Two unimpressive Atlantic disturbances to watch

By: Dr. Jeff Masters , 1:32 PM GMT on October 15, 2007

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A low pressure system (99L) that tried to organize into a tropical depression Sunday in the Western Caribbean moved inland Sunday evening over the Yucatan Peninsula before being able to do so. The system is headed west-northwest at about 10-15 mph, and should emerge over the Gulf of Mexico tonight. This morning's QuikSCAT pass showed top winds of about 25 mph to the northwest of 99L in the Gulf of Mexico. Satellite loops show only limited heavy thunderstorm activity at present. Wind shear is about 10-15 knots, and is expected to remain 10-20 knots through Tuesday afternoon. This may allow 99L to organize into a tropical depression by Tuesday night. A trough of low pressure is expected to pull 99L northwards by Tuesday night, and a landfall in Texas on Wednesday is a likely scenario. Since the storm may be moving almost parallel to the coast, it is difficult to say where in Texas landfall might occur. The trough will also bring increased levels of wind shear to 99L Tuesday night as it approaches Texas, and there is also some very dry air over the Gulf of Mexico for the storm to contend with. These factors should keep 99L from getting any stronger than a 45 mph tropical storm. I don't expect the system will become a tropical depression, and NHC does not think highly enough of 99L to bother putting the Hurricane Hunters on call to fly the storm on Tuesday. The primary threat from 99L will be heavy rain.

On Sunday afternoon, 99L gave us a lesson on why it is difficult to predict the track and intensity of a system trying to get organized into a tropical depression. The storm initially attempted to form in the extreme southwestern Caribbean (Figure 1). However, strong upper level winds from the northeast were creating about 15 knots of wind shear here. When a new burst of heavy thunderstorms developed underneath an upper level anticyclone with very low wind shear (Figure 2), the center of 99L reformed there, jumping over 100 miles to the north-northwest.


Figure 1. Satellite image of 99L Sunday afternoon, showing the old center in the southwest corner of the Caribbean Sea, which strong wind shear due to upper-level northeasterly winds had exposed to view. A new center formed to the north-northwest of the old center. Image credit: NASA/MSFC.


Figure 2. Wind shear map of 99L Sunday afternoon, showing that wind shear was 15 knots over the old center in the southwest corner of the Caribbean Sea. The new center developed to the north-northwest of the old center, in a region where wind shear was only 5 knots. Image credit: University of Wisconsin CIMSS group.

Tropical wave approaching Nicaragua
A tropical wave (98L) in the southern Caribbean will move ashore over Nicaragua and Honduras later today. This morning's QuikSCAT pass showed no circulation and top winds of only 25 mph. The system is under about 25 knots of wind shear, and no development is expected before the system makes landfall. The center will remain over land the next two days, spreading heavy rains across Nicaragua and Honduras today, then into Mexico, Guatemala, and Belize on Tuesday.

I'll have an update Tuesday morning, and present my hurricane season outlook for the remainder of October.

Jeff Masters

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985. sporteguy03
11:24 AM GMT on October 17, 2007
Old blog rules!
Member Since: July 7, 2005 Posts: 0 Comments: 5417
984. cattlebaroness
3:12 PM GMT on October 16, 2007
Morning yall. Just a reminder that Patrap is suppose to have his surgery today. Might want to drop him a note on his blog. I believe his wife is passing on our good thoughts for a speedy recovery.
983. icmoore
2:59 PM GMT on October 16, 2007
The Times-Union In Jacksonville,FL has an article on the front page of the Lifestyle section about buoys and how they track storms.They talk about how this year is a shake down test and they will retrieve this buoy in December for further data testing.The project cost $945,000. Of course hoping to improve intensty forecasting,etc.
Member Since: July 18, 2005 Posts: 9 Comments: 4147
982. gulfbreezewill
2:56 PM GMT on October 16, 2007
Oh yes, let it rain, let it rain......Whoever that was that put up Grace Kelley's photo yesterday offering a rain dance to the gods did the trick, we are getting some steady down pours here the panhandle........now if it could stick around for a day or two........
981. Floodman
2:54 PM GMT on October 16, 2007
Has anyone noted the very large area of spin at 16N78W? Is that upper level?
Member Since: August 2, 2006 Posts: 10 Comments: 9922
980. V26R
2:53 PM GMT on October 16, 2007
New Blog is up guys
Member Since: July 20, 2006 Posts: 0 Comments: 1762
979. BajaALemt
2:52 PM GMT on October 16, 2007
Doesn't EVERY good Yankee Redneck have an outhouse?
Member Since: September 25, 2007 Posts: 53 Comments: 8533
978. BajaALemt
2:51 PM GMT on October 16, 2007
They mentioned that in the area forecast this morning, JP..minimal risk here, tho
Member Since: September 25, 2007 Posts: 53 Comments: 8533
977. TampaSpin
2:51 PM GMT on October 16, 2007
972. Bonedog 2:49 PM GMT on October 16, 2007
closest 80knt shear on the map is over the TN valley LOL


