TD 2 struggling; new African wave bears watching
Tropical Depression Two is struggling. The depression still has a good chance of becoming the Atlantic hurricane season's first named storm this week, but the dry, Saharan air that surrounds the storm, combined with moderately high levels of wind shear, are interfering with the storm's organization. Satellite loops of the storm show that heavy thunderstorm activity is limited to the west side of the depression. This is due to strong winds out of the southeast that are creating a moderate 15 - 20 knots of wind shear. The intensity and coverage of these thunderstorms is meager, thanks to the large amount of dry air to TD 2's north that is getting wrapped into the circulation. This morning's QuikSCAT pass showed a well-formed surface circulation, with top winds of about 30 - 35 mph.
Wind shear over TD 2 is expected to remain in the moderate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures (SSTs) are a marginal 26 - 27°C, and will not change much over the next three days. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to to TD 2's north that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that TD 2 will not be able to intensify quickly. However, it does appear likely that TD 2 has enough going for it that it will eventually be able to become Tropical Storm Ana sometime in the next three days. Most of the computer models show some weak development, but none of them predict TD 2 will become a hurricane. It is unusual for storms forming this far north to make it all the way across the Atlantic to hit the Lesser Antilles Islands. For now, TD 2 doesn't concern me as much as the new tropical wave to its southeast, just off the coast of Africa.
Figure 1. Tropical Depression Two (left center of image) and a new tropical wave (right side of image), newly emerged from the coast of Africa.
Elsewhere in the Atlantic
A strong tropical wave with some rotation and plenty of heavy thunderstorm activity left the coast of Africa yesterday, and is located a few hundred miles south of the Cape Verdes Islands. The GFS and ECMWF models continue to predict the development of this wave late this week. Both of these models indicate that the wave would track further south than Tropical Depression Two, and could impact the Lesser Antilles Islands in about seven days. This storm bears close attention over the coming days.
Two other tropical waves, one that just passed through the Lesser Antilles Islands, and one about 300 miles east of the islands, are mentioned in NHC's Graphical Tropical Weather Outlook. Both of these waves have very limited heavy thunderstorm activity that is not increasing, and are not a threat to develop over the next two days. None of the computer models develop either of these waves.
Felicia moves through Hawaiian Islands as a tropical depression
Tropical Storm Felicia weakened to a tropical depression before passing through the Hawaiian Islands yesterday. The storm brought scattered heavy rains of 1 - 2 inches to the islands, and no damage was reported. Felicia is only the 10th tropical cyclone of tropical depression strength or higher to hit the islands since 1950. Four other tropical cyclones have passed within 75 miles of the islands during that time period.
Be careful clicking on external links in blog comments
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I'll have an update Thursday morning.
Jeff Masters
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Thats the old TD2 floater, note time stamp at the bottom.
It's not over yet... Notice the burst of convection, it's getting a bit bigger.
I see 2 new swirls... Bahammas and right off the swfl coast. anyone have a current vorticity map handy?
Just a AOI for now,as its in a Favored spot and some energy is on the way in that Gen Direction too
For 12z, 850mb.
So it's more like a Gremlin then? Scary!
It's the latest image on the ramsdis site.
WTNT22 KNHC 131433
TCMAT2
TROPICAL DEPRESSION TWO FORECAST/ADVISORY NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
1500 UTC THU AUG 13 2009
TROPICAL DEPRESSION CENTER LOCATED NEAR 14.0N 37.6W AT 13/1500Z
POSITION ACCURATE WITHIN 20 NM
PRESENT MOVEMENT TOWARD THE WEST OR 270 DEGREES AT 8 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 1008 MB
MAX SUSTAINED WINDS 25 KT WITH GUSTS TO 35 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
REPEAT...CENTER LOCATED NEAR 14.0N 37.6W AT 13/1500Z
AT 13/1200Z CENTER WAS LOCATED NEAR 14.0N 37.2W
FORECAST VALID 14/0000Z 14.0N 39.1W
MAX WIND 25 KT...GUSTS 35 KT.
FORECAST VALID 14/1200Z 14.2N 41.3W
MAX WIND 25 KT...GUSTS 35 KT.
FORECAST VALID 15/0000Z 14.4N 43.9W
MAX WIND 25 KT...GUSTS 35 KT.
FORECAST VALID 15/1200Z 14.8N 46.6W
MAX WIND 25 KT...GUSTS 35 KT.
FORECAST VALID 16/1200Z 16.0N 52.5W
MAX WIND 25 KT...GUSTS 35 KT.
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 225 NM
ON DAY 4 AND 300 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY
OUTLOOK VALID 17/1200Z 18.5N 59.5W
MAX WIND 25 KT...GUSTS 35 KT.
