INVEST 90L: Gulf of Mexico : Gone from NRL

[Ed Mahmoud]

Well, a few meager storms near the low level center, but -40 to -50ºC tops don't suggest rip-roaring convection.

[Ed Mahmoud]

Will someone tell me why this thing is going SW Louisiana? Is the trough over the mid US strong enough? Don't disagree with the models or the boggy man will get you

Boogy, not boggy.

Hey, just based on climatology, I knew this (probably) wasn't coming to Texas when the models did aim it at your house in Corpus Christi.

But the trend is your friend, if the models keep trending away form one solution and towards another, one has to wonder why.

[Buck]

It's definitely looking like we'll break the Subtropical formation record this year.

[cycloneye]

TASKING FOR 03/1800Z AND 04/0600Z,1200Z ON THIS
AREA CANCELLED AT 03/1200Z.

http://www.nhc.noaa.gov/text/MIAREPRPD.shtml?

Recon canceled for today and tommorow.

[tailgater]

Looks like it's will pulse up shortly. low level circ. starting to pull in some more tropical air from the south and shear dropping but still lots of cold dry air aloft to the north and west.

[Sanibel]

Looks like it took a hard right towards the north Gulf coast. The lower level is nice and organized because of Loop Current influence. It just isn't strong enough to cook up the upper with a tropical core just yet. It will be interesting to see if this will rapidly develop like Humberto or not because it is over the central Gulf.

Woke up to a good pool in the back yard -Finally!- The south flow behind 90L must have had a 2-3 inch train last night.

[HouTXmetro]

TASKING FOR 03/1800Z AND 04/0600Z,1200Z ON THIS
AREA CANCELLED AT 03/1200Z.

http://www.nhc.noaa.gov/text/MIAREPRPD.shtml?

Recon canceled for today and tommorow.

lol, nothing to see here... Move along

[rockyman]

Although there is less convection today, the low-level center seems (based on visible loops) to be a lot more defined this morning than yesterday.

[mightyerick]

TASKING FOR 03/1800Z AND 04/0600Z,1200Z ON THIS
AREA CANCELLED AT 03/1200Z.

http://www.nhc.noaa.gov/text/MIAREPRPD.shtml?

Recon canceled for today and tommorow.

That hurts!!! I was expecting the Tropical storm Noel!!!

[dwg71]

Chance of getting a name, less than 10% imo. I really dont expect much rain from it here in SETX.

[Steve]

Agreed rockyman. It isn't much, but visible confirms the swirl at the 1005mb low.

http://www.ssd.noaa.gov/goes/flt/t1/loop-vis.html

Doesn't look like much, but we've got between 36-48 hours to see if anything can get going. Early cycle 12z guidance (BAM suite, LBAR, CONU) shows a LA/MS hit. If it's intensifying tomorrow at landfall as all the western gulf storms have done or not remains to be seen.
http://euler.atmos.colostate.edu/~vigh/ ... early1.png

Steve

[BigA]

That hurts!!! I was expecting the Tropical storm Noel!!!

As I said when they took the INVEST off the last 90L in the Gulf, the NHC and NRL do not decide whether or not a storm will form. Their decision to not fly recon will not cause 90L to form or not form. That said, it needs to fire convection before it becomes anything.

[Chacor]

TASKING FOR 03/1800Z AND 04/0600Z,1200Z ON THIS
AREA CANCELLED AT 03/1200Z.

http://www.nhc.noaa.gov/text/MIAREPRPD.shtml?

Recon canceled for today and tommorow.

That hurts!!! I was expecting the Tropical storm Noel!!!

Ugh, stop -removed- already.

———————————————————————

SHOWER ACTIVITY WITH THE NON-TROPICAL AREA OF LOW PRESSURE IN THE
GULF OF MEXICO HAS BECOME LESS ORGANIZED TODAY...AND THE
RECONNAISSANCE AIRCRAFT MISSION SCHEDULED FOR THIS AFTERNOON HAS
BEEN CANCELLED. HOWEVER...THIS SYSTEM STILL HAS SOME POTENTIAL TO
EVOLVE INTO A TROPICAL OR SUBTROPICAL DEPRESSION DURING THE NEXT
DAY OR TWO AS IT MOVES TO THE WEST-NORTHWEST OR NORTHWEST AT ABOUT
10 MPH.

[mightyerick]

TASKING FOR 03/1800Z AND 04/0600Z,1200Z ON THIS
AREA CANCELLED AT 03/1200Z.

http://www.nhc.noaa.gov/text/MIAREPRPD.shtml?

Recon canceled for today and tommorow.

That hurts!!! I was expecting the Tropical storm Noel!!!

Ugh, stop -removed- already.

i am just a met student. everything i can do is that!!!!

[Thunder44]

TASKING FOR 03/1800Z AND 04/0600Z,1200Z ON THIS
AREA CANCELLED AT 03/1200Z.

http://www.nhc.noaa.gov/text/MIAREPRPD.shtml?

