ATL: DON - Remnants - Discussion

[Alyono]

may not be that much shear south of 12-13N though

new convective burst starting over the center

[RL3AO]

With such a tiny storm, it doesn't take much for it to get convectively active and build up. Tomas in 2010 might be a good parallel, went from nothing to a Cat 2 landfall in barely 36 hours...

But here was Tomas just after becoming a tropical storm. It already had well-defined banding features.




Don just looks like a blob.

[1900hurricane]

I agree with Cody's premise. While Don is proven to be a tropical storm, microwave imagery reveals that Don's banding remains very shallow and generally convectionless. That's typically not a good sign for intensification, even for a small system.

[Alyono]

think there is a greater chance for this to become a hurricane in the eastern Caribbean than there is east of the Caribbean

[Weather150]

think there is a greater chance for this to become a hurricane in the eastern Caribbean than there is east of the Caribbean

What would cause it to get stronger in the eastern Caribbean, would shear be strong at that time or would it be a reasonable setting?

[Alyono]

think there is a greater chance for this to become a hurricane in the eastern Caribbean than there is east of the Caribbean

What would cause it to get stronger in the eastern Caribbean, would shear be strong at that time or would it be a reasonable setting?

may not be as much shear in the extreme southeastern Caribbean

[txwatcher91]

think there is a greater chance for this to become a hurricane in the eastern Caribbean than there is east of the Caribbean

What would cause it to get stronger in the eastern Caribbean, would shear be strong at that time or would it be a reasonable setting?

may not be as much shear in the extreme southeastern Caribbean

Maybe that’s what the HMON and HWRF are seeing as they seem to intensity it quickly in this area.

[Alyono]

the shear gradient looks very high. If this even gets to 12.5N, it may be sheared apart. If it stays south, the shear may enhance the northern outflow.

The possibilities range from cat 2 to an open wave

[stormreader]

http://www.ssd.noaa.gov/goes/east/tatl/ ... mated.Nice pic from NHC site of Don and a very impressive looking ball of convection behind it (96l).

[Aric Dunn]

not large and expansive convection but its maintaining quite well considering. Not much in the way of banding but that has not stopped systems from getting to hurricane strength. A certain structure by definition fro a hurricane is needed but not always the case. I dont however think this is even close to a hurricane. however satellite appearance does not tell all.. Humberto is a great example...

[Sciencerocks]

[Sciencerocks]

000
WTNT45 KNHC 180834
TCDAT5

Tropical Storm Don Discussion Number 3
NWS National Hurricane Center Miami FL AL052017
500 AM AST Tue Jul 18 2017

Don's convective pattern has continued to improve overnight and
early this morning, including the development of a pronounced
central dense overcast (CDO) feature. There have also been periodic
bursts of deep convection very near the center, accompanied by
significant clusters of lightning activity, which is indicative of
strong updrafts in or near the radius of maximum winds. The last
recon data around 0000Z indicated peak SFMR surface winds of 41 kt.
Given the marked increase in convective organization since that
time, the initial intensity has been increased to 45 kt.

The initial motion estimate remains 280/16 kt. There is no change
to the previous track forecast or reasoning. Although the models
continue to differ some on Don's forward speed, there is very little
cross-track difference. The models are in good agreement that the
broad Bermuda-Azores ridge to north of the cyclone will remain
strong and move little for the next several days, which should act
to keep Don moving briskly westward until dissipation occurs at
around 72 hours. The new NHC forecast track is essentially just an
extension of the previous advisory track, and is slightly north of
the multi-model consensus TVCN.

Don is expected to remain embedded within a narrow east-west zone of
low vertical wind shear for another 24-36 hours, which should allow
for some additional strengthening. Since Don is a compact tropical
cyclone, significant changes in intensity -- both up and down --
can occur due to small fluctuations in wind shear and/or interaction
with the mountainous Windward Islands. By 36 hours, increasing
westerly shear is expected to cause Don to weaken while it moves
across the southeastern Caribbean Sea, and degeneration into an open
wave is forecast to occur by 72 hours. The NHC intensity forecast
is similar to the previous advisory and remains below the consensus
models ICON and IVCN. However, the intensity guidance continues to
vary widely between only showing an open wave (most of the global
models) to Don achieving hurricane strength (HWRF, ECMWF, and some
of the statistical models). As a result, confidence in the intensity
forecast remains low.

FORECAST POSITIONS AND MAX WINDS

INIT 18/0900Z 11.5N 56.2W 45 KT 50 MPH
12H 18/1800Z 11.8N 59.1W 50 KT 60 MPH
24H 19/0600Z 12.1N 63.2W 50 KT 60 MPH
36H 19/1800Z 12.4N 67.4W 50 KT 60 MPH
48H 20/0600Z 12.7N 71.6W 40 KT 45 MPH
72H 21/0600Z...DISSIPATED

$$
Forecaster Stewart

[Yellow Evan]

I don't like it's appearance (no rainbands) and without recon this wouldn't be a tropical storm, but I like this storm's chance to become the strongest storm of the season and reach 55-60 knots.

[brunota2003]

Morning flight is warming up and waiting to take off...expected to be on station by 7 am EDT, with first fix by 7:30 am EDT:

000
URNT15 KNHC 180917
AF300 0205A DON HDOB 01 20170718
090730 1742N 06448W 0162 ///// 0143 +265 +211 000000 000 /// /// 23
090800 1742N 06448W 0162 ///// 0143 +265 +211 000000 000 /// /// 23
090830 1742N 06448W 0162 ///// 0144 +265 +211 000000 000 /// /// 23
090900 1742N 06448W 0162 ///// 0144 +265 +212 000000 000 /// /// 23
090930 1742N 06448W 0162 ///// 0144 +260 +213 000000 000 /// /// 23
091000 1742N 06447W 0159 00004 0156 +259 +214 000000 000 /// /// 03
091030 1742N 06448W 0159 00004 0165 +255 +214 000000 000 /// /// 03
091100 1742N 06448W 0159 00006 0167 +255 +213 000000 000 /// /// 03
091130 1742N 06448W 0159 00006 0167 +258 +214 000000 000 /// /// 03
091200 1742N 06448W 0161 00005 0167 +258 +215 000000 000 /// /// 03
091230 1742N 06448W 0159 00005 0166 +257 +215 000000 000 /// /// 03
091300 1742N 06448W 0158 00006 0165 +254 +214 000000 000 /// /// 03
091330 1742N 06448W 0155 00009 0166 +250 +210 000000 000 /// /// 03
091400 1742N 06448W 0153 00012 0168 +245 +204 000000 000 /// /// 03
091430 1742N 06449W 0150 00015 0168 +245 +196 000000 000 /// /// 03
091500 1742N 06449W 0146 00016 0166 +245 +191 000000 000 /// /// 03
091530 1742N 06449W 0145 00016 0165 +245 +186 000000 000 /// /// 03
091600 1742N 06449W 0143 00019 0166 +242 +184 000000 000 /// /// 03
091630 1742N 06449W 0145 00018 0165 +240 +181 000000 000 /// /// 03
091700 1742N 06449W 0145 00016 0164 +240 +179 000000 000 /// /// 03
$$
;

[brunota2003]

And LIFTOFF of AF300 on it's way to Tropical Storm Don as part of mission STS-002, to test the windspeeds and restock Don's dropsonde supplies.

000
URNT15 KNHC 180927
AF300 0205A DON HDOB 02 20170718
091730 1742N 06449W 0145 00018 0165 +240 +178 000000 000 /// /// 03
091800 1742N 06449W 0143 00018 0165 +240 +177 000000 000 /// /// 03
091830 1742N 06449W 0139 00017 0161 +244 +212 081003 006 /// /// 03
091900 1742N 06448W 0042 00077 0149 +251 +248 082010 014 /// /// 03
091930 1742N 06446W 9846 00271 0155 +243 +241 090019 020 /// /// 05
092000 1742N 06445W 9612 00483 0157 +229 +224 096020 021 /// /// 03
092030 1742N 06443W 9339 00735 0157 +211 +195 102022 022 /// /// 03
092100 1742N 06441W 9003 01053 0158 +194 +174 102023 023 /// /// 03
092130 1741N 06439W 8747 01304 0159 +178 +166 100020 022 /// /// 03
092200 1740N 06438W 8469 01581 0157 +167 +155 097018 020 /// /// 03
092230 1739N 06436W 8196 01858 0155 +153 +145 107017 019 /// /// 03
092300 1738N 06435W 7966 02102 0154 +141 +132 105019 021 /// /// 03
092330 1737N 06433W 7747 02335 0146 +134 +118 108021 021 /// /// 03
092400 1736N 06432W 7503 02602 0133 +127 +107 116023 024 /// /// 03
092430 1735N 06430W 7281 02858 0133 +111 +109 118025 026 /// /// 05
092500 1734N 06429W 7082 03088 //// +099 //// 122024 026 /// /// 05
092530 1732N 06427W 6896 03309 0125 +090 +087 118027 028 /// /// 03
092600 1731N 06426W 6719 03525 0118 +079 +077 116025 026 /// /// 05
092630 1730N 06424W 6556 03726 //// +064 //// 116024 024 /// /// 05
092700 1729N 06423W 6402 03922 //// +053 //// 122024 025 /// /// 05
$$
;

[brunota2003]

000
URNT15 KNHC 180937
AF300 0205A DON HDOB 03 20170718
092730 1728N 06421W 6261 04103 //// +041 //// 126024 025 /// /// 05
092800 1727N 06420W 6118 04291 //// +030 //// 126025 026 /// /// 05
092830 1726N 06418W 5975 04490 //// +015 //// 126025 026 /// /// 05
092900 1725N 06417W 5853 04655 //// +010 //// 123022 025 /// /// 05
092930 1724N 06415W 5736 04817 //// +001 //// 122021 022 /// /// 05
093000 1723N 06413W 5626 04971 //// -006 //// 115019 020 /// /// 05
093030 1722N 06412W 5520 05123 //// -012 //// 113019 020 /// /// 05
093100 1720N 06410W 5418 05271 0296 -023 //// 111019 019 /// /// 05
093130 1719N 06409W 5316 05423 0304 -033 //// 109019 020 /// /// 05
093200 1718N 06407W 5224 05561 0313 -041 //// 108018 019 /// /// 05
093230 1717N 06405W 5127 05709 0322 -054 //// 116019 020 /// /// 05
093300 1716N 06404W 5046 05834 0329 -066 //// 113018 018 /// /// 05
093330 1715N 06402W 4965 05959 0335 -073 //// 110020 020 /// /// 05
093400 1713N 06401W 4882 06093 0343 -080 //// 106020 021 /// /// 05
093430 1712N 06359W 4817 06197 0351 -079 //// 096019 020 /// /// 05
093500 1711N 06357W 4755 06298 0356 -076 //// 088019 020 /// /// 05
093530 1710N 06356W 4694 06399 0363 -083 //// 087018 019 /// /// 05
093600 1709N 06354W 4630 06506 0369 -087 //// 090018 018 /// /// 05
093630 1708N 06352W 4574 06601 0376 -094 //// 091017 018 /// /// 05
093700 1706N 06351W 4516 06697 0381 -101 //// 093018 018 /// /// 05
$$
;

[brunota2003]

Reached Cruising Altitude

000
URNT15 KNHC 180947
AF300 0205A DON HDOB 04 20170718
093730 1705N 06349W 4463 06790 0388 -106 //// 087017 018 /// /// 05
093800 1704N 06348W 4414 06874 0393 -111 //// 086016 017 /// /// 05
093830 1703N 06346W 4347 06989 0398 -119 //// 094016 016 /// /// 05
093900 1702N 06344W 4284 07103 0406 -127 //// 093016 016 /// /// 05
093930 1700N 06343W 4231 07197 0411 -129 //// 087019 019 /// /// 05
094000 1659N 06341W 4162 07323 0423 -135 //// 078019 019 /// /// 05
094030 1658N 06339W 4114 07417 0433 -143 //// 075018 018 /// /// 05
094100 1657N 06338W 4095 07452 0435 -145 //// 075018 018 /// /// 05
094130 1656N 06336W 4097 07447 0433 -145 //// 077018 019 /// /// 05
094200 1655N 06334W 4097 07446 0432 -148 //// 083018 018 /// /// 05
094230 1653N 06333W 4095 07447 0431 -147 -153 083018 018 /// /// 05
094300 1652N 06331W 4098 07442 0430 -148 -169 084017 017 /// /// 03
094330 1651N 06329W 4099 07441 0430 -150 -178 081016 017 /// /// 03
094400 1649N 06327W 4098 07441 0429 -147 -184 079017 017 /// /// 03
094430 1648N 06325W 4098 07441 0429 -145 -190 079016 017 /// /// 03
094500 1646N 06323W 4098 07441 0429 -148 -197 088014 016 /// /// 03
094530 1645N 06321W 4099 07439 0429 -148 -201 086013 014 /// /// 03
094600 1643N 06319W 4099 07440 0430 -145 -204 078013 013 /// /// 03
094630 1642N 06317W 4098 07442 0430 -145 -208 079012 013 /// /// 03
094700 1640N 06315W 4098 07440 0429 -145 -207 083012 012 /// /// 03
$$
;

[brunota2003]

000
URNT15 KNHC 180957
AF300 0205A DON HDOB 05 20170718
094730 1639N 06313W 4099 07439 0429 -145 -208 080013 014 /// /// 03
094800 1637N 06311W 4099 07440 0430 -148 -212 080014 015 /// /// 03
094830 1636N 06309W 4098 07443 0430 -150 -208 081015 015 /// /// 03
094900 1634N 06306W 4101 07437 0430 -146 -212 082014 015 /// /// 03
094930 1633N 06304W 4098 07442 0430 -146 -211 081014 015 /// /// 03
095000 1631N 06302W 4098 07441 0430 -145 -209 080014 014 /// /// 03
095030 1630N 06300W 4099 07438 0430 -145 -216 081013 014 /// /// 03
095100 1628N 06258W 4098 07441 0430 -145 -229 077013 013 /// /// 03
095130 1627N 06256W 4099 07441 0430 -146 -227 085013 014 /// /// 03
095200 1625N 06254W 4098 07442 0430 -146 -214 092014 014 /// /// 03
095230 1623N 06252W 4098 07441 0430 -148 -210 097015 016 /// /// 03
095300 1622N 06250W 4099 07440 0429 -150 -203 099016 017 /// /// 03
095330 1620N 06247W 4099 07438 0429 -150 -197 094016 016 /// /// 03
095400 1619N 06245W 4099 07438 0428 -152 -202 091015 016 /// /// 03
095430 1617N 06243W 4098 07441 0428 -155 -223 095014 015 /// /// 03
095500 1616N 06241W 4098 07438 0427 -152 -226 094013 014 /// /// 03
095530 1614N 06239W 4101 07435 0426 -151 -222 091013 013 /// /// 03
095600 1613N 06237W 4099 07437 0426 -151 -220 091012 013 /// /// 03
095630 1611N 06235W 4098 07437 0426 -150 -216 089013 013 /// /// 03
095700 1610N 06233W 4098 07437 0425 -152 -222 097014 015 /// /// 03
$$
;

[brunota2003]

000
URNT15 KNHC 181007
AF300 0205A DON HDOB 06 20170718
095730 1608N 06231W 4099 07436 0425 -150 -228 094014 015 /// /// 03
095800 1607N 06229W 4099 07435 0425 -150 -224 094013 014 /// /// 03
095830 1605N 06226W 4099 07435 0425 -150 -223 093014 015 /// /// 03
095900 1603N 06224W 4098 07438 0425 -150 -229 090015 016 /// /// 03
095930 1602N 06222W 4099 07435 0425 -154 -234 088016 017 /// /// 03
100000 1600N 06220W 4098 07436 0425 -154 -231 086015 016 /// /// 03
100030 1559N 06218W 4099 07433 0425 -150 -230 086014 014 /// /// 03
100100 1557N 06216W 4099 07436 0426 -155 -230 082015 015 /// /// 03
100130 1556N 06214W 4099 07438 0429 -151 -229 077012 015 /// /// 03
100200 1554N 06212W 4098 07441 0431 -149 -220 079012 012 /// /// 03
100230 1553N 06210W 4099 07443 0434 -148 -217 084012 012 /// /// 03
100300 1551N 06208W 4098 07449 0436 -145 -225 086014 014 /// /// 03
100330 1550N 06205W 4099 07448 0438 -143 -238 096013 014 /// /// 03
100400 1548N 06203W 4098 07450 0440 -140 -244 093013 013 /// /// 03
100430 1546N 06201W 4098 07449 0438 -144 -243 087015 016 /// /// 03
100500 1545N 06159W 4101 07446 0438 -141 -243 093014 015 /// /// 03
100530 1543N 06157W 4099 07448 0437 -138 -242 097012 015 /// /// 03
100600 1542N 06155W 4105 07436 0435 -141 -236 090016 020 /// /// 03
100630 1540N 06153W 4099 07448 0437 -150 -242 094018 021 /// /// 03
100700 1539N 06151W 4094 07454 0437 -153 -239 103018 019 /// /// 03
$$
;

[brunota2003]

000
URNT15 KNHC 181018
AF300 0205A DON HDOB 07 20170718
100730 1537N 06149W 4103 07438 0436 -160 -213 097017 018 /// /// 03
100800 1536N 06147W 4097 07452 0437 -158 -209 094014 016 /// /// 03
100830 1534N 06144W 4094 07454 0436 -155 -215 092016 016 /// /// 03
100900 1532N 06142W 4105 07436 0434 -150 -220 093014 016 /// /// 03
100930 1531N 06140W 4097 07449 0435 -150 -220 093013 014 /// /// 03
101000 1529N 06138W 4102 07439 0434 -148 -218 091014 015 /// /// 03
101030 1528N 06136W 4100 07444 0435 -149 -219 098014 015 /// /// 03
101100 1526N 06134W 4100 07443 0435 -143 -218 083010 014 /// /// 03
101130 1525N 06132W 4097 07448 0435 -140 -230 090012 013 /// /// 03
101200 1523N 06130W 4102 07442 0436 -140 -240 102014 014 /// /// 03
101230 1522N 06128W 4101 07444 0435 -145 -234 106015 017 /// /// 03
101300 1520N 06126W 4095 07453 0437 -144 -226 103015 017 /// /// 03
101330 1519N 06124W 4101 07439 0433 -146 -226 104018 020 /// /// 03
101400 1517N 06122W 4101 07443 0435 -155 -178 109023 023 /// /// 03
101430 1515N 06119W 4098 07447 0435 -158 -166 110024 025 /// /// 03
101500 1514N 06118W 4099 07444 0434 -160 -166 109023 024 /// /// 03
101530 1513N 06116W 4102 07440 0435 -158 -165 111021 022 /// /// 03
101600 1511N 06113W 4101 07445 0437 -150 -173 115021 022 /// /// 03
101630 1509N 06111W 4095 07454 0436 -150 -171 114019 020 /// /// 03
101700 1508N 06109W 4098 07445 0434 -149 -170 117019 020 /// /// 03
$$
;