LOW FORMING IN NW Caribbean RECON TOMORROW

[wxman57]

It looks like the low center at the surface is near 19N-87W, just south of Cozumel - this isn't too far from the TPCs location at 19N-86W this morning.

http://www1.cira.colostate.edu/ramm/rms ... PICAL.html

That's the upper level low center you're looking at. Nothing at the surface there in the way of an LLC. There is a surface trof axis extending from the central Bahamas to Cozumel.

[djones65]

After looking at the few marine reports over the NW Caribbean and surface observations from Yucatan and northern Belize is that a weak suface circulation has formed and from the surface reports over Yucatan is moving northward over the eastern Yucatan Peninsula near 19N - 19.5N and 87.5W - 88W. There is a broad and flat pressure pattern over all of the western Caribbean with pressures around 1009 and 1010 mb. However winds over the Yucatan are NW and Northerly with ENE winds at Merida, and Westerly winds over northern Belize which indicates a surface circulation over land of the eastern Yucatan. The lowest pressure I saw was 1009.3 mb with 10-15kt winds so I believe it is reasonable to assume 1008 mb as the minimum pressure near the center. It is under diffluent westerly upper winds and with the mid level trof shifting south over the SE US there should be some northwesterly shear impinging later. This would result in the cloud pattern evident on satellite imagery of all the clouds and convection located east and southeast of the surface circulation center. As for recon requested for SE Gulf of Mexico tomorrow it obviously is just a precaution in case a deeper cyclone began developing at the base of the trough over the eastern Gulf.
I expect this system to remain nearly stationary and a broad area of unsettled weather will likely persist over the western Caribbean throughout the weekend as it has been for the past week. But if you look at the visible loops closely you will see the low level turning is centered over the eastern Yucatan. If this thing does strengthen in the near-term it undoubtedly would be another hybrid or subtropical system.

[wxman57]

Here's a GARP screen shot of satellite with surface obs across the NW Caribbean. You can clearly see a surface trof axis in the area, but no focus for convection yet. So what you're seeing is a trof/front axis, not an LLC there.

[Aric Dunn]

After looking at the few marine reports over the NW Caribbean and surface observations from Yucatan and northern Belize is that a weak suface circulation has formed and from the surface reports over Yucatan is moving northward over the eastern Yucatan Peninsula near 19N - 19.5N and 87.5W - 88W. There is a broad and flat pressure pattern over all of the western Caribbean with pressures around 1009 and 1010 mb. However winds over the Yucatan are NW and Northerly with ENE winds at Merida, and Westerly winds over northern Belize which indicates a surface circulation over land of the eastern Yucatan. The lowest pressure I saw was 1009.3 mb with 10-15kt winds so I believe it is reasonable to assume 1008 mb as the minimum pressure near the center. It is under diffluent westerly upper winds and with the mid level trof shifting south over the SE US there should be some northwesterly shear impinging later. This would result in the cloud pattern evident on satellite imagery of all the clouds and convection located east and southeast of the surface circulation center. As for recon requested for SE Gulf of Mexico tomorrow it obviously is just a precaution in case a deeper cyclone began developing at the base of the trough over the eastern Gulf.
I expect this system to remain nearly stationary and a broad area of unsettled weather will likely persist over the western Caribbean throughout the weekend as it has been for the past week. But if you look at the visible loops closely you will see the low level turning is centered over the eastern Yucatan. If this thing does strengthen in the near-term it undoubtedly would be another hybrid or subtropical system.

your position is too far north and flawed.... you are seeing reports from stations that have probably been reporting t'storm winds that are in the area not any actual low center... if anything the only evidence is the 1km visible loop that show ese winds coming ashore in the Yucatan and some possibly wnw nw winds on the north part Belize .... as for sw or west.... that even more of a problem ... but up north at 19n there is ese winds..

[ronjon]

It looks like the low center at the surface is near 19N-87W, just south of Cozumel - this isn't too far from the TPCs location at 19N-86W this morning.

http://www1.cira.colostate.edu/ramm/rms ... PICAL.html

That's the upper level low center you're looking at. Nothing at the surface there in the way of an LLC. There is a surface trof axis extending from the central Bahamas to Cozumel.

Then why does the TPC and SSD indicate a 1009 mb low there?

[Aric Dunn]

It looks like the low center at the surface is near 19N-87W, just south of Cozumel - this isn't too far from the TPCs location at 19N-86W this morning.

http://www1.cira.colostate.edu/ramm/rms ... PICAL.html

That's the upper level low center you're looking at. Nothing at the surface there in the way of an LLC. There is a surface trof axis extending from the central Bahamas to Cozumel.

Then why does the TPC and SSD indicate a 1009 mb low there?

its old!!!!

[wxman57]

It looks like the low center at the surface is near 19N-87W, just south of Cozumel - this isn't too far from the TPCs location at 19N-86W this morning.

http://www1.cira.colostate.edu/ramm/rms ... PICAL.html

That's the upper level low center you're looking at. Nothing at the surface there in the way of an LLC. There is a surface trof axis extending from the central Bahamas to Cozumel.