Heck that would blow the outhouses over in Jersey....LMAO
Member Since: September 2, 2007 Posts: 179 Comments: 20448
975. V26R
2:50 PM GMT on October 16, 2007
Okay so I was reading it correctly
Thats where I saw it Bone
Member Since: July 20, 2006 Posts: 0 Comments: 1762
974. SamTeam
2:50 PM GMT on October 16, 2007
New Blog!
Member Since: September 22, 2007 Posts: 0 Comments: 213
972. Bonedog
2:49 PM GMT on October 16, 2007
closest 80knt shear on the map is over the TN valley LOL
Member Since: July 14, 2005 Posts: 14 Comments: 7418
971. BajaALemt
2:49 PM GMT on October 16, 2007
I saw 50's to the north *shrugs*
Member Since: September 25, 2007 Posts: 53 Comments: 8533
970. TampaSpin
2:49 PM GMT on October 16, 2007
Taz must have been up drinking all nite in Califorina. I don't see any 80kt shear in the GOM.......lol
Member Since: September 2, 2007 Posts: 179 Comments: 20448
969. V26R
2:48 PM GMT on October 16, 2007
JP I was just looking at the Map Taz just posted and couldn't find 80k shear either, thought maybe I was reading it wrong
Max I could find over GOM was @20k
Member Since: July 20, 2006 Posts: 0 Comments: 1762
968. Bonedog
2:46 PM GMT on October 16, 2007
No Name the blob has detached yes but doest appear to be amounting to anything. Not much in the way of favorable conditions to it.
Member Since: July 14, 2005 Posts: 14 Comments: 7418
967. TampaSpin
2:46 PM GMT on October 16, 2007
StormW those are 2 great links.....but with that much reading, i just as well go back to school......lol
Member Since: September 2, 2007 Posts: 179 Comments: 20448
966. V26R
2:46 PM GMT on October 16, 2007
WOW what a mess Baja
Member Since: July 20, 2006 Posts: 0 Comments: 1762
965. BajaALemt
2:45 PM GMT on October 16, 2007
it IS!! lol
Member Since: September 25, 2007 Posts: 53 Comments: 8533
964. BajaALemt
2:44 PM GMT on October 16, 2007
Link
Member Since: September 25, 2007 Posts: 53 Comments: 8533
962. sporteguy03
2:41 PM GMT on October 16, 2007
Taz,
Hows your day in California any snow yet?
Member Since: July 7, 2005 Posts: 0 Comments: 5417
961. Floodman
2:41 PM GMT on October 16, 2007
You got that right, JP...
Member Since: August 2, 2006 Posts: 10 Comments: 9922
960. NoNamePub
2:40 PM GMT on October 16, 2007
Are my posts getting Through?

