Tropical Wave east of Lesser Antilles (Is Invest 96L)

[TheStormExpert]

Ok, stupid question time. Where did the term "lemon" come from?

The fact that the NHC gives these areas a shaded Yellow Circle when development chances are within 0-20%. In some ways it looks like a huge Lemon!

[Hurricaneman]

I dont know but it looks like 017L absorbs 018L in this run and something else that is different from the GFS compared to the other models is that it seems to break down the ridge more which has been a known bias of the GFS

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.

[TheStormExpert]

TWC isn't crazy with it. Says it's pulling in SAL/Dry Air from the North and will struggle like all the others.

[Sanibel]

What usually happens is there's an invisible threshold that has to do with climatological forcing that gets broken and the storm bursts. Forget about the SAL once that happens.

[Hurricane Andrew]

Ok, stupid question time. Where did the term "lemon" come from?

The fact that the NHC gives these areas a shaded Yellow Circle when development chances are within 0-20%. In some ways it looks like a huge Lemon!

With the 5 day graphics it's more of a Banana...LOL

[cycloneye]

8 AM TWD:

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 19N29W TO A 1010 MB LOW
PRESSURE CENTER THAT IS NEAR 10N31W. THE WAVE IS MOVING WESTWARD
10 TO 15 KNOTS. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO
STRONG FROM 6N TO 10N BETWEEN 35W AND 39W. ISOLATED MODERATE TO
LOCALLY STRONG ELSEWHERE FROM 5N TO 12N BETWEEN 26W AND 45W.
BROKEN TO OVERCAST MULTILAYERED CLOUDS...CYCLONIC WIND FLOW...
AND OTHER POSSIBLE RAINSHOWERS COVER THE AREA THAT IS FROM THE
EQUATOR TO 17N BETWEEN 24W AND 50W.

[gatorcane]

The 12Z ECMWF is actually now maintaining a vorticity for the full run instead of the previous runs which kept this as a wave that got stretched out north of the ITCZ:

120 hours, south-central tropical Atlantic:


216 hours approaching the Leewards:

[TheStormExpert]

This would be for the pouch just ahead of Pouch 018L right?

[wxman57]

I suppose that a forecast of a tropical wave approaching the Leeward Islands is a big event for this season. We may well get through August without an additional TC.

[TheStormExpert]

I suppose that a forecast of a tropical wave approaching the Leeward Islands is a big event for this season. We may well get through August without an additional TC.

We technically haven't had a TC form in August to begin with! So going the whole month without any TC's would not be out of the question.

It also further proves that we are more than likely out of the active era that we were probably in from 1995-2010.

[gatorcane]

:uarrow: This would be for the pouch just ahead of Pouch 018L right?

Yes, Pouch 17L.

Here is what the upgraded UKMET is doing with this system...keeps it a low also heading more WNW than the ECMWF:

132 hours:

[TheStormExpert]

:uarrow: This would be for the pouch just ahead of Pouch 018L right?

Yes, Pouch 17L.

Here is what the upgraded UKMET is doing with this system...keeps it a low also heading more WNW than the ECMWF:

132 hours:
http://i59.tinypic.com/2il1qat.jpg

I'm assuming neither model shows anything coming out of Pouch 018L, right?

[wxman57]

I suppose that a forecast of a tropical wave approaching the Leeward Islands is a big event for this season. We may well get through August without an additional TC.

We technically haven't had a TC form in August to begin with! So going the whole month without any TC's would not be out of the question.

It also further proves that we are more than likely out of the active era that we were probably in from 1995-2010.

I don't think we'll be out of the current active cycle until 2025-2030. Cool and relatively inactive periods were common in previous active cycles. The last active cycle began in 1926 and ended in 1969 (44 years). It's only been 19 years since this cycle started.

[floridasun78]

so models want bring Pouch 017 back to life??? now fight for his life

[gatorcane]

I'm assuming neither model shows anything coming out of Pouch 018L, right?

