ATL: INVEST 95L - DISCUSSION

[Thunder44]

Special TWO: 60% for development for 95L.

000
ABNT20 KNHC 052109
TWOAT
SPECIAL TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
510 PM EDT MON JUL 5 2010

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

A SMALL WELL-DEFINED LOW PRESSURE SYSTEM LOCATED ABOUT 50 MILES
SOUTH-SOUTHEAST OF MORGAN CITY LOUISIANA IS MOVING ONSHORE
TERREBONNE PARISH NEAR CAILLOU BAY. DOPPLER RADAR AND SATELLITE
DATA INDICATE THAT SUSTAINED WINDS NEAR TROPICAL-STORM-FORCE COULD
OCCUR ACROSS TERREBONNE PARISH...ESPECIALLY IN TERREBONNE
BAY...LATE THIS AFTERNOON AND EARLY EVENING AS THE SYSTEM MOVES
ONSHORE. THERE IS A HIGH CHANCE...60 PERCENT...OF THIS SYSTEM
BECOMING A TROPICAL CYCLONE BEFORE IT MOVES ONSHORE. THIS SYSTEM
WILL MOVE SLOWLY NORTHWESTWARD AFTER LANDFALL AND PRODUCE LOCALLY
HEAVY RAINFALL OVER PORTIONS OF SOUTH-CENTRAL AND SOUTHEASTERN
LOUISIANA. INTERESTS SHOULD MONITOR PRODUCTS ISSUED BY THEIR LOCAL
NATIONAL WEATHER FORECAST OFFICE FOR ADDITIONAL UPDATES AND ANY
WATCHES OR WARNINGS.

A BROAD AREA OF LOW PRESSURE OVER THE NORTHWESTERN CARIBBEAN SEA AND
THE SOUTHEASTERN GULF OF MEXICO IS PRODUCING WIDESPREAD CLOUDINESS
AND DISORGANIZED THUNDERSTORMS. UPPER-LEVEL WINDS ARE FORECAST TO
BECOME MORE CONDUCIVE FOR DEVELOPMENT...AND A TROPICAL DEPRESSION
COULD FORM OVER THE NEXT COUPLE OF DAYS AS THIS SYSTEM MOVES
NORTHWESTWARD AT ABOUT 15 MPH. THERE IS A MEDIUM CHANCE...30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINFALL
AND GUSTY WINDS ARE POSSIBLE OVER THE YUCATAN PENINSULA AND WESTERN
CUBA OVER THE NEXT DAY OR SO.

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

$$
FORECASTER STEWART/CANGIALOSI

[ConvergenceZone]

Luckily this ran out of real-estate. It really started to get that spinning look.

Well, guess it's time to get some yard work done and work on some things in July during this Lull, because I have a feeling August is going to be off the charts!
and I probably won't ever leave the computer on the weekends

[Alacane2]

Wow! From 0% chance to 60% chance. I think they would have to write an advisory on it immediately if it is ever to become a named system. Looks to be about to make landfall.

[rockyman]

this might continue increasing in intensity for a while after landfall

[HURAKAN]

Latest

[Cyclone1]

0%, to 60% right at landfall. I will never fully understand the mysterious labyrinth that is the NHC.

[brunota2003]

As a side note...Stewart wrote that, and he has been writing very good TWOs, along with the fact when he writes them, the chances are way higher too.

[Cainer]

I really don't understand anything about the NHC's reasoning on this system. I found it especially odd that during the day when the system was becoming better organized, they not only ignored it's better organization but lowered the chances of development to near 0%. And now that it's about to make landfall, they suddenly up the chances to 60%! If this does become a named storm, I think the NHC will have some questions to answer.

[CrazyC83]

Probably is a tropical storm right now. If it doesn't become Bonnie, I think it will be the No-Name TS.

[HURAKAN]

Could this be Arthur-part II? Named after landfall? Stay tuned.

[chzzdekr81]

How is this not a tropical depression!?!?!?!?

[HURAKAN]

How is this not a tropical depression!?!?!?!?

I guess there is a debate raging in the NHC right now.

[Ivanhater]

Looks like Bonnie is making landfall...should be named imo

[wxman57]

DOPPLER RADAR indicates maybe TS winds? The nearest Doppler is 110 miles away looking at a height of 12,500 feet above the low. There are plenty of surface obs around the weak low that indicate 15-20 kts (one 25kt wind in a squall). And winds W-NW of the low are blowing AWAY from the center. I could see calling it the mini TD it's been for 24 hours now, but a TS??

[Ivanhater]

I mean a decision should be named now..I don't get how it jumps to 60 percent as it is making landfall...is it named or not? I don't understand how you play the fence when it is already making landfall

[chzzdekr81]

Can they issue another special advisory anytime now? This is a bad call...

[Ivanhater]

AT 213 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS INDICATED A
LARGE AREA OF SHOWERS AND THUNDERSTORMS...PRODUCING STRONG WINDS UP
TO 33 KNOTS...9 NM SOUTHWEST OF ISLE DERNIERS...MOVING NORTHWEST AT
10 KNOTS.

[djones65]

Wxman57, 12,500 feet, wouldn't that be similar to a recon plane at 700 mb or 10000 feet? Using a .90 conversion factor, or even a .85 would be an accurate way to measure potential surface winds. If the Doppler velocities were 40 knots or so then surface winds could reasonably be estimated at 34 knots. This storm is a very small compact system. We have a large network of ship, buoys, and oil platforms offering observations, but relative to the size of the circulation and the area being affected, they are still few and far between. If this was a larger circulation then I would agree that the surface obs do not substantiate a storm, but this is a tiny system and I believe it is possible for much stronger winds to exist near the center where no obs are being made. Even in your satellite and observation graphic, there were only 7 surface obs being utilized over an area in excess of 200 miles. That is a lot of "holes" for stronger winds to be observed. With all that being said, I thought this system was a tropical storm yesterday very similar to Marco of 2008 which many others posted similar thoughts. Today it is not as well organized but I definitely think it is a tropical depression, and I would not at all be surprised if tropical storm force winds were observed around the center especially to the east.

[cycloneye]

I would have put a special advisory instead of a special tropical weather outlook.

[lester]

NHC screwed up on this one. No doubt about it