Recon canceled for today and tommorow.

They only cancelled the flight going out early tomorrow morning. They scheduled more beginning tomorrow afternoon for this system:

I. ATLANTIC REQUIREMENTS
1. SUSPECT AREA (GULF OF MEXICO)
FLIGHT ONE --TEAL 70
A. 04/1600Z
B. AFXXX 01LLA INVEST
C. 04/1500Z
D. 27.0N 91.0W
E. 04/1530Z TO 2130Z
F. SFC TO 10,000 FT

FLIGHT TWO --TEAL 71
A. 05/0600Z,1200Z
B. AFXXX 02LLA CYCLONE
C. 05/0400Z
D. 29.0N 92.5W
E. 05/0500Z TO 1200Z
F. SFC TO 10,000 FT

[Sanibel]

The lower level is better organized. It just isn't strong enough to bring all that upper dry business to tropical (like TD10). The Loop Current does wonders for storms. Sometimes it is slow to react.

[Ed Mahmoud]

This will be lucky to be a sub-tropical depression at landfall, and my lawn will be on the Western side of the circulation, ie, dry.


Maybe the parent ULL might give the lawn some needed showers.

[MGC]

90L is currently under some dry air that is limiting convection. It does have a very good circulation which appears to be moving slowly northward. I don't see much happening here today but perhaps by tomorrow conditions will improve some.....MGC

[HURAKAN]

[Steve]

Here's a copy and paste from T. Scott Barry's e-mail generated last night in the wee hours if anyone is interested:

October 3, 2007
this Wednesday morning
317 AM CDT


* * * Tropical low pressure development, again looking likely today through Thursday in the Gulf of Mexico; a threat to Louisiana's coast Thursday night - Friday * * *


* * * A Tropical Storm watch issuance is probable on the Louisiana coast by Thursday, including Southeast Louisiana, the way it looks to me * * *


* * * 3 - star writing * * *



I. Foreward.


Similar to 11 days ago, when a tropical depression formed, here's another one in the Gulf of Mexico to keep an eye on. As of these early pre-dawn Wednesday morning hours, there is not a classified tropical depression or storm...just yet. I think this will change and gradual development will take place today or tomorrow on Thursday and we'll likely see a tropical depression or storm later develop.


Our forecasting problems at the current moment, this morning, center around the center---(?)--- What this means is that I have spotted at least 2 smaller vortices overnight on Tuesday night spinning within an embedded very large, and slow-spinning low pressure circulation. This makes tracking most difficult, when the REAL parent center cannot be located. This is because we just don't know WHICH of the 2 smaller low-pressures will spin-up and become the dominant one to ultimately track. There's one in the Southeast Gulf of Mexico, and there's another one in the Eastern Gulf of Mexico, northeast of it. If the one further north is the one that spins-up, then I think that most likely it will be a Southeast Louisiana threat again. In the event the southern one in the Southeast Gulf spins up, then South-Central Louisiana will be the threat. I just doubt that it will make it as far west as Texas, before turnin g north.


The timing impacts for Southeast Louisiana appear to come late Thursday and Friday. As far as the homework I've done, the earliest time for a Louisiana landfall will be Thursday night. I believe that the tracking guidance looks way off base as I've reviewed the 00Z 10/3 Tuesday night tracks. They appear too far west. I favor more of a Louisiana impact, than Texas. This won't be a significantly harmful threat, the way I see it; just a bit of some rain and few breezes by the end of the week. But I'll need to keep up on it, (and so do you.)


The strength should graduate to a weak tropical storm on this go around, barring no early displacements of a re-located center much further northeast as in last time. However, I don't think this will get to be anything out of control, nor anything major. My thinking is that it will graduate to a weak tropical storm.


II. Tracks and my adjustments.


From one suite of multiple trajectory forecast tracks that came in overnight, shows what I think to be too many tracks into Texas, or near the mouth of the Sabine River along the border. The cluster takes a landfall anywhere between Southwest Louisiana to the middle Texas coastline. I feel that those tracks should be adjusted more eastward into Louisiana, and even Southeast Louisiana; I'll get into why later.


There are another spread of tracks that have greater diversity. A couple tracks go as far east as South-Central and Southeast Louisiana, and other tracks as far west as the mid-to-upper Texas coastline.


So, in summary, the spread of tracks vary from the Southeast Louisiana coast to the mid-Texas coast. This is too much spread for a 60-hour, Friday morning forecast.


III. Forecasting strength.


There are 5 indicators showing a tropical storm will develop, and there are 3 indicators showing only a tropical depression will ensue either today or by tomorrow, Thursday. This is a very similar synoptic situation as 11 days ago. A surface low is there. In fact, I see a couple of lows, nested within a large area of existing low pressure. It is likely that your NHC will have to RE-LOCATE a surface low in the Gulf of Mexico, one that is further south in the South-Central Gulf of Mexico, and another in the East-Central Gulf of Mexico, to the northeast of the southern one. But they'll have to ultimately decide which ONE is the parent low to track, with help of the surveillance aircraft. Only atmospheric dynamics and thermodynamic processes will determine which one will be the dominant one. This will play out on satellite imagery today.