Then why does the TPC and SSD indicate a 1009 mb low there?

There is lower pressure on the trailing end of the trof/front, but not an LLC. That would be the area to watch for potential development, though. What you need to look for the next 24 hours is a concentrated, persistent mass of thunderstorms. Without that, no convergence can be generated and no development will occur. That still looks unlikely, but not impossible.

[Aric Dunn]

this is a very crude image .. but works .. satellite and surface obs do not tell the same story!!
i just cant find a discernible area that everyone is thinking they are seeing.. up north.. i can almost bet money that there is nothing but that ull at around 19N .. and surface that may be around is where i have labeled it .. in the image below!!




the sea breeze boundary to the south over easter Honduras is moving east to west .. which would not support and circulation

[jrod]

Thats about where i'd guess on a center if there is one. It does look better on the IR than when I saw it earlier on the Visible. Not impressive but it has been persistant.

[shannon]

Quick question about the Bahamas. My husband works for a marina and they take an annual boat trip to the bahamas. They are leaving early tomorrow and returning on Monday. What kind of weather/seas does anyone think they will have. Anything to be concerned about? Oh, by the way, they are leaving from Jupiter, Florida.

[tailgater]

It's still there in the GOH but the ULL is ripping it apart. Naked swirl watch shortly.

Dont even think there is that much there to even have a naked swirl

Your right Dunn can't hardy produce a cloud, I still think that what's left of it is just NW of Roatan, as I write this I'm thinking how bored I must be.
1007 mb obs from SW corner of the GOH
http://weather.noaa.gov/weather/current/MZBZ.html
http://weather.noaa.gov/weather/current/MGPB.html
http://weather.noaa.gov/weather/current/MHRO.html

[tropicwatch]

but it this area of disturbed weather persists, something could brew.

[windstorm99]

000
ABNT20 KNHC 142122
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
530 PM EDT THU JUN 14 2007

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A LARGE AREA OF CLOUDINESS AND SHOWERS OVER THE NORTHWESTERN
CARIBBEAN SEA IS ASSOCIATED WITH A BROAD AREA OF LOW PRESSURE.
UPPER-LEVEL WINDS REMAIN UNFAVORABLE FOR DEVELOPMENT.

TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE NEXT 48 HOURS.

$$
FORECASTER BEVEN

[Tampa Bay Hurricane]

ULL will rip this apart...

[Matt-hurricanewatcher]

Based on Buoys and obs over land...There appears to be a closed surface low at near 20.3 north/87 west off the northeast coast of the yucatan. It appears to be moving very slowly Northeastward. Also there appears based on buoys to its south another surface area(LLC) of low pressure near 17.2 north/86 west. I think that the northern one is the main one, and you can see how the clouds are spreading north,east,west around that area. I remember how fast Barry took off; so its worth watching.

[southerngreen]

Weatherfreak14,

Well, just remember that the first two storms were both fairly weak sub-tropical or tropical systems, and, this one will likely be the same if it does develop, which is questionable, as others here have mentioned...

yea, these are just for fun. call them "practice sessions". gives everyone a chance to get their plans in order and/or their ducks in a row. 3 - 2 - 1. just don't go getting complacent!

[BigA]

Does anyone have good links to shear forecasts for the next 72 hours? Much thanks.

[ronjon]

Well, regardless if this forms into anything tropical, the 18Z GFS rainfall totals for FL look very heavy this weekend. I posted the 24 hr totals for Saturday and Sunday. This model brings vorticity into the FL big bend region on Sunday. I'm starting to get the feeling that this mass of weather may not move quickly off to the NE as I first thought. The NAM actually moves the convection into the central GOM and north-central gulf coast and leaves a surface low hanging around the north side of the Yucatan peninsula. There isn't another trough due in the central part of the county until Tuesday or Wednesday. We may be watching this mass of weather for some time.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 4_072s.gif

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 4_096s.gif

[ronjon]

Does anyone have good links to shear forecasts for the next 72 hours? Much thanks.

Here's one.

http://www.wunderground.com/data/640x480/atlm_shear.gif

[djones65]

I do not see any evidence of any significant organization within the broad low pressure area in vicinity of NW Caribbean and Yucatan peninsul, however surface pressures have fallen 3 mb in the past 24 hours. Here is the link to the National Data Buoy Center and buoy #42056 which is located in the NW Caribbean near 19.9N and 85.1W which shows at 2250 UTC the pressure was 29.70" or 1006mb. The pressure 24 hours earlier at 2250UTC on the 13th of June was 29.79" or 1009mb. Pretty significant pressure falls in that area, although upper level winds are strong from the northwest. Pressure falls of 3mb within 24 hours is not that common so this area continues to hold my interest.
http://seaboard.ndbc.noaa.gov/station_p ... tion=42056