ATL: TROPICAL DEPRESSION BONNIE - DISCUSSION

[bvigal]

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.

[MiamiHurricanes10]

The system is drying up quite a bit tonight, maybe the mid level circulation is displaced east?

Long-range radar imagery shows that the mid-level circulation is nestled under the deepest convection, just north of Puerto Rico.

[Blown Away]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
327 PM EDT MON JUL 19 2010

.DISCUSSION...

WED-THU...(MODIFIED PREV DISC) RIDGE TO OUR NORTH WL CONTINUE TO
PROVIDE A DEEP ONSHORE FLOW BUT STILL TAPPING SUBSIDENT AIR OVER
THE WESTERN ATLANTIC INTO THU. HAVE MAINTAINED A PRIMARILY DRY
FORECAST EXCEPT IN THE SOUTH WHERE CLOUD LINES OFF THE BAHAMAS
SHOULD BRING A SLIGHT CHANCE FOR SHOWERS/STORMS.

MOISTENING IS INDICATED FOR LATE WEEK AND OVER THE WEEKEND AS A
TROPICAL WAVE MOVES ACROSS SOUTH FLORIDA AND INTO THE GULF. AXIS
OF THE WAVE APPEARS TO PASS JUST SOUTH OF THE AREA...STEEPENING
GRADIENT FLOW TEMPORARILY. EXPECT SLIGHTLY HIGHER CHANCES OVER
SOUTH CENTRAL FLORIDA. OVER THE WEEKEND MOS POPS CONTINUE AROUND
40 PERCENT AREA WIDE AND SEE NO REASON TO DIFFER AT THIS
TIME...THOUGH WOULD EXPECT VALUES TO DIMINISH SOME BY SUN/MON AS
THE WAVE PULLS FARTHER AWAY.

[Ivanhater]

I am very impressed with the deep convection sustained throughout the day

[wxman57]

Well, nothing more to see tonight. Time for bed. Give it another day or two to get away from the upper low. It does look more impressive tonight, outflow-wise. Might have to up my 40% chance of development (beyond 48 hrs) tomorrow.

[MiamiHurricanes10]

Well, nothing more to see tonight. Time for bed. Give it another day or two to get away from the upper low. It does look more impressive tonight, outflow-wise. Might have to up my 40% chance of development (beyond 48 hrs) tomorrow.

Got to agree there. 97L definitely looking somewhat better organized tonight. Let's see if it can continue this and possibly develop a low level circulation.

[Blown Away]

Well, nothing more to see tonight. Time for bed. Give it another day or two to get away from the upper low. It does look more impressive tonight, outflow-wise. Might have to up my 40% chance of development (beyond 48 hrs) tomorrow.

Does a deeper 97L system go more poleward and a shallower 97L go more west in this situation?

[Vortex]

The overall presentation continues to slowly improve late this evening. In fact, the MLC continues very vigirous and a renewed deep convective cell has blossomed over the center as of 125 utc image. I wouldn't be surprised to see this work down to the surface earlier than expected.

[cycloneye]

SPECIAL MARINE WARNING
AMZ710-715-200345-
/O.NEW.TJSJ.MA.W.0035.100720T0143Z-100720T0345Z/

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

THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED 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 1145 PM AST

* AT 935 PM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
CLUSTER OF THUNDERSTORMS...PRODUCING STRONG WINDS 34 KNOTS OR
GREATER OVER ATLANTIC WATERS OF PUERTO RICO AND USVI FROM 10 NM TO
19.5N...OR ABOUT 37 NM NORTH OF CABO SAN JUAN...MOVING NORTHWEST 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.

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

[Dean4Storms]

Looks like a ridge is building in over this..........


http://www.ssd.noaa.gov/goes/east/carb/flash-wv.html

[Vortex]

Unfortunately, I think this stands the chance to produce devastating floods for the DR...

[cycloneye]

Unfortunately, I think this stands the chance to produce devastating floods for the DR...

And more sadly, Haiti.

[Dean4Storms]

From the radar trends this evening I think they ought to raise the chance to 30% at 11pm. This continuous convection NNE of PR is bound to create a surface low and possibly an LLC if it continues overnight.

[blp]

Guys, vorticity has improved at the lower levels and that was two hours ago.

[MiamiHurricanes10]

Guys, vorticity has improved at the lower levels and that was two hours ago.

850mb is 5000ft up in the atmosphere, thus in the mid levels. However, 925mb vorticity has also increased which is in the lower levels.

[MiamiHurricanes10]

[Dylan]

Guys, vorticity has improved at the lower levels and that was two hours ago.

[img]

850mb is 5000ft up in the atmosphere, thus in the mid levels. However, 925mb vorticity has also increased which is in the lower levels.

Sorry sir but you are incorrect. H85 is the low levels of the atmosphere.

[Dean4Storms]

I went to my weathertap acct. and used the Radarlab HD, looks like the center of the MLC is near 19n 65.7 west and drifting WNW. I also see an outflow racing SW toward PR so I don't think we got anything at the surface quite yet.

[ConvergenceZone]

I'm also wondering if they might bump up the chances of development to 30% on the next TWO that should be rolling in shortly. More than likely though they will wait until mornring.

[MiamiHurricanes10]

Guys, vorticity has improved at the lower levels and that was two hours ago.

[img]

850mb is 5000ft up in the atmosphere, thus in the mid levels. However, 925mb vorticity has also increased which is in the lower levels.

Sorry sir but you are incorrect. H85 is the low levels of the atmosphere.

I could be very well be wrong, I learned it from a met on weather underground though.