This bubbles down to whichever one has the greater amount of PERSISTENT showery weather gathered around the center, and whose central pressure is lower than the other as well. In the event a more northern re-location occurs, then tracks shift significant east as in the central Gulf of Mexico coast; Louisiana; MS/AL. The further south it is, then probably more of a South-Central Louisiana threat.


One comforting factor I seen, is that there is forecast to be pockets of drier air surrounding the area that the low pressure it will be drawing upon which is not a benefactor for strong development, but gradual development still remains distinct, I believe. But a benefactor to compensate will be minimal shear that's forecast. In fact, I see that there is forecast to be two outflow channels to the southwest and northeast of proposed center. Upper level outflow channels help to spin-up a surface low at the lower levels.


The one general similarity in this forecast of this tropical low, is that nearly all the guidance I've reviewed indicates that it will weaken BEFORE reaching the coast. The low pressure "fills" is the correct term used.


Adding to this, the rainfall configurations show less, and less rainfall as time goes on, indicating a decaying cycle just prior to reaching the coastline.


'Tis is the season for sub-tropical storms. You've seen this language before. But what are the effects on a sub-tropical storm, vs. a tropical storm? A sub-tropical storm is one whose sensible effects of squalls and wind gusts extend a few or even several hundred miles AWAY from the center. A tropical storm has the winds and squalls much more closely to the center, either on the center, or a short distance as in 50 - 100 miles away in a sheared storm.


IV. Effects.


The effects on Southeast Louisiana is most contingent on which side it passes or onto. From the rainfall patterns, it looks like it shouldn't be a large area it blankets with rain; again, real similar to last time, 11 days ago. Best timing for rain in Southeast Louisiana may begin as soon as Thursday, with another shot of rain, a day later on Friday of this week.


Winds slowly increase and in the coastal waters will become 20 - 30 mph should be commonplace in the coastal waters with gusts going to 35 mph, particularly if it's a sub-tropical depression. These winds should start from the northeast on Wednesday, a drainage wind for south-facing coastlines except Lk. Pontchartrain; then easterly winds on Thursday. If this area of low pressure comes closer to us than I think models indicate, then Thursday could be getting increased winds.


Thursday needs to be watched closely, as we near the best estimate of the track. Again, I feel it will be further east as in Louisiana, rather than most current guidance that showed Texas, and this will more likely be seen in a sharp turn north, or even a re-curve north and northeast. I don't feel models are handling the digging trough over California Thursday night and Friday. Too much west motion on Thursday night and Friday.


V. Steering Influences.


Since it's not developed yet this early pre-dawn Wednesday morning, I've elected to view lower-tropospheric steering. To the northeast of the low, there is a ridge in the Western Atlantic and Southeast U.S. that is oriented from southeast to northwest, that I believe ought to let it guide on a northwest slower movement than yesterday. Last night they set an intial motion of west at 17 mph, at 23.7 and 85.8 at 7 PM yesterday. That's not going to be anywhere near that fast today, and the center will have to be re-located. It'll have to be back-pedaled. The northwest edge of that ridge to the north of it is weak, so it'll slow down today. Also, 2 short-wave troughs dip into the central part of the U.S.; the first passes by Missouri early this morning, and scoots off. The 2nd more important one comes by tonight on Wednesday night.


And while the 1st one does not look strong enough to lure it north, it could be enough to cause it to slow down in its tracks. The 2nd one that comes across the Southern Plains tonight should certainly cause it to slow down and probably get some more northwest to north motion on it.


However, on Thursday, the ridge begins building back in from the east and north of it. This should place it back on a northwest movement. Now, I reviewed upper ridging and lower ridging levels on Thursday. So, interestingly it turns out that there is less ridging in the upper levels than middle levels. No wonder why Bam - D is farther east then! Did you see? It makes sense then. A more well-developed tropical storm will threaten South-Central Louisiana & Southeast Louisiana. A weaker depression or wave will make it further west with ridging holding on a bit longer.


A really deep, long-wave trough is digging into the Southwest U.S. and California on Thursday night. I think a bit too much ridging is hanging on with Gfs, I believe. So I still maintain that this will be a Louisiana threat; but thankfully none of the forecasting solutions indicate anything stronger than a tropical storm.


After going through this, I feel the best threat will be between Vermilion Bay, Louisiana EASTward to the mouth of the Pearl River, on the Louisiana/Miss state line, between Thursday night to Friday morning. That's quite a bit removed & further east than models. One intensity forecasting scheme that I thought looked reasonable was a pressure of around 1000 mb and a maximum sustained surface wind of about 40 mph gusts to 50 mph in the very worst squally weather. This looked doable. That would mean a weak tropical storm. Didn't really care for the wildly varying 06z output.