ATL: TROPICAL DEPRESSION HENRI (10L)

[Dean4Storms]

Surprised a bit with this development, but not out of the question once deep convection got sustained. Be interesting to see if the total dissipation occurs or if we don't get the back and forth convection to naked swirls keeping it barely alive.

[Blown Away]

Interesting track.

[Dean4Storms]

maybe a more realistic scenario is the Bay of Campeche cyclone CMC is spinning up

I saw that, you got a link that takes CMC beyond 5 days? I saw the low closing off around the 4-5 day threshold but I don't have a link for the CMC beyond that. What does it do with it?

[Aric Dunn]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.


So here is the deal .. I just spent a few moments going over the forecast shear from nogaps,gfs,Nam. Now there will be an opportunity for strengthening in about 48 hours but is completely dependent on its latitude. All models dissipate the weak elongated upper low over the eastern carribean by 48 hours which slowly builds into a weak upper ridge from about 200 miles north of PR south into the eastern carribean. the area of lighter shear is forecast to last for a few days but migrate west over the central carribean. So here is the kicker the models all agree on one thing and that henri or its remnants will turn sharply wsw to sw and in some cases SSW, this motion would potentially put henri in a better environment to either come back to life or strengthen. but if it continues to gain as much latitude as the nhc has forecast than the shear will most likely win out and leave a remnant low;however if henri begins to slow down earlier in response to the building ridge and gains less latitude than the nhc forecast, than it will miss the highest shear and will turn wsw to sw sooner putting it into low shear sooner. SO one thing to keep a eye on and that is if it can maintain at least some convection as it is doing now an does not weaken to a remnant low in the next 24 hours then a more wnw track will continue which keeps it south of the highest shear in 48 hours. so more convection means deeper system and farther south.

Edited post to include disclaimer=cycloneye

[wxman57]

Convection appears to be getting sheared away from the center again. Looks exposed now.

[ozonepete]

Convection appears to be getting sheared away from the center again. Looks exposed now.

Do you agree with the 36 hours dissipated forecast?

[Aric Dunn]

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.


So here is the deal .. I just spent a few moments going over the forecast shear from nogaps,gfs,Nam. Now there will be an opportunity for strengthening in about 48 hours but is completely dependent on its latitude. All models dissipate the weak elongated upper low over the eastern carribean by 48 hours which slowly builds into a weak upper ridge from about 200 miles north of PR south into the eastern carribean. the area of lighter shear is forecast to last for a few days but migrate west over the central carribean. So here is the kicker the models all agree on one thing and that henri or its remnants will turn sharply wsw to sw and in some cases SSW, this motion would potentially put henri in a better environment to either come back to life or strengthen. but if it continues to gain as much latitude as the nhc has forecast than the shear will most likely win out and leave a remnant low;however if henri begins to slow down earlier in response to the building ridge and gains less latitude than the nhc forecast, than it will miss the highest shear and will turn wsw to sw sooner putting it into low shear sooner. SO one thing to keep a eye on and that is if it can maintain at least some convection as it is doing now an does not weaken to a remnant low in the next 24 hours then a more wnw track will continue which keeps it south of the highest shear in 48 hours. so more convection means deeper system and farther south.

Edited post to include disclaimer=cycloneye

Quick image of potential area.. also henri is south of the forecast track as its motion over the last few hours has been 285 to 290 or so .. the red circle is its present location and the white line is just a extrapolation.


just a closer view ... yellow line here is the extrapolation..



here is the gfs 200mb forecast so you dont think im talking out of my rear lol .. its showing that weak upper ridge that builds in about 60 hours.

[Dionne]

I couldn't be happier.....finished a job in NYC while worrying about weather in St Croix next week. Our October Carib escape. For awhile there I actually thought it might be another Hugo. Friends on St Kitts worried similarly. I am surprised to see the center that far north. What happened to the shear we saw on GOES yesterday? Or was it the day before?

