ATL: INVEST (97L)

[Aric Dunn]

00z Euro develops 97L near the bahamas..

[jinftl]

great...we don't need a system developing in water 85-90 degrees and doing this developing close to land

00z Euro develops 97L near the bahamas..

[marciacubed]

I think it is looking healthy today , yesterday I didn't see any chance that there was going to be any development. The trough should send it to the north and hopefully a fish storm.

[jinftl]

Latest models show whatever there is of this system not getting north of 20N until it reaches almost 70W...west of puerto rico..and doing so with a wnw to nw motion..hopefully it is weak and continue to stay weak if that pans out

I think it is looking healthy today , yesterday I didn't see any chance that there was going to be any development. The trough should send it to the north and hopefully a fish storm.

[Dean4Storms]

It is apparent 97L took in a big gulp of dry air, note the lack of moisture to its south even down to the ITCZ!

[poof121]

It is apparent 97L took in a big gulp of dry air, note the lack of moisture to its south even down to the ITCZ!

The source of the dry air seems to be cut off now.

http://cimss.ssec.wisc.edu/tropic/real-time/tpw2/natl/main.html

[jinftl]

Model runs converging on system approaching se bahamas at end of period after crossing nothern islands and near puerto rico...watch the trend...

[Ed Mahmoud]

Remarkably close correlation of all three BAM models for the first three days. After that, it looks like it runs into the subtropical jet, with the shallow bam running ahead of the deeper models.

But if it tracks more westerly into the Caribbean, it might be that it mises the jet to the south, in which case the prospect for development gets much better.

BAM models in close agreement means the GFS is predicting low shear. When they start diverging, it means deep, medium and shallow steering are not the same speed or direction.

[cycloneye]

398
ABNT20 KNHC 181731
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SAT JUL 18 2009

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

A TROPICAL WAVE LOCATED NEAR THE LESSER ANTILLES IS PRODUCING
NUMEROUS SHOWERS AND THUNDERSTORMS AS IT INTERACTS WITH AN
UPPER-LEVEL TROUGH. WHILE RAINFALL ASSOCIATED WITH THE WAVE MAY BE
LOCALLY HEAVY AT TIMES...UPPER-LEVEL WINDS ARE NOT CURRENTLY
CONDUCIVE FOR SIGNIFICANT DEVELOPMENT OF THE SYSTEM AS IT MOVES
WEST-NORTHWESTWARD AT AROUND 15 MPH. THERE IS A LOW CHANCE...LESS
THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS.

A TROPICAL WAVE LOCATED ABOUT 1000 MILES EAST OF THE WINDWARD
ISLANDS CONTINUES TO PRODUCE DISORGANIZED SHOWER ACTIVITY. ANY
DEVELOPMENT OF THIS SYSTEM WILL BE SLOW TO OCCUR AS IT MOVES
WESTWARD AT AROUND 20 MPH. THERE IS A LOW CHANCE...LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

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

$$
FORECASTER BRENNAN/LANDSEA

I noticed two words left out (If Any).Nothing important but only I am pointing out that.

[Blown Away]

Good catch, I wonder if there is anything behind it or if we are over analyzing the summary.

[Aric Dunn]

There is clearly still a low to mid level rotation .. only problem ia again this nagging but slowly dimishing pocket of dry air which is nearly worked out .. and the system entering in the carrib is both leaving more moisture behind for 97L but also maybe causing some substunance ( cant spell ) or sinking air over 97L.

so its not over till there is nothing left .. lol

[KWT]

Equally cycloneye the first wave is mentioned as having "upper winds not *currently* favorable" which is another interesting phrase to use, do they expect it to get better with time?

[Aric Dunn]

Equally cycloneye the first wave is mentioned as having "upper winds not *currently* favorable" which is another interesting phrase to use, do they expect it to get better with time?

yeah actually thats exactly whats forecast... gfs for instance calls for it to drop of fast and be replaced by a upper high in 24 to 36 hours..

