TD 8 forms; 97L a potential threat to the Caribbean and U.S.
Tropical Depression Eight formed last night near the coast of Honduras, and is headed westwards towards a landfall in Belize on Saturday. TD 8 is a small storm, so will impact a relatively small area of northern Honduras, northern Guatemala, all of Belize, and southern portions of Mexico's Yucatan Peninsula. TD 8 has just enough room between its center and the coast of Honduras to intensify into a moderate strength tropical storm with 50 - 60 mph winds before landfall. It is very unlikely TD8 has the time or room to intensify into a hurricane; NHC gave the storm just a 7% chance of making it to hurricane strength in their 11am EDT wind probability forecast. Should TD8 make it to tropical storm strength, it would be called Harvey.
Figure 1. Morning satellite image of TD 8.
Invest 97L likely to become a tropical storm next week, could threaten the U.S.
A tropical wave near 14°N 48°W, about 800 miles east of the Lesser Antilles Islands, is moving westward near 20 mph. This wave, designated Invest 97L by NHC yesterday, has seen a marked increase in its heavy thunderstorm activity this morning, but dry air to the north and west is slowing development. An impressive amount of large-scale spin is obvious in visible satellite loops, but the storm is at least a day away from forming a well-defined surface circulation. Ocean temperatures are about 28.5°C, about 2°C above the threshold needed to support a tropical storm, and wind shear is low, 5 - 10 knots.
Figure 2. Morning satellite image of the tropical wave 97L.
The computer models have shown an unusual amount of agreement in developing 97L over the past few days, and all the ingredients seem to be in place for a tropical storm to form by Monday or Tuesday as 97L crosses the Northeast Caribbean. The atmosphere is expected to be moister over the Caribbean, wind shear will remain a low 5 - 10 knots, and sea surface temperatures will increase to near 29°C. The main impediment for development will likely be two-fold: too much dry, stable air, and proximity to land.
As seen in Figure 3, there has been an unusual amount of dry, stable air in the Atlantic this year, due to a combination of dry air from Africa, and upper-atmosphere dynamics creating large areas of sinking air that dry as they warm and approach the surface. This stable air has been largely responsible for the fact that none of our seven tropical storms so far this year has made it to hurricane strength, despite the presence of sea surface temperatures that are the 3rd warmest on record across the tropical Atlantic. Tropical Storm Emily in early August encountered problems with dry air when it crossed the Northeast Caribbean, and 97L may have similar difficulties.
Figure 3. Vertical instability of the atmosphere during 2011 in the Caribbean (left) and tropical Atlantic between the Lesser Antilles Islands and coast of Africa (right.) The instability is plotted in °C, as a difference in temperature from near the surface to the upper atmosphere. Thunderstorms grow much more readily when vertical instability is high. Observed vertical instability (blue line) has been much lower than the climatological average from previous years (black line), due to an unusual amount of dry air in the atmosphere, inhibiting tropical storm development this year. Image credit: NOAA/CIRA.
Encounters with land will be another potential major problem for 97L. Most of the computer models take 97L near or over Puerto Rico Sunday night, then very close to or over mountainous Hispaniola Monday night through Tuesday. It is unlikely that 97L will be stronger than a 55 mph tropical storm when it encounters these islands, and passage over the islands could severely disrupt the storm. However, if 97L takes a path just south or north of Hispaniola, the potential exists for the storm to intensify into a hurricane.
There will be moderate wind shear of 10 - 20 knots to the north of the islands early next week, so a path just to the south of the Dominican Republic and Haiti would be more likely to let 97L intensify into a hurricane. A west-northwest motion is likely for 97L through Wednesday, which would bring the storm to the vicinity of Jamaica-Central Cuba-the Central Bahamas on Wednesday. On Wednesday and Thursday, the models agree that a trough of low pressure will dip down over the Eastern U.S., which is likely to turn 97L to the north. The exact timing and strength of this trough varies considerably from model to model, and will be critical in determining where and when 97L will turn to the north. The best model for predicting the timing and strength of such troughs over the past two years has been the ECMWF (European Center model), and this model currently brings 97L into the Florida Keys on Thursday night next week. You can view ECMWF forecasts on our wundermap with the model layer turned on. The European Center does not permit public display of tropical storm positions from their hurricane tracking module of their model, so we are unable to put ECMWF forecasts on our computer model forecast page that plots positions from the other major models.
Remember that a 7-day forecast by even our best model will be off by an average of over 700 miles, so it is too early to tell what part of the U.S. might be most at risk from a strike by 97L. This weekend would be a good time to go over your hurricane preparedness.
Figure 4. Morning satellite image of Invest 98L off the coast of Africa.
