Atlantic tropical disturbance 91L poses little threat
A tropical disturbance (91L) near 24N, 63W, midway between the Virgin Islands and Bermuda, is moving north-northwest at about 8 mph. The system's heavy thunderstorm activity has increased since yesterday, but 91L has an elongated and poorly-organized circulation, thanks to a hefty 80 knots of wind shear. The storm is over waters of 25°C, and these waters will cool to 24°C by Friday as the storm continues to the north-northwest. Before 91L reaches Bermuda, steering currents will reverse and force 91L to the south-southwest on Saturday, into a region of higher wind shear. The latest SHIPS model forecast predicts wind shear will drop to 50 knots over 91L by Friday, then increase again to 70 knots by Sunday. The high shear and relatively cool water temperatures will make it difficult for 91L to organize into a subtropical depression. I give 91L a 10% of becoming a subtropical depression. Climatology argues against 91L becoming the first named storm of the year; there has only been once named April storm in the Atlantic since 1851, Tropical Storm Ana of 2003. The formation of a tropical disturbance at this location this time of year is unusual, but is not necessarily a harbinger of a active season ahead.
Figure 1. Morning satellite image of the Atlantic tropical disturbance 91L.
Jeff Masters
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WHXX01 KWBC 221219
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS NATIONAL HURRICANE CENTER MIAMI FL
1219 UTC FRI APR 22 2011
DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.
ATLANTIC OBJECTIVE AIDS FOR
DISTURBANCE INVEST (AL912011) 20110422 1200 UTC
...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
110422 1200 110423 0000 110423 1200 110424 0000
LAT LON LAT LON LAT LON LAT LON
BAMS 26.9N 62.9W 27.3N 64.0W 27.2N 65.6W 27.1N 67.8W
BAMD 26.9N 62.9W 28.0N 62.2W 27.6N 62.6W 26.9N 63.2W
BAMM 26.9N 62.9W 27.2N 63.2W 26.5N 64.4W 25.7N 65.8W
LBAR 26.9N 62.9W 28.0N 61.4W 28.4N 60.1W 28.8N 58.7W
SHIP 30KTS 31KTS 30KTS 24KTS
DSHP 30KTS 31KTS 30KTS 24KTS
...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
110424 1200 110425 1200 110426 1200 110427 1200
LAT LON LAT LON LAT LON LAT LON
BAMS 27.1N 70.2W 28.2N 75.5W 31.2N 80.3W 36.5N 80.9W
BAMD 26.2N 63.5W 25.0N 63.1W 25.8N 62.9W 26.7N 63.9W
BAMM 25.3N 67.4W 25.9N 70.5W 27.9N 74.0W 31.6N 75.1W
LBAR 28.3N 57.4W 26.7N 55.0W 25.9N 53.3W 25.2N 51.2W
SHIP 15KTS 0KTS 0KTS 0KTS
DSHP 15KTS 0KTS 0KTS 0KTS
...INITIAL CONDITIONS...
LATCUR = 26.9N LONCUR = 62.9W DIRCUR = 0DEG SPDCUR = 8KT
LATM12 = 25.3N LONM12 = 63.0W DIRM12 = 3DEG SPDM12 = 9KT
LATM24 = 23.7N LONM24 = 63.0W
WNDCUR = 30KT RMAXWD = 60NM WNDM12 = 35KT
CENPRS = 1007MB OUTPRS = 1013MB OUTRAD = 150NM SDEPTH = M
RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM
$$
NNNN
Still, 91L seems a harbinger of things to come.
Why does Shakespeare always come to mind as hurricane season begins to show itself? (rhetorical question)
For me, it's because we humans have no control over these events and can only observe what happens.
This was what Shakespeare was particularly good at showing about the ultimate human condition.
Once events begin to play out, we can only watch and wonder and try to adjust.
Pretty safe bet neutral is coming our way. It doesn't make me rest easy in FL. Neutral brings with it an increased hurricane threat to the peninsula and seems an increased threat to the Leewards, PR ect.. naturally being downwind and all.
22/1145 UTC 26.7N 63.0W ST1.5 91L
22/0615 UTC 25.9N 63.0W ST1.5 91L
21/2345 UTC 25.3N 62.9W TOO WEAK 91L
21/1745 UTC 24.2N 63.1W TOO WEAK 91L
21/1145 UTC 23.4N 62.9W TOO WEAK 91L
21/0515 UTC 23.1N 62.5W TOO WEAK 91L
20/2345 UTC 23.2N 62.0W TOO WEAK 91L
20/1745 UTC 23.0N 60.8W ST1.5 91L
It is already quite hot here in Barbados, last night was unusually warm for this time of year.
Together with that and 91L, three weeks ago we had a squall coming through here and the islands that caused severe flooding. It had some high winds too, again, unusual.
I think we are looking at 2011=2005, or thereabouts.
But, as I have warned many times in the past, I am no meteorologist.
Take care.
Back on the map for the time being. I personally don't think they will call it though.
Link
DESIGNATE IT!
They won't.....not w/a 20% chance. They would up the odds first.
[cheeky grin] Looka the people.....
I haven't been following 91L very closely, but have been keeping an eye on it since last week in the unlikely hope that it will drift far enough west to bring us some showers here in the Bahamas. A pleasure to see it bringing some non-winter bloggers in, though....
If 91L was to be designated shortly there would be a TWO upping it to 80-90% followed by an upgrade.
They won't go from 20% to STS Arlene.
Competing centers would be my guess. Surely on an organizational trend though. Looks a little better with each refresh.
Ike, you leave a little to be desired on your wishcasting. Just not quite the enthusiasm I expected.
That 91L is a real fighter. It is hanging in there. It could be a contender. It is not going to let go easily. It is one tough hombre. Those winds are going to have to kick butt to kill this little die-hard. It has stamina. Dare I say it ------ we are all DOOM.
Shear is not ideal but lower for the time being.
Maybe they got tired of all those last year who accused them of "promoting GW hype" by "naming storms they shouldn't have". ;-)
Come on 91L! Do it! Do it now!
That better?
So let'em choose a dominant one!They are professionalists,should be able to do this.
They won't name it with 2 vortice. Should acquire enough organization to be named 91L will eat that second center for lunch.
There ya go!!!!
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