[jinftl]

Also keep in mind the NHC is talking about development in the next 48 hours....doesn't mean that after 48 hours, that couldn't change.

THERE IS A LOW CHANCE...LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

398
ABNT20 KNHC 181731
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SAT JUL 18 2009

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

A TROPICAL WAVE LOCATED NEAR THE LESSER ANTILLES IS PRODUCING
NUMEROUS SHOWERS AND THUNDERSTORMS AS IT INTERACTS WITH AN
UPPER-LEVEL TROUGH. WHILE RAINFALL ASSOCIATED WITH THE WAVE MAY BE
LOCALLY HEAVY AT TIMES...UPPER-LEVEL WINDS ARE NOT CURRENTLY
CONDUCIVE FOR SIGNIFICANT DEVELOPMENT OF THE SYSTEM AS IT MOVES
WEST-NORTHWESTWARD AT AROUND 15 MPH. THERE IS A LOW CHANCE...LESS
THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING
THE NEXT 48 HOURS.

A TROPICAL WAVE LOCATED ABOUT 1000 MILES EAST OF THE WINDWARD
ISLANDS CONTINUES TO PRODUCE DISORGANIZED SHOWER ACTIVITY. ANY
DEVELOPMENT OF THIS SYSTEM WILL BE SLOW TO OCCUR AS IT MOVES
WESTWARD AT AROUND 20 MPH. THERE IS A LOW CHANCE...LESS THAN 30
PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS.

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

$$
FORECASTER BRENNAN/LANDSEA

I noticed two words left out (If Any).Nothing important but only I am pointing out that.

[Aric Dunn]

awwwww.. what a happy little low level circ with little convection and partially still attached to the ITCZ...

http://www.ssd.noaa.gov/goes/flt/t1/loop-rgb.html

[Aric Dunn]

000
AXNT20 KNHC 181758
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT JUL 18 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES..

A TROPICAL WAVE IS ALONG 44W S OF 16N MOVING W NEAR 20 KT. THIS
WAVE COINCIDES WITH A LOW TO MIDDLE LEVEL CYCLONIC CIRCULATION
ALONG THE WAVE AXIS NEAR 12N. SCATTERED MODERATE CONVECTION IS
FROM 10N-14N BETWEEN 43W-47W.

A TROPICAL WAVE EXTENDS ALONG 21N58W 15N61W TO 10N62W MOVING
W NEAR 18 KT. THIS WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER
MOISTURE BASED ON THE TOTAL PRECIPITABLE WATER PRODUCT FROM
CIMSS. WATER VAPOR IMAGERY INDICATES THE WAVE IS BEGINNING TO
MOVE BENEATH AN UPPER LEVEL RIDGE ACROSS THE ERN CARIBBEAN AND
THE NRN PORTION OF THE WAVE IS COMING UNDER THE IMPACTS OF AN
UPPER LOW CENTERED NE OF PUERTO RICO NEAR 23N58W. UPPER LEVEL
DIFFLUENCE BETWEEN THESE TWO FEATURES ARE ENHANCING SCATTERED
MODERATE CONVECTION FROM 13N-18N BETWEEN 55W-62W.

[jinftl]

keep in mind we have an invest here...if it was organized we would probably be talking a depression. Satellite shows a disorganized system gaining longitude....add in some model support for development down the road...what we see now may not be the end of the story (or it could be!)....stay tuned

awwwww.. what a happy little low level circ with little convection and partially still attached to the ITCZ...

http://www.ssd.noaa.gov/goes/flt/t1/loop-rgb.html

[Rainband]

Good catch, I wonder if there is anything behind it or if we are over analyzing the summary.

it say any just not if.

[Aric Dunn]

Here is a image of the system and the white dot is this bouy, circle is a rough estimate from satellite where the overall center of the broad area is located.

[JonathanBelles]

It's apparent to me that 97L is moving a bit faster than Wave #1. What happens if 97L gets pulled up under Wave #1. Wave #1 has convection and 97L is a bit more organized...anything?