Did the Bahamas Blb Seperate from the front?
Member Since: July 13, 2007 Posts: 0 Comments: 530
959. BajaALemt
2:39 PM GMT on October 16, 2007
Welp, that was LAST NITE...lol. Thanks goodness for a new day (clean slate)
Member Since: September 25, 2007 Posts: 53 Comments: 8533
958. Tazmanian
2:39 PM GMT on October 16, 2007
G'morning all now i am off to work
Member Since: May 21, 2006 Posts: 5091 Comments: 115456
956. Floodman
2:38 PM GMT on October 16, 2007
Wow...it's truly dead in the ATL. This has been one strange season...kind of like 1931...few majors, and a lot of short-lived systems
Member Since: August 2, 2006 Posts: 10 Comments: 9922
955. Bonedog
2:38 PM GMT on October 16, 2007
your welcome Baja
Member Since: July 14, 2005 Posts: 14 Comments: 7418
954. BajaALemt
2:37 PM GMT on October 16, 2007
G'mornin Mr Taz
Member Since: September 25, 2007 Posts: 53 Comments: 8533
953. nrtiwlnvragn
2:37 PM GMT on October 16, 2007
TD15E in the east pacific is now TS Kiko.
Also, the 8:00 am update on 99L has wind speed up to 25kt.


Kiko

99L
Member Since: September 23, 2005 Posts: 15 Comments: 11346
952. V26R
2:36 PM GMT on October 16, 2007
Baja you really hit the nail on the head especally last nights fiasco
Member Since: July 20, 2006 Posts: 0 Comments: 1762
950. Tazmanian
2:36 PM GMT on October 16, 2007
wind shear is 80kt in the gulf go out and in joy your day

Link
Member Since: May 21, 2006 Posts: 5091 Comments: 115456
949. NEwxguy
2:36 PM GMT on October 16, 2007
935. BajaALemt 2:31 PM GMT on October 16, 2007
AND...you guys are SO MUCH MORE interesting to listen to ANYWAY!!!!

AWW,Shucks!!!!
Member Since: September 6, 2007 Posts: 888 Comments: 15989
947. BajaALemt
2:35 PM GMT on October 16, 2007
I hear ya Bone. Like I was saying yesterday. If I dont hit the ball back, the tennis game's over. I come here because I really like listening to you guys...and I learn alot listening to you (thanks, btw)
Member Since: September 25, 2007 Posts: 53 Comments: 8533
946. V26R
2:35 PM GMT on October 16, 2007
Storm those are two great links gonna read them tonight instead of reading the Nite Stuff here
Thanx!
Member Since: July 20, 2006 Posts: 0 Comments: 1762
945. TEXASYANKEE43
2:35 PM GMT on October 16, 2007
I wonder where the good Dr M's update is this AM?
943. Bonedog
2:34 PM GMT on October 16, 2007
Thanks StormW for the info. I have that link in my favs. Just havent made it through the severe chapters yet. LOL

I appreciate the few moments you took to explain what to look for.
Member Since: July 14, 2005 Posts: 14 Comments: 7418
942. NoNamePub
2:34 PM GMT on October 16, 2007
Hey all -
Bahamas Blob seems to be seperating from the front...and convection is getting going...
Thoughts?
Member Since: July 13, 2007 Posts: 0 Comments: 530
941. Winterstormsblog
2:34 PM GMT on October 16, 2007
There is still time to enter the NYC snowfall contest! Come to my blog and check it out.
Member Since: October 5, 2007 Posts: 86 Comments: 5650
940. icmoore
2:33 PM GMT on October 16, 2007
Good morning ,Flood.
Member Since: July 18, 2005 Posts: 9 Comments: 4147
939. V26R
2:33 PM GMT on October 16, 2007
Morning Flood
Member Since: July 20, 2006 Posts: 0 Comments: 1762
938. BajaALemt
2:32 PM GMT on October 16, 2007
g'mornin Flood
Member Since: September 25, 2007 Posts: 53 Comments: 8533
937. NEwxguy
2:32 PM GMT on October 16, 2007
morning,Flood
Member Since: September 6, 2007 Posts: 888 Comments: 15989
936. Bonedog
2:32 PM GMT on October 16, 2007
BajaALemt. Your so right. Thats also why I have such an extensive list. At the first signs of bait I add them. At least I dont have to see the bickering that way.
Member Since: July 14, 2005 Posts: 14 Comments: 7418
935. BajaALemt
2:31 PM GMT on October 16, 2007
AND...you guys are SO MUCH MORE interesting to listen to ANYWAY!!!!
Member Since: September 25, 2007 Posts: 53 Comments: 8533

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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