ATL: CRISTOBAL - Post-Tropical - Discussion

[Evil Jeremy]

Strengthening and organizing:

18z:


21z (aprox):

[sunnyday]

I heard on the Weather Channel that it has been over 3200 days since Fl was hit by a hurricane. They seem to have good luck down there most of the time.

[cycloneye]

50%-70%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED AUG 20 2014

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Shower and thunderstorm activity associated with an elongated area
of low pressure located several hundred miles east of the Windward
Islands is slowly becoming better organized. Additional development
is possible during the next day or two, and a tropical depression
could form as the system moves west-northwestward at 10 to 15 mph
across the Lesser Antilles and into the Caribbean Sea. After that
time, land interaction could limit development potential over the
weekend. Regardless of tropical cyclone formation, gusty winds and
heavy rainfall are possible across portions of the Lesser Antilles,
Puerto Rico, and the Virgin Islands on Thursday night and Friday.
Interests in those islands should closely monitor the progress of
this system. An Air Force Reserve Hurricane Hunter aircraft is
scheduled to investigate the low tomorrow afternoon, if necessary.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Beven

[SouthDadeFish]

I am very impressed by recent microwave imagery as well the most recent satellite trends. Convection has been persistent during diurnal minimum and deep convection continues to fire and expand near the suspected LLC. I am thinking a LLC may be forming around 12.7 N and 53.4 W.

Edit: Still no observational evidence for a LLC yet, though.

[toad strangler]

I heard on the Weather Channel that it has been over 3200 days since Fl was hit by a hurricane. They seem to have good luck down there most of the time.

Well actually FL is in the midst of it's longest hurricane drought of any intensity back to the US Civil War. Florida is a HUGE state when you look at the map and realize the multiple directions a system can come in and nail a gigantic amount of coastline.

Of course, there is no such thing as "overdue" in weather so the US Civil War note is just that. A note!

[ozonepete]

Boy the visual clues from rgb satellite sure look like it's developing rapidly now. Seems to have consolidated a COC both at mid-levels and quite likely down to the surface just in the last few hours. Interesting too that this is the first time since 2012 I've seen the MJO this conducive for development in the western Atlantic (negative 200 hPA velocity potential anomalies) and it's only going to get more conducive. (Green lines are negative anomalies which aid in vertical thunderstorm development, and these anomalies move from west to east so you can see how the core of very negative anomalies are going to move over this system soon.)

[cycloneye]

I am very impressed by recent microwave imagery as well the most recent satellite trends. Convection has been persistent during diurnal minimum and deep convection continues to fire and expand near the suspected LLC. I am thinking a LLC may be forming around 12.7 N and 53.4 W.

Edit: Still no observational evidence for a LLC yet, though.

They may wait for recon to confirm unless there is an ASCAT pass showing a well defined LLC before that afternoon mission.

[gatorcane]

Saved loop, it's organizing for sure, a bit faster than I expected:

[ozonepete]

I am very impressed by recent microwave imagery as well the most recent satellite trends. Convection has been persistent during diurnal minimum and deep convection continues to fire and expand near the suspected LLC. I am thinking a LLC may be forming around 12.7 N and 53.4 W.

Edit: Still no observational evidence for a LLC yet, though.

They may wait for recon to confirm unless there is an ASCAT pass showing a well defined LLC before that afternoon mission.

I have the same point, SDF.
And yes I agree Luis, a new ASCAT pass or a 37 GHZ microwave pass could tell us.

[ozonepete]

For those who don't know, 37 GHz microwave detects circulation returns from much lower than 85 GHz so they give us a good idea if there's an LLC present when clouds obscure the center during the day or at night when no visible images are available.

[TheStormExpert]

50%-70%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT WED AUG 20 2014

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Shower and thunderstorm activity associated with an elongated area
of low pressure located several hundred miles east of the Windward
Islands is slowly becoming better organized. Additional development
is possible during the next day or two, and a tropical depression
could form as the system moves west-northwestward at 10 to 15 mph
across the Lesser Antilles and into the Caribbean Sea. After that
time, land interaction could limit development potential over the
weekend. Regardless of tropical cyclone formation, gusty winds and
heavy rainfall are possible across portions of the Lesser Antilles,
Puerto Rico, and the Virgin Islands on Thursday night and Friday.
Interests in those islands should closely monitor the progress of
this system. An Air Force Reserve Hurricane Hunter aircraft is
scheduled to investigate the low tomorrow afternoon, if necessary.
* Formation chance through 48 hours...medium...50 percent.
* Formation chance through 5 days...high...70 percent.

$$
Forecaster Beven

Looks like I was spot on correct earlier when I predicted it would possibly be 50/70% @ 8pm.

