ATL: TROPICAL DEPRESSION BONNIE - DISCUSSION

[LaBreeze]

Could we possibly be looking at "Bonnie" out of this in 3-4 days? Just wondering ~

[ROCK]

defintely has a MLC with it with some new convection near it. still though shear is still there but decreasing.....orange tonight if convection doesnt wane after sunset.

[jlauderdal]

I'm thinking they are going to raise the percentage up to 30%.

That seems more likely than code orange at 8:00 pm to me.

well we dont have long to wait for the official color from NHC, shows how desperate we are for something that an upgrade from lemon to orange can get so much debate

[cycloneye]

Mantains at 20%

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUL 19 2010

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

A TROPICAL WAVE LOCATED NEAR PUERTO RICO CONTINUES TO PRODUCE
DISORGANIZED SHOWERS AND THUNDERSTORMS. SURFACE PRESSURES ARE NOT
FALLING SIGNIFICANTLY OVER THE AREA...AND UPPER-LEVEL WINDS ARE
EXPECTED TO BE ONLY MARGINALLY FAVORABLE FOR DEVELOPMENT AS THE
DISTURBANCE MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A
LOW CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS...ALTHOUGH CONDITIONS COULD BECOME MORE
FAVORABLE FOR DEVELOPMENT AFTER THAT TIME. REGARDLESS OF
DEVELOPMENT...GUSTY WINDS AND LOCALLY HEAVY RAINFALL COULD AFFECT
THE NORTHERN LEEWARD ISLANDS...THE VIRGIN ISLANDS...PUERTO
RICO...THE DOMINICAN REPUBLIC...HAITI...EASTERN CUBA...THE TURKS
AND CAICOS ISLANDS...AND THE SOUTHEASTERN BAHAMAS DURING THE NEXT
COUPLE OF DAYS.

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

$$
FORECASTER PASCH

[alienstorm]

This is actually a complex weather system, we have two waves merging together and what is clear a MLC north of San Juan.

The question is will this consolidate and drop to the surface. All seems to point to yes, it may happen in the next 24 - 48 hours as the entire system moves WNW slowly.

[KWT]

Looks like the surface pressures are the clincher for the NHC to up it to 30% which is fair enough, as Wxman57s image shows the surface obs are going to be very good to use in this sort of set-up given the obs nearby.

That being said shear really isn't that much of an issue right now, but it takes some time after several days of very high shear values to sort itself out.

[jlauderdal]

Mantains at 20%

TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUL 19 2010

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

A TROPICAL WAVE LOCATED NEAR PUERTO RICO CONTINUES TO PRODUCE
DISORGANIZED SHOWERS AND THUNDERSTORMS. SURFACE PRESSURES ARE NOT
FALLING SIGNIFICANTLY OVER THE AREA...AND UPPER-LEVEL WINDS ARE
EXPECTED TO BE ONLY MARGINALLY FAVORABLE FOR DEVELOPMENT AS THE
DISTURBANCE MOVES WEST-NORTHWESTWARD AT 10 TO 15 MPH. THERE IS A
LOW CHANCE...20 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS...ALTHOUGH CONDITIONS COULD BECOME MORE
FAVORABLE FOR DEVELOPMENT AFTER THAT TIME. REGARDLESS OF
DEVELOPMENT...GUSTY WINDS AND LOCALLY HEAVY RAINFALL COULD AFFECT
THE NORTHERN LEEWARD ISLANDS...THE VIRGIN ISLANDS...PUERTO
RICO...THE DOMINICAN REPUBLIC...HAITI...EASTERN CUBA...THE TURKS
AND CAICOS ISLANDS...AND THE SOUTHEASTERN BAHAMAS DURING THE NEXT
COUPLE OF DAYS.

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

$$
FORECASTER PASCH

as predicted by myself and wxman57, be interesting too watch but dont expect too much except for frustration between now and Thursday, happy hurricane hunting, real season starts aug. 1 and anything before then is a bonus for those that like them

[Gustywind]

LATEST

[Ivanhater]

[xcool22]

Ivanhater .hmmm

[Vortmax1]

Your radar looks like it's showing an MCS to the NE of PR.
This is the 500mb vorticity chart:

[lrak]

http://radar.weather.gov/radar.php?rid= ... 1&loop=yes

looking good.

