ATL: TROPICAL DEPRESSION BONNIE - DISCUSSION

[Gustywind]

LATEST

[Gustywind]

Looks like 3 big bulks of convection are concerning each an area: DR, PR &BVI and much of the Leewards. Another one much smaller is further east of the EC near the 57west.
Impressive cyclonic signature...monstruous twave given its size

[thetruesms]

http://radar.weather.gov/radar.php?product=NCR&rid=JUA&loop=yes
...Any doppler nerds care to say what the radar return elevation is of that apparent "center"?

I was wondering the same. It's about 68 miles from the radar location, which is at 18.1156 -66.0781 at elevation 851 metres (2794 feet). Can somebody calculate this for us?

Here's a beam height calculator:
http://www.wdtb.noaa.gov/tools/misc/bea ... width.html

At 60nm, beam height is about 5800ft. Roughly 850mb.

My inspection tool shows last night's area of interest at about 8600 feet - I'm not very familiar with San Juan's scan strategy. Perhaps terrain forces their base scan to be 0.9 degrees?

Keep getting mid level spins in the thunderstorm complexes, but they don't have staying power. Now it looks like one is to the SE or PR.

[img]http://img210.imageshack.us/img210/9403/wunidsmapl.gif[img]

Looks like this one's spent the last several hours just figuring out where it wants to be. Still a while to go on this one, but it'll be fun to watch

[Gustywind]

Nice close up of the convective activity spreading on the islands...

[cycloneye]

Oh boy,I wake up with this thing relocating further SE? That is not good for us here that has seen flooding in many areas.If is confirmed that is relocating,then is a new ballgame down the road for the models and for the system itself.

[Vortmax1]

Multiplatform Satellite Surface Wind Analysis:

[Gustywind]

That's not good for all the islands afterwords Cycloneye!!!

[Vortmax1]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUL 20 2010


...SPECIAL FEATURE...

AN AREA OF DISTURBED WEATHER IS OVER THE LEEWARD ISLANDS...
PUERTO RICO...AND HISPANIOLA ASSOCIATED WITH A TROPICAL WAVE
ALONG 71W...AND UPPER LEVEL DIFFLUENT FLOW FROM AN UPPER LEVEL
LOW CENTERED N OF HISPANIOLA NEAR 26N68W MOVING SW. RECENT
UPPER-AIR DATA INDICATE THE SYSTEM IS BECOMING BETTER ORGANIZED
IN THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE. THERE IS A
MEDIUM CHANCE OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS AS THE DISTURBANCE MOVES WEST-NORTHWEST.
REGARDLESS OF DEVELOPMENT... LOCALLY HEAVY RAINFALL AND GUSTY
WINDS 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.

[Nimbus]

The remnants of that TUTT have dug down over Haiti so that may be responsible for shear induced convection SW of PR. The MSSW is interesting, small area of circulation but it might not get blown out since the TUTT looks like it is on its last legs.

[cycloneye]

[cycloneye]

Here is an excerpt from this mornings San Juan NWS discussion related to the TUTT.

.SYNOPSIS...TUTT WILL REMAIN LOCATED NORTH NORTHWEST OF THE LOCAL
AREA TODAY AND TONIGHT AND WILL LIFT FURTHER WEST NORTHWEST
WEDNESDAY AND THURSDAY...AS UPPER LEVEL HIGH PRESSURE EXTENDS INTO
THE NORTHEAST CARIBBEAN.

[cycloneye]

Up to 40%

ABNT20 KNHC 201140
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT TUE JUL 20 2010

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

A VIGOROUS TROPICAL WAVE LOCATED NEAR PUERTO RICO IS PRODUCING A
LARGE AREA OF CLOUDINESS AND THUNDERSTORMS ACROSS THE NORTHERN
LEEWARD ISLANDS...THE VIRGIN ISLANDS...PUERTO RICO...THE DOMINICAN
REPUBLIC...AND THE ADJACENT WATERS. ALTHOUGH THE THUNDERSTORM
ACTIVITY HAS BECOME MORE CONCENTRATED NEAR PUERTO RICO AND THE
VIRGIN ISLANDS THIS MORNING...THERE ARE CURRENTLY NO SIGNS OF A
SURFACE CIRCULATION. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE
SOMEWHAT FAVORABLE FOR DEVELOPMENT DURING THE NEXT DAY OR SO. THERE
IS A MEDIUM CHANCE...40 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS THE DISTURBANCE MOVES
WEST-NORTHWESTWARD AT 5 TO 10 MPH. REGARDLESS OF DEVELOPMENT...
LOCALLY HEAVY RAINFALL AND GUSTY WINDS WILL LIKELY 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 BROWN/CANGIALOSI

[Vortmax1]

AREA FORECAST DISCUSSION...DELAYED
NATIONAL WEATHER SERVICE SAN JUAN PR
706 AM AST TUE JUL 20 2010


.AVIATION...FORECAST DIFFICULTIES THIS MORNING REGARD THE TROPICAL
WAVE WITH AN AXIS AT EASTERN PR ESPECIALLY SINCE SATELLITE SHOWS
WIDESPREAD CONVECTION EXTENDING EASTWARD TO BEYOND THE NORTHERN
ANTILLES. BELIEVE JMZ AND JPS WILL STAY CLEAR OF MOST CONVECTION
THROUGH TONIGHT BUT OTHER TAF SITES WILL OFTEN BE MVFR IN SHRA/TSRA.
WIND DIRECTION IS TOUGH SINCE MODELS DO NOT KNOW WHERE TO DEVELOP A
STRONGER CIRCULATION IF ONE OCCURS WHILE RADAR HAS SHOWN MANY SMALL
SCALE BUT SHORT-LIVED CIRCULATIONS. FOR NOW HAVE CHANGED LITTLE
REGARDING ONGOING WINDS.

[wzrgirl1]

Hmmm....keeping a watchful eye on this puppy. Now that they have raised the chances 20% in the past 12 hours is indicative that they see something.

[HURRICANELONNY]

97L looked alot better yesterday when there was a 20% chance then now. Maybe it will get some llc in the next couple days. Have to wait and see.

[rockyman]

The models are within 5 days of a potential northern Gulf Coast strike (and even faster for a south Florida strike). I'm definitely starting to get that "serious feeling"....that moment when idly sitting back and watching the computer turns into thoughts such as "where and when should I book my hotel reservation, just in case?" Anyone else there yet?

[Blown Away]

Luis, walk outside and see if the LLC is forming over your house? I knew this slowdown/relocation would result in a east shift with the models down the road.

[KyleEverett]

I think its up to 40% because of the facts that shear is decreasing, and circulations are trying to form. It seems to just be a matter of one taking hold and going from there.

Am I right in thinking that most of the convection has detached from the wave or are they still one feature?

[rockyman]

If the LLC forms to the SOUTHeast of the model initialization, I'm not sure the models will shift east...but maybe just be slower...they could even shift west, if the next ridge begins to build in.

Now if the LLC forms to the NORTHeast of the model initialization, I would expect an east shift in the models.

[tolakram]

Where?

Long radar loop.