MikeCAdministrator
(Admin)
Sun Jul 29 2007 09:27 AM
July Nearing End, Tropics Waking Up

The tropics may be waking up again, albeit a bit slowly. There is a slight chance we may have a named system or at least a depression in July. And right now the main focus is on the area northeast of the Bahamas, being referred to as investigation 98L.



This system likely will not affect any land area. It has a fairly good shot to develop into a system over the next few days or so. A recon flight may be scheduled for this afternoon (Sunday) to check it out (Edit: This flight has been canceled now). There is a chance for it to become a tropical depression within the next few days. Right now convection is still too far away from the center and isn't really organized enough to get going today, but if it persists it could develop.

If it does form, like mentioned it will likely move north and northeast avoiding land areas, (Both the US and Bermuda) entirely, so it will likely be a fish spinner type system.

Beyond that, there is not much else going on, although into August we start expanding the area we look for systems to develop. The only other outside chance is something happening in the Gulf, as shear in that area will start to weaken by the end of the week.

{{StormLinks|99L|99|4|2007|2|99L (Area East of Caribbean)}}
{{StormLinks|98L|98|3|2007|1|98L (Area Northeast of the Bahamas)}}

{{StormCarib}}


dem05
(User)
Sun Jul 29 2007 10:06 AM
Re: July Nearing End, Tropics Waking Up

It isinteresting to see the improved organization on 98L this morning. Fish spinner for sure, but the tropics are definately starting to wake up a bit.

I know I will be watching the Gulf of Mexico with great interest this week. Still rubbing my eyes this morning from a long nights slumber, so I really haven't had a chance to look at many models. However, in viewing this mornings satellite images, it does appear that a general area of low pressure is forming in the Gulf already....So there may be something towatch before the late week period. Give or take a few miles, the area is about 200 miles west of SW FLorida or about 250 miles southof Apalachicola. If the area, gets better organized throught the next 24 hours, itmay become a pointof further discussion in the forum.

If ya'd like to have a look, here's the link: http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html


stormchazer
(Storm Tracker)
Sun Jul 29 2007 01:27 PM
Re: July Nearing End, Tropics Waking Up

I know 98L is the player being watched, but I wonder if a little something is not trying to get going in the GOM.

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

There has been some model support for a Low developing in the GOM for a few days now and shear is suppose to decrease.


cieldumort
(Moderator)
Sun Jul 29 2007 03:56 PM
Re: July Nearing End, Tropics Waking Up

NRL has hoisted a TCFA for 98L

TROPICAL CYCLONE FORMATION ALERT

SUBJ/TROPICAL CYCLONE FORMATION ALERT//
RMKS/1. FORMATION OF A TROPICAL CYCLONE IS POSSIBLE
WITHIN 100NM EITHER SIDE OF A LINE FROM 30.0N 73.5W
TO 34.6N 70.5W WITHIN THE NEXT 24 HOURS.
AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF A
NUMBERED TROPICAL CYCLONE WARNING AT THIS TIME.

2. A LOW PRESSURE CENTER LOCATED NORTHEAST OF NASSAU,
BS HAS FORMED UNDERNEATH VERY INTENSE CONVECTIVE
ACTIVITY JUST TO THE EAST OF THE BAHAMAS. SYNOPTIC
OBSERVATIONS INDICATED LOW PRESSURE CENTERED NEAR
30.0N 73.5W WITH A CENTRAL PRESSURE OF 1013.0 MB.
WIND SHEAR OVER THE SYSTEM IS ANALYZED AT 10 TO 15
KNOTS. THE CONVECTION ASSOCIATED WITH THE SYSTEM IS
BEING PLACED 60NM TO THE SOUTH OF THE CENTER. HOWEVER,
WARM SEA SURFACE TEMPERATURES IN THE AREA CAN ENHANCE
TROPICAL CYCLONE DEVELOPMENT OVER THE NEXT 24 TO 48
HOURS.

3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR
CANCELLED BY 301600Z JULY 2007.//
(LINK)



It is a bit odd that the 98L floater has been removed in light of everything else. (For now). The system appears to be slowly organizing -very- slowly, with two baby steps forward and one or one and a half baby step/s back. The combination of still difficult shear imparted mainly from the ULL to its northeast, and extratropical interaction with a preexisting trough seem to be hindering anything more at this time. 98L has a good 400 - 500 miles of acceptable SSTs ahead for possible subtropical and/or tropical development, and not an impossible atmosphere to work with.


danielwAdministrator
(Moderator)
Sun Jul 29 2007 11:45 PM
GOM Low?

