Wave in Eastern Atlantic - Is now ATLC Invest 96L

[gatorcane]

Latest image:


Vis loop, shows some spin:
http://rammb.cira.colostate.edu/ramsdis ... display=12

UKMET: develops
GFS: shows a closed low moving west across the MDR

Rest of models do not develop

[cycloneye]

Thank you for making the thread for this wave.This is pouch P20L.

http://www.met.nps.edu/~mtmontgo/storms2015/P20L.html

[cycloneye]

From TWD:

A W AFRICAN TROPICAL WAVE WILL BE EMERGING OFF THE COAST OVER
THE NEXT 24 HOURS. OBSERVATIONS SHOW A 4 MB DROP IN SURFACE
PRESSURE AS THE WAVE HAS PASSED LOCATIONS OVER W
AFRICA...INDICATING A WELL DEFINED WAVE REACHING THE SURFACE.
LOOK FOR THIS WAVE TO BE ADDED TO THE SURFACE ANALYSIS OVER THE
NEXT 24 HOURS.

[gatorcane]

12Z UKMET more bullish:

[gatorcane]

GFS definitely not killing this system in the Eastern Atlantic...18Z run shows a broad closed low heading west.

It's emerging off the coast as I type this:

[cycloneye]

A W AFRICAN TROPICAL WAVE EMERGED OFF THE COAST WITH AXIS FROM
15N18W TO 09N15W. OBSERVATIONS SHOW A 4 MB DROP IN SURFACE
PRESSURE AS THE WAVE HAS PASSED LOCATIONS OVER W
AFRICA...INDICATING A WELL DEFINED WAVE REACHING THE SURFACE. A
CLUSTER OF MODERATE TO STRONG CONVECTION IS FROM 09N-14N AND E
OF 23W.

[Hammy]

It looks more like just a line of thunderstorms than an actual tropical wave, and seems to be lessening in intensity where the low pressure center is actually at. Either way the models should have better accuracy now that it's moved over water.

[Gustywind]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT AUG 15 2015

A TROPICAL WAVE IS IN THE E ATLC ASSOCIATED WITH A 1012 MB LOW NEAR
11N18W AT 0300 UTC. CIRA LAYER PRECIPITABLE WATER IMAGERY FROM
THE SURFACE TO 850 MB SHOW THE WAVE IS ASSOCIATED WITH A BROAD
AREA OF MODERATE MOISTURE THAT ALONG WITH A DIFFLUENT WIND
ENVIRONMENT ALOFT SUPPORT SCATTERED MODERATE CONVECTION AND
ISOLATED TSTMS FROM 08N TO 13N BETWEEN 19W AND 25W AND ISOLATED
SHOWERS AND TSTMS ELSEWHERE E OF 19W.

[Gustywind]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT AUG 15 2015

A TROPICAL WAVE IS IN THE E ATLC ASSOCIATED WITH A 1011 MB LOW
NEAR 10N20W. CIRA LAYER PRECIPITABLE WATER IMAGERY FROM THE
SURFACE TO 850 MB SHOW THE WAVE IS ASSOCIATED WITH A BROAD AREA
OF MODERATE MOISTURE THAT ALONG WITH A DIFFLUENT WIND
ENVIRONMENT ALOFT SUPPORT SCATTERED TO ISOLATED SHOWERS AND
TSTMS FROM 05N TO 13N E OF 24W.

[gatorcane]

The UKMET is really bullish on this wave developing next week:

[gatorcane]

it's a small area of convection but convection is gradually on the increase after it lost a lot of convection moving off Africa. Latest image:

Loop where the rotation is quite clear:
http://rammb.cira.colostate.edu/ramsdis ... display=12



The 12Z ECMWF is now showing a closed low around 1012-1013MB maintaining through 144 hours the run is out so far:

[gatorcane]

12Z ECMWF run rolling and it has changed it's tune a bit on this wave. At 168 hours is now showing a 1012MB closed low that is further to the north and much slower than the GFS and 00Z ECMWF run:

[gatorcane]

192 hours, 1010MB low and heading W to WNW:

[crownweather]

192 hours, 1010MB low and heading WNW:

That situational development south of New England forecast by the Euro and to some extent the CMC has gotten my interest over the last 2-3 days. Definitely something to look out for.

Even more interesting is that the 6-10 day analog 500 mb forecast by both the GFS and CMC matches late August of 1962 when Hurricane Alma tracked right along the US East Coast. Link: http://www.cpc.ncep.noaa.gov/products/p ... idance.php .

[Gustywind]

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT AUG 15 2015


AN EASTERN ATLC TROPICAL WAVE HAS AN AXIS THAT EXTENDS FROM
17N22W TO 06N22W...MOVING W AT 15 TO 20 KT OVER THE PAST 24
HOURS. A 1012 MB LOW IS CENTERED NEAR 10N22W ALONG THE WAVE IN
THE VICINITY OF THE MONSOON TROUGH. SSMI TPW IMAGERY INDICATES
HIGH MOISTURE IS IN THE WAVE ENVIRONMENT. AN INVERTED 700 MB
TROUGH IS INDICATED IN MODEL FIELDS BETWEEN 17W AND 27W.
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION ARE FROM 08N
TO 14N BETWEEN 19W AND 27W.

[gatorcane]

Here is how the ECMWF run ends at 240 hours. Looking at the 500MB height forecast from the model (second image), there is a lot or ridging building in over the Western Atlantic and Eastern North America allowing the low to move W or WNW even if it were to deepen and develop into something more significant. The question is - would there be more favorable conditions downstream further west (say if it got into the area just north of the Leeward islands / Puerto Rico / Hispaniola)?

[TheStormExpert]

That area just off the NC OBX is what I'm now more interested in. Of course whenever the Euro shows something it's worth keeping an eye on IMO.

[gatorcane]

Yes that area off the Mid-Atlantic is interesting too for sure. Will have to watch future models runs on that.

But I find it interesting the Euro has changed it's tune quite a bit from previous runs on this Eastern Atlantic wave. We may very well now see the NHC mention this area now in an upcoming Outlook.

[Kingarabian]

Well at least if it doesn't make it in the Atlantic then it has the potential to make it to the EPAC and become something nice.

[blp]

12z UKMET is stronger. The models look to be in general agreement on some type of development. Let's see if it continues.