The tropics are quiet

By: Dr. Jeff Masters , 1:11 PM GMT on September 06, 2009

Share this Blog
3
+

Considering that this is historically the peak week of the Atlantic hurricane season, the tropics are quiet. There is an area of disturbed weather in the middle Atlantic (95L) that NHC has been mentioning in their Tropical Weather Outlook the past day, but this disturbance is entering a region of high wind shear and is not a threat to develop.

A strong tropical wave with plenty of rotation is emerging off the coast of Africa this morning, and this wave is a good candidate to show some development this week as it heads west-northwest over the Atlantic. The wave is under about 15 knots of wind shear, and is being developed by several models, including the GFS and ECMWF. However, the models show that this new wave will be pulled northwestward by a strong trough of low pressure this week, and it appears unlikely that the wave will make the long crossing of the Atlantic necessary to threaten any land areas. Another wave with plenty of spin will emerge from the coast of Africa two days from now, and will also have a chance to develop.


Figure 1. Morning satellite image of 95L and a new tropical wave with potential to develop, emerging from the coast of Africa.

An area of concentrated thunderstorms has developed off the North Carolina coast in association with the remains of an old cold front. This system is under about 20 - 30 knots of shear, and is not tropical. However, it will bring heavy rain just offshore of North Carolina's Outer Banks today as it slides north-northeastward along the coast.

I'll have an update Monday.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1394 - 1344

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 | 38Blog Index

1393. Patrap
00 Z 96L Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)

Member Since: July 3, 2005 Posts: 421 Comments: 127559
1392. JLPR
Quoting VAbeachhurricanes:


that sure looks like a vigorous circulation with 96L
Member Since: Posts: Comments:
Member Since: Posts: Comments:
This is what Futuremet wrote earlier.....
It looks like we will have to monitor the GOM closely during the latter part of next week, as a potent longwave trough traverses across the Midwest. The trough is expected to split and slightly troughing in southward, thus kindling upper level anticyclogenesis across the area. The anticyclone will form due to positive vorticity advection at the eastern axis of the longwave trough. Like fluids, air has a tendency to rotate at its own axis, and typically flows from areas of higher speed to lower speed. Therefore some the fast moving air moving from the southwest will start curving toward the south. This is why upper level anticyclones typically form proportionally by the area of highest winds along the trough axis. The formation of the upper ridge will help decrease wind shear values over the GOM, which will great tropical cyclone formation. Since upper level ridges do not have a pronounced effect on steering current, the longwave trough to the north will likely steer anything that forms NE. Now, I am not saying anything will form, but there is a possibility something will. This may very well be the last chance for anything to form in the GOM, before it closes down in October due to shear. The anomalously warm SSTs in the GOM will propagate southward to the Caribbean as we near the month of October. In addition, the MJO will help increase values across the Caribbean. Troughs nosing in southward will provide additional energy for tropical cyclone formation; like in hurricane Wilma of 2005. Hopefully this weak el nino will induce adequate shear to stop anything major from forming; or hopefully the troughs are so strong that the cause these storms to move ENE , like we saw in latter part of 2008 with Omar and Paloma.
Member Since: Posts: Comments:
1386. Patrap


484
fxus64 klix 070145
afdlix


Area forecast discussion
National Weather Service New Orleans la
845 PM CDT sun Sep 6 2009



Update...
..sounding discussion...


No significant problems with the flight this evening although the
balloon did burst much sooner than normal...at around 70 mb. There
was a light rain at launch today which could have contributed to
the early burst. The sounding shows what you would expect
launching into an extremely moist atmosphere with precipitable water values just
above two and a quarter inches. The sounding is moist throughout
and so it is not surprising that we have an overcast cloud deck
this evening just above the surface at 100 feet. Winds were very
light and variable throughout the first six km which led to what
amounts to a none storm motion. This was apparent during the day as
several Urban and Small Stream flood advisories were necessary due
to slow...and non-moving showers and thunderstorms. The activity
has waned this evening but a large area of showers is still
affecting a good portion of the area.


