TS Harvey

[Srain]

I'll post this just because Adam loves the word pouch...

SYNOPSIS

2011081100P15L11N, 19W700 hPa

ECMWF: The high resolution of the ECMWF leads to the depiction of two tiny pouches within the larger pouch for many of the forecast charts.

GFS: Distinct, strong pouch.

UKMET: Distinct, pouch.

NOGAPS: OUTLIER! Barely a pouch in the analysis. Then, like yesterday, the hint of pouch slowly crawls west-southwestward away from the African coast. Perhaps the -8.6 m/s phase speed is incorrect and not indicative of the movement of this particular "pouch", which only appears as an OW max when displayed with that fast phase speed.

HWRF-GEN: Very strong pouch. Unlike ECMWF, HWRF-GEN depicts only one distinct pouch position.

ECMWF -7.3 v700 120h

GFS -7.6 v700 120h

UKMET -8.6 v700 120h

NOGAPS -8.6 v700 0h

HWGEN -6.8 v700 120h

[am19psu]

I think that's 93L.

Yeah, it was. But just posting images from the 300 hr GFS with no analysis doesn't exactly inspire confidence in a poster.

[am19psu]

I am not saying it's a sure thing, and I realize that it's the fantasy area of the GFS, but the NAO index is forecast to rise during that time frame, and the PNA is supposed to fall also which would suggest more of a ridge and a increased risk along the east coast.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/new.nao_index_ensm.html

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/new.pna_index_ensm.html

Sure, this is a fine post. You're defending your results and creating discussion. That's always going to be cool by me.

[Srain]

AMSUB suggests the better rotation is with the convection to the E...dry air to the N will keep 93L in check for the next several days as well...

[OSUmetstud]

AMSUB suggests the better rotation is with the convection to the E...dry air to the N will keep 93L in check for the next several days as well...

for what it's worth..the GFS takes weak TC into shrederrola and then dissipates it.

[am19psu]

for what it's worth..the GFS takes weak TC into shrederrola and then dissipates it.

Go forward, grasshopper

[am19psu]

AMSUB suggests the better rotation is with the convection to the E...dry air to the N will keep 93L in check for the next several days as well...

Yep, we're going to have 4-6 days to watch this before anything exciting happens.

[CUmet]

I don't think the dry air to the north is the main problem per se, but it coupled with the presence of moderate easterly shear over the next couple days will slow down development. I'm not sure if it'll take quite as long as 5 days for TC genesis, but the GFS on the other hand is almost certainly too aggressive in the short term.

In general, I tend to be more cautious about invoking the dry air explanation because there are often times, especially in low-moderate shear cases, it's not clear at all whether it will actually have a detrimental influence. Many TCs in the Atlantic, whether they are weakening, steady, or intensifying, have a significant amount of dry air somewhere in the environment. Even invoking the SAL is kind of tricky in the absence of mid-level wind/RH data, because many times the presence of dry air in the Central/Eastern Atlantic is really the product of large-scale subsidence and not necessarily Saharan air.

[Cory]

Did something a bit different this time. The model ran to 144 hours and I then plotted past 12-hourly positions. Also, I overlayed an intensity forecast with the other models.

[Ivanhater]

Up to 40 percent

A WELL-DEFINED LOW PRESSURE SYSTEM LOCATED ABOUT 275 MILES SOUTH

OF THE SOUTHERN CAPE VERDE ISLANDS IS PRODUCING A LARGE AREA OF

CLOUDINESS AND SCATTERED THUNDERSTORMS. ENVIRONMENTAL CONDITIONS

ARE EXPECTED TO GRADUALLY BECOME MORE CONDUCIVE FOR DEVELOPMENT

OVER THE NEXT SEVERAL DAYS AS IT MOVES WESTWARD AT 15 TO 20 MPH.

THE SYSTEM HAS A MEDIUM CHANCE...40 PERCENT...OF BECOMING A

TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

[Ivanhater]

12z GFDL

[Ed Lizard]

SSD website has a mislabeled 93 floater now, labelled '93W', just waiting for 93 to get a little further from Africa.

