Azores storm could become Subtropical Storm Alberto
An interesting and surprising hybrid low pressure system with both tropical and extratropical characteristics has formed over the far Eastern Atlantic, about 400 miles southwest of the southern Azores Islands. This low, designated Invest 92L by NHC today, has developed an impressive amount of heavy thunderstorm activity near its center, despite the fact that it is over cold ocean waters with temperatures of 66°F (19°C.) This is well below the 26°C usually needed for a tropical storm to form. However, there is quite cold air aloft, so the temperature difference between the surface the upper levels has been great enough to create sufficient instability for 92L to organize. Wind shear is a moderate 15 - 20 knots, and satellite estimates of 92L's winds were 63 mph at 1:45 pm EDT Saturday, according to NOAA/NESDIS. NHC estimated that 92L had top winds of 50 mph at 2 pm EDT Saturday.
Figure 1. Afternoon satellite photo of Invest 92L, taken at 16 UTC May 12, 2012, by NASA's Aqua satellite. Image credit: NASA.
NHC is giving 92L a 40% chance of developing into a named storm by Monday. They will be reluctant to name it Alberto unless the storm can maintain it's current level of heavy thunderstorm activity for at least 6 - 12 hours. The storm's heavy thunderstorms have weakened some during the afternoon, making it less likely NHC will be inclined to name it; the fact that 92L is over waters of 66°F (19°C) hurts its chances. The coldest waters I've seen a tropical storm form in were 19°C, during Tropical Storm Grace of 2009. Grace holds the record for being the farthest northeast forming tropical cyclone in the Atlantic basin. Like 92L, Grace also formed near the Azores Islands, but in early October. The coldest waters I've seen a hurricane form in were 22°C, for Hurricane Epsilon of 2005. Latest guidance from the computer models show 92L meandering to the south of the Azores through Monday, then beginning a slow motion towards the northeast by Tuesday.
Jeff Masters
Reader Comments
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Theres a chance of like a 40/100 for alberto out of any three
Yep, Around the area Where Fay(08') made landfall, but it sideswipes the system across florida very quickly and then heads off to the Northeast.
Yes i agree i was just noting
the Euro had it hours 144 on the 00Z run but has pushed it back to 168 on the 12Z run..I believe the GFS is initalizing its storm around the 180 mark if I remember correctly..it gets to florida around the 300 mark..I havent look at the models but the east coast storm looks to be first if it materializes
North side is firing
Its heading back toward slightly warmer waters, if it means much...
Ehhh, not necessarily... And i imagine 3 storms before june would be a record breaker.
I have a very plausible explanation for the lack of sustained convection, due to the cooler waters the low has less energy to work with. Therefore, it relies on atmospheric instability, steepness of lapse rates, to make up for the colder water. That being said the system is much more subject to the diurnal cycle, as well as the convective cycle, in that instability increases in the lull of convection till it increases enough again for a larger bursts of convection, then decreases again.
I was discussing this yesterday, that if you understand atmospheric physics well enough, you know that a rule cannot be placed on a given water temperature to be sufficient for tropical development. While its true that 80 plus is the safe zone, given steep enough lapse rates you have a similar relationship found with warmer water, the math comes out the same. However because there is much less energy with such cooler waters, even if lapse rates are quite steep, the lack of energy limits the strength of persistent convection and how deep the convection is. Because of this, a tropical cyclone can develop or persist over waters much cooler than 80 given the right conditions, but because of less available energy and a dependence on instability, not only is convective intensity limited, but the ability to maintain consistent deep convective development also becomes limited.
You'll notice that while stronger hurricanes over very warm waters still get effected by the diurnal cycle, the convective min period becomes less important.
I dont see the Invest being named but if both of those storms actually formed and were named, I have to question the low average season prediction especially with early formation before the season actually started
:)
Not necessarily, the area is under the influence of high clouds, and the system to the west is also moving slower than predicted so I'm not that surprised there isn't much going on over much of Florida yet today, but that doesn't mean we won't get rain. Look at the meso-analysis maps I posted, moisture ahead of the approaching trough continues to be deeper than expected as it approaches Florida, and there are also some rather impressive severe parameters in the gulf approaching Florida, considering the fact that there is no mention of stronger thunderstorms possible. The atmosphere ahead of the trough/cold front is actually looks pretty impressive right now, more so then yesterday actually.
Now granted, I'm not saying its guaranteed that will remain so once the system moves in, but it looks more impressive that forecasters seem to indicate so far, whether this persists when it arrives or not will remain to be seen.
Not Always... look at 2008, Arthur formed a day early ;)
And you cant count 2009(It was a tropical depression)
2007- Andrea= 2 category 5 hurricanes, 15 named storms
So what happens when seasons start late? Are they very active?
Not Exactly either... you cant conclude to how a season will turn out on what the activity was early on in the season... And more than likely a season that starts off very late is an inactive one, but you can never underestimate mother nature...
2004- Alex formed in Late July, there was 8 Hurricanes, and 6 of them became majors, 3 of em went on to destroy the US coastlines.
2009- Ana formed in mid-august, was one of the quietest seasons on record..
both of them were El Nino seasons..
04' CPAC El nino.
09' EPAC El Nino.
If this persists into diurnal min the NHC might have something on their hands.
Haha.
5 Pm advisory would be iniated about now, if Alberto was gonna happen, still got about 5 minutes or so though, but i think if Alberto is gonna happen, its gonna happen at the 11 pm
Yesterday
Now
I'd say just as good, except this time it happened during DMIN...
Storm appears to be moving WSW to SW now.
Whoa whoa, back off man. This is Grace's Brother Alberto... Maybe..
Or a "quas-eye". *ducks*
Lbar seems to be getting it right... others, not so much.
Maybe the chamber of commerce has develop secret technology capable of stabilizing the atmosphere, because at some point they realized that Florida is only the sunshine state of part of year, and for another part is the heavy downpour state, so they are trying to change our climate into the boring, dry climate of Southern California in order to bring in more tourism profits, I got it I got it!!!!!!!!!
13/1800 UTC 34.7N 33.5W ST3.0 92L -- Atlantic
IMO, give it an hour or two and convection will start to wane. If it holds this convective burst until 8/11pm EST , then the NHC may consider naming it. I doubt this will be our Alberto though.
Well, at its peak yesturday it was estimated at 3.5 but it crashed after dmax ended.. today looks much more promising.
Hmmmm.... Maybe not a "quas-eye"....
I said the same thing yestuday, and i was right... Hopefully in this case it can hold on... I mean its in Dmin right now and holding up okay, yesturday it only survived through dmax... so In my logic it would be surviving through the worst part of the day, which means it might have a chance.
That is literally the best idea this blog has ever produced.
3.0 T3 =
50 Mph
1000 Mb
If only...
Translates to a weak tropical storm out there.
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