Current WV imagery does indicate cyclonic circulation in the Middle GOM. Centered near 25N/ 88W. It appears to be a mid-level circulation, and I'm not certain at this point if it has closed off.
Wind directions from the Slidell, Mobile, and Eglin NWS radar profiles indicate westerly winds from the surface to around 3000 feet. And Northerly winds above 3000 feet. More indicative of the weak, unusual for July, front poised near the Northern Gulf Coast.

Buoy observations are showing light winds with pressures below 29.92 in Hg.
Not much to look at for now. Enjoy the peace and quiet.

Excerpt from the QUANTITATIVE PRECIPITATION FORECAST DISCUSSION

ALL OF THE MODELS ARE SHOWING SOME TYPE OF
UPPER-LEVEL DISTURBANCE ENHANCING OVER THE ERN GULF OF MEXICO AND THE GFS IS THE BOLDEST IN ALLOWING THIS FEATURE TO GET CAUGHT UP IN THE SWRLY STEERING FLOW AHEAD OF THE UPPER TROUGH TO ENHANCE
RAINFALL TOTALS ACROSS FL. HPC FOLLOWED THIS TREND AND BUMPED UP QPF VALUES ACROSS THE FL PENINSULA FROM THE PREVIOUS FORECAST. (QPF values are rainfall totals~danielw)


dem05
(User)
Mon Jul 30 2007 12:41 AM
Re: GOM Low?

Beyond my last post earlier on Sunday, I have been keeping an eye out there. You are pretty much correct. At the surface, a high pressure ridge (centered around Louisianna) is bringing westerly winds across the nothern portion of the Gulf of Mexico. Not so good for providing immediate tropical development in the Gulf from an area such as the one that was lurcking aroud today. Easterly winds in the Northern Gulf may have made a different case. In the mean time, many people saw some vorticiy out there, that was definately NOT at the surface and was more indicitave of a mid level low attempting to spin up. In the upper levels, winds were blowing out of the north and north north east as could be seen in the thunderstorm blow off across western Florida and the eastern half of the Gulf. Final nail in the coffin for any increased organization today was the abundance of outflow boundries from the thunderstorms in the eastern Gulf. Outflow boundries to some degree are not a bad thing for a developing system, as in the appropriate circumstances, they create lift that adds to additional thunderstorm development. However and for the most part in tropical development, you look for thunderstoms moving inward...today, there were large outflow boundries heading outward and the shear magnitude of these boundries probably limited the lifting action over the eastern Gulf and has squlched thunderstorm development this evening. There may have even been enough energy in some of these large boundries to disrupt that mid-levelvorticity that wasmore noticable earlier in the day...Not quite the right ingreedients for tropical development in the Gulf just yet, but some levelof thunderstormactivity has waxwd and wanned out there for about a week now. Being an "old salt" to GoMex weather, it is wiser to keep at least a half of one eye on the Gulf throught the week, something may still pop up out there...For now, this current feature looks pretty beaten up...

...Rest of the Basin: 98L pretty much looks like something that wanted to walk the talk, but didn't in the end. I give it less than a 10% shot now. In the end, timing is everything, and it was looking like a "lopsided" by this afternoon and it is fairly apparent that the upper trough was a bit too close to let this domuch more.

As fot the ITCZ...Nothing to write home about there either. Some interesting kinks affliliated with tropical waves are out there, but everything along the ITCZ looks too continuous (from Africa on Westward). Also, the ITCZ seems pretty flat in it's east to west orientation (kinks included). There are no definative systems there right now. Enjoy the break gang...things will probably kick up sometimesoon soon, so the down time is a great thing!


cieldumort
(Moderator)
Mon Jul 30 2007 02:14 AM
Re: GOM Low?

Quiet in the GOM, alright - conditions are definitively unfavorable for development there, at this time. Subject to change.

My attention remains drawn to 98L, as it ebbs and flows within its environment. Fair to call it a subtropical low riding along and within the parent trof, but none too impressive thus far. Still, 98L might have a window of as many as up to 2 or 3 or even 4 more days to pull something off. Given this large of a window, it might yet ratchet itself up for entry into the season totals. Some model support for brushing Nova Scotia with it later during extratropical transition.

Changing scenes a bit to areas that might actually impact the lower 48, a LLC appears to be forming within a convectively-active wave, located around 9N 45W. If it doesn't drive into northern South America and/or meet any untimely final death in the eastern Caribbean, this could be of far more interest later this week. Behind this feature is one rather large, but relatively dry, low level circulation, as well as numerous individual thunderstorm clusters, and at least one more impressive wave. Rolling off the tip of western Africa are two more ready-made Lows, although the associated convection is seriously starting to wane as they prepare to roll offshore.

