wxmx Posted September 1, 2014 Share Posted September 1, 2014 000 WTNT45 KNHC 012036 TCDAT5 TROPICAL DEPRESSION FIVE DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL052014 400 PM CDT MON SEP 01 2014 An Air Force Reserve Unit reconnaissance aircraft investigating the low pressure area over the southwest Gulf of Mexico found a well-defined center of circulation. The system has a curved band of deep convection that wraps around the southern and eastern portions of the circulation. Thus the system is being designated as a tropical depression at this time. The maximum winds reported by the aircraft so far support an intensity of 25 kt. Although the cyclone is situated over very warm waters of near 30 deg C, the atmospheric environment is not ideal for strengthening. Dynamical models indicate that significant northerly to northwesterly vertical shear should affect the tropical cyclone for the next 36 hours and this is likely to limit intensification up to landfall. After landfall, dissipation should be quick due to the mountainous terrain of Mexico. The official wind speed forecast is a little above the intensity model consensus. The initial motion is west-northwestward or around 295/11. The steering scenario appears to be fairly straightforward. The flow to the south of a mid-level ridge along the northern Gulf of Mexico coast should maintain a west-northwestward track for the next 36 hours, i.e. through the expected time of landfall. The official track forecast is very close to the latest dynamical model consensus. FORECAST POSITIONS AND MAX WINDS INIT 01/2100Z 20.1N 93.6W 25 KT 30 MPH 12H 02/0600Z 21.1N 94.8W 30 KT 35 MPH 24H 02/1800Z 21.9N 96.3W 35 KT 40 MPH 36H 03/0600Z 22.4N 97.9W 40 KT 45 MPH...INLAND 48H 03/1800Z...DISSIPATED INLAND $ Forecaster Pasch Link to comment Share on other sites More sharing options...
Srain Posted September 1, 2014 Share Posted September 1, 2014 Link to comment Share on other sites More sharing options...
Cheeznado Posted September 1, 2014 Share Posted September 1, 2014 Yawn. A weak TS into Mexico. The lame 2014 season continues. Link to comment Share on other sites More sharing options...
wxmx Posted September 1, 2014 Author Share Posted September 1, 2014 Shear forecasted to drop gradually starting early morning tomorrow up until landfall (from around midnight to 6am 09/03). If it gets it's act together for the last 12 hours, we can see a high end TS from this. Link to comment Share on other sites More sharing options...
Kory Posted September 1, 2014 Share Posted September 1, 2014 I'm thinking we could see a center relocation more north. The center the NHC is tracking is very weak. I'm thinking a LLC is forming more toward 21.5N and 93W. Link to comment Share on other sites More sharing options...
TropicalAnalystwx13 Posted September 1, 2014 Share Posted September 1, 2014 I'm thinking we could see a center relocation more north. The center the NHC is tracking is very weak. I'm thinking a LLC is forming more toward 21.5N and 93W. I second this; when recon investigated both areas, the southwest one (the one NHC used in the 21z advisory) was better defined. However, based on visible satellite loops, the northeast one seems to be becoming dominant. If that were the case, the ultimate landfall location would shift farther north, and this would have slightly more time to organize. Link to comment Share on other sites More sharing options...
Kory Posted September 1, 2014 Share Posted September 1, 2014 Looks like the NHC adjusted the center practically due north. Still not north enough in my opinion. Movement is now NW, which it looks like it could continue NW before bending back west as the ridge builds in. This looks like it's going to be more on the northern end of the forecast guidance. SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION ---------------------------------------------- LOCATION...20.5N 93.7W ABOUT 240 MI...390 KM E OF TUXPAN MEXICO MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H PRESENT MOVEMENT...NW OR 305 DEGREES AT 12 MPH...19 KM/H MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES It was 20.1N 93.6W last advisory. Link to comment Share on other sites More sharing options...
Srain Posted September 2, 2014 Share Posted September 2, 2014 Link to comment Share on other sites More sharing options...
NaoPos Posted September 2, 2014 Share Posted September 2, 2014 20140901.2330.goes13.x.vis1km_high.05LFIVE.25kts-1009mb-199N-932W.100pc.jpg On par with the last few years.... Nasty, exposed, LLC's with distorted convection. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 ... little love for our soon-to-be Dolly...it's trying to form a CDO, let's see if it doesn't get sheared apart. Link to comment Share on other sites More sharing options...
thewxmann Posted September 2, 2014 Share Posted September 2, 2014 Please please please do not waste a name on this piece of junk PLEASE. (Dolly is so deserving to be used with a Cat 2+ hurricane) Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 Shear has dropped below 20 kts and CDO like feature now covers the center of the LLC... Link to comment Share on other sites More sharing options...