[Ivanhater]

12z Euro is coming in stronger with 93L

[Ivanhater]

216 hours is interesting

[Riptide]

GFDL and HWRF somehow don't develop this. Really disappointing...perhaps it's an effect of poor organization and things will change when an LLC comes about.

[Ivanhater]

And finally this is what the 12z Euro ends up with

[wxsmwhrms]

GFDL and HWRF somehow don't develop this. Really disappointing...perhaps it's an effect of poor organization and things will change when an LLC comes about.

Doesn't the GFDL have a hurricane approaching the Islands at 120 hours??

[MarkSC]

12Z Euro much more bullish and now takes it into the Bahamas.

[Srain]

GFDL and HWRF somehow don't develop this. Really disappointing...perhaps it's an effect of poor organization and things will change when an LLC comes about.

The hurricane models should be taken with a grain of salt at this point. They really offer no viable solution regarding intensity and until the HWRF can prove it is a reasonable model, I regard it as an extreme outier. What I do take from the 12Z operational suite is a trend to better agreement with what the overnight ensembles suggested.

[Cory]

The hurricane models should be taken with a grain of salt at this point. They really offer no viable solution regarding intensity and until the HWRF can prove it is a reasonable model, I regard it as an extreme outier. What I do take from the 12Z operational suite is a trend to better agreement with what the overnight ensembles suggested.

HWRF will have a northward-moving Cat 3 in 48 hours anyway .

[Riptide]

Doesn't the GFDL have a hurricane approaching the Islands at 120 hours??

It's a moderate tropical storm when it approaches the Islands and the intensity remains pretty constant across the EATL. You'd think this would be approaching major status based on the lack of dry air and convective patterns.

[Ed Lizard]

And finally this is what the 12z Euro ends up with

Euro might be suggesting an Andrew or Betsy type double tapper, although double checking Wiki track maps it doesn't really follow either storm, except for the Florida hit and possible path to Louisiana. Last big Louisiana hurricane that came across Florida, Rita, only gave us about an inch of rain. Hard to tell, but the rare Miami to South Texas track could be possible based on the Euro ridge forecast at day 10. And that probably would be happy for the lawn. Sorry for the IMBYism, but we got a disasterous drought going on.

[Juliancolton]

Last big Louisiana hurricane that came across Florida, Rita, only gave us about an inch of rain.

Rita went through the FL Straits, so I'm not sure that counts tbh.

[Cheeznado]

This is going to be a tough one as the US landfall threat will be totally dependent on transient short wave in the northern stream- the models will likely be all over the place for quite a few days as they shift on the timing of those waves- we will have to be lucky (or unlucky, depending on your point of view) in getting the correct mid-latitude configuration to be in place just as this comes into either the Bahamas or the Caribbean. Right now with the general long-wave pattern being a ridge in the Rockies/Plains and a trough in the east a recurve is still the scenario that is probably the most likely but this one does at least have a shot at a landfall (assuming it develops and misses Hispaniola). Finally something to watch in the next week in any event, unlike the certain fish 92L.

[Srain]

One of the better track clusters we've seen in a long time. Consensus suggests a Westerly track via 18Z guidance...

[HurricaneJosh]

One of the better track clusters we've seen in a long time. Consensus suggests a Westerly track via 18Z guidance...

Agreed. Hawt. Got wood lookin' at that.

[HurricaneJosh]

Jorge's lurking. Perhaps he might find a moment in his busy vacation schedule to pleasure us with a comment.

[wxmx]

93l is still not worth spending much of my time, i rather lie down looking at the 29c SSTs while emptying a beer bottle. Maybe in 2-3 days

[HurricaneJosh]

93l is still not worth spending much of my time, i rather lie down looking at the 29c SSTs while emptying a beer bottle. Maybe in 2-3 days

[EasternUSWX]

I believe this is 93?