PSUBlizzicane2007 Posted August 2, 2012 Share Posted August 2, 2012 GFS ensembles, for what its worth, are weaker and further South than 6Z ensembles. Wow... the op barely even touches them at 192 hrs. Link to comment Share on other sites More sharing options...
thegreatdr Posted August 2, 2012 Share Posted August 2, 2012 When I looked at the medium range guidance on Sunday, the ECMWF was taking the system into the Guyanas and the GFS/UKMET were most bullish taking it through the east-central Caribbean. The guidance is having issues with the strength of the low-level ridging to its northeast (which polar orbiter information could help with), as well as the degree of vertical wind shear it seems (which may not connected with the upper trough to its north in this case unless the system gains latitude). Even without the upper level trough to its north, there would still be shear due to the low level jet in its vicinity...a pattern more reminiscent of July than August. This is why it's usually not a good idea to pin hopes on the development of a system entering the Caribbean until it passes/survives past the 70th meridian. Climatologically, there is an upper level trough centered mid-Caribbean throughout the hurricane season (our friend the TUTT)...which is stronger during El Nino years...which this year is quickly becoming. The LOL is more how the Euro and GFS just refuse to get on the same page with each other... yesterday the situation was almost entirely reversed. Link to comment Share on other sites More sharing options...
tmagan Posted August 2, 2012 Share Posted August 2, 2012 18Z Observations Link to comment Share on other sites More sharing options...
Ed Lizard Posted August 2, 2012 Share Posted August 2, 2012 Getting close... 193600 1323N 05456W 9777 00276 0092 +209 +196 133042 043 032 007 00 Edit closer 194000 1335N 05450W 9766 00291 0102 +196 +167 142047 049 044 016 00 Link to comment Share on other sites More sharing options...
phil882 Posted August 2, 2012 Author Share Posted August 2, 2012 Getting close... 193600 1323N 05456W 9777 00276 0092 +209 +196 133042 043 032 007 00 Edit closer 194000 1335N 05450W 9766 00291 0102 +196 +167 142047 049 044 016 00 The 49 knot flight level winds are probably enough to upgrade... the 44 knot SFMR wind is probably rain contaminated, however given the rain rate. Link to comment Share on other sites More sharing options...
PennyForYourThoughts Posted August 2, 2012 Share Posted August 2, 2012 194100 1338N 05448W 9769 00290 0100 +220 +162 143051 052 037 006 0 That should do it. Link to comment Share on other sites More sharing options...
Snow_Miser Posted August 2, 2012 Share Posted August 2, 2012 ATCF now has TS Ernesto with maximum sustained winds of 40 kt. or 45 mph. http://ftp.nhc.noaa.gov/atcf/tcweb/invest_al052012.invest Link to comment Share on other sites More sharing options...
Superstorm93 Posted August 2, 2012 Share Posted August 2, 2012 It's improving durng the diurnal minimum, which is a big plus. Looks 10x better than yesterday. Link to comment Share on other sites More sharing options...
andyhb Posted August 2, 2012 Share Posted August 2, 2012 It's improving durng the diurnal minimum, which is a big plus. Looks 10x better than yesterday. Yeah, doesn't look anywhere close to as naked as it did. Link to comment Share on other sites More sharing options...
Superstorm93 Posted August 2, 2012 Share Posted August 2, 2012 45 mph Tropical Storm at 5pm AL, 05, 2012080218, , BEST, 0, 128N, 556W, 40, 1008, TS Link to comment Share on other sites More sharing options...
HurricaneJosh Posted August 2, 2012 Share Posted August 2, 2012 Woo hoo! It's the li'l wave that could. Link to comment Share on other sites More sharing options...
Amped Posted August 2, 2012 Share Posted August 2, 2012 Center is consoliidating , maybe globals will get a reasonable track at 00z Link to comment Share on other sites More sharing options...