[HURAKAN]

Latest

[Derek Ortt]

well... the accuwx track sure looks familiar. Seems similar to the nwhhc track

[Macrocane]

Wow! I left home this morrning and it was code yellow, and I've just came back and I found Henri. Who said that the season was over? Two TS in 3 days shows that the season was not over. Ok, I know Henri it's a sheared system but it's something to track for a couple o days. Again the Euro was the first that predicted the development of Henri, then the CMC agreed with it. I think that it maybe no longer a tropical cyclone in 36 hours, but if the LLC survives as Fred did then it will have the chance to regenerate in 72-96 hours when conditions may improve.

[cycloneye]

Wow! I left home this morrning and it was code yellow, and I've just came back and I found Henri. Who said that the season was over? Two TS in 3 days shows that the season was not over. Ok, I know Henri it's a sheared system but it's something to track for a couple o days. Again the Euro was the first that predicted the development of Henri, then the CMC agreed with it. I think that it maybe no longer a tropical cyclone in 36 hours, but if the LLC survives as Fred did then it will have the chance to regenerate in 72-96 hours when conditions may improve.

You missed the best part.At 2 PM it was yellow,at 3:15 PM a special TWO was out and at 5 it was Henri.

[expat2carib]

My guess is that it will dissipate within 16 hours from now. The remnants can redevelop and have a SW track if (big IF) conditions are OK. ( not necessarily perfect)

My .25 cents

[Sanibel]

It has been unusually humid over here the last two days. Better hope this doesn't reach and touch off those STT's jfl has been talking about.

[Macrocane]

You missed the best part.At 2 PM it was yellow,at 3:15 PM a special TWO was out and at 5 it was Henri.

Yes I just can imagine the excitement, I guess it was similar to what we experienced with Grace, a big surprise.

[cycloneye]

WTNT35 KNHC 070238
TCPAT5
BULLETIN
TROPICAL STORM HENRI ADVISORY NUMBER 2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102009
1100 PM AST TUE OCT 06 2009

...HENRI A LITTLE STRONGER...

AT 1100 PM AST...0300 UTC...THE CENTER OF TROPICAL STORM HENRI WAS
LOCATED NEAR LATITUDE 18.4 NORTH...LONGITUDE 55.3 WEST OR ABOUT 510
MILES...825 KM...EAST OF THE NORTHERN LEEWARD ISLANDS.

HENRI IS MOVING TOWARD THE WEST-NORTHWEST NEAR 17 MPH...28 KM/HR...
AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE OVER THE NEXT DAY
OR SO. ON THIS TRACK...THE CENTER OF HENRI AND THE ASSOCIATED
STRONG WINDS ARE EXPECTED TO PASS NORTH OF THE LESSER ANTILLES
DURING THE NEXT DAY OR TWO.

MAXIMUM SUSTAINED WINDS ARE NEAR 45 MPH...75 KM/HR...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS EXPECTED TONIGHT. WEAKENING
IS FORECAST TO BEGIN ON WEDNESDAY AND HENRI COULD BECOME A REMNANT
LOW BY THURSDAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 70 MILES...110 KM
FROM THE CENTER.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

...SUMMARY OF 1100 PM AST INFORMATION...
LOCATION...18.4N 55.3W
MAXIMUM SUSTAINED WINDS...45 MPH
PRESENT MOVEMENT...WEST-NORTHWEST OR 290 DEGREES AT 17 MPH
MINIMUM CENTRAL PRESSURE...1006 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 AM AST.

$$
FORECASTER CANGIALOSI/BROWN

000
WTNT45 KNHC 070239
TCDAT5
TROPICAL STORM HENRI DISCUSSION NUMBER 2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL102009
1100 PM AST TUE OCT 06 2009

