Superstorm93 Posted June 21, 2012 Share Posted June 21, 2012 That's not particularly the most informative graphic at the moment. Not sure why I posted it so early. It's going to be interesting to see how the GFDL/HWRF handle this system. Link to comment Share on other sites More sharing options...
wxmx Posted June 21, 2012 Share Posted June 21, 2012 Not sure why I posted it so early. It's going to be interesting to see how the GFDL/HWRF handle this system. Looking for a sub 950 in either of those ... too bad they are based on the current outlier. Link to comment Share on other sites More sharing options...
phil882 Posted June 21, 2012 Share Posted June 21, 2012 I love it when the models start windshield-wiping. I'd like to add to phil's point above that the timing/strength of the trough is really the big key as to how this shapes up. How the models portray this in each run will need to be watched. Indeed. With the consistent -NAO in place, there will be multiple upper-level impulses that will swing southeastward across Canada into the eastern US. If this were a relatively small TC, I would ordinarily say these small impulses wouldn't be enough to pick up the system if it were in the central GOM. However, with a very large broad circulation such as this, it won't take much to steer this system further northward into a weakness. Thus, if the central ridge is just a hair weaker, 96L might move inland across the central Gulf coast rather than make its way further westward as the ECMWF, GGEM, and UKMET show. We saw a very similar synoptic evolution with Lee last year, where the ECMWF incorrectly forecasted the system to move further west and stall, when it made landfall in LA a good deal earlier than it had forecasted in the medium range. Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 21, 2012 Share Posted June 21, 2012 The Yucatan low is getting mighty close to the convection. Link to comment Share on other sites More sharing options...
turtlehurricane Posted June 21, 2012 Share Posted June 21, 2012 Impressive jets ventilating the convection to the north and south, could be a key factor in maintaining convection, and probably explains how this convective complex got so big. More details on my blog at http://weather.schematical.com/ Link to comment Share on other sites More sharing options...
PSUBlizzicane2007 Posted June 21, 2012 Share Posted June 21, 2012 Impressive jets ventilating the convection to the north and south, could be a key factor in maintaining convection, and probably explains how this convective complex got so big. More details on my blog at http://weather.schematical.com/ Wow. With the way the convection is blowing up, we may be about 36 hours from a classification (assuming over the course of the next day, a firm low center develops). Link to comment Share on other sites More sharing options...
wxmx Posted June 21, 2012 Share Posted June 21, 2012 Yucatan low has been drifting south, mostly inland now...but convection is firing over it...maybe thanks to diurnal land convection, at least in part. Now it's under where the anticyclone is. Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 21, 2012 Share Posted June 21, 2012 Surface obs support some kind of low-level circulation over the Yucatan. Anticyclone is right over the system as well. Link to comment Share on other sites More sharing options...
wxmx Posted June 21, 2012 Share Posted June 21, 2012 It might be over land...but it certainly looks that it has improved in organization. Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 21, 2012 Share Posted June 21, 2012 RAP has 96L down to 1005mbs Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 21, 2012 Share Posted June 21, 2012 70% Cherry Wow... A LARGE LOW PRESSURE SYSTEM LOCATED JUST NORTH OF THE NORTHERN COAST OF THE YUCATAN PENINSULA IS PRODUCING AN EXTENSIVE AREA OF CLOUDINESS...SHOWERS AND SCATTERED THUNDERSTORMS OVER MUCH OF THE CENTRAL AND EASTERN GULF OF MEXICO AND THE NORTHWESTERN CARIBBEAN SEA...AND ALSO OVER THE YUCATAN PENINSULA...WESTERN AND CENTRAL CUBA...SOUTHERN FLORIDA...AND THE NORTHWESTERN BAHAMAS. SATELLITE DATA AND SURFACE OBSERVATIONS INDICATE THAT THE LOW PRESSURE SYSTEM IS GRADUALLY BECOMING BETTER DEFINED AND SURFACE PRESSURES ARE SLOWLY FALLING ACROSS THE AREA. UPPER-LEVEL WINDS ARE ALSO IMPROVING AND ARE FORECAST TO BECOME MORE CONDUCIVE FOR DEVELOPMENT OF A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. THIS SYSTEM HAS A HIGH CHANCE...70 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY NORTHWARD INTO THE CENTRAL GULF OF MEXICO. INTERESTS ALONG THE ENTIRE UNITED STATES GULF COAST SHOULD MONITOR THE PROGRESS OF THIS LARGE DISTURBANCE THROUGH THE WEEKEND. HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE ACROSS THE YUCATAN PENINSULA...WESTERN CUBA...AND SOUTHERN FLORIDA THROUGH SATURDAY. AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM TOMORROW AFTERNOON...IF NECESSARY. Link to comment Share on other sites More sharing options...
