ATL: DEBBY - Post-Tropical

[Tampa Bay Hurricane]

I hope El Nino brings an early end to this hurricane season which has already been bad for Florida with the
tornadoes and flooding from 2 tropical cyclones.

[Sanibel]

Always watch anything that still has spin and crosses over the Gulf Stream.

[northjaxpro]

I hope El Nino brings an early end to this hurricane season which has already been bad for Florida with the
tornadoes and flooding from 2 tropical cyclones.

From someone here who is extremely weary of all of the tropical activity in this part of the world this past month, I 100% say AMEN to this!!!

[brunota2003]

Looking at the latest with Ex-Debby...I think it has a good 50% or 60% chance of regeneration. Tight LLC, good fanning out of cirrus clouds (means low shear), the thunderstorms are no longer being blown away, and a band of convection is setting up on the SE side of the circulation and is starting to feed into her. Also of note, the circulation is heading east, but in the last couple hours it appeared to start dropping to the ESE and maybe slowing a little.

Current intensity seems to be 40 knots (1 minute sustained winds of 40 knots measured at Buoy 41048). Lowest pressure at that buoy was 999 millibars at 4:16 pm EDT, with winds of roughly 30 knots...so minimum pressure is likely around 996 or 997 millibars.

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[Fyzn94]

She's looking pretty durn intense for a typical extratropical cyclone.

[Cainer]

To my amateur eye, looks like there's a front extending to the southwest. Still looks pretty extratropical IMO.

[brunota2003]

There is...the analysis has a cold front to the south and warm front to the north at this time.

[ozonepete]

There is...the analysis has a cold front to the south and warm front to the north at this time.

Here's the last statement from NHC:

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT THU JUN 28 2012

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

1. A LOW PRESSURE AREA...THE POST-TROPICAL REMNANTS OF DEBBY...IS MOVING NORTHEASTWARD AT 20 TO 25 MPH ALONG OR JUST SOUTH OF A FRONTAL BOUNDARY ABOUT 300 MILES WEST OF BERMUDA. THE LOW IS PRODUCING SOME SHOWER AND THUNDERSTORM ACTIVITY AND WINDS TO GALE FORCE. THIS SYSTEM HAS A LOW CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT 48 HOURS. ADDITIONAL INFORMATION ON THIS LOW CAN BE FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE.

It is so hard to tell without enough data in the vicinity that they said "along or just south of the boundary". What you can take away from this is that there is plenty of concern that it will become tropical again.

So yes, brunota, I agree with your 50-60% chance. Looks more and more tropical.

[ozonepete]

Do these satellite images remind you of Chris or what? And right now it's over warmer water than Chris was when it started strengthening into a hurricane.

[cycloneye]

8 PM EDT TWO:

A LOW PRESSURE AREA...THE POST-TROPICAL REMNANTS OF DEBBY...IS
LOCATED ABOUT 225 MILES WEST OF BERMUDA AND MOVING EAST-
NORTHEASTWARD AT 20 TO 25 MPH. THE LOW IS PRODUCING GALE-FORCE
WINDS NEAR THE CENTER. HOWEVER...THE ASSOCIATED SHOWER ACTIVITY IS
CURRENTLY MINIMAL...AND ABUNDANT DRY AIR NEAR THE LOW IS EXPECTED
TO PREVENT RE-DEVELOPMENT. THIS SYSTEM HAS A LOW CHANCE...10
PERCENT...OF BECOMING A TROPICAL CYCLONE AGAIN DURING THE NEXT
48 HOURS. ADDITIONAL INFORMATION ON THIS LOW CAN BE FOUND IN HIGH
SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE.

[ozonepete]

Ok, the dry air is a good point but I need to look through the archives because that sounds familiar.

[cycloneye]

The 00z Best Track has the pressure down to 997 mbs.

AL, 04, 2012062900, , BEST, 0, 326N, 683W, 40, 997, LO

http://ftp.nhc.noaa.gov/atcf/tcweb/inve ... 012.invest

[ozonepete]

Thanks for the update, Luis. Still looks like a replay of Chris in a lot of respects. Shear is low, SSTs are better than they were under Chris for now. Mid-level dry air is the only issue.

[ozonepete]

Hey Luis, do you know how ACE is counted for post-tropical systems? Not at all I would guess but I'm not sure.

[cycloneye]

Hey Luis, do you know how ACE is counted for post-tropical systems? Not at all I would guess but I'm not sure.

Dont count.

[wxman57]

It lost all of its convection this evening and is still attached to the cold front. As the NHC indicates, not a great chance they're going to mess with it any more.

[ozonepete]

Don't worry. I will watch Debby to the bitter end. Like I did with Chris.

[ozonepete]

And there is one more factor I forgot to mention, which was a major factor in why Chris developed after everyone left it for dead and became a hurricane after everyone said the SSTs were too low: symmetry. Symmetry allows for very efficient transfer of energy in towards the center from the outer edges at the surface and then upward as it reaches the COC, and it can compensate for lower SSTs as we clearly saw for Chris. Right now Debby has a nearly perfectly circular eye, or COC, and that is a major reason it has not dissipated. I still would agree that the dry air situation is key and could kill it really easily, but it looks 50/50 because the storm itself is still sucking up a lot of warm moist air up from the ocean which serves to gradually moisten its own environment. Just fascinating to watch. I live for this stuff. lol.

Btw, if the center gets stretched again, it's all over.

[cycloneye]

8 AM TWO:

A LOW PRESSURE AREA...THE POST-TROPICAL REMNANTS OF DEBBY...IS
LOCATED ABOUT 90 MILES NORTH-NORTHWEST OF BERMUDA AND MOVING EAST-
NORTHEASTWARD AT 20 TO 25 MPH. ALTHOUGH THIS DISTURBANCE IS
PRODUCING GALE-FORCE WINDS NEAR THE CENTER...SHOWER ACTIVITY
REMAINS MINIMAL AND ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN
UNFAVORABLE FOR RE-DEVELOPMENT TO OCCUR. THIS SYSTEM HAS A LOW
CHANCE...10 PERCENT...OF BECOMING A TROPICAL CYCLONE AGAIN DURING
THE NEXT 48 HOURS. ADDITIONAL INFORMATION ON THIS LOW CAN BE FOUND
IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE.

[wxman57]

Debby is quite tenacious, refusing to be beaten down by the cold front it's still attached to. Will our strongest storms this season all be north of 35N?