98/so

Long term...
upper trough will shift eastward for a short time on Thursday and
Friday...with diurnally driven convection on tap for those
days...scattered areal coverage expected...and slightly above
normal temperatures.


Both European model (ecmwf) and GFS are coming around to similar solutions in developing an unseasonably strong upper level system across the northern portion of the nation Saturday or Sunday.

Probability of precipitation will be elevated a little from previous days...but due to timing
differences...will keep probability of precipitation in the chance range until details
become a little more firm. 35


Member Since: July 3, 2005 Posts: 421 Comments: 127559
Quoting KATRINABILOXIGIRL:
not sure...earlier futuremet was here about 6:00 or so and said something about a trough split and possible formation from it I think...


makes sense.
Member Since: Posts: Comments:
Member Since: Posts: Comments:
Quoting truecajun:


i saw that too....in about 5 days. where does this "possibility" originate?
not sure...earlier futuremet was here about 6:00 or so and said something about a trough split and possible formation from it I think...
Member Since: Posts: Comments:
Quoting tornadodude:


first time for everything :P


LOL
Member Since: June 9, 2007 Posts: 4 Comments: 15776
Quoting KATRINABILOXIGIRL:
Hey Patrap, was skimming over the posts quickly and saw something about models showing something in the GOMEX in the future...what is up please...thanks


i saw that too....in about 5 days. where does this "possibility" originate?
Member Since: Posts: Comments:
1379. MSKajun
Quoting MiamiHurricanes09:
Am i on everybody's ignore list?






not on mine....not that that would matter to you lol
Member Since: Posts: Comments:
Quoting Stormchaser2007:

Nope their right on.


first time for everything :P
Member Since: Posts: Comments:
will the comet ever get out of the shear??
Member Since: Posts: Comments:
Hey Patrap, was skimming over the posts quickly and saw something about models showing something in the GOMEX in the future...what is up please...thanks
Member Since: Posts: Comments:
Quoting Tazmanian:
dont you think the nhc is jumping the gune on 96L a little too fast???

Nope their right on.
Member Since: June 9, 2007 Posts: 4 Comments: 15776
Weak LLC under some convection.

Member Since: June 9, 2007 Posts: 4 Comments: 15776
1373. Drakoen
Member Since: Posts: Comments:
dont you think the nhc is jumping the gune on 96L a little too fast???
Member Since: May 21, 2006 Posts: 5091 Comments: 114728
Quoting CatastrophicDL:
Hey has anyone seen CaneWarning for a while?


I haven't been on since last Wed., but I don't recall seeing him or her then.
Member Since: Posts: Comments:
Hey has anyone seen CaneWarning for a while?
Member Since: Posts: Comments:
1369. Patrap
Quoting truecajun:


Oh my! I've never heard of that one. Thank goodness I didn't have my six and 7 year old. I don't how I would have explained those images. The baby didn't know the difference! We got out of there very quickly and headed to Mandinas instead.


That was a very wise decision..LOL

..but as Kramer from Seinfeld might say,.."Not that there's anything wrong with that..?"
Member Since: July 3, 2005 Posts: 421 Comments: 127559
Quoting somemalayguy117:
The Navy issued a TCFA on 96L but still a medium potential from the NHC.


They work together, so probably red on the next TWO.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
1367. Drakoen
Member Since: Posts: Comments:
Red is likely by 2am.
Member Since: June 9, 2007 Posts: 4 Comments: 15776
Quoting Patrap:




That would be the "Southern Decadence" Festival In the French Quarter.


Oh my! I've never heard of that one. Thank goodness I didn't have my six and 7 year old. I don't how I would have explained those images. The baby didn't know the difference! We got out of there very quickly and headed to Mandinas instead.
Member Since: Posts: Comments:
Quoting Stormchaser2007:


Tropical cyclone formation alert.