DopplerWx Posted June 21, 2012 Share Posted June 21, 2012 Wow, future Debby sure has gotten her act together quickly. With the nice SSTs in the gulf we may see our 2nd hurricane of the season sooner rather than later. Link to comment Share on other sites More sharing options...
SN_Lover Posted June 21, 2012 Share Posted June 21, 2012 70% Cherry Wow... A LARGE LOW PRESSURE SYSTEM LOCATED JUST NORTH OF THE NORTHERN COAST OF THE YUCATAN PENINSULA IS PRODUCING AN EXTENSIVE AREA OF CLOUDINESS...SHOWERS AND SCATTERED THUNDERSTORMS OVER MUCH OF THE CENTRAL AND EASTERN GULF OF MEXICO AND THE NORTHWESTERN CARIBBEAN SEA...AND ALSO OVER THE YUCATAN PENINSULA...WESTERN AND CENTRAL CUBA...SOUTHERN FLORIDA...AND THE NORTHWESTERN BAHAMAS. SATELLITE DATA AND SURFACE OBSERVATIONS INDICATE THAT THE LOW PRESSURE SYSTEM IS GRADUALLY BECOMING BETTER DEFINED AND SURFACE PRESSURES ARE SLOWLY FALLING ACROSS THE AREA. UPPER-LEVEL WINDS ARE ALSO IMPROVING AND ARE FORECAST TO BECOME MORE CONDUCIVE FOR DEVELOPMENT OF A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. THIS SYSTEM HAS A HIGH CHANCE...70 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT MOVES SLOWLY NORTHWARD INTO THE CENTRAL GULF OF MEXICO. INTERESTS ALONG THE ENTIRE UNITED STATES GULF COAST SHOULD MONITOR THE PROGRESS OF THIS LARGE DISTURBANCE THROUGH THE WEEKEND. HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE ACROSS THE YUCATAN PENINSULA...WESTERN CUBA...AND SOUTHERN FLORIDA THROUGH SATURDAY. AN AIR FORCE RESERVE RECONNAISSANCE AIRCRAFT IS SCHEDULED TO INVESTIGATE THE SYSTEM TOMORROW AFTERNOON...IF NECESSARY. That's a stark difference from a day ago when it was 10-20%. SST's are amazing for hurricane development Link to comment Share on other sites More sharing options...
turtlehurricane Posted June 21, 2012 Share Posted June 21, 2012 Pressure falls across the northern Yucatan. http://www.wunderground.com/cgi-bin/histGraphAll?day=21&year=2012&month=6&ID=MMMD&type=3&width=614 http://www.wunderground.com/cgi-bin/wxStationGraphAll?day=21&year=2012&month=6&ID=IYUCATAN16&type=3&width=500&showtemp=1&showpressure=1&showwind=1&showwinddir=1&showrain=1 Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 22, 2012 Share Posted June 22, 2012 There's a 500mb low becoming established overhead along with the ULAC Some very decent outflow now Link to comment Share on other sites More sharing options...
Srain Posted June 22, 2012 Share Posted June 22, 2012 Link to comment Share on other sites More sharing options...
phil882 Posted June 22, 2012 Share Posted June 22, 2012 Before we get too excited about the prospects of development... I think this system will still struggle in the short term to organize. If the ECMWF is any indication, the low and mid level circulations are likely to remain disjointed for the better part of the next 3 days. First looking at 500 hPa we see a developing mid-level vortex over the Yucatan. I've placed a small dot showing roughly where the vorticity axis is located in order to be able to track this feature over time. The animation below is the ECMWF from 12z initialization today to day 3 at 12z 24 June. Notice on several occasions a smaller scale is trying to spin up, but seems to struggle to develop sufficient mid-level vorticity . It also seems to be rotating about a much larger axis. This feature we are tracking in this loop would probably be more akin to a mesovorticy that is rotating around a much larger circulation. Now lets look at the 10 meter winds and plot the same track of the 500 hPa vorticity center... we see just how poorly organized the disturbance is. The surface circulation is hundreds of miles away from the strongest mid-level vortex and is far smaller that what feeble mid-level vortex tries to develop. This disjointed nature of the circulation is most likely a result of vertical wind shear. While there is an anticyclone over the convection as many have noted, it may not be large enough to cover the entire scope of the circulation, which is very broad. Thus, while the east portion of the circulation may be under light shear (where the convection is firing) the western portion of the circulation is under much higher vertical wind shear as a consequence of upper level winds on the western portion of the anticyclone. Indeed, that appears to be what is happening currently, with the anticyclone disjointed east of the low-level circulation center. Thus the important take home point here is that you need an anticyclone that covers the entire circulation. Indeed, most TCs that have robust convection have some sort of anticyclone generated via deep convection. However, sheared TCs have a displaced anticyclone that does not cover the entire circulation, and the models are hinting that this particular issue may plague 96L in the days to come. Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 22, 2012 Share Posted June 22, 2012 A bit messy, but MSLP/Surface winds (RAP)/15min Lightning/Surface Obs Link to comment Share on other sites More sharing options...
tmagan Posted June 22, 2012 Share Posted June 22, 2012 00Z Observations Link to comment Share on other sites More sharing options...
