159 replies to this topic

[Paranoid]

Up to 65mph.


000
WTNT31 KNHC 262031
TCPAT1
BULLETIN
TROPICAL STORM ALEX ADVISORY NUMBER 5
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL012010
400 PM CDT SAT JUN 26 2010

...AIR FORCE PLANE FINDS A STRONGER ALEX...WEATHER DETERIORATING
FAST IN BELIZE AND THE YUCATAN PENINSULA...


SUMMARY OF 400 PM CDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.3N 87.8W
ABOUT 30 MI...50 KM ESE OF BELIZE CITY
ABOUT 90 MI...145 KM SSE OF CHETUMAL MEXICO
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/HR
PRESENT MOVEMENT...W OR 280 DEGREES AT 12 MPH...19 KM/HR
MINIMUM CENTRAL PRESSURE...996 MB...29.41 INCHES


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

NONE.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE COAST OF BELIZE AND THE EAST COAST OF THE YUCATAN PENINSULA OF
MEXICO FROM CHETUMAL TO CANCUN
* THE ISLANDS OF ROATAN...GUANAJA...AND UTILA IN HONDURAS

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* THE COAST OF HONDURAS FROM LIMON WESTWARD TO THE BORDER OF
HONDURAS AND GUATEMALA

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


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
AT 400 PM CDT...2100 UTC...THE CENTER OF TROPICAL STORM ALEX WAS
LOCATED NEAR LATITUDE 17.3 NORTH...LONGITUDE 87.8 WEST. ALEX IS
MOVING TOWARD THE WEST NEAR 12 MPH...19 KM/HR...AND THIS GENERAL
MOTION IS EXPECTED TO CONTINUE FOR THE NEXT TWO DAYS. ON THIS
TRACK...ALEX WILL MOVE INLAND OVER BELIZE AND THE YUCATAN PENINSULA
IN THE NEXT FEW HOURS.

DATA FROM A RECONNAISSANCE PLANE INDICATE THAT THE MAXIMUM SUSTAINED
WINDS HAVE INCREASED TO NEAR 65 MPH...100 KM/HR...WITH HIGHER GUSTS.
THESE WINDS ARE CONFINED TO A SMALL AREA SOUTH OF THE CENTER. NO
SIGNIFICANT CHANGE IN STRENGTH IS EXPECTED BEFORE ALEX MOVES INLAND
...BUT GRADUAL WEAKENING IS EXPECTED WHILE THE CYCLONE MOVES OVER
YUCATAN. SOME STRENGTHENING IS FORECAST AS ALEX MOVES OVER THE
GULF OF MEXICO BY MONDAY.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115 MILES...185 KM
FROM THE CENTER.

THE MINIMUM CENTRAL PRESSURE REPORTED BY A RECONNAISSANCE PLANE WAS
996 MB...29.41 INCHES.


HAZARDS AFFECTING LAND
----------------------
RAINFALL...ALEX IS EXPECTED TO PRODUCE TOTAL RAIN ACCUMULATIONS OF
4 TO 8 INCHES OVER THE YUCATAN PENINSULA...NORTHERN GUATEMALA...MUCH
OF HONDURAS AND BELIZE THROUGH SUNDAY EVENING. ISOLATED MAXIMUM
AMOUNTS OF 15 INCHES ARE POSSIBLE OVER MOUNTAINOUS AREAS. THESE
RAINS COULD CAUSE LIFE-THREATENING FLASH FLOODS AND MUDSLIDES.

WIND...TROPICAL STORM FORCE WINDS ARE AFFECTING PORTIONS OF BELIZE
AND THE YUCATAN PENINSULA WITHIN THE WARNING AREA. WINDS WILL
BEGIN TO SUBSIDE TONIGHT IN THE BAY ISLANDS OFF THE NORTHERN COAST
OF HONDURAS.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...700 PM CDT.
NEXT COMPLETE ADVISORY...1000 PM CDT.

$$
FORECASTER AVILA

[Rob]

Alex only just a Tropical Storm, much strong and it'll be classed a Cat 1

[kold weather]

Bursting towards a landfall means it will probably strengthen onto landfall, which probably means winds in the 55-60kts are quite possible and it may well make landfall just shy of hurricane status...quite an impressive climb.

Usually bursting storms tend to hold onto thier energy across land very well becuase it means the atmosphere is already unstable and its far easier to keep the energy going in that way. So whilst it will weaken the system may do surprisingly well inland as long as it doesn't spend too much time inland...

Once it emerges conditions aloft look decent so I'd expect strengthening and it probably has the time to become a hurricane before a second landfall. Track to me looks like a WNW as an upper trough digs down from the NW states and slightly weaknes the upper high pressure ridge which induces a very slight northerly lift of the track towards a WNW/NW direction for about 24-36hrs before the upper high exerts its strength again and bends the system back towards the west.

How strong it becomes really does depend on how much latitude the system can gain over the next 36hrs or so, there is a small chance it never even makes it into the BoC if it stays on its current heading...

[cookie]

Cracking system this one and thanks for the updates guys



and this stunning image from NASA

[kold weather]

One quick last post...

Structure has improved yet further in the last few hours, probably is undergoing a brief phase of RI in the final hours before landfall as the land fricition helps to tighten up the system.

Dvorak estimates are now at 65kts, so the NHC will at least raise the system upto 60kts next advisory if its not inland and there is a chancer they may even go to hurricane strength, though I think they may well favour going upto 60kts given its more or less inland.

Very impressive system, considering it was only progged to be 40kts and LF according to the NHC, its got a good deal stronger then that, which is what happens when you have good conditions aloft and explosive heat content.

[Rob]

Alex had made landfall overnight, now crossing the Yucatan Peninsula as a Tropical Storm, but soon expected to downgrade to a depression (by next advisory at 1pm uk time).

He looks to move into the gulf of mexico late today where he will rapidy develop to a Category 2 Hurricane before making his second landfall in the North of Mexico late Thursday, the track shows that he could cross over into the the Pacific Ocean as a depression, if this happens it could develop rapidly again as a Pacific Storm, most likely to Major Hurricane status as conditions seem favourable.

Very intestesting first storm!

[Iceberg]

Very much rob, I had a quick look at Alex earlier and thought he seemed to look very good for a cane over land.
Then saw this update from NHC 30 mins ago. Which talked about eye features, more like a hurricane, banding features etc.

"RATHER THAN BECOMING DISORGANIZED AFTER MOVING INLAND...RADAR AND
SATELLITE DATA INDICATE THAT ALEX HAS ACTUALLY BECOME MUCH BETTER
DEFINED. AN EYE FEATURE HAS BEEN NOTED IN BELIZE RADAR DATA AND
SATELLITE IMAGERY INDICATES THAT CLOUD TOPS HAVE COOLED
SIGNIFICANTLY WITH A NEARLY CLOSED RING OF -80C AND COLDER TOPS
ENCIRCLING THE RADAR CENTER. THE UPPER-LEVEL OUTFLOW PATTERN
REMAINS IMPRESSIVE AND ADDITIONAL CONVECTIVE BANDING FEATURES HAVE
DEVELOPED IN ALL QUADRANTS. THE RADAR AND SATELLITE DEPICTIONS OF
ALEX LOOKS MORE LIKE A HURRICANE THAN A LOW-END TROPICAL STORM."


It's clear that thanks to it's initial size and make up Alex is not starving as he crosses the Yucatan, all it's rally doing is tightening him up ready for entry into the GOM. NHC have duly raised there estimate to a CAT 2 storm and a CAT 3 is not beyond the realms of possibility either. Having the first named storm of the season a Hurricane and possibly a major one.

Path is still highly debatable with two distinct camps as NHC go on to say.

Heres the Radar pic with the eye feature at 18.3N 89.5W

Attached Thumbnails

• 
• 

Edited by Iceberg, 27 June 2010 - 09:34 .

[kold weather]

kold weather, on 26 June 2010 - 22:02 , said:

Usually bursting storms tend to hold onto thier energy across land very well becuase it means the atmosphere is already unstable and its far easier to keep the energy going in that way. So whilst it will weaken the system may do surprisingly well inland as long as it doesn't spend too much time inland...

Well this is what I posted last night, I expected Alex to hold its energy but I'll be frank and say I didn't expect the structure of Alex to carry on and tighten a good 6hrs into land. This is a *very good* sign for what will happen when it gets out to water, with it still having plenty of energy and the core being small (though the actual system is quite large) I'd expect this to ramp up quite nicely.

How strong will it get, I see no reason why we don't get upto cat-2 as the NHC have called for, esp if it does take the more northerly route. Conditions aloft are very condusive with a strong upper high aloft over the sytstem finally vertically stacked with the system and some great upper divergence over the system. Heat content should support a cat-2/3 quite readily throughout a good chunk of the basin, therefore I wouldn't rule out a major hurricane at all...

Models still flip-flopping all over the place with some real uncertainty over what exactly Alex does. For now it is tracking just shy of NW across Yucatan at a decent clip. It is taking more or less the shortest route to water with the convective burst last night proving a good indcator of direction of movement...I'm becoming much more concerned about a Texas threat now, quite a few of the big models are now rather close to Texas and the GFS/CMC are in fact not even that far away from LA and the big oil spill...a large major hurricane (which is possible...) would certainly test out some of the theory of what a hurricane would do to the oil spill. That being said I'd still suggest the most likely option is njust south of the Mexico border, possibly a MW/TX hit which would mean Brownsville is at threat. The best case for land is if this system hits in a similar area to Bret in 1999.

My own personal analog would be the June 1921 hurricane, look it up and see how close it has been to Alex thus far, that one was just shy of cat-2 at 90mph...

[Paranoid]

May be worth noting that if Alex reaches hurricane strenth, it will be the first A storm to reach hurricane strength since 2004. Co-incidentally, that storm was also called Alex and reached Category 3.