Invest 98L near the coast of Africa
A tropical wave near the coast of Africa, a few hundred miles southeast of the Cape Verde Islands, is moving west to west-northwestward at 10 - 15 mph. This wave, designated Invest 98L by NHC yesterday, is large and well-organized, with a modest amount of spin and heavy thunderstorm activity. 98L will bring strong, gusty winds and heavy rains to the Cape Verde Islands today and Saturday as the storm skirts to the south. So far this morning, top sustained winds measured in the islands were 24 mph at Mindelo. Water temperatures are warm, near 27 - 28°C, and wind shear is low, 5 - 10 knots, so 98L should continue to organize today. NHC gave the storm a 50% chance of developing into a tropical depression in their 8am advisory. Once 98L passes to the west of the Cape Verde Islands, it has a long stretch of ocean to cross before it could affect any other land areas. Approximately 70 - 80% of all tropical cyclones that pass this close to the Cape Verde Islands end up curving out to sea and not affecting any other land areas, according to Dr. Bob Hart's excellent historical probability of landfall charts. The latest set of long-range model runs go along with this idea, but it is too early to be confident of this.
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 — Blog Index
So this doesn't bode well for a Hispainola strike and leads more to the agreement of a south track under Hisp & Cuba and then North into the gulf/fl?
OK, this is all a big joke, right? Right?
Ditto That!
Brilliant.
Got to LOVE it.
LOL, too funny
starting at TX is 5 points LA 30 points MS and AL 50 points
and FL 100 points so whats see where the mode runs end up this sould be fun
whats the gussing game start
If this scenario plays out it could definitely be a trouble maker for the northeast. They have recently received too much rain. With the ground already saturated those guys could be looking at some flooding issues depending on the speed of the system after landfall!!
The flare up of convection seen during the early morning hours is known as diurnal maximum.
And I think I may be a troll. Not sure yet.
Hes a pretty cool blogger, but he can sometimes get a little troll obsessed, He doesnt give trolls any chance, I cant blame him. Shall we get back to Harvey and 97,98,99,Fernanda, Greg.
right right
You don't need to be concerned yet. It is still too early to know so relax and stay tuned. First dont rely 100 percent in those models they will shift from left to right and back before the system show a definite center which they need to be properly initialized. Yesterday runs where showing that texas LA impact you mention, Today the models are predicting an impact over the extreme east Gulfcoast. Does it mean we here in Mississippi and there where you are in Texas or Lousiana are in clear? the answer is no, but it is a waste of energy to panic about this at this point. As a matter of fact even if you were in the middle of the cone for a Katrina like event, it is pointless and a waste of energy to panic. Stay tuned to this site and enjoy the ride. A few days from now the news will start picking up on this so stay tuned to them as well when it happens but just as efore dont base your plans on their info and do not panic. Only follow NHC and your local emergency management agency advisories to make plans, but as before without panicking. Especially in your delicate condition.
2am 8am 2pm 8pm is the two
Don't worry, someone will let you know.
Next two is at 2AM
Harvey skirting the coast tonight.
Just asking, thanks for the answer I am trying to figure out the bloggers... Thanks for the reply
Troll car like the ISUZU D-MAX will allow you to drive through the tough roads of the highlands of Iceland with a variety of cargo.
http://www.elvesandtrolls.com/CARRENTAL/troll-car s/Booking/3/isuzu-d-max
I just spilled/spit beer all over my keyboard.
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.3
Tropical Cyclone Intensity Algorithm
----- Current Analysis -----
Date : 20 AUG 2011 Time : 014500 UTC
Lat : 16:36:36 N Lon : 85:25:24 W
CI# /Pressure/ Vmax
3.5 / 993.0mb/ 55.0kt
Final T# Adj T# Raw T#
3.1 3.5 3.7
A troll is a person who makes inflammatory comments just to get a reaction, in this blog there are a few chronic trolls who come back again and again making remarks designed to get the people here all riled up.
DMAX is diurnal maximum, it's the period of time when the atmosphere has cooled enough to provide maximum growth for thunderstorms. There is also a DMin when the opposite happens, i.e. the atmosphere is more stable and thunderstorms are a minimum. Mature storms are not affected much, but invests and depressions and even weak tropical storms can have dramatic changes due to this cycle.
Thank you. That is exactly what I was looking for. And it is good to see no ominous comments about was coming from the east. Again thanks.
would you like me too ander that for you lol
All the highest cloud tops in W CONUS look like 93s, especially that one in KS.
Ok, well that explains it...
Link
Hope this link/graphic works... have not tried to post one before :o)
No problem, I'm happy to help out a fellow blogger anytime.
yes...Taz runs the blog....don't mess with him....he has powers to make people...well....evaporate...
thats even better
i pick LA on the gfs
lol
Development has always been expected to be slow, and the track through the eastern Caribbean largely depends on where a surface center finally develops with 97L. It's very large, and thus the center could form anywhere within a bulky region.
My Gardens happy now!
It works. :)
Yup I'm sure they will. Lots of different opinions on here fur shure man.
Mobile, AL LOL
Viewing: 2651 - 2701
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 — Blog Index