CONVECTION HAS CONTINUED TO PULSATE NEAR THE CENTER OF HENRI THIS
EVENING AND THE AREA OF COLD CLOUD TOPS HAVE EXPANDED CONSIDERABLY.
DVORAK T-NUMBERS HAVE INCREASED...SUGGESTING AN IMPROVEMENT IN
ORGANIZATION. A 2151 UTC QUIKSCAT PASS SHOWED SOME 40 KT WIND
VECTORS TO THE NORTHEAST OF THE CENTER THAT SEEM BELIEVABLE.
ON THIS BASIS...THE INITIAL INTENSITY IS RAISED TO 40 KT. THE
LOW-LEVEL CENTER IS LOCATED NEAR THE WESTERN EDGE OF THE CONVECTION
DUE TO STRONG SOUTHWESTERLY VERTICAL WIND SHEAR. THE SHEAR IS
EXPECTED TO REMAIN STRONG OVER THE NEXT COUPLE OF DAYS AND SHOULD
CAUSE THE CYCLONE TO DECOUPLE AND WEAKEN. THE INTENSITY FORECAST
IS SIMILAR TO THE PREVIOUS ADVISORY AND CALLS FOR HENRI TO WEAKEN
TO A TROPICAL DEPRESSION IN ABOUT 24 HOURS AND DEGENERATE TO A
REMNANT LOW SHORTLY THEREAFTER. THIS IS IN GOOD AGREEMENT WITH THE
DYNAMICAL MODELS WHICH ALL WEAKEN THE CYCLONE DURING THE NEXT DAY
OR TWO.

THE INITIAL MOTION IS 290/15...A LITTLE TO THE LEFT OF THE PREVIOUS
ESTIMATE. HENRI IS CURRENTLY LOCATED ALONG THE SOUTHWESTERN
PERIPHERY OF A MID-LEVEL RIDGE OVER THE EASTERN ATLANTIC. THE
CYCLONE IS EXPECTED MOVE IN A GENERAL WEST-NORTHWESTWARD TO
NORTHWESTWARD HEADING UNTIL DISSIPATION. THE NEW NHC TRACK
FORECAST IS SLIGHTLY SOUTH OF THE PREVIOUS ADVISORY...MAINLY
TO ACCOUNT FOR THE INITIAL POSITION AND MOTION.

FORECAST POSITIONS AND MAX WINDS

INITIAL 07/0300Z 18.4N 55.3W 40 KT
12HR VT 07/1200Z 19.3N 57.3W 35 KT
24HR VT 08/0000Z 20.5N 59.7W 30 KT
36HR VT 08/1200Z 21.8N 61.9W 25 KT...REMNANT LOW
48HR VT 09/0000Z...DISSIPATED

$$
FORECASTER CANGIALOSI/BROWN

[cycloneye]

A little stromger.

...SUMMARY OF 1100 PM AST INFORMATION...
LOCATION...18.4N 55.3W
MAXIMUM SUSTAINED WINDS...45 MPH
PRESENT MOVEMENT...WEST-NORTHWEST OR 290 DEGREES AT 17 MPH
MINIMUM CENTRAL PRESSURE...1006 MB

[gatorcane]

GFS zonal shear forecast still not bad, could develop more it looks like or at least maintain.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation

In fact I still can't find why Henri is going to go poof in a few days. Still looking for that reason. Also looks like a WNW movement in general. I can't see why it would recurve.

Here is the shear tendency, look how it is decreasing north of the Caribbean....with that swath of unfavorable shear it is entering into now. SHIPS must be picking up on this scenario.

[Gustywind]

[blp]

GFS zonal shear forecast still not bad, could develop more it looks like or at least maintain.

http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation

In fact I still can't find why Henri is going to go poof in a few days. Still looking for that reason. Also looks like a WNW movement in general. I can't see why it would recurve.

Here is the shear tendency, look how it is decreasing north of the Caribbean....with that swath of unfavorable shear it is entering into now. SHIPS must be picking up on this scenario.

It would be interesting to see if any ULL might develop in its path. This year they have been especially prevelant. Looking at the 200MB Vorticity, I do see little more vorticity around PR now than 12 hours ago, which could suggest a small ULL is forming, and maybee that might cause the shear.

Current:



12hrs ago: