Rina rapidly intensifies into a hurricane

By: Dr. Jeff Masters , 7:59 PM GMT on October 24, 2011

Share this Blog
34
+

Rina is now a hurricane, just 21 hours after becoming a tropical depression. An Air Force Reserve hurricane hunter aircraft found winds of 75 mph--Category 1 hurricane strength--at 1:40 pm EDT in the north eyewall of Rina, using their SFMR surface wind instrument. Winds at flight level of 5,000 feet peaked at 78 mph, which typically translates to surface winds of 62 mph. On their second pass through the eye at 3:30 pm EDT, the winds were about 5 mph less, but the central pressure had fallen by two millibars, to 989 mb. Visible satellite loops show that Rina now has an eye, and the storm is steadily expanding in size and developing an impressive upper-level outflow channel to the north. Wind shear is a moderate 15 - 20 knots due to strong upper-level winds out of the southeast, and these winds are injecting dry air into Rina's southeast side, inhibiting heavy thunderstorm development there. Water temperatures are very warm, 29 - 30°C, and these warm waters extend to great depth.


Figure 1. Afternoon satellite image of Rina. An intense thunderstorm with a top that reaches into the stratosphere is visible on the southwest side of the eye. These "hot towers" are commonly seen in hurricanes undergoing rapid intensification.

Rina in historical context
Rina intensified into a hurricane just 21 hours after the first advisory was issued for it as a tropical depression. This is the second fastest such intensification since record keeping began in 1851. Hurricane Humberto of 2007 holds the Atlantic record for fastest intensification from first advisory issued to hurricane strength--18 hours. (Actually, Humberto did the feat in 14 1/4 hours, but this was rounded off to 18 hours in the final data base, which stores points every six hours). There have been six storms that accomplished the feat in 24 hours. Rina's formation brings this year's tally of hurricanes to six, which is average for an Atlantic hurricane season. The number of named storms this season is now seventeen, making it the 7th busiest Atlantic hurricane season since record keeping began in 1851. Only 2005, 1933, 1995, 1887, 2010, and 1969 had more named storms. However, 2011 has had an unusually low percentage of its named storms reach hurricane strength. Only 35% of this year's named storms have made it to hurricane strength, and normally 55 - 60% of all named storms intensify to hurricane strength in the Atlantic. The rare combination of near-record ocean temperatures but unusually dry, stable air over the Atlantic is no doubt at least partially responsible for this very unusual occurrence.


Figure 2. Microwave satellite image from 11:39 am EDT October 24, 2011, showing that Rina had a partially complete eyewall, which was open on the east side. Image credit: Navy Research Lab, Monterey.

Forecast for Rina
The hurricane hunters found an elliptical eyewall that had a gap in it during their 3:30 pm eye penetration. The aircraft measured a temperature difference of 6°C between the eye and the region outside the eye, which is difficult to get unless an eyewall is on its way to completion. Rina will need to complete its eyewall if it is to intensify into a major hurricane. Given the fact wind shear is not expected to increase until Wednesday, Rina has a 2-day period to close off an eyewall and intensify, and it will probably reach Category 3 or Category 4 strength by Wednesday. On Wednesday, Rina will encounter a dry airmass with high wind shear that lies over the extreme northwestern Caribbean. These conditions should weaken the hurricane, but Rina could still be a major hurricane if it makes landfall in the Yucatan Peninsula on Wednesday or Thursday.

A trough of low pressure is predicted to pass to the north of Rina late this week, and now that the hurricane is expected to be a Category 2 or stronger storm, the chances for Rina to make it farther north and affect the Florida Keys and Southwest Florida have increased. The latest 8 am EDT runs of the GFDL and HWRF models both predict that Rina will pass through the Yucatan Channel on Thursday and make landfall on Friday in the Florida Keys or extreme Southwest Florida, south of Naples. The NOGAPS and GFS models predict a weaker storm, and keep Rina trapped in the Caribbean. I think it is more likely that Rina will pass through the Keys. If Rina does make it to the Keys, it would likely be as a tropical storm, since wind shear, dry air, and possible land interaction with Western Cuba and Mexico would potentially knock down the storm's strength. Heavy rains from Rina should begin affecting Mexico's Yucatan Peninsula, northern Belize, and extreme Western Cuba on Wednesday. Rina's intensification into a hurricane over the Western Caribbean during the last half of October bring to mind Hurricane Wilma, which also performed such a feat in 2005. Wilma went on to become a Category 5 monster, the strongest Atlantic hurricane of all-time. I don't think Rina will be another Wilma, even though the ocean temperatures and total heat content are similar to what Wilma experienced. Wilma had nearly ideal upper-level atmospheric conditions with an anticyclone aloft and light wind shear, under 5 knots. Rina is experiencing 15 - 20 knots of wind shear and is also a smaller storm, and is thus more vulnerable to the effects of wind shear and dry air.

97L approaching ABC islands
A broad region of low pressure approaching the ABC islands of Aruba, Bonaire, and Curacao (Invest 97L), is moving west-northwest at 10 mph. Heavy thunderstorm activity has increased today, but the activity is not organized into spiral bands, as is apparent from Curacao radar. 97L is surrounded by a large region of dry air, and this dry air will retard development. 97L is under low wind shear less than 10 knots, and this shear is expected to remain low through Thursday. By the time 97L reaches the region between Jamaica and Nicaragua in the Central Caribbean on Thursday or Friday, the storm should find a moister environment, and could develop into a tropical depression. However, none of the reliable models are predicting that 97L will develop. NHC is giving 97L just a 10% chance of developing into a tropical depression by Wednesday. I put the odds higher, at 20%.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1014 - 964

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23Blog Index

986 BahaHurican "I also note the 4-5 day forecast still seems iffy....
997 barotropic "Going to be interesting. 97L is moving up on slow moving Rina rather quickly."

97L is getting ~100miles(161kilometres) closer to Rina every 6hours.
IF Rina keeps on dawdling along (while changing direction to minimize land interactions) and 97L continues speeding along its heading, 97L will have caught up with Rina in ~2&1/2days from now.
(MHIC on my mapping in comment_1001 is about where Rina should be now, and 97L should be at least 85miles closer to MHIC by now.)

Long before which, Rina would have already begun a Fujiwhara-like interaction with 97L's convection. In a little more than 1day from now, Rina would begin using its strength to strip 97L of its convection -- instead of using that strength to intensify -- while sacrificing its travel-speed to counterbalance the momentum change in 97L's(former)convection.

No wonder forecasts are iffy.

IF such an interaction were to occur, Rina would end up much bigger&stronger but a lot less intense than would have been the case without such interaction.
Probably so MUCH bigger that Intensification would be slowed enough to produce a hurricane similar to Ike: MaximumSustainedWinds lower than expectable from its MinimumPressure, and pushing along a HUGE storm surge totally out of proportion to its Cat. number.
And like Ike, that hypothetical Rina would probably create its own environment; allowing it to ignore what the models say it should be doing.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
Good Morning, in the 5 AM Forecast Discussion on Rina, NHC says this:
RINA CONTINUES TO EXHIBIT STRONG UPPER-LEVEL OUTFLOW...PARTICULARLY OVER THE NORTHERN SEMICIRCLE AND WILL CONTINUE TO TRAVERSE WATERS OF HIGH OCEANIC HEAT CONTENT FOR THE NEXT COUPLE OF DAYS.

ADDITIONAL STRENGTHENING SEEMS LIKELY UNTIL INCREASING SOUTH-SOUTHWESTERLY SHEAR HALTS THE INTENSIFICATION PROCESS...WHICH IS EXPECTED TO OCCUR IN ABOUT 48 HOURS.