[Blown Away]

Ivanhater, we need to keep bumping that radar because, IMO it's showing a developing system. Clearly a MLC/LLC is developing by the minute and we can see deep convection blowing up near this area on the IR loop. I think this will be a SFL/NE GOM storm if this develops because this system has slowed way down and will be feeling the ridge breaking down as it approaches SFL, JMHO.

[Recurve]

Does it reach Florida? I know it's not yet and may not become an "it", but does the disturbance make it in this direction or get driven farther north?

[KWT]

Thats certainly a decent looking radar presentation I've gotta admit, the MLC is more then evident there thats for sure!

The fact the Vorticity has become concentrated near where convection is as well which is another sign of things getting going. That being said the rest of the convection doesn't look quite so good as it did earlier on.

BA, I agree with that but I think the only reason its slowed down is the upper high hasn't really gotten going yet, the system should start to speed up as the high forms over the next 24-36hrs and IMO bend near due west for a time before the upper high starts to erode again.

[jlauderdal]

Thats certainly a decent looking radar presentation I've gotta admit, the MLC is more then evident there thats for sure!

The fact the Vorticity has become concentrated near where convection is as well which is another sign of things getting going. That being said the rest of the convection doesn't look quite so good as it did earlier on.

BA, I agree with that but I think the only reason its slowed down is the upper high hasn't really gotten going yet, the system should start to speed up as the high forms over the next 24-36hrs and IMO bend near due west for a time before the upper high starts to erode again.

that radar shot is rather impressive and its over water so none of this land BS we usually get around PR, so now if we can just put together a decent sat presentation with that radar than we have something

[Vortmax1]

Certainly looks nice in the mid-level. There's no evidence of a surface circulation yet.
And no associated low pressure area.

Give it another 48-72 hours...maybe near the Florida Straits.

[gatorcane]

The ULL to the N of 97L is drifting SW and should weaken as a ridge builds in over Florida, Northern Bahamas, and Western Atlantic over the next couple of days. Assuming we have convection left and some rotation, would be interesting to see how it responds to the better upper-level conditions. How many times have we seen a pathetic looking system fighting a ULL in this part of the Atlantic only to hang in there long enough to take advantage of much better upper-level conditions from a building high? That said, we just don't see models coming on board, so the chances are this remains a strong tropical wave heading towards the SE Bahamas. Still, have to pay attention because of where it is headed and the fact upper-level conditions may become favorable in the SE Bahamas / FL straits area where some of the warmest SSTs in the basin exist.

[cycloneye]

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE SAN JUAN PR
749 PM AST MON JUL 19 2010

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS REISSUED A

* SPECIAL MARINE WARNING FOR...
ATLANTIC WATERS OF PUERTO RICO AND USVI FROM 10 NM TO 19.5N...
COASTAL WATERS OF NORTHERN USVI AND CULEBRA OUT 10 NM...

* UNTIL 945 PM AST

* AT 745 PM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
THUNDERSTORM...PRODUCING SEVERE WINDS IN EXCESS OF 40 KNOTS OVER
ATLANTIC WATERS OF PUERTO RICO AND USVI FROM 10 NM TO 19.5N...OR
ABOUT 24 NM NORTH OF CULEBRA...MOVING WEST AT 5 KNOTS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MARINERS CAN EXPECT GUSTY WINDS...HIGH WAVES...DANGEROUS LIGHTNING...
AND HEAVY RAINS. BOATERS SHOULD SEEK SAFE HARBOR IMMEDIATELY...UNTIL
THIS STORM PASSES. IF CAUGHT ON THE OPEN WATER STAY BELOW DECK IF
POSSIBLE...KEEP AWAY FROM UNGROUNDED METAL OBJECTS.

THUNDERSTORMS CAN PRODUCE SUDDEN WATERSPOUTS. WATERSPOUTS CAN EASILY
OVERTURN BOATS AND CREATE LOCALLY HAZARDOUS SEAS. SEEK SAFE HARBOR
IMMEDIATELY.

[dolebot_Broward_NW]

http://radar.weather.gov/radar.php?product=NCR&rid=JUA&loop=yes

Definitely something going on. See the composite NWS doppler out of Puerto Rico. That far away from radar you are looking at least a few thousand feet up. THe composite combines returns from a number of different radar elevations. Any doppler nerds care to say what the radar return elevation is of that apparent "center"?