OUTLOOK VALID 18/1200Z 22.0N 66.0W
MAX WIND 25 KT...GUSTS 35 KT.
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 14.0N 37.6W
NEXT ADVISORY AT 13/2100Z
$$
FORECASTER BEVEN
The didn't discontinue it.
I just saw the shear map, it's under 5-10 knots of wind shear.. This may allow slow development afterall.
WITH ISOLATED SHOWERS AND THUNDERSTORMS...TOO FEW TO GET A DATA-T
NUMBER USING THE DVORAK TECHNIQUE. SSMI/DATA AT ABOUT 09Z
SUGGESTED 25 KT WINDS IN THE NORTHERN SEMICIRCLE...AND THAT IS USED
AS THE INITIAL INTENSITY. SSM/I AND AMSR-E PRECIPITABLE WATER
IMAGERY SUGGESTS THAT A TONGUE OF DRIER AIR HAS WRAPPED ALMOST ALL
THE WAY AROUND THE CIRCULATION...AND WATER VAPOR IMAGERY SHOWS
MID/UPPER-LEVEL DRY AIR IN THE VICINITY OF THE DEPRESSION. THESE
FACTORS...COMBINED WITH ABOUT 15 KT OF EASTERLY VERTICAL WIND
SHEAR...MAY BE PREVENTING THE SYSTEM FROM MAINTAINING ORGANIZED
CONVECTION.
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT
48 HR. SATELLITE IMAGERY INDICATES THAT ONLY A FEW SHOWERS AND
THUNDERTSTORMS ARE ASSOCIATED WITH THE DEPRESSION...AND IF THIS
TREND CONTINUES THE SYSTEM COULD DECAY TO A REMNANT LOW PRESSURE
AREA LATER TODAY.
just look at 850mb 7ooMB and 500MB vorticity 90L is very well stacked and has strong vorticity if this keeps up code red at 2 and TD 03 soon within the next 2 advisories after that.
TTAA00 KNHC DDHHMM
BULLETIN
TROPICAL DEPRESSION TWO ADVISORY NUMBER 10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
1100 AM AST THU AUG 13 2009
...DEPRESSION REMAINS WEAK AND POORLY ORGANIZED...
AT 1100 AM AST...1500 UTC...THE CENTER OF TROPICAL DEPRESSION TWO
WAS LOCATED NEAR LATITUDE 14.0 NORTH...LONGITUDE 37.6 WEST OR ABOUT
885 MILES...1425 KM...WEST OF THE SOUTHERNMOST CAPE VERDE ISLANDS.
THE DEPRESSION IS MOVING TOWARD THE WEST NEAR 9 MPH...14 KM/HR.
THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF
DAYS WITH A GRADUAL INCREASE IN FORWARD SPEED.
MAXIMUM SUSTAINED WINDS ARE NEAR 30 MPH...45 KM/HR...WITH HIGHER
GUSTS. LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT
48 HR. SATELLITE IMAGERY INDICATES THAT ONLY A FEW SHOWERS AND
THUNDERTSTORMS ARE ASSOCIATED WITH THE DEPRESSION...AND IF THIS
TREND CONTINUES THE SYSTEM COULD DECAY TO A REMNANT LOW PRESSURE
AREA LATER TODAY.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.
...SUMMARY OF 1100 AM AST INFORMATION...
LOCATION...14.0N 37.6W
MAXIMUM SUSTAINED WINDS...30 MPH
PRESENT MOVEMENT...WEST OR 270 DEGREES AT 9 MPH
MINIMUM CENTRAL PRESSURE...1008 MB
THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 PM AST.
$$
FORECASTER BEVEN
NNNN
Right on cue!
New blog entry.
5pm maybe the breaker unless it continues this recent trend of progress.
http://www.daughtersoftiresias.org/buoygraph/product/pressure_change_large.jpg
Probably a mid level entity at present, but it bears watching since it is close to any significant populated land mass. The area aprox. 21-23 north & 68-69 west
sorry for repost, got lost in the transition to new blog
Just an observation and something that may need to be monitored a little more closely. Watching quite a few satelite images and loops for the last few hours. AOI just to the east of the SE Bahamas is showing more signs of circulation and much more convection quickly.
Probably a mid level entity at present, but it bears watching since it is close to any significant populated land mass. The area aprox. 21-23 north & 68-69 west
I concur there appears to be a rough circulation along the north coast of Cuba at about 23N, 85W. Even a little burst right in the middle of it.
Another model
No telling when I'll turn it off. Find me and my videos / animations on YouTube.
Best Wishes everyone! :)
CycloneOz - Out...
/lurk mode now on
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