Srain Posted September 2, 2014 Share Posted September 2, 2014 TROPICAL STORM DOLLY DISCUSSION NUMBER 3NWS NATIONAL HURRICANE CENTER MIAMI FL AL052014400 AM CDT TUE SEP 02 2014An Air Force Reserve reconnaissance aircraft investigating thecyclone early this morning found 925 mb flight-level winds of 50-53kt in the northeast quadrant and adjusted SFMR winds of at least 40kt. In addition, two ASCAT overpasses at 0313 UTC and 0406 UTCindicated surface winds of 40-41 kt in the eastern quadrant. Basedon these wind data, the intensity has been increased to 40 kt,making the cyclone the fourth tropical storm of the 2014 Atlantichurricane season. These wind data also required the initialposition to be relocated about 60 nmi north of the previous track.The initial motion estimate is northwestward or 305/12 kt, which isbased on a blend of passive microwave, scatterometer, andconventional satellite fix data. Other than the northward relocationof the center position, the forecast track reasoning remainsunchanged from the previous advisories. The tropical storm isexpected to gradually turn more toward the west-northwest as Dollyskirts along the southern periphery of a strong mid-level ridge thatis located across most of the Gulf of Mexico and the southeasternUnited States. Landfall along the northeastern coast of Mexico isexpected in about 24 hours, followed by dissipation in 48 hoursover the rugged terrain of the Sierra Madre Oriental mountains. TheNHC forecast track is similar to the consensus model TVCA, and liesroughly in the middle of the guidance envelope.About 20 kt of north-northwesterly vertical shear is affectingDolly, which has resulted in most of the convection being displacedwell to the south and east of the exposed low-level circulation.However, new convection has recently developed near and just to thesoutheast of the center, and with the shear forecast to decrease toabout 15 kt during the next 12 hours, some additional slightstrengthening is possible before Dolly makes landfall.The surface wind data from the reconnaissance aircraft and thetwo scatterometer passes indicate that the tropical-storm-force windfield has expanded significantly in the eastern semicircle. Sincethe pressure gradient between Dolly and the large high over theGulf of Mexico is expected to remain quite strong for the next 36hours or so, the Government of Mexico has extended the tropicalstorm warning area northward to Barra El Mezquital. However, noadditional northward extension of the warning area appears likelyat this time.The primary threat from this system is expected to be heavyrainfall, which is likely to cause flash flooding and mud slidesover portions of eastern Mexico.FORECAST POSITIONS AND MAX WINDSINIT 02/0900Z 22.6N 94.8W 40 KT 45 MPH12H 02/1800Z 23.1N 95.9W 45 KT 50 MPH24H 03/0600Z 23.7N 97.5W 45 KT 50 MPH36H 03/1800Z 24.1N 98.9W 35 KT 40 MPH...INLAND48H 04/0600Z...DISSIPATED INLAND$$Forecaster Stewart Link to comment Share on other sites More sharing options...
Kory Posted September 2, 2014 Share Posted September 2, 2014 She's racing NW. Shear looks to have let up as well...we're now seeing thunderstorms over the LLC. Link to comment Share on other sites More sharing options...
Srain Posted September 2, 2014 Share Posted September 2, 2014 Nice overshooting top developing in the south and east quadrant. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 It's about 6-8 hours from landfall. I expect no significant changes intensity wise, shear just didn't subsided enough...maybe it's 50kts now, would have to wait for recon. It also turned more to the W, it's been heading 290 degrees for the last 3 hours or so..maybe even more west the last hour, but that's not a significant time window. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 Ha! is Dolly moving SW? relocating south? Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 this is what I'm looking at...it's definitely going for the strong convection to it's south http://1.usa.gov/1CmZxLq Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 Recon may have missed the center... Looks exposed and racing west, as you stated. It's not racing west...it's mostly exposed but going after the deep convection south (it's moving around 200-210)...it has lost half a degree in the last 1.5 hours. Maybe a new center is forming near the deep convection? Low level vorticity would backup this idea Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 We probably have no closed circulation anymore. It looks like Dolly is trying to do an extreme makeover, but there's little real estate to work with. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 aaaand...indeed, reformation well south....recon found another vortex around 21.8N 96.4W...well within developing strong convection...rain contaminated SFMR up to 66kts Link to comment Share on other sites More sharing options...
icebreaker5221 Posted September 2, 2014 Share Posted September 2, 2014 I found this ASCAT pass to be rather interesting... Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 I found this ASCAT pass to be rather interesting... WMBas63.png Yes, saw that one, but recon confirmed a closed circulation around that time (that's from late evening yesterday our time) Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 Anyway, the new center looks better positioned for intensification, especially after absorbing the energy from the old LLC. Too bad it's around 12 hours away from landfall (my guess is that it bought some time after reformation) Link to comment Share on other sites More sharing options...
icebreaker5221 Posted September 2, 2014 Share Posted September 2, 2014 Yes, saw that one, but recon confirmed a closed circulation around that time (that's from late evening yesterday our time) Ah my bad, here's the new one. Definitely a closed circulation. You can see with the NW-SE elongated center where the old one is beginning to die and a new one is trying to form, but looks especially awkward during the transition stage. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 Ah my bad, here's the new one. Definitely a closed circulation. You can see with the NW-SE elongated center where the old one is beginning to die and a new one is trying to form, but looks especially awkward during the transition stage. WMBds63.png Yeah, kinda of 8 shaped. Anyhoo, it's official now, reformed to the south 22N 96.5W Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 Exceptional rainfall rates in that new burst of convection...recon finding close to 3"/h rates. Link to comment Share on other sites More sharing options...
eyewall Posted September 2, 2014 Share Posted September 2, 2014 It looks to me this thing will come ashore near Tampico with the re-location. I am not sure why NHC didn't adjust the track accordingly. Link to comment Share on other sites More sharing options...
wxmx Posted September 2, 2014 Author Share Posted September 2, 2014 It looks to me this thing will come ashore near Tampico with the re-location. I am not sure why NHC didn't adjust the track accordingly. They don't do track adjustments for the intermediate advisories...they simply adjust the initialization point, but keep the forecasted track. Link to comment Share on other sites More sharing options...
Srain Posted September 2, 2014 Share Posted September 2, 2014 Meso vorts are rotating all around the elongated 'center'. With the large wind field, it probably doesn't make any difference at this point. This mess will be inland in a few hours and dump copious rainfall amounts from Coatzacoalcos to just S of La Pesca. Link to comment Share on other sites More sharing options...
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