159 replies to this topic

[kold weather]

Right well looks like we will have TD1 offically shortly...

Recon has found a whole swath of west winds in 93L circulations along with a organised deep convective apperence and this has prompted the NHC to upgrade the region. Conditions aloft appear to have improved a little recently and my intial ide aof 30-35kts landfall on the Yucatan looks a little undercooked now IMO, depending on the exact track and exact location of the LLC, we will probably see something into the mid TS range and I certainly wouldn't rule out higher given conditions are improving. Current pressure estimate is down to 1003mbs which is very low considering everything, suggestive of low background pressures, just as the long range forecasts was calling for.

Models are still in two camps. The 12z ECM is very far south barely making into the BoC...whilst some of the GFS based models have this system reaching the central Gulf. Personally from what I've seen I perfer something in the middle as the ECM doesn't develop the system enough, whilst the GFS based models appear to be over egging the upper trough. Therefore I think first landfall S.Yucatan/N.Belieze (as the center appears to be further south than the NHC estimates expected.) then back into the BoC and moving WNW bending back westwards into N.Mexico, possibly Texas.

I'll make another indepth post tomorrow morning at some point when hopefully some more information is avaible, plus I'll have time to have a much better look at everything.

Ps, probably will be Alex sooner rather than later...and its current taking on a very good presentation so even my mid TS call could end up being too low...I'm impressed...

Here is the offical forecast by the way people:

000
WTNT31 KNHC 252159
TCPAT1
BULLETIN
TROPICAL DEPRESSION ONE SPECIAL ADVISORY NUMBER 1
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010
600 PM EDT FRI JUN 25 2010

...FIRST TROPICAL DEPRESSION OF THE ATLANTIC SEASON FORMS IN THE
WESTERN CARIBBEAN...


SUMMARY OF 600 PM EDT...2200 UTC...INFORMATION
----------------------------------------------
LOCATION...16.5N 83.5W
ABOUT 355 MI...570 KM SE OF COZUMEL MEXICO
ABOUT 345 MI...555 KM ESE OF CHETUMAL MEXICO
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/HR
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/HR
MINIMUM CENTRAL PRESSURE...1004 MB...29.65 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF MEXICO HAS ISSUED A TROPICAL STORM WARNING FOR THE
EAST COAST OF THE YUCATAN PENINSULA FROM CHETUMAL NORTHWARD TO
CANCUN.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE EAST COAST OF THE YUCATAN PENINSULA FROM CHETUMAL NORTHWARD TO
CANCUN

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 600 PM EDT...2200 UTC...THE CENTER OF NEWLY FORMED TROPICAL
DEPRESSION ONE WAS LOCATED NEAR LATITUDE 16.5 NORTH...LONGITUDE
83.5 WEST. THE DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR
10 MPH...17 KM/HR. THIS GENERAL MOTION IS EXPECTED TO CONTINUE FOR
THE NEXT COUPLE OF DAYS. ON THE FORECAST TRACK...THE DEPRESSION
WILL REACH THE YUCATAN PENINSULA BY LATE SATURDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST...AND THE DEPRESSION IS
EXPECTED TO BECOME A TROPICAL STORM TONIGHT OR SATURDAY.

THE MINIMUM CENTRAL PRESSURE REPORTED BY AN AIR FORCE RESERVE
HURRICANE HUNTER AIRCRAFT WAS 1004 MB...29.65 INCHES.


HAZARDS AFFECTING LAND
----------------------
WIND...TROPICAL STORM FORCE WINDS ARE EXPECTED TO REACH THE COAST
WITHIN THE WARNING AREA BY SATURDAY AFTERNOON.