WTNT21 KNGU 070201
SUBJ/TROPICAL CYCLONE FORMATION ALERT 070200Z SEP 09//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 12.6N 19.6W TO 13.0N 26.5W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.

WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 25 KNOTS. METSAT IM-
AGERY AT 070200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.6N 19.6W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 13
KNOTS.
2. REMARKS:
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 080200Z.//


one word off :(
Member Since: Posts: Comments:
Quoting tornadodude:


TCFA- Tropical Cyclone Formation Advisory?


Tropical cyclone formation alert.

WTNT21 KNGU 070201
SUBJ/TROPICAL CYCLONE FORMATION ALERT 070200Z SEP 09//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 12.6N 19.6W TO 13.0N 26.5W
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.

WINDS IN THE AREA ARE ESTIMATED TO BE 25 TO 25 KNOTS. METSAT IM-
AGERY AT 070200Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 12.6N 19.6W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 13
KNOTS.
2. REMARKS:
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 080200Z.//
Member Since: June 9, 2007 Posts: 4 Comments: 15776
Quoting BurnedAfterPosting:
3 out of 4 correct tornadodude lol

TCFA = Tropical Cyclone Formation Alert


aw! close lol
Member Since: Posts: Comments:
1360. Patrap
Quoting truecajun:


ok thanks. we just got back from New Orleans. we were trying to eat at Irene's on St. Peter, but it was too hard to get to. There were naked men running around (well only there you know whats were covered) their rears were not. What was going on? was there a festival or something?




That would be the "Southern Decadence" Festival In the French Quarter.
Member Since: July 3, 2005 Posts: 421 Comments: 127559
I got to go to bed early to catch up on my school book.

Goodnight all!
Member Since: August 9, 2009 Posts: 10 Comments: 4898
Quoting serialteg:


...looks like a comet...


Surprising we all don't - 600 kilometers per second: APOD
Member Since: Posts: Comments:
3 out of 4 correct tornadodude lol

TCFA = Tropical Cyclone Formation Alert
Should go ahead and develope but it might not make it to 40w with the trof in place.
Member Since: May 14, 2006 Posts: 8 Comments: 13626
1354. Patrap
NexSat African View,Loop 96L/a>

Member Since: July 3, 2005 Posts: 421 Comments: 127559
Quoting truecajun:
tornadodude, i see you too.


ok good
Member Since: Posts: Comments:
Quoting somemalayguy117:
The Navy issued a TCFA on 96L but still a medium potential from the NHC.


TCFA- Tropical Cyclone Formation Advisory?
Member Since: Posts: Comments:
tornadodude, i see you too.
Member Since: Posts: Comments:
The Navy issued a TCFA on 96L but still a medium potential from the NHC.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
go to the filter and click "show all"

Thanks, Miami.
Member Since: August 9, 2009 Posts: 10 Comments: 4898
Quoting Patrap:


Yes I believe that would be 96L.


ok thanks. we just got back from New Orleans. we were trying to eat at Irene's on St. Peter, but it was too hard to get to. There were naked men running around (well only there you know whats were covered) their rears were not. What was going on? was there a festival or something?
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
go to the filter and click "show all"

Thanks, Miami.
Member Since: August 9, 2009 Posts: 10 Comments: 4898
I am not up for much longer. Can someone explain to me why there is a large difference, circulation, between the QuickSat ascending and descending views. I have noticed this for a long time now that the descending pass seems to show more circulation where expected than the acending pass but I don't know why.
Thanks.
Member Since: Posts: Comments:
Hi guys! I see we have potential for a little development in the ATL this week.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Yes, that area is being monitored closely, but if anything were to form it will be subtropical or extratropical...Track wise it will just scrape along the US eastern seaboard bringing some rain to the coastal cities.



Yes, it's the front & it's early enough in the season that I don't have to worry about anything that should develop in that area retrograding.
Member Since: Posts: Comments:

Viewing: 1394 - 1344

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 | 38Blog Index

Top of Page

About

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

Local Weather

Scattered Clouds
78 °F
Scattered Clouds