THE OFFICIAL WIND SPEED FORECAST IS ABOUT THE SAME AS IN THE PREVIOUS ADVISORY ALBEIT A LITTLE LOWER NEAR THE END OF THE PERIOD. THIS IS IN REASONABLE AGREEMENT WITH THE CONSENSUS OF THE INTENSITY FORECAST MODELS.

IT SHOULD BE NOTED THAT THE NORMALLY RELIABLE ECMWF MODEL SHOWS RINA DISSIPATING OVER NORTHERN YUCATAN.

... GIVEN THE LARGE SPREAD IN THE MODEL SOLUTIONS IN THE EXTENDED RANGE...THE CONFIDENCE IN THE LATTER PART OF THE TRACK FORECAST REMAINS LOW.

Link to 5 AM Forecast Discussion for Rina
Member Since: Posts: Comments:
Quoting FlyingScotsman:
Anyone notice the dropsonde in the western eyewall that just reported 112 mph at surface?

Looks like the NHC shoulda waited a few more minutes on that advisory...


Hmm...no, no one seems to have noticed the dropsonde, or my comment for that matter.

So, I'll reiterate--looks like Rina might actually be a Cat. 3 right now! Either that or that dropsonde got hit by a bird or something....
Member Since: Posts: Comments:
Rina isn't exactely a "Small" Hurricane. If you compare it to the Florida peninsula - it extends from Jacksonville - almost all the way down to the keys. Just a lurking who is not an expert-but I was always under the impression that systems "Larger in size" were less affected by wind shear? And in this case the wind shear that Rina is expected to run into in the future?
Member Since: Posts: Comments:
Quoting hydrus:
Good morning..You might have those for some time.
I think you are right because Rina is in no hurry to go anywhere.
Member Since: Posts: Comments:
some wrong data in that square
Member Since: Posts: Comments:
Quoting TropicalBruce:
It looks like 97L will meet its demise in a day or two as it is moving faster than Rina and will eventually be affected by the outflow of Rina.

no cause 97L is the one with a lage ULAC not rina and the outflow on rinas E,SE ain't doing so good plus you could see that on the WV and by the time 97L gets here rina will be at the Yucattan

Member Since: June 13, 2009 Posts: 2 Comments: 12716
Is it likley that NE fla will get any rain from Rina? Why don't ULL form into storms? The one in the atlantic has lot of clouds and spin?
Member Since: Posts: Comments:
Dont like the model set up for Cozmel. Some models take 97L there as a cat 2 and RINA will most likely hit as a cat 2.
Member Since: Posts: Comments:
Good morning.

Still no floater for 97L?
Member Since: Posts: Comments:
1004. hydrus
Quoting stormwatcherCI:
Good morning. Very heavy rain here this morning and strong gusts.
Good morning..You might have those for some time.
Member Since: Posts: Comments:
Good morning. Very heavy rain here this morning and strong gusts.
Member Since: Posts: Comments:
It looks like 97L will meet its demise in a day or two as it is moving faster than Rina and will eventually be affected by the outflow of Rina.
Member Since: Posts: Comments:
12.1n61.4w, 12.3n62.8w, 12.5n64.3w have been re-evaluated&altered for Invest97L's_6amGMT_ATCF
12.2n61.7w, 12.3n63.5w, 12.6n65.3w, 13.0n67.0w are now the most recent positions
Starting 24Oct_6amGMT and ending 25Oct_6amGMT

The 4 line-segments represent Invest97L's now WestNorthWestward path
(281.25degrees is midway between W and WNW)

Copy&paste bon, cur, aua, mhic, lcl, 12.0n60.1w-12.2n61.7w, 12.2n61.7w-12.3n63.5w, 12.3n63.5w-12.6n65.3w, 12.6n65.3w-13.0n67.0w into the GreatCircleMapper for more info

The previous mapping for 25Oct_12amGMT
Member Since: August 21, 2007 Posts: 0 Comments: 4860
Quoting ANOTHERBADFORCAST:
florida is always protected by fronts from storms hitting no matter what direction they come from


Actually, we were NOT protected from Wilma! Don't say "never" or "ever" or "always" or anything that puts an absolute value on your comments when discussing storms. AND check your history BEFORE you comment.

