Henri hanging on in the face of high wind shear
Our second October surprise this week in the Atlantic, Tropical Storm Henri, continues to defy 25 knots of wind shear. Henri has strengthened to a 50 mph tropical storm this morning, but wind shear is keeping the storm's heaviest thunderstorms confined to the southeast side of the circulation. Satellite loops show that Henri's low level center is exposed to view, and that the heavy thunderstorms may be retreating from the center, a sign that shear could be starting to rip the storm apart. This morning's QuikSCAT pass missed Henri, and last night's pass showed winds of 40 - 45 mph.
All of the reliable global computer models show weakening and dissipation of Henri by Thursday, due to high wind shear. The official NHC forecast goes along with this scenario, and I'll go along, given the unanimity and persistence of the models in forecasting this. Wind shear in the vicinity of Henri's remains is predicted to fall to the moderate range by Saturday, so we will have to be concerned with regeneration after Henri dissipates. It appears likely that moisture from Henri will affect Puerto Rico by Friday, the Dominican Republic on Saturday, and Haiti on Sunday. It is too early to tell if Henri's remains will be capable of causing flooding rains in these regions.
Figure 1. Morning satellite image of Henri (top) and a new tropical wave we're watching (bottom). The tropical wave south of Henri, just off the coast of South America, has become more organized this morning. This wave is under about 10 knots of wind shear, but is too close to the Equator to be able to take advantage of the Earth's spin to help it spin up into a tropical depression very quickly. NHC is giving this disturbance a low (less than 30% chance) or developing into a tropical depression by Friday.
Pacific typhoons
In the Philippines, Tropical Storm Parma completed its second traverse of the Philippines' Luzon island, and has emerged over the Philippine Sea to the east of the country. Parma is expected to reverse course and cross Luzon a third time over the next three days. Parma is expected to dump another 1 - 2 inches of rain today on northern Luzon.
Typhoon Melor has weakened to a Category 2 typhoon with 100 mph winds, thanks to high wind shear and cool ocean waters. The typhoon should weaken to Category 1 strength before making landfall near 3am Japanese time on the main island of Honshu, just south of Osaka. Melor will probably bring sustained winds of 40 mph to Tokyo. You can follow the landfall of Melor with our interactive wundermap for the region. Several coastal locations are already reporting sustained winds near 40 mph.
Some tropical weather for England
The remnant circulation of Tropical Storm Grace made landfall in Southwest England last night. Grace's remains brought sustained winds of tropical storm force--41 mph--to one buoy off the coast, and 38 mph to the Sevenstones Lightship buoy.
Figure 2. The remnant circulation of Tropical Storm Grace scoots by to the south of Ireland in this visible satellite image taken at 1pm EDT 10/06/09. Image credit: UK Met Office.
I'll have an update late this afternoon.
Jeff Masters
Reader Comments
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ha yeah, there is so much corn here. Was it June last year?
doesn't seem to be waning, its where the strongest convection is, it seems the convection is going SW with that supposedly new center and it is where the best lower level convergence is according to CIMMS
I will wait till a quickscat to confirm anything :)
Oh wow, thanks. Yes, worst floods since '93 which were supposed to be the 100 year floods.
I'll read this when I get back from walking the canines that own me which I said I was going to do many posts back after temporarily murdering the blog (run-on sentence; college was a long long time ago).
Yeah, I was in Daviess county at the time which had levees break. Pictures on my blog. Have fun on your walk
Oh, yeah -- I don't know whether to make frownie or smiley face. I HATE flooding, stinky mold & mildew, pew-ie! But you can't choose your disasters and I'd get karmically creamed if I said I preferred tornadoes. And Ike & the Portlight crew would smack me, too.
exactly, but one or the other is bound to happen sometime. Definitely appreciate Portlight and what they do
TCPAT5
BULLETIN
TROPICAL STORM HENRI ADVISORY NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102009
500 PM AST WED OCT 07 2009
...HENRI CONTINUING TO WEAKEN...
AT 500 PM AST...2100 UTC...THE CENTER OF TROPICAL STORM HENRI WAS
LOCATED NEAR LATITUDE 19.4 NORTH...LONGITUDE 58.6 WEST OR ABOUT
305 MILES...490 KM...EAST-NORTHEAST OF THE NORTHERN LEEWARD ISLANDS.
HENRI IS MOVING TOWARD THE WEST-NORTHWEST NEAR 15 MPH...24 KM/HR...
AND A TURN TOWARD THE WEST WITH A DECREASE IN FORWARD SPEED IS
EXPECTED TOMORROW.
MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 40 MPH...65 KM/HR...
WITH HIGHER GUSTS. ADDITIONAL WEAKENING IS FORECAST AND HENRI
COULD DISSIPATE BY THURSDAY.
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 105 MILES...165 KM
FROM THE CENTER.
THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.
...SUMMARY OF 500 PM AST INFORMATION...
LOCATION...19.4N 58.6W
MAXIMUM SUSTAINED WINDS...40 MPH
PRESENT MOVEMENT...WEST-NORTHWEST OR 290 DEGREES AT 15 MPH
MINIMUM CENTRAL PRESSURE...1008 MB
THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
1100 PM AST.
$$
FORECASTER BLAKE
TCDAT5
TROPICAL STORM HENRI DISCUSSION NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102009
500 PM AST WED OCT 07 2009
HENRI IS WEAKENING THIS AFTERNOON WITH THE LOW-LEVEL CENTER MOVING
EVEN FARTHER AWAY FROM A PERSISTENT AREA OF STRONG CONVECTION. THE
LOW-LEVEL CIRCULATION ALSO IS BECOMING LESS WELL-DEFINED WITH A
SECONDARY CENTER NOTED ON RECENT VISIBLE IMAGES. A BLEND OF THE
TAFB/SAB DVORAK ESTIMATES GIVEN AN INITIAL WIND SPEED OF 35 KT...
BUT THIS COULD BE A LITTLE GENEROUS. STRONG WEST TO SOUTHWEST
SHEAR IS LIKELY FOR A DAY OR SO...WHICH WILL CONTINUE TO WEAKEN THE
CYCLONE. IF HENRI SURVIVES THAT SHEAR...AN UPPER-TROUGH AXIS WITH
CONFLUENT FLOW ALOFT SHOULD PROVIDE THE KNOCKOUT BLOW TO THE
TROPICAL CYCLONE. THE OFFICIAL FORECAST IS BASICALLY AN UPDATE TO
THE PREVIOUS ONE...SHOWING DISSIPATION WITHIN 24 HOURS. HOWEVER...
IF DEEP CONVECTION DOES NOT RETURN NEAR THE CENTER...THIS SYSTEM
COULD BECOME A REMNANT LOW SOONER THAN INDICATED BELOW.
USING A MEAN MOTION OF THE TWO CENTERS...THE INITIAL MOTION IS
290/12. A WEST-NORTHWEST PATH IS PROBABLE FOR THE NEXT DAY OR SO
BEFORE RIDGING BUILDS OVER THE WESTERN ATLANTIC. THIS RIDGE SHOULD
CAUSE HENRI...OR THE REMNANTS THEREOF...TO TURN WESTWARD OR EVEN
SOUTH OF WEST UNTIL THE LOW DISSIPATES. THIS SOLUTION HAS GOOD
SUPPORT FROM MODEL GUIDANCE...AND THE OFFICIAL FORECAST IS CLOSE TO
THE PREVIOUS ONE...REMAINING ON THE SOUTHERN SIDE OF THE GUIDANCE
ENVELOPE NEAR BAM SHALLOW.
FORECAST POSITIONS AND MAX WINDS
INITIAL 07/2100Z 19.4N 58.6W 35 KT
12HR VT 08/0600Z 20.1N 60.3W 30 KT
24HR VT 08/1800Z 20.9N 62.0W 25 KT...REMNANT LOW
36HR VT 09/0600Z 21.2N 63.6W 20 KT...REMNANT LOW
48HR VT 09/1800Z 21.0N 66.0W 20 KT...REMNANT LOW
72HR VT 10/1800Z...DISSIPATED
EVEN FARTHER AWAY FROM A PERSISTENT AREA OF STRONG CONVECTION.
OMG! I just looked at pics quickly. If you don't have description on how it affected you and yours, please put it on your blog! If you already do, sorry, I'll read it later (canines staring, woeful eyes).
go walk the dogs (:
but the floods didnt do any damage to my house, but I did do alot of volunteer work around the county and helped clean up, pack buckets full of useful items for the victims, and helped with sandbagging etc. Loved helping those in need, it is a tremendous feeling knowing that there are people here for eachother, you know?
Congrats Matt on the new job.
My post was extended
Chances are this will move more west than north through the Caribbean. Everything is being determined by the deep layer ridge, even Henri potential track. I have noticed its rather south of 10N so it needs to pull north to prevent from interacting with SA. It is amazing that this may look like it will run into the continent then when you look its passing through the windwards, they normally turn just before 55W, so we will see.
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