No but the ECMWF rarely shows development of something in the MDR and UKMET is also a very conservative model. But they are both tracking some kind of low/vorticity for the next 5+ days unlike invest 94L which they both killed off.

Here is a link to the to the Central Atlantic IR JAVA loop. It seems this pouch has a nice feed of moisture coming up from the ITCZ and the mid-level cloud canopy is expanding on the southern/Eastern sides of the low - maybe we will see a burst of convection later around DMIN? No doubt it is battling dust and sinking air to the north though:

http://www.ssd.noaa.gov/goes/east/catl/loop-avn.html

[blp]

I'm assuming neither model shows anything coming out of Pouch 018L, right?

Not but the ECMWF rarely shows development of something in the MDR and UKMET is also a very conservative model. But they are both tracking some kind of low/vorticity for the next 5+ days unlike invest 94L which they both killed off.

Here is a link to the to the Central Atlantic IR JAVA loop. It seems this pouch has a nice feed of moisture coming up from the ITCZ and the mid-level cloud canopy is expanding on the southern/Eastern sides of the low - maybe we will see a burst of convection later around DMIN? No doubt it is battling dust and sinking air to the north though:

http://www.ssd.noaa.gov/goes/east/catl/loop-avn.html

Ukmet is latching onto 17l. The Euro also likes it better in the long run but further South as you said. The GFS, CMC and NAVGEM like either 18l or a merger of the two.

[cycloneye]

:uarrow: This would be for the pouch just ahead of Pouch 018L right?

Yes, Pouch 17L.

Here is what the upgraded UKMET is doing with this system...keeps it a low also heading more WNW than the ECMWF:

132 hours:
http://i59.tinypic.com/2il1qat.jpg

Text of the UKMET developing this pouch.

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 90 HOURS

FORECAST POSITION AT T+ 90 : 13.5N 40.8W



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

12UTC 19.08.2014 14.0N 41.7W WEAK WEAKENING SLIGHTLY

00UTC 20.08.2014 15.3N 45.6W WEAK LITTLE CHANGE

12UTC 20.08.2014 16.2N 50.2W WEAK LITTLE CHANGE

00UTC 21.08.2014 17.2N 55.7W WEAK LITTLE CHANGE

12UTC 21.08.2014 18.3N 61.1W WEAK LITTLE CHANGE

[Hurricaneman]

By the looks of the 0zGFS it looks like this is in the islands by day 7 and doesnt absorb or combine with 95L but remains its own separate entity and may need to be watched next week as we have no real idea what this will do as it does currently have a LLCC and most of the models develop something from this closer to the islands it still has dry and stable air to work with

Another thing about this is the models don't really do anything with it until about 50W and basically the GFS does nothing with either pouch 017L or 95L so either the GFS is correct or its another fail for the GFS and this, 95L or both develop into tropical systems

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.

[gatorcane]

The 00Z ECMWF and UKMET are even a little more bullish than their 12Z runs yesterday:

UKMET 132 hours, approaching NE Leewards:


ECMWF 168 hours:

[cycloneye]

The 00z UKMET text.

NEW TROPICAL STORM FORECAST TO DEVELOP AFTER 60 HOURS

FORECAST POSITION AT T+ 60 : 13.2N 38.3W



VERIFYING TIME POSITION STRENGTH TENDENCY

-------------- -------- -------- --------

12UTC 18.08.2014 13.2N 38.3W WEAK

00UTC 19.08.2014 14.0N 38.9W WEAK LITTLE CHANGE

12UTC 19.08.2014 14.9N 42.1W WEAK LITTLE CHANGE

00UTC 20.08.2014 15.4N 45.8W WEAK INTENSIFYING SLIGHTLY

12UTC 20.08.2014 16.6N 50.2W WEAK LITTLE CHANGE

00UTC 21.08.2014 17.7N 55.4W WEAK LITTLE CHANGE

12UTC 21.08.2014 18.0N 60.4W WEAK INTENSIFYING SLIGHTLY

00UTC 22.08.2014 18.8N 64.6W WEAK INTENSIFYING SLIGHTLY