With so much brewing in the wave train, as detailed above, this is the area I am most interested in for the coming week.


nc_tropical_wx79
(Weather Guru)
Mon Jul 30 2007 09:22 AM
Re: GOM Low?

99L is up on the navy site and floater is over the area. 99l is about (not being exact) 48W and 9N.

Ron Basso
(Storm Tracker)
Mon Jul 30 2007 10:03 AM
Re: 99L in Central Atlantic

ok folks time to wake up - 99L is up on the NRL site. Time for new thread? This is the one the GFS has been developing on and off the last week. Gonna be a Caribbean rider - looks like trouble ahead.

http://www.ssd.noaa.gov/goes/flt/t2/loop-avn.html

http://www.sfwmd.gov/org/omd/ops/weather/plots/storm_99.gif


nc_tropical_wx79
(Weather Guru)
Mon Jul 30 2007 10:08 AM
Re: 99L in Central Atlantic

99l is up and alive but there's an awful lot of dry air ahead of it so I am starting to doubt it will be long lived unless it can win the difficult fight it has ahead of it w/ that dry air.

CaneTrackerInSoFl
(Storm Tracker)
Mon Jul 30 2007 11:30 AM
Re: 99L in Central Atlantic

The dry air isn't as expansive as we saw with the last system that tried to run the gauntlet there. In fact, I'd say that the dry air isn't nearly a detriment to this system as it is still in a moist environment and the dry air ahead appears to be waning in strength.


http://www.ssd.noaa.gov/goes/east/tatl/wv-l.jpg


WARNING: Image is time sensitive.


LoisCane
(Veteran Storm Chaser)
Mon Jul 30 2007 11:51 AM
id give it chances based on ships model

these are pretty high figures

SHIPS INTENSITY FORECAST

very impressive actually

and the orientation of the high has changed
sal isn't a problem

i think it's pretty impressive!!!


Rabbit
(Weather Master)
Mon Jul 30 2007 11:59 AM
Re: id give it chances based on ships model

NRL appears to have removed 98L

D3m3NT3DVoRT3X
(Weather Watcher)
Mon Jul 30 2007 12:24 PM
Re: 99L in Central Atlantic

I saw this on bay news 9's website though it was pretty nifty off thier tropical update page .. shows current wind data Bay News 9 tropical update Once u get there open the page just click Atlantic Wind data pretty nifty stuff sorry if somebody has posted this already

Steve H1
(Storm Tracker)
Mon Jul 30 2007 12:27 PM
Re: id give it chances based on ships model

It is lacking moisture though. Although not a terribly dry environment, could be a lot of sinking/stable air in the Caribbean. It looks like she's drying up, but she is trying to pull up moisture from the south. Shear is not a factor. Let's see how she does today and tonight.

Rich B
(British Meteorologist)
Mon Jul 30 2007 01:14 PM
Re: id give it chances based on ships model

OK, a little confused now but NRL have 98L up as 98L.LIMA... odd! Perhaps its gonna get classified. It certainly has become better organised, and has taken on a somewhat subtropical appearance. The strongest convection, in fact the only convection, is in a curved band in the eastern semi-circle. The llcc has also become somewhat better defined. However, time is not on its side as it trundles slowly north-northeast towards cooler waters.

99L is also worth watching, but i havent looked at this much yet so i'll post on it later. However, suffice it to say this is easily more of a threat than 98L.

Regards


LoisCane
(Veteran Storm Chaser)
Mon Jul 30 2007 01:47 PM
Re: id give it chances based on ships model

yeah, sort of a battle between invests

though 98 still looks very subtropical to me.. moisture is mostly displaced from the center though some is trying to wrap in...


nice view
http://www.ssd.noaa.gov/goes/flt/t2/sloop-ir2.html


and 99 looks healthy and keeps moving west.. looks good on various sats and has a large pocket of moisture
http://www.nrlmry.navy.mil/sat-bin/displ...RENT=LATEST.jpg


doug
(Weather Analyst)
Mon Jul 30 2007 03:53 PM
Re: id give it chances based on ships model

Actually 98 appears to be improving with time, and my guess is it will get classified.
99 is a very nice system. I do not see the dry air problem at all as it is in a nice envelope of moisture.