RAINFALL...THE DEPRESSION IS EXPECTED TO PRODUCE TOTAL RAIN
ACCUMULATIONS OF 4 TO 8 INCHES OVER THE YUCATAN PENINSULA...EASTERN
GUATEMALA...AND MUCH OF HONDURAS AND BELIZE THROUGH SUNDAY MORNING.
ISOLATED MAXIMUM AMOUNTS OF 15 INCHES ARE POSSIBLE OVER MOUNTAINOUS
AREAS. THERE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND
MUDSLIDES.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...800 PM EDT.
NEXT COMPLETE ADVISORY...1100 PM EDT.

$$
FORECASTER AVILA/BRENNAN

Edited by kold weather, 25 June 2010 - 22:06 .

[cookie]

[kold weather]

FWIW whilst the NHC are the experts, I'd make a cheeky little punt and say the NHC map will slowly be adjusted westwards with time and the TS warnings in the Yucatan will also have to be brought a little southwards to cover N.Belieze.

I'm favouring a border MX/TX landfall, but of course I'm personally not going to rule out anything just yet because its too early to know the longer term motion of the system at the moment, I'd want to wait till sometime tomorrow before feeling any more confidence, esp as the models will have fresh data by then on the true location of this system.

[cookie]

Thanks for the updates Kold

[Paranoid]

Models seem to favour two landfall possibilities currently; the Mexico/Texas border as Kold mentioned above, and the other is a landfall between NO and the end of the Florida Panhandle. Seems dependant on the position of an area of high pressure over the SW USA.

[Katherine]

This has been so long-lasting, it ought to be renamed Tropical Depression Mahut-Isner!

[MAF]

Katherine, on 26 June 2010 - 00:04 , said:

This has been so long-lasting, it ought to be renamed Tropical Depression Mahut-Isner!

latest from NHC
WIND...TROPICAL STORM FORCE WINDS ARE EXPECTED TO REACH THE COAST
WITHIN THE WARNING AREA BY SATURDAY AFTERNOON.

RAINFALL...THE DEPRESSION IS EXPECTED TO PRODUCE TOTAL RAIN
ACCUMULATIONS OF 4 TO 8 INCHES OVER THE YUCATAN PENINSULA...EASTERN
GUATEMALA...AND MUCH OF HONDURAS AND BELIZE THROUGH SUNDAY MORNING.
ISOLATED MAXIMUM AMOUNTS OF 15 INCHES ARE POSSIBLE OVER MOUNTAINOUS
AREAS. THERE RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND
MUDSLIDES.

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE EAST COAST OF THE YUCATAN PENINSULA FROM CHETUMAL NORTHWARD TO
CANCUN

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

TROPICAL DEPRESSION CENTER LOCATED NEAR 16.5N 83.5W AT 25/2200Z
POSITION ACCURATE WITHIN 30 NM

PRESENT MOVEMENT TOWARD THE WEST-NORTHWEST OR 300 DEGREES AT 9 KT

ESTIMATED MINIMUM CENTRAL PRESSURE 1004 MB
MAX SUSTAINED WINDS 30 KT WITH GUSTS TO 40 KT.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.


update in an hours time

[Somerset Squall]

Looking very well organised at present, should be Alex at next advisory. A very large system too, flooding could be a serious issue...

[MAF]

Somerset Squall, on 26 June 2010 - 01:00 , said:

Looking very well organised at present, should be Alex at next advisory. A very large system too, flooding could be a serious issue...

next advisory due shortly SS.
BP must be hoping its going to be a quiet start to the season so they can get the oil disaster sorted out. but then again mother nature might have other ideas. and who knows. strong winds and heavy rain may even help to dissipate the oil slicks

[Iceberg]

Recon are currently in TD1 trying to find enough evidence to upgrade to TS Alex.

Bit mixed atm surface winds have be found upto and above 40kts, but flight winds don't quite back it up.

The models re path of TD1/Alex are really split into 2 groups one taking him into Mexico and one group into the LA region.
Of the two main hurricane models, GFDL takes him to LA and HWRF into Mexico/US boarder so there really isn't much to choose between them.

If it takes the northern route it will very likely be stronger (GFDL take him to a boarderline CAT3 as per below).

Globals take different views again, GFDL into Texas, but forms a complicated low pressure system, ECM makes very little of and to be honest probably is initialising the system correctly.


Recon have just found the below. Basically they are all flight winds above 40Ktds with close surface winds to 35kt all to the east of the centre, this should be enough evidence for Alex now, the once caveat is how much convective contamination as this was in the veyr stormy component.

Atlantic USAF High-Density Observations
--------------------------------------------------------------------------------


000
URNT15 KNHC 260609
AF305 0201A CYCLONE HDOB 27 20100626
055930 1601N 08259W 9243 00772 0093 +215 +211 156041 041 034 002 00
060000 1604N 08258W 9248 00768 0093 +216 +210 155041 041 035 001 00
060030 1606N 08257W 9244 00771 0094 +215 +210 156041 041 034 000 00
060100 1608N 08257W 9249 00767 0094 +214 +213 157040 041 034 001 00
060130 1610N 08256W 9244 00771 0095 +211 +211 155042 043 034 000 00
060200 1612N 08255W 9247 00769 0094 +214 +206 156042 043 034 000 00
060230 1614N 08254W 9246 00770 0094 +215 +206 155042 043 033 002 03
060300 1617N 08254W 9245 00769 0093 +214 +204 154044 044 036 001 03
060330 1619N 08255W 9247 00767 0094 +212 +212 154042 043 035 001 00
060400 1621N 08255W 9247 00767 0093 +211 +211 152041 042 035 002 00
060430 1623N 08256W 9251 00764 0094 +211 +211 153041 043 033 002 00
060500 1626N 08256W 9243 00772 0094 +213 +208 155043 044 034 001 00
060530 1628N 08256W 9249 00765 0095 +209 +209 153042 043 034 001 00
060600 1630N 08257W 9249 00767 0096 +209 +209 153043 044 035 000 00
060630 1633N 08257W 9247 00769 0095 +213 +205 150043 043 034 001 00
060700 1635N 08258W 9247 00768 0094 +215 +205 147045 046 035 002 00
060730 1637N 08258W 9244 00771 0095 +212 +205 149045 045 035 003 00
060800 1640N 08258W 9246 00771 0096 +210 +208 147045 045 034 003 00
060830 1642N 08259W 9248 00769 0097 +209 +209 144042 043 032 001 00
060900 1644N 08259W 9246 00771 0097 +208 +208 145041 042 032 001 00

Attached Thumbnails

• 
• 

[Iceberg]

Recon have foud so much now that this will definately be Alex in the next 2 hrs.
Convection has been exploding almost off the scale near the centre and question is really what's happening inside, pressure will be interesting to see if any intensification is ongoing.
Got a sneaky feeling that Alex's strength might go up quite alot today.

[Iceberg]

Latest Vortex, which really just confirms the TS Alex status and the angry monster as he is atm.
Maybe worth saying that conditions are so unstable that the NOAA flight is struggling to get accurate reading atm, must be fantastically scary in there.

VORTEX DATA MESSAGE AL012010
A. 26/07:01:30Z
B. 16 deg 53 min N
084 deg 34 min W
C. 925 mb 728 m
D. 41 kt
E. 094 deg 21 nm
F. 133 deg 43 kt
G. 061 deg 64 nm
H. EXTRAP 1004 mb
I. 22 C / 764 m
J. 24 C / 767 m
K. 21 C / NA
L. NA
M. NA
N. 134 / 9
O. 0.02 / 2 nm
P. AF305 0201A CYCLONE OB 09
MAX FL WIND 43 KT NE QUAD 06:21:40Z
SLP EXTRAP FROM 925 MB

Attached Thumbnails

• 

Edited by Iceberg, 26 June 2010 - 08:20 .

[Iceberg]

As expected given the recon data NHC have now named him officially Alex and at Day 5 take him to hear hurricane strength

AN AIR FORCE RESERVE HURRICANE HUNTER INVESTIGATING TROPICAL
DEPRESSION ONE REPORTED 925 MB FLIGHT-LEVEL WINDS OF 46 KT ABOUT 90
NM EAST OF THE CENTER...WHICH SUGGEST SURFACE WINDS OF NEAR 35 KT.
THE STEPPED FREQUENCY MICROWAVE RADIOMETER ON THE AIRCRAFT SHOWED A
LARGE AREA OF WINDS NEAR 35 KT THAT DID NOT APPEAR TO BE RAIN-
CONTAMINATED. BASED ON THIS..THE DEPRESSION IS UPGRADED TO
TROPICAL STORM ALEX. WITH AN INITIAL INTENSITY OF 35 KT. THE
AIRCRAFT DATA SUGGESTS THAT THE CIRCULATION OF ALEX REMAINS
BROAD...AND THAT THE RECENTLY REPORTED CENTRAL PRESSURE OF 1004 MB
MAY HAVE BEEN MEASURED IN A MESOSCALE LOW PRESSURE AREA. IT SHOULD
BE NOTED THAT THE AIRCRAFT REPORTED SFMR WINDS IN EXCESS OF 40 KT
WHICH APPEAR SUSPECT DUE TO RAIN CONTAMINATION.

Heres an interesting set of obs just in the last few mins.
Meso feature or centre ?.

Atlantic USAF High-Density Observations
--------------------------------------------------------------------------------


000
URNT15 KNHC 260859
AF305 0201A CYCLONE HDOB 44 20100626
084930 1734N 08532W 9246 00737 0058 +216 +216 104022 023 007 006 00
085000 1735N 08532W 9246 00739 0057 +224 +210 107025 025 012 003 00
085030 1737N 08532W 9243 00743 0059 +221 +211 110025 025 017 003 00
085100 1739N 08532W 9246 00741 0059 +219 +216 114023 024 019 004 00
085130 1741N 08532W 9034 00944 0061 +208 +208 110023 024 022 003 03
085200 1743N 08532W 8599 01384 0073 +190 +190 109023 024 999 999 03
085230 1745N 08532W 8106 01898 0076 +168 +159 105023 024 999 999 03
085300 1746N 08532W 7716 02284 0050 +145 +136 098021 021 999 999 03
085330 1748N 08533W 7390 02655 0043 +109 +109 093020 021 999 999 05
085400 1750N 08534W 7036 03064 0024 +109 +109 066026 031 999 999 03
085430 1751N 08534W 6774 03397 0032 +095 +094 067032 034 999 999 03
085500 1753N 08534W 6548 03684 0033 +080 +074 066030 031 029 007 03
085530 1755N 08535W 6320 03970 0034 +063 +054 068029 031 026 001 00
085600 1757N 08535W 6126 04228 0026 +053 +053 077031 031 025 001 03
085630 1758N 08535W 5932 04460 9987 +039 +029 077033 035 024 001 03
085700 1800N 08534W 5739 04731 9990 +022 +014 076036 038 029 003 00
085730 1802N 08534W 5552 05000 9990 +007 +004 074037 038 026 003 03
085800 1803N 08533W 5408 05211 0221 -006 -006 076034 035 025 003 00
085830 1805N 08532W 5264 05428 0234 -015 -015 075033 033 026 002 00
085900 1806N 08531W 5111 05660 0250 -026 -026 080038 040 023 002 00
$$

[cookie]

Good morning tropical storm Alex

[Iceberg]

Sorry for filling up the thread with recon data.

But this second lot would strongly indicate that pressure is alot lower than NHC previously thought.

If it's a meso low then it's an incredibly large one with a low pressure swave this deep.One possibiliy is that the deep convection is causing a deeper centre to form within the broad 1005mb area.

AF305 0201A CYCLONE HDOB 45 20100626
085930 1808N 08530W 4981 05867 0267 -037 -038 079038 039 020 002 03
090000 1810N 08530W 4872 06039 0279 -045 -050 081038 039 021 001 00
090030 1812N 08530W 4753 06238 0293 -054 -062 080038 040 021 002 00
090100 1814N 08529W 4633 06428 0303 -064 -073 074034 036 020 002 03
090130 1816N 08529W 4491 06681 0325 -080 -087 070033 033 018 002 00
090200 1818N 08529W 4398 06841 0337 -091 -099 070032 032 021 000 00
090230 1820N 08529W 4321 06982 0348 -096 -109 075031 032 017 001 00
090300 1822N 08529W 4235 07138 0359 -104 -120 077033 033 017 002 00
090330 1824N 08529W 4155 07285 0370 -112 -132 078034 034 013 002 00
090400 1826N 08529W 4067 07451 0385 -115 -157 071033 033 018 002 00
090430 1828N 08528W 3996 07591 0400 -127 -166 071033 034 019 004 00
090500 1830N 08528W 3941 07700 0409 -132 -180 071031 032 021 006 00
090530 1832N 08528W 3922 07735 0414 -135 -189 069030 030 023 004 00
090600 1834N 08528W 3923 07732 0412 -130 -194 070031 033 021 003 00
090630 1836N 08528W 3926 07727 0412 -130 -193 070032 033 020 002 00
090700 1838N 08528W 3929 07723 0412 -127 -196 068032 033 020 002 00
090730 1841N 08527W 3926 07729 0414 -127 -199 067032 032 023 002 00
090800 1843N 08527W 3926 07731 0415 -129 -198 070033 034 027 003 00
090830 1845N 08527W 3925 07732 0416 -129 -199 072033 035 031 008 00
090900 1847N 08527W 3923 07738 0417 -129 -168 078034 037 034 010 00
$$

[cookie]

Iceberg, on 26 June 2010 - 09:22 , said:

Sorry for filling up the thread with recon data.

But this second lot would strongly indicate that pressure is alot lower than NHC previously thought.

Don't say sorry mate I for one find it really interesting

[Iceberg]

Cheers Cookie, Recon are now leaving Alex and these where found on the way out, just to the NW of the really heavy convection.

Could be instrument error, all a bit strange really, If they are real and NHC are probably interrigating them atm, them I would expect a quick update on the NHC site in the next hr.

[Katherine]

And we do indeed have Tropical Storm Alex!

[kold weather]

I think Iceberg we may have been seeing is the center really wobbling about in the deep convection, it is probably trying to move into the most favourable region it can and wth explosive convection all around no doubt that is constantly changing. It'll probably eventually settle on a center location and stick with it.

Looking at the co-ordinates it looks like its still on the NW side of the deep convection which would suggest despite the explosive convection shear is still slightly on the system. This probably won't be able to prevent strengthening, esp with such potent convection but it could prevent rapid strengthening from occuring. Thay all being said the models are pretty keen for the system scoop under the upper high in the next 12hrs so if that does occur we could well see this make a run for high TS strength...

Models still are split with the ECM being the furtherest south still heading into C.Mexico, whilst some of the other dynamic models have shifted northwards a little and are in line with the NHC track.

Conditions on the other side of the Yucatan look decent enough for now and I'd suggest as long as any center doesn't get too torn apart overland (it'll actually be best for the system *not* to form an inner core at this stage) then I think conditions probably are going to be condusive for a borderline hurricane. For now I'll go to the higher end of the range I have been forecasting for a 2nd landfall at 60kts but there is every chance IMO that this could end up a hurricane, its certainly been suggested by the hurricane models.

Edited by kold weather, 26 June 2010 - 10:04 .

[Iceberg]

What do you think the min pressure is atm Kold, given the recon and the NHC statement ?.

Have to admit I am not at all sure it could be 1005 or even 999 ?