Other than that, good morning all. I see our gal grew up some more overnight while I blissfully slept and is a Cat 2. Models still all over the place. Well, this S FL gal is still going to keep a very close eye on Rina and plan for the "worst" and hope for the best. My major worry right now is a direct hit on the Keys. Scary thought especially if she continues to strengthen!

Member Since: Posts: Comments:
Quoting barotropic:


Going to be interesting. 97L is moving up on slow moving Rina rather quickly.
Rina may absorb 97L and the unltimate track could be shifted a little as it happens..
Member Since: Posts: Comments:
<
Member Since: Posts: Comments:
Quoting BahaHurican:
Let's not be getting TOO gung ho with the Wilma comparisons.... lol... though I doubt we'll see another 100mb drop anytime soon.

I notice that 97L seems to be looking quite well organized compared with last night. I'll be very interested to see how it develops over the next 24 as it gets out of that doldrums area W of the Lesser Antilles.


Going to be interesting. 97L is moving up on slow moving Rina rather quickly.
Member Since: Posts: Comments:
Quoting barotropic:


Yep...I misread the post...sorry.
Yeah, I saw ur comment... after I posted.... lol... shoulda read down some more.

Anyway, I'm out for now. If things aren't too swift at work today I may get a chance to check in later.

Ya'll have a good one.
Member Since: Posts: Comments:
I propose to put all I and R names to... well, IR. A suitable place for them. ;)

Rina's looking impressive and sure could aim for a Cat 4. Said yesterday it was too early to compare it to Paloma (difference in track remains), but it's certainly ramped up fast. I didn't expect it to go that fast.

With the record on intensification, truth is we don't know. A lot of storms, particularly prior to satellite and moreso before radar, held intensities without fluctuation for a suspiciously long time. Also remember that tropical depressions were not even logged until the 70s.

That doesn't take away from the fact she's been impressive. Unfortunately, what with being in the Caribbean, you can only avoid things for so long usually. Hopefully, she'll weaken appreciably prior to impact.

And yes, too early for wilma comparisons. Some people need to stop getting so overexcited.
Member Since: Posts: Comments:
Let's not be getting TOO gung ho with the Wilma comparisons.... lol... though I doubt we'll see another 100mb drop anytime soon.

I notice that 97L seems to be looking quite well organized compared with last night. I'll be very interested to see how it develops over the next 24 as it gets out of that doldrums area W of the Lesser Antilles.
Member Since: Posts: Comments:
Quoting BahaHurican:
Isn't that where the cruise boat sank?

I mentioned this last night. Rina is second to Humberto. The record is for intensification from 1st advisory to hurricane.


Yep...I misread the post...sorry.
Member Since: Posts: Comments:
Quoting GBguy88:
Nevermind, I found them...Swan Islands. Didn't realize Mitch passed over them at peak intensity.
Isn't that where the cruise boat sank?

Quoting barotropic:
"Rina intensified into a hurricane just 21 hours after the first advisory was issued for it as a tropical depression. This is the second fastest such intensification since record keeping began in 1851."






Dont have time to check the above comment this morning but find that hard to believe. While Rina has intensified kinda quickly, consider Wilma. Rina dropped 28 mb (appx) in 24 hours. Wilma dropped 56 mb in six hours and 100mb in 24 hours. I find it very hard to believe that Rina is running second to Wilma. I know Allen, Gilbert, Katrina - a bunch of storms strengthend quicker than Rina.
I mentioned this last night. Rina is second to Humberto. The record is for intensification from 1st advisory to hurricane.
Member Since: Posts: Comments:
Rina should show us an "eye" soon. Possibly in next few sat frames.
Member Since: Posts: Comments:
Quoting BahaHurican:
Morning all.

I see Rina is up to cat 2 this a.m. I would not be at all surprised to see a major out there this afternoon around this same time. It's still looking pretty good.



