Disturbance 90L close to tropical depression strength; TD 2 may rise again
A strong tropical wave (90L), with a large circulation and a moderate amount of heavy thunderstorm activity, is a few hundred miles southwest of the Cape Verdes Islands, off the coast of Africa. This morning's QuikSCAT pass shows that 90L has a large circulation, but this circulation is not yet well-formed, as it is elongated along an east-west axis. Satellite imagery from the European METEOSAT satellite show that the heavy thunderstorms associated with 90L are gradually becoming better organized, with some spiral banding evident on the south side of the storm. Satellite intensity estimates from NOAA already put 90L at tropical depression strength with 30 mph winds, but the storm does not yet have a well enough formed circulation to be classified as a depression. Water vapor imagery shows that since 90L is forming several hundred miles south of the dry air of the Saharan Air Layer (SAL), the storm should not be affected by dry air and dust as much as Tropical Depression Two was. However, there is some dry air from the SAL being sucked into the circulation of 90L, and this is retarding its development.
Wind shear is moderate, about 10 - 15 knots, but is forecast to fall to the low range, 5 - 10 knots, later today. Shear is then forecast to remain low for the next five days. Sea Surface Temperatures are about 28°C, and will remain in the 27 - 28°C range the next five days. The combination of low wind shear and sufficiently warm SSTs should allow 90L to develop into a tropical depression by Saturday, and potentially reach hurricane strength by Wednesday. Most of our reliable models strengthen 90L into a hurricane by Wednesday, when the storm is expected to be near the northern Lesser Antilles Islands. One important outlier is the ECMWF model, which has 90L passing to the north of the islands, and eventually recurving out to sea east of Bermuda. The ECMWF was by far the most reliable model for forecasting hurricane tracks last year. However, all of our models are pretty unreliable going out 5 days in advance for systems that have yet to reach tropical depression strength. Once 90L becomes a tropical depression and develops a well-formed circulation, the models will have a better handle on forecasting where it will go.
Figure 1. The remnants of Tropical Depression Two (left side of image) and tropical wave 90L (right side of image).
Tropical Depression Two may come back
Tropical Depression Two died yesterday, but may rise again. Satellite loops of the remnants of the storm show that heavy thunderstorms are again attempting a comeback near the axis of what is now a tropical wave. However, dry air continues to interfere with the development of the thunderstorm activity, and moderately high wind shear of 15 - 20 knots is also inhibiting the process. Wind shear over the remnants of TD 2 is expected to remain in the moderate range, 10 - 20 knots, over the next four days. Sea Surface Temperatures (SSTs) are 27°C, but will warm to 28°C two days from now. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to the north and west that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that any re-development of the storm will be slow to occur. NHC has given the system a medium (30 - 50% chance) of becoming a tropical depression again by Sunday morning. Only one reliable model, the NOGAPS, is predicting regeneration of TD 2. The NOAA Hurricane Hunters are flying research missions into the remnants of TD 2 today and Saturday.
I'll have an update Saturday morning, or earlier, if significant developments occur.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 — Blog Index
Why hasn't he been permanently banned then?
Can someone with a better eye than mine comment on the slight rotation at roughly 67W 25N? Looks like an accumulation of water vapor starting to rotate under the Bermuda high. Vorticity maps are picking it up a well.
No humans involved, though.
(Sorry I wasn't able to post a translation earlier. I've just joined the blog and there's a 12-hour wait period before a first post).
Your guess is as good as mine...
Its almost impossible to permanently ban someone.
They just need to change their name.. or get a hotmail account.
And no, you cannot IP ban someone.. their IP changes all the time also (very few people have static IP's). The only way to make it harder is to Ban the MAC address, and even that can be spoofed.
Why do you wanna throw TX in there? lol
Just wanted to say hello!
Am looking for "AH-NA" to kind of come and go, typical for these very tiny systems. Also moving pretty fast for this latitude, doesn't make it any easier to get its act together. Not ready to write it off though, been pretty tenacious thus far.
off to work folks, back tonight.