[cookie]

Quote

THE CURRENT PROGRESSIVE 5-WAVE NORTHERN
HEMISPHERIC FLOW PATTERN WOULD TEND TO FAVOR THE THE GFS-CANADIAN
SOLUTION...BUT AT LEAST ONE MORE MODEL CYCLE WILL BE REQUIRED TO
CONFIRM THAT TREND. THE OFFICIAL FORECAST TRACK IS TO THE RIGHT OF
AND SLOWER THAN THE PREVIOUS ADVISORY...AND IS SIMILAR TO THE
CONSENSUS MODEL...TVCN. NOTE...IF THE RECENT NORTHWARD SHIFT IN THE
MODELS CONTINUES...THEN ALEX COULD REMAIN OVER WATER FOR THE NEXT 5
DAYS RESULTING IN A VERY POWERFUL HURRICANE.

[kold weather]

Yep Paranoid, and given conditions aloft are pretty good as long as it can sort its inner core out pretty quickly I see no reason why it won't get to hurricane strength given there is good heat content and some very good upper air conditions right now.

Cookie, yeah that was quite an eye opener really, whilst I think its still an outside risk the fact some of the models are still trying to go that far north is something that needs watching closely. I personally would be surprised if this ended up getting north of say far S.Texas. However that being said anaylsis of the upper pattern right now does show the upper ridge has decayed a slack upper trough is trying to force the upper high further to the east, however the upper high is stil lstrong to the east so there is only so far the upper trough will get before it has to lift out and the weakness closes. Therefore I suspect what will happen is a NW/WNW track for a while, then possibly a bend back westwards. Some of the GFS ensembles do try and bring it back northwards after that bendback which does need to be watched as well but thats some way off yet.

Should be back over water in about 6-9hrs, then the real fun and games can begin...

[cookie]

first visible of the day

[The PIT]

cookie, on 27 June 2010 - 13:15 , said:

first visible of the day

Look pretty good this morning isn't he. So is this going bash up BP's clean up job ???

[Iceberg]

Looking at the latest visuals and Alex is still tighening IMO, with more and better banding. Well over half way across the Yucatan now and according to the NHC he has only lost 2mb or so of pressure, I think a very good chance this will be a hurricane within 12 hrs of being over water, so maybe by tomorrow morning.
Pretty much everything is in place for large pressure drops.

[ukweathergirl]

Is there a chance that the oil slick will be blown inland should the TS pass over the slick?

[kold weather]

Iceberg, on 27 June 2010 - 14:04 , said:

Looking at the latest visuals and Alex is still tighening IMO, with more and better banding. Well over half way across the Yucatan now and according to the NHC he has only lost 2mb or so of pressure, I think a very good chance this will be a hurricane within 12 hrs of being over water, so maybe by tomorrow morning.
Pretty much everything is in place for large pressure drops.

Presentation has decayed in the last 2-3hrs, esp in terms of deep convection which is much more shallow then it was even 2-3hrs ago, though the structure is still decent. I think this may take a little longer then 12hrs to get going because of this quick decay and the system is actually slowing down right now so more weakening is likely in the next 3-5hrs before it finally makes it into the waters but then again a good convective blow up could well help to speed up the process. Still once it does finally end up sorting its inner core out again after land conditions aloft look decent so strengthening looks very likely, may even be good enough for some rapid strengthening.

GFS and CMC on thier 12z going for a landfall in the USA...however Alex has actually tracked only slightly north of west over the last few hours and so if these solutions are to come off Alex best lift out pretty soon, the models that make landfall in C/N.Mexico have a far more realisitic motion at the moment and therefore I still think those models are more likely to come off but we shall see, I'd never rule out anything just yet...

Edited by kold weather, 27 June 2010 - 16:54 .

[crimsone]

So, a TD again... the question is, how well will its core be doing by the time it makes it back out to sea, and how long will it spend there before landfalling again? North Mexico seems increasingly likely... keep watching that ridge

[summer blizzard]

http://www.ssd.noaa....flt/t1/ft-l.jpg

Centres coming offshore now, however it has very little convection around it.

[Somerset Squall]

Indeed SB, about another hour and the centre should move over water. As has been said, the structure of Alex is still very good for a system that has been over land for so long, the lack of convection is to be expected without the warm water beneath the cyclone.

Attached Thumbnails

• 

[Iceberg]

Yep leaving land now, convection is poor, not surprising given the land and the time of day, however as the NHC put it "SATELLITE IMAGES SHOW THAT ALEX CONTINUES TO HAVE A LARGE AND
WELL-DEFINED CIRCULATION WITH PLENTY OF BANDING FEATURES. NEAR THE
CENTER...HOWEVER...CONVECTION HAS DECREASED...PROBABLY DUE TO THE
INFLUENCE OF LAND. THE MEXICAN NAVY SURFACE STATION AT ISLA PEREZ
RECENTLY REPORTED 30 KT WINDS...SO THE INITIAL WIND SPEED IS KEPT
AT 30 KT. AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS
SCHEDULED TO INVESTIGATE ALEX THIS EVENING AFTER THE CENTER MOVES
OFFSHORE. "

Now it's just await and see to how Alex reacts over the next 12 hrs.