WeatherNut
(Weather Master)
Mon Jul 30 2007 04:44 PM
Re: id give it chances based on ships model

Looks like 99L has some pretty good rotation. Its also really starting to fire some convection west of what looks like a COC. Also looks like some good outflow is developing

MichaelA
(Weather Analyst)
Mon Jul 30 2007 05:21 PM
Re: id give it chances based on ships model

I'm putting my marbles on 99L as the one that will form into something. 98L is sub-trop at best. Another wave East of 99L has some potential as well.

dem05
(User)
Mon Jul 30 2007 07:18 PM
Re: id give it chances based on ships model

98L is better organized as a surface feature this afternoon/evening...However, the storm activity around the center remains limited. One good long burst of thunderstorms around the center could push this over the edge and get it classified...but the upper and mid level flow does remain unfavorable for development and/or a lot of deep cenvective development around the center for extended periods of time. If 98L does push over the threshold, it will likely be on a subtropical level as satellite imagery depicts mid/upper level troughing close to the center and the front will be closing in. Link: http://www.ssd.noaa.gov/goes/flt/t1/loop-avn.html (Don't forget to click on the HDW-mid and HDW-high radio buttons on top of the image). I'll give it a 20% shot (up from 10% last night) due to the increased organization/presentation of the low level structure throughout the afternoon. Otherwise, outside of the front, 98L will likely pass the northern extent of the Gulf Stream by the time it reaches the same latitude as New Jersey (around 39 degrees north), after that, the chances will be nada. Will be interesting to see if a suubtropical storm can fire off from this one, but the odds are against it.

As for 99L...I will bite my tounge as I did not expect to see this kind of activity along the ITCZ region as of last night. It was interesting/surprising to see something a little better organized down there today...and some of you may agree with that. Mean time, 99L needs to get a lot more thunderstorm activity going. Especially considering that it is in the deep tropics (at lower latitudes, strong thunderstorm cloud tops grow to a higher altitude), so at this point, there needs to be a deeper flare-up of thunderstorms to really get things going. With favorable conditions as we see here, that is definately possible and the expectation of slow development is not unreasonable.

Interestingly, even though the thunderstorms have not grown/become stronger around 99L, the low level structure of 99L has been improving. Thoughout the day, easterly winds to the north of it, northerly winds to the west of it, and westerly winds to the south of the system were readily apparent at the lower levels (Low level cloud motion around the periphery). What was not apparent this afternoon on the satellite was a southerly wind on the east side of 99L. As we have moved into the evening, the last visible frames did indicate that there may have been some north winds (versus the westward cloud motion I had been seeing through the afternoon along the ITCZ). The shortwave continues to echo that the eastern side of 99L may be showing signs of closing off a circulation (at the low cloud levels). 99L may be starting to break free of the ITCZ this evening...Link to Shortwave loop: http://www.ssd.noaa.gov/goes/flt/t2/loop-ir2.html


cieldumort
(Moderator)
Mon Jul 30 2007 10:30 PM
Re: id give it chances based on ships model

98L is now Noname.

In all fairness to the guys at NHC, they could have pulled the trigger earlier this afternoon, but waiting around to see if it would be more tropical vs subtropical makes sense. I expect it will be referred to as tropical, given the deep central convection now present.

In many ways 98L/3 is very similar to Invest 91L from back on May 18, which peaked out at an estimated 40 knots by NRLs assessment. Perhaps a candidate for post-season reanalysis there, although its life was cut short, whereas 98L has persisted and grown steadily stronger (to about where 91L peaked just before giving it up to the parent trof and other unfavorable conditions.)


dem05
(User)
Mon Jul 30 2007 10:37 PM
Re: id give it chances based on ships model

Hi mort, you are right and the word on the street is that 98L is getting classified at 11PM...It looks like I should have gone with odds of higher than 20%, huh...LOL! It almost looked like the low reformed toward the thunderstorms that were NE of the center earlier today. Shear has probably treaked downward a bit too. Those develoments of t-storms closer to the center probably got it over the NHC threshold...We will soon know if it is tropical or subtropical...Interesting!

In the mean time, 99L is trying to getmore in the way of deep thunderstorm development on the NE side (make no correlation to98L/Noname 3). This system looks like it is getting even better organized mid-levels, but still needs more thunderstorms (as in my previous discussion). However, it is in a favorable environment. It is possible that for a brief time at least, there may be two systems to track.


danielwAdministrator
(Moderator)
Mon Jul 30 2007 11:31 PM
New Thread

New Thread...Tropical Depression 3

Please post there. Thanks.


LoisCane
(Veteran Storm Chaser)
Tue Jul 31 2007 09:44 AM
Re: New Thread

why isnt anyone talking about the tropical wave in the atlantic? where is that thread?

Chantal is worth watching for lack of anything better to do but I would think we should be talking about the Low that is part of the Tropical Wave in the Atlantic

I think this is worth watching even if I don't think this model will play out

http://moe.met.fsu.edu/cgi-bin/cmctc2.cg...;hour=Animation


mead9536
(Registered User)
Wed Aug 01 2007 03:54 PM
Re: July Nearing End, Tropics Waking Up

anyone else notice that they've started an invest on the area off the west coast of florida?


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