Cindy in the making? Pretty ferocious.....

[mobilebay]

It's dropping but not at rate you are saying, Matt. Using estimates, it's only falling about 2 mb in the last hour and about 3 mb from 2 hours ago. Pressure went from about 1014mb to 1011mb.

I agree. He is using inches instead of Millibars. However, that is pretty good drop over two hours. Also whats really interesting is that the bouy is located on the periphery of deep convection. Low forming?

[Thunder44]

It's dropping but not at rate you are saying, Matt. Using estimates, it's only falling about 2 mb in the last hour and about 3 mb from 2 hours ago. Pressure went from about 1014mb to 1011mb.

I agree. He is using inches instead of Millibars. However, that is pretty good drop over two hours. Also whats really interesting is that the bouy is located on the periphery of deep convection. Low forming?

Not now. I don't see any obs in South America reporting westerly winds this morning.

[dixiebreeze]

It's a ripe area for development and it appears the NHC is in agreement with that. GOMers need to be alert.

[dixiebreeze]

There actually appears to be minimal shear right now in the central/west Caribbean -- or the GOM, for that matter. I think all systems are go for possible development.

[loon]

Welp, I guess I'll get out the lawn chairs, cooler, and pretzels...I hope you guys are right.

cheers,
loon

[dixiebreeze]

Caribbean QuikScat July 1:

http://manati.orbit.nesdis.noaa.gov/oce ... atl_12.png

[frederic79]

Buoy 42058 south of Hispaniola shows wind gusts to 29.1 knots and 7.9 ft seas. These numbers have steadily increased for some time, but pressure tendencies so far look durinial. Let's see if they continue to drop. Time will tell but the sat pics look interesting and shear lessening.

[dixiebreeze]

Noticed winds are up, though the pressures are pretty steady right now. As the day progresses, I think we may see some drops.

[skysummit]

So where you guys think something may begin to pop up? In the SW Carribean where the spin was yesterday (which I was wrong about by the way ), just south of Jamaica, or somewhere in between?

[tw861]

So where you guys think something may begin to pop up? In the SW Carribean where the spin was yesterday (which I was wrong about by the way ), just south of Jamaica, or somewhere in between?

There may be a hint of rotation just south of Jamaica this morning.

[skysummit]

So where you guys think something may begin to pop up? In the SW Carribean where the spin was yesterday (which I was wrong about by the way ), just south of Jamaica, or somewhere in between?

There may be a hint of rotation just south of Jamaica this morning.

Yea, that's what I see also. I was just wondering since JB's prize location was just a bit south of this. Nevertheless, it looks to be an interesting weekend.

[Scorpion]

Pressure is now rising in that buoy. Hmmmm...

[dhweather]

I'm not going to get really excited until I see sustained convection
and better organization.

[Air Force Met]

Holy #$@ it is now falling for this hour 3.7 millibars or 6.9 millibars for the last two hours. Something is trying to develop.

http://www.ndbc.noaa.gov/station_page.php?station=42058

I hate to bust your bubble Matt, but this is incorrect. The pressure tendancy is NOT the change in pressure over the last hour....it is the tendancy over the last 3 hours. It is also not in MB...it is in inches. You might should have noticed that the overall pressure on each hour did not match the pressure falls you were giving it In other words, if the pressure was 29.89 2 hours before, then it should have been 29.69 2 hours later with a 6.9 mb pressure fall, right? But it's not...it's 29.85.

So...pressure falls are over the last 3 hours...and in inches. You need to take the inches in change and divide that by .02953 in order to get your millibars.

Last bit of advice (and to answer the question some had as to why it was rising now). Matt, when dealing with short term pressure falls, you have to take into account diurnal changes. The time you were looking at the pressure changes, you were looking at the max diurnal low...the time when the pressure drops the most. So that would be added with any falls in that area. Now...it certainly wouldn't account for all of it...but it would account for a couple of millibars of that 3.7 mb fall over 3 hours. And now we are headed into a diurnal peak...that is why it is rising again....because any falls can't offset the peak enough to account for an overall fall.

So...some advice for next time...remember these are 3 hour pressure falls, remember to look at the overall pressure, remember to account for the diurnal changes (peak at 10Am/10PM with a max fall at 4am/4Pm ...give or take an hour...depending on where you are), and remember the formula for conversion.

Last piece of advice...and it's meteorological. The next time you think you see pressure falls like that, you better see some massive thunderstorms with some massive outflow around a nice LLC...or a tropical cyclone moving towards the buoy. Pressure falls of that rate do not happen in the atmosphere unless there are some really good dynamics causing them to fall...or a tropical system moving towards a fixed location. Pressure falls of that much must be caused by some great dynamics...and if you don't see some really great dynamics...ask questions about your observation.

The very reason I posted to you was because I had previously looked at a sat pic...and when I saw you quote the pressure falls...I knew there was no way it was accurate because I did not see the dynamic setup to cause it. I know you're excited about tropical season...but don't let excitement overtake reason I say this because when I was a young weather nut...I made that mistake more times than you ever will...or I will ever admit at least. With age comes wisdom (and a bunch of blown forecasts because you let youthful enthusiasm get the best of you).

