVING A LITTLE FASTER TOWARD THE NORTHEAST...
AT 5 PM AST...2100Z...THE TROPICAL STORM WARNING FOR BERMUDA HAS
BEEN DISCONTINUED.
AT 5 PM EDT...2100Z...THE CENTER OF HURRICANE NATE WAS LOCATED NEAR
LATITUDE 31.8 NORTH...LONGITUDE 62.0 WEST OR ABOUT 170 MILES...
270 KM...EAST OF BERMUDA.
HURRICANE OPHELIA ADVISORY NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT THU SEP 08 2005
...OPHELIA BECOMES THE SEVENTH HURRICANE OF THE SEASON...STILL NOT
MOVING...
By WU's page, Ophelia gained hurricane between 18 Z and 00 Z on the 9th.
And Maria lost it about the same time.
Almost looks like some southerly spinnage.
Ah ok thanks. :) It's hard to tell from what I have to look at but the EURO still looks to be trying to bring something to the TX/LA area at the end of their run. It shows as a faint yellow blip on this model. Lol.
It may be so on the operational data but have a look at the post season analysis to see if they existed at the same time too. There might have been some changes.
Hmmm. Might have to carve out some more time to look closer.
That isn't necessarily the data that goes into HURRDAT though. The final data is in the post storm analysis and sometimes changes from the operational advisory.
http://www.liveweatherblogs.com/Levi32
It is answerable. Go ahead.
No Atlantic storms. Here, I will show you. I was quite old at the time, but I do remember it well. Here is an interesting image. I thought atmo could answer this, but I guess he couldn't.
From Max Mayfield:
I recall we had five Atlantic tropical cyclones simultaneously when I was a hurricane forecaster at National Hurricane Center (NHC) in 1995. The NHC best track files from that year between 1200 UTC August 27 to 0000 UTC August 28 show Hurricane Humberto, Tropical Storm Iris (soon to become a hurricane), Tropical Depression Jerry, Tropical Depression Twelve (soon to become Tropical Storm Karen), and Tropical Depression Thirteen (soon to become Hurricane Luis) all ongoing at the same time. Unfortunately, I don’t have a satellite image from that exact time period, but Idid find some from just before and after.
Groth- thats a cool post of the 5 storms at once
quick question does admin have a top number on how many post get censored before they ban for 24 hours
also it looks like "J" is getting her act together in the last couple of frames
http://www.examiner.com/science-policy-in-austin/christine-o-donnell-is-deeply-confused-on-geology- and-science
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