I also note the 4-5 day forecast still seems iffy....



Looks like the front will get into the keys sat. Temps in upper 50's for Orlando area. If Front gets in Keys....dont think Fla will see Rina or 97.
Member Since: Posts: Comments:
Morning all.

I see Rina is up to cat 2 this a.m. I would not be at all surprised to see a major out there this afternoon around this same time. It's still looking pretty good.



I also note the 4-5 day forecast still seems iffy....

Member Since: Posts: Comments:
Quoting FlyingScotsman:
Anyone notice the dropsonde in the western eyewall that just reported 112 mph at surface?

Looks like the NHC shoulda waited a few more minutes on that advisory...


Sat shows Rina begining to move finally a bit W or WNW. Has been in same area now for nearly 18 hours (upwelling). May start to see some fresh warmer waters ahead. Seems to be strengthening.
Member Since: Posts: Comments:
Quoting Bobbyweather:

Hmm, I believe that Wilma dropped 56mb and 100mb while it was a hurricane.


Yer right...I kinda misread that post. Think post meant ..from depression to hurricane status. My mistake!
Member Since: Posts: Comments:
Quoting barotropic:
"Rina intensified into a hurricane just 21 hours after the first advisory was issued for it as a tropical depression. This is the second fastest such intensification since record keeping began in 1851."






Dont have time to check the above comment this morning but find that hard to believe. While Rina has intensified kinda quickly, consider Wilma. Rina dropped 28 mb (appx) in 24 hours. Wilma dropped 56 mb in six hours and 100mb in 24 hours. I find it very hard to believe that Rina is running second to Wilma. I know Allen, Gilbert, Katrina - a bunch of storms strengthend quicker than Rina.

Hmm, I believe that Wilma dropped 56mb and 100mb while it was a hurricane.
Member Since: Posts: Comments:
Anyone notice the dropsonde in the western eyewall that just reported 112 mph at surface?

Looks like the NHC shoulda waited a few more minutes on that advisory...
Member Since: Posts: Comments:
"Rina intensified into a hurricane just 21 hours after the first advisory was issued for it as a tropical depression. This is the second fastest such intensification since record keeping began in 1851."



Quoting drg0dOwnCountry:


I have a bad feeling about this




Dont have time to check the above comment this morning but find that hard to believe. While Rina has intensified kinda quickly, consider Wilma. Rina dropped 28 mb (appx) in 24 hours. Wilma dropped 56 mb in six hours and 100mb in 24 hours. I find it very hard to believe that Rina is running second to Wilma. I know Allen, Gilbert, Katrina - a bunch of storms strengthend quicker than Rina.
Member Since: Posts: Comments:
The 5:00 AM TWO listing here on the WU is rather bizarre. It has this info...

Maximum Winds: 100 mph
Wind Gusts: 95 mph
Min. Pressure: 975 mbs

Does anyone know what the gusts actually might be? :-)

Jo
Member Since: Posts: Comments:
Flood-soaked Central America also braced for more rain as Rina lumbered along.
In Nicaragua and Honduras, where flooding and mudslides have affected thousands and killed dozens of people, authorities issued alerts warning residents that more precipitation could be on the way.
October marks the end of the rainy season in the region and is when the area is most susceptible to flooding because the ground is already saturated, CNN International weather anchor Mari Ramos said.
Heavy rains have hit Honduras for several weeks, killing at least 29 people, according to government statistics.
In Guatemala, 39 people have been killed and thousands remain at risk, the state-run AGN news agency reported.
Civil protection officials in El Salvador reported 34 rain-related deaths. And Nicaragua has reported at least 12 deaths.

CNN
Member Since: Posts: Comments:
Rina's hit the triple digits, 100mph and growing! It will be interesting to see what happens to Rina in the next 24 hours, but a Category Four is definately not out of the question.
Member Since: Posts: Comments:
Rina intensified into a hurricane just 21 hours