[dixiebreeze]

Excellent informative and diplomatic post, Air Force Met. Thank you.

[dhweather]

Holy #$@ it is now falling for this hour 3.7 millibars or 6.9 millibars for the last two hours. Something is trying to develop.

http://www.ndbc.noaa.gov/station_page.php?station=42058

I hate to bust your bubble Matt, but this is incorrect. The pressure tendancy is NOT the change in pressure over the last hour....it is the tendancy over the last 3 hours. It is also not in MB...it is in inches. You might should have noticed that the overall pressure on each hour did not match the pressure falls you were giving it In other words, if the pressure was 29.89 2 hours before, then it should have been 29.69 2 hours later with a 6.9 mb pressure fall, right? But it's not...it's 29.85.

So...pressure falls are over the last 3 hours...and in inches. You need to take the inches in change and divide that by .02953 in order to get your millibars.

Last bit of advice (and to answer the question some had as to why it was rising now). Matt, when dealing with short term pressure falls, you have to take into account diurnal changes. The time you were looking at the pressure changes, you were looking at the max diurnal low...the time when the pressure drops the most. So that would be added with any falls in that area. Now...it certainly wouldn't account for all of it...but it would account for a couple of millibars of that 3.7 mb fall over 3 hours. And now we are headed into a diurnal peak...that is why it is rising again....because any falls can't offset the peak enough to account for an overall fall.

So...some advice for next time...remember these are 3 hour pressure falls, remember to look at the overall pressure, remember to account for the diurnal changes (peak at 10Am/10PM with a max fall at 4am/4Pm ...give or take an hour...depending on where you are), and remember the formula for conversion.

Last piece of advice...and it's meteorological. The next time you think you see pressure falls like that, you better see some massive thunderstorms with some massive outflow around a nice LLC...or a tropical cyclone moving towards the buoy. Pressure falls of that rate do not happen in the atmosphere unless there are some really good dynamics causing them to fall...or a tropical system moving towards a fixed location. Pressure falls of that much must be caused by some great dynamics...and if you don't see some really great dynamics...ask questions about your observation.

The very reason I posted to you was because I had previously looked at a sat pic...and when I saw you quote the pressure falls...I knew there was no way it was accurate because I did not see the dynamic setup to cause it. I know you're excited about tropical season...but don't let excitement overtake reason I say this because when I was a young weather nut...I made that mistake more times than you ever will...or I will ever admit at least. With age comes wisdom (and a bunch of blown forecasts because you let youthful enthusiasm get the best of you).

Exceptional post AFM !!!!!!!!!! Thank you !

[Brent]

11:30 TWO:

A LARGE AREA OF DISORGANIZED CLOUDINESS AND THUNDERSTORMS CONTINUES
OVER PORTIONS OF THE CENTRAL AND SOUTHWESTERN CARIBBEAN
SEA...PRIMARILY ASSOCIATED WITH A WESTWARD MOVING TROPICAL WAVE.
THERE ARE NO SIGNS OF A SURFACE CIRCULATION...BUT UPPER-LEVEL WINDS
ARE BECOMING A LITTLE MORE FAVORABLE FOR SOME DEVELOPMENT DURING
THE NEXT DAY OR TWO...AS THE SYSTEM MOVES OVER THE WESTERN
CARIBBEAN SEA.

[Air Force Met]

11:30 TWO:

A LARGE AREA OF DISORGANIZED CLOUDINESS AND THUNDERSTORMS CONTINUES
OVER PORTIONS OF THE CENTRAL AND SOUTHWESTERN CARIBBEAN
SEA...PRIMARILY ASSOCIATED WITH A WESTWARD MOVING TROPICAL WAVE.
THERE ARE NO SIGNS OF A SURFACE CIRCULATION...BUT UPPER-LEVEL WINDS
ARE BECOMING A LITTLE MORE FAVORABLE FOR SOME DEVELOPMENT DURING
THE NEXT DAY OR TWO...AS THE SYSTEM MOVES OVER THE WESTERN
CARIBBEAN SEA.

Another hint that you would see with pressure falls like that...you would see a well defined circulation. You can't have pressure falls of that magnitude without having a closed low.

[wxman57]

Looks like just a wave to me now - absolutely no signs of any surface circulation (See the GARP image below). Pressures are now rising in the region, by the way. With the upper low heading out to the west, wind shear is dropping across the wave. So we'll have to keep an eye on it, for sure. But nothing is imminent in the way of development.

Best chances will come if/when it moves into the southwest Gulf or BoC early next week. Perhaps a 20% chance by then. Most likely track would be toward northern Mexico or the lower Texas coast, as a high pressure area will be building eastward across the Gulf early next week.

Here's the image, in full (non 256-color) resolution from work

<img src="http://myweb.cableone.net/nolasue/carib.gif">

[Stormcenter]

Local mets have this disturbance moving toward the upper Texas (Please we need the rain but NO hurricane) or the SW La. coastline.