no its a strong middle level low with a strengthening surface area of low pressure based on observations
Station LONF1 - Long Key, FL
MM DD TIME (EDT) WIND PRES TEND ATMP WTMP SAL
08 15 11:00 am S 24 G28 - - - - 30.04 +0.07 76.6 86.4 - 38.60 -
08 15 10:00 am SSE 18 21 - - - -30.01 +0.04 77.7 86.7 - 37.94 - -
08 15 9:00 am ESE 7 8 - - - - 30.00 +0.04 82.2 87.1 - 37.17 - -
08 15 8:00 am - 0 2 - - - - 29.98 +0.01 82.4 87.1 - 36.77 - -
08 15 7:00 am SE 6 7 - - - - 29.97 +0.00 82.6 87.3 - 36.76 - -
08 15 6:00 am SE 15 17 - - - - 29.96 -0.01 80.2 87.4 - 36.97 - -
08 15 5:00 am SSE 13 15 - - - -29.97 -0.01 83.7 87.8 - 38.25 - -
08 15 4:00 am SE 14 16 - - - - 29.97 -0.03 83.8 88.0 - 38.71 - -
08 15 3:00 am ESE 14 15 - - - -29.97 -0.06 84.7 88.2 - 38.58 -
Water Temp 86.4 degrees. WOW.
.CURRENTLY...
THE NORTHERN EXTENT OF A WESTWARD MOVING TROPICAL WAVE IS TRAVERSING
THE KEYS AND COASTAL WATERS. THE AXIS OF THE WAVE APPEARS TO BE
MOVING THROUGH THE LOWER KEYS AND THE FLORIDA STRAITS SOUTH OF THE
LOWER KEYS...WITH A BROAD CIRCULATION FROM AROUND 850 TO 700MB STILL
NOTICEABLE ON KEY WEST RADAR IN THE GENERAL VICINITY OF THE LOWER
KEYS. A SHEAR ZONE ALONG THE AXIS HAS BEEN EVIDENT ON KBYX RADAR
THROUGH THE MORNING...WITH NEAR SURFACE SOUTHWESTERLY WINDS OPPOSING
SOUTHEASTERLY WINDS. LOOKING AT BOTH THE KBYX AND KAMX RADARS...A
NORTHEASTWARD PROPAGATING WIND MAXIMUM FROM AROUND 2KFT TO 5KFT
SEEMS TO BE MOVING ALONG THE SHEAR LINE...WHICH MAY HAVE HELPED
INITIATE SOME OF THE STRONGER CELLS. THIS SHEAR ZONE HAS FORCED
SEVERAL VERY STRONG CELLS FROM 15 TO 40 MILES SOUTH OF THE LOWER
KEYS...INCLUDING AT LEAST THREE RELATIVELY DEEP MESOCYCLONES...
BASICALLY IN THE SAME GENERAL AREA...ONE OF WHICH TRIGGERED A MESO
ALERT. THE MESOS WERE FAIRLY SHORT LIVED...LASTING LESS THAT ONE HALF
HOUR. ALL OF THESE MESOCYCLONES WERE PRODUCING IMPRESSIVE
UPDRAFTS...WITH TOPS EXCEEDING 55KFT ABOVE THEM. THE SHEAR ZONE HAS
BEEN ALMOST STATIONARY FOR THE PAST SEVERAL HOURS...THUS THE
STRONGEST CELLS HAVE THANKFULLY REMAINED SOUTH OF THE LOWER KEYS.
EVEN WITH THE WORST SOUTH OF THE KEYS...AREAS ALONG THE LOWER KEYS
HAVE EXPERIENCED HEAVY RAIN WITHIN A RELATIVELY SHORT PERIOD OF TIME.
A SPOTTER ON CUDJOE KEY CALLED IN WITH 2 INCHES OF RAIN SINCE THE
BEGINNING OF THE EVENT EARLIER THIS MORNING. AN OFF DUTY NWS EMPLOYEE
ON BIG COPPITT KEY REPORTED ABOUT AN INCH OF STANDING WATER ON THE
LOWEST FLOOR OF HIS HOUSE...THE ACCUMULATION OF WATER POSSIBLY AIDED
BY 30MPH WINDS WHICH ACCOMPANIED THE HEAVER STORMS THAT TRAVERSED THE
LOWER KEYS.
Link
Viewing: 5651 - 5684
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61 | 62 | 63 | 64 | 65 | 66 | 67 | 68 | 69 | 70 | 71 | 72 | 73 | 74 | 75 | 76 | 77 | 78 | 79 | 80 | 81 | 82 | 83 | 84 | 85 | 86 | 87 | 88 | 89 | 90 | 91 | 92 | 93 | 94 | 95 | 96 | 97 | 98 | 99 | 100 | 101 | 102 | 103 | 104 | 105 | 106 | 107 | 108 | 109 | 110 | 111 | 112 | 113 | 114 — Blog Index