Amped Posted June 22, 2012 Share Posted June 22, 2012 Before we get too excited about the prospects of development... I think this system will still struggle in the short term to organize. If the ECMWF is any indication, the low and mid level circulations are likely to remain disjointed for the better part of the next 3 days. First looking at 500 hPa we see a developing mid-level vortex over the Yucatan. I've placed a small dot showing roughly where the vorticity axis is located in order to be able to track this feature over time. The animation below is the ECMWF from 12z initialization today to day 3 at 12z 24 June. Notice on several occasions a smaller scale is trying to spin up, but seems to struggle to develop sufficient mid-level vorticity . It also seems to be rotating about a much larger axis. This feature we are tracking in this loop would probably be more akin to a mesovorticy that is rotating around a much larger circulation. Now lets look at the 10 meter winds and plot the same track of the 500 hPa vorticity center... we see just how poorly organized the disturbance is. The surface circulation is hundreds of miles away from the strongest mid-level vortex and is far smaller that what feeble mid-level vortex tries to develop. This disjointed nature of the circulation is most likely a result of vertical wind shear. While there is an anticyclone over the convection as many have noted, it may not be large enough to cover the entire scope of the circulation, which is very broad. Thus, while the east portion of the circulation may be under light shear (where the convection is firing) the western portion of the circulation is under much higher vertical wind shear as a consequence of upper level winds on the western portion of the anticyclone. Indeed, that appears to be what is happening currently, with the anticyclone disjointed east of the low-level circulation center. Thus the important take home point here is that you need an anticyclone that covers the entire circulation. Indeed, most TCs that have robust convection have some sort of anticyclone generated via deep convection. However, sheared TCs have a displaced anticyclone that does not cover the entire circulation, and the models are hinting that this particular issue may plague 96L in the days to come. In other words, it's a SlopGyre. We'll see if this years overperforming trend will stop here. Link to comment Share on other sites More sharing options...
andyhb Posted June 22, 2012 Share Posted June 22, 2012 In other words, it's a SlopGyre. We'll see if this years overperforming trend will stop here. Glass four thirds empty... Link to comment Share on other sites More sharing options...
Amped Posted June 22, 2012 Share Posted June 22, 2012 Glass four thirds empty... SREF ( and most other guidance) kind of looks like TS lee. More of a coma shape than a TS shape. http://www.meteo.psu.edu/~gadomski/SREF21PRSUS_21z/srefloop.html Link to comment Share on other sites More sharing options...
thewxmann Posted June 22, 2012 Share Posted June 22, 2012 SREF ( and most other guidance) kind of looks like TS lee. More of a coma shape than a TS shape. http://www.meteo.psu...z/srefloop.html ARN5 <3 But in all seriousness, what else would you expect? GFS keeps 20kt westerlies over most of the GOM through the next five days. Link to comment Share on other sites More sharing options...
SN_Lover Posted June 22, 2012 Share Posted June 22, 2012 The convection has REALLY died down in the past few hours. Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 22, 2012 Share Posted June 22, 2012 The convection has REALLY died down in the past few hours. Diurnal minimum and half the circulation is still over the Yucatan. Should look fine by tomorrow morning. Link to comment Share on other sites More sharing options...
Riptide Posted June 22, 2012 Share Posted June 22, 2012 The convection has REALLY died down in the past few hours. Now it should be easier to see the low-level center. Link to comment Share on other sites More sharing options...
Ed Lizard Posted June 22, 2012 Share Posted June 22, 2012 Glass four thirds empty... Just looking at new NAM (don't laugh, not staying up for globals)) 850 mb vorticity and heaviest rain East of surface low, Like that on a variety of different models. Shear, I'd guess. At least on the NAM (don't laugh) it starts aliging better somewhat starting in 3 days. Link to comment Share on other sites More sharing options...
SN_Lover Posted June 22, 2012 Share Posted June 22, 2012 Diurnal minimum and half the circulation is still over the Yucatan. Should look fine by tomorrow morning. hope your right. looking pathetic on IR at the moment. ________ Before Now Link to comment Share on other sites More sharing options...
Superstorm93 Posted June 22, 2012 Share Posted June 22, 2012 Not sure what changed, but that doesn't look good... Upper-level high has become displaced to the far SW Link to comment Share on other sites More sharing options...
Ed Lizard Posted June 22, 2012 Share Posted June 22, 2012 0Z Merida sounding didn't look too bad shear wise, http://weather.uwyo.edu/cgi-bin/sounding?region=naconf&TYPE=TEXT%3ALIST&YEAR=2012&MONTH=06&FROM=2200&TO=2200&STNM=76644 Link to comment Share on other sites More sharing options...
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