phil882 Posted August 2, 2012 Author Share Posted August 2, 2012 When I looked at the medium range guidance on Sunday, the ECMWF was taking the system into the Guyanas and the GFS/UKMET were most bullish taking it through the east-central Caribbean. The guidance is having issues with the strength of the low-level ridging to its northeast (which polar orbiter information could help with), as well as the degree of vertical wind shear it seems (which may not connected with the upper trough to its north in this case unless the system gains latitude). Even without the upper level trough to its north, there would still be shear due to the low level jet in its vicinity. This is why it's usually not a good idea to pin hopes on the development of a system entering the Caribbean until it passes/survives past the 70th meridian. Climatologically, there is an upper level trough centered mid-Caribbean throughout the hurricane season (our friend the TUTT)...which is stronger during El Nino years...which this year is quickly becoming. The low-level jet in the Caribbean is worrysome and has done in tropical cyclones in the past (Isidore 2002, Lili 2002, TD#2 2004, Earl 2004). However, the upper level flow in the Caribbean is still easterly with no TUTT feature in the Caribbean that the system might run into. This is an important distinction from the other systems I have listed above, which were origionally under favorable conditions, but the strong low-level jet caused them to move into more unfavorable upper level flow. It is also worth nothing that these systems had a fragile surface circulation that was not very large and was more suceptable to vertical wind shear. Ernesto already has a decent surface circulation (although somewhat elongated), and if it can develop good upper level outflow in the next 24 hours, it can strengthen the upper level anticyclone to the point the shear is not fatal. Link to comment Share on other sites More sharing options...
Ed Lizard Posted August 2, 2012 Share Posted August 2, 2012 The low-level jet in the Caribbean is worrysome and has done in tropical cyclones in the past (Isidore 2002, Lili 2002, TD#2 2004, Earl 2004). However, the upper level flow in the Caribbean is still easterly with no TUTT feature in the Caribbean that the system might run into. This is an important distinction from the other systems I have listed above, which were origionally under favorable conditions, but the strong low-level jet caused them to move into more unfavorable upper level flow. It is also worth nothing that these systems had a fragile surface circulation that was not very large and was more suceptable to vertical wind shear. Ernesto already has a decent surface circulation (although somewhat elongated), and if it can develop good upper level outflow in the next 24 hours, it can strengthen the upper level anticyclone to the point the shear is not fatal. The Yucatan did in Isidore. Claudette and Dolly would seem possible analogs, early season storms which fail to thrive in the Caribbean, but wound up making a decent, if not spectacular comeback in the Western Caribbean and Gulf. Link to comment Share on other sites More sharing options...
Eskimo Joe Posted August 2, 2012 Share Posted August 2, 2012 Rumor has (Facebook, Twitter) it that TD #5 is getting upgraded to Ernseto with the next advisory. Link to comment Share on other sites More sharing options...
phil882 Posted August 2, 2012 Author Share Posted August 2, 2012 The Yucatan did in Isidore. Claudette and Dolly would seem possible analogs, early season storms which fail to thrive in the Caribbean, but wound up making a decent, if not spectacular comeback in the Western Caribbean and Gulf. Many people don't remember but Isidore was a TD just east of the Lesser Antillies before it accelerated in the low-level flow right on the South American coastline. Claudette is another really good analog where the low-level flow put it from very favorable to marginal at best conditions. My argument is that this system can run way out into the Caribbean, but as long as the upper level outflow follows it, there is no TUTT feature that can impeed the upper level flow's progress. Link to comment Share on other sites More sharing options...
toxictwister00 Posted August 2, 2012 Share Posted August 2, 2012 TS Ernesto is listed on the NHC site, but it hasn't updated to show the 5pm advisory yet. Link to comment Share on other sites More sharing options...
Snow_Miser Posted August 2, 2012 Share Posted August 2, 2012 Recon found 45 kt. uncontaminated surface winds so the NHC upgraded it to a 45 kt. TS with minimum pressure of 1006 mb. http://www.nhc.noaa.gov/text/refresh/MIATCPAT5+shtml/021752.shtml Link to comment Share on other sites More sharing options...
Snow_Miser Posted August 2, 2012 Share Posted August 2, 2012 NHC intensity table now has Ernesto reaching 70 kt. Cat 1 Hurricane status in 5 days FWIW Link to comment Share on other sites More sharing options...
phlwx Posted August 2, 2012 Share Posted August 2, 2012 any weather radar sites in the Windward Islands? Link to comment Share on other sites More sharing options...
phil882 Posted August 2, 2012 Author Share Posted August 2, 2012 any weather radar sites in the Windward Islands? http://www.meteo.fr/temps/domtom/antilles/pack-public/animation/animMOSAIC2.html Link to comment Share on other sites More sharing options...
andyhb Posted August 2, 2012 Share Posted August 2, 2012 NHC intensity table now has Ernesto reaching 70 kt. Cat 1 Hurricane status in 5 days FWIW Josh is gonna like this... Link to comment Share on other sites More sharing options...
phlwx Posted August 2, 2012 Share Posted August 2, 2012 Many people don't remember but Isidore was a TD just east of the Lesser Antillies before it accelerated in the low-level flow right on the South American coastline. Claudette is another relaly good analog where the low-level flow put it from very favorable to marginal at best conditions. My argument is that this system can run way out into the Caribbean, but as long as the upper level outflow follows it, there is no TUTT feature that can impeed the upper level flow's progress. It actually went over parts of Venezuela for a time...that didn't do it any favors. Link to comment Share on other sites More sharing options...
Superstorm93 Posted August 2, 2012 Share Posted August 2, 2012 Guadaloupe has a brand new radar site. Probably the most advanced in the Caribbean. Should come in handy when the NHC begins to collaborate with them. Anyways, it's always nice to see a jump from depression to a moderate tropical storm. Sent from my 4G 2 Link to comment Share on other sites More sharing options...
HurricaneJosh Posted August 2, 2012 Share Posted August 2, 2012 Josh is gonna like this... Oh, yeah. This kind of forecast definitely has a pornographic look to me. I'm still worried about the lack of intensity support from the Euro and GFS-- but it's hard not to get a little excited by forecast. Link to comment Share on other sites More sharing options...
Roger Smith Posted August 2, 2012 Share Posted August 2, 2012 Another radar site for Barbados here: http://www.barbadosweather.org/ Link to comment Share on other sites More sharing options...
Scott747 Posted August 2, 2012 Share Posted August 2, 2012 I believe the HS3 mission went operational on the 30th with deployment beginning this coming Monday. Perfect timing if so... Link to comment Share on other sites More sharing options...
Ed Lizard Posted August 2, 2012 Share Posted August 2, 2012 I believe the HS3 mission went operational on the 30th with deployment beginning this coming Monday. Perfect timing if so... Is that the long loiter time drone I heard about? Nevermind, interent knows all: http://www.nasa.gov/mission_pages/hurricanes/missions/hs3/news/hs3.html Link to comment Share on other sites More sharing options...
Scott747 Posted August 2, 2012 Share Posted August 2, 2012 Looks like I'm a month early for actual flights... Bummer. Link to comment Share on other sites More sharing options...
icebreaker5221 Posted August 2, 2012 Share Posted August 2, 2012 The SFC to 700 hPa shear roughly equals the SFC to 600 hPa shear, but I prefer measuring from the low levels to the bottom of a jet stream (not the top) when calculating things like that. But is that what you were asking? Both of those soundings show deep easterlies through 600 hPa. Not sure what you mean by SFC to 700 hPa shear. They probably won't cancel a recon mission if they are trying to confirm that the TD has a closed circulation Good morning turtle. I'm confused (scientifically) by your post. Perhaps you or another might clear things up for me. You mention "SFC to 600 hPa" then refer to "the bottom of the jet stream." As I understand things, the jet stream is around 300 hPa in winter and 200 hPa in summer. Of course we have Low Level Jets too but I'll ignore them for this case. Would one typically (or ever) find the bottom of the jet stream anywhere near 600 hPa? From my amateur understanding the bottom of the jet should be around 400 hPa. Additionally, when looking at the soundings posted earlier, I don't a jet stream, unless 10-15 kts qualifies as a "jet stream." Is it in meteorology that the jet stream is defined by hPa regardless of wind speeds or is it defined by an area of unusually high winds? I've always thought of the jet stream as an area of actual wind but perhaps in science it's technically a height regardless of wind speed? Thank you. Sorry if I'm late to the party, super busy all day. Turtle, the sfc to 600 shear in the San Juan sounding is actually fairly low. There's a sfc-600 mb jet, but the shear within that particular layer is fairly small as there are strong easterlies throughout. The 850-400 mb shear, on the other hand, is fairly large, as the winds relax above 600. So the vertical change in winds, or shear, is large if you take the difference between the LL jet and the relative calm winds above. It's also not technically correct to refer to it as a 'jet steam'. One typically refers to a jet stream when talking about the subtropical jet or mid-latitude jet, or some other feature at or above 300 mb. This, much lower feature is more of a low-level jet in response to warmer SAL air to the north, where easterlies develop in thermal wind balance in response to a low-level south-to-north temperature gradient in the vicinity of the SAL. Link to comment Share on other sites More sharing options...
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