[gatorcane]

NWS Miami brings some sanity to the situation:

LONG TERM...
SATURDAY THROUGH WEDNESDAY...
FRIDAY PATTERN FAVORING INLAND AND WEST COAST IN THE AFTERNOON
AND EVENING WILL EXTEND THROUGH THE WEEKEND AS RIDGE OF HIGH
PRESSURE REMAINS TO OUR NORTH. FOR THE EARLY PART OF NEXT WEEK ALL
EYES ARE IN THE TROPICS. AT THIS TIME THE UNCERTAINTY IS JUST TOO
LARGE. GLOBAL MODELS DIVERGE SIGNIFICANTLY IN TERMS OF DEGREE OF
STORM DEVELOPMENT, WHERE IT WILL GO AND TIMING. SO AT THIS TIME
SOUTH FLORIDA RESIDENTS ARE JUST ADVISED TO STAY TUNED OVER THE
WEEKEND. NOTHING TO WORRY ABOUT AT THIS TIME OTHER THAN CHECKING
OUR PREPAREDNESS PLANS. AFTER ALL, WE ARE HEADING INTO THE PEAK OF
THE HURRICANE SEASON.

http://forecast.weather.gov/product.php ... glossary=1

[Hurricane Andrew]

Strengthening and organizing:

18z:


21z (aprox):

That is a fairly impressive microwave pass. (21z)
PS: Good to see you again, Jeremy. Been a while.

[TropicalAnalystwx13]

Invest 96L has organized quite nicely today, with blossoming convection over what an afternoon microwave pass indicated was a fairly well-defined low-level circulation. Moving forward in time, the environment looks generally favorable for development. First off, a large anticyclone has setup over 96L, lowering wind shear to 5 to 10 knots and negating any potential shear from the upper-level low northwest of Puerto Rico. There is some dry air in the vicinity of 96L as evidenced by some outflow boundaries earlier this evening, but this shouldn't inhibit development altogether. Third, a strong convectively-coupled kelvin wave is currently pushing over Panama into the Atlantic Ocean. It's important to note that disturbances and tropical cyclones often benefit most from CCKWs two days after they pass by (Ventrice, 2012). The biggest issue for Invest 96L during its lifetime will be interaction with the Greater Antilles; if this passes over Hispaniola, it could just dissipate (and potentially reform in the Bahamas). If not, it looks (from my perspective) at this point that this would have a good chance to appreciably intensify in the Bahamas region. It's too early to say how strong this would be at peak and where it would make landfall, if it ever does.

[cycloneye]

00z Best Track.

AL, 96, 2014082100, , BEST, 0, 125N, 543W, 25, 1009, DB

[Gustywind]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED AUG 20 2014

...SPECIAL FEATURES...

A 1009 MB ATLANTIC OCEAN LOW PRESSURE CENTER IS NEAR 12N53W...IN
THE MONSOON TROUGH. SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION IS FROM 10N-13N BETWEEN 51W-58W. GRADUAL DEVELOPMENT
OF THIS FEATURE IS POSSIBLE DURING THE NEXT FEW DAYS...WHILE IT
WILL BE MOVING WESTWARD-NORTHWESTWARD 10-15 KNOTS...ACROSS THE
LESSER ANTILLES INTO THE CARIBBEAN SEA. PEOPLE WHO LIVE IN THE
LESSER ANTILLES AND THE ISLANDS OF THE NORTHEASTERN CARIBBEAN
SEA SHOULD MONITOR CLOSELY THE PROGRESS OF THIS FEATURE. THE
CHANCE FOR DEVELOPMENT INTO A TROPICAL CYCLONE DURING THE NEXT
48 HOURS IS MEDIUM.

[cycloneye]

Here is the RAMSDIS loop that shows how it is organizing and the movement.

http://rammb.cira.colostate.edu/ramsdis ... display=12

[floridasun78]

NWS Miami brings some sanity to the situation:

LONG TERM...
SATURDAY THROUGH WEDNESDAY...
FRIDAY PATTERN FAVORING INLAND AND WEST COAST IN THE AFTERNOON
AND EVENING WILL EXTEND THROUGH THE WEEKEND AS RIDGE OF HIGH
PRESSURE REMAINS TO OUR NORTH. FOR THE EARLY PART OF NEXT WEEK ALL
EYES ARE IN THE TROPICS. AT THIS TIME THE UNCERTAINTY IS JUST TOO
LARGE. GLOBAL MODELS DIVERGE SIGNIFICANTLY IN TERMS OF DEGREE OF
STORM DEVELOPMENT, WHERE IT WILL GO AND TIMING. SO AT THIS TIME
SOUTH FLORIDA RESIDENTS ARE JUST ADVISED TO STAY TUNED OVER THE
WEEKEND. NOTHING TO WORRY ABOUT AT THIS TIME OTHER THAN CHECKING
OUR PREPAREDNESS PLANS. AFTER ALL, WE ARE HEADING INTO THE PEAK OF
THE HURRICANE SEASON.

http://forecast.weather.gov/product.php ... glossary=1

i here miami live mobile home so watching with you all 96l

[Gustywind]

Here is the RAMSDIS loop that shows how it is organizing and the movement.

http://rammb.cira.colostate.edu/ramsdis ... display=12

Good catch Luis very interresting! Given my untrained eyes, 96L continues to take shape tonight and having a decent sat appearence now...

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[meriland23]

Seems to be huddling up now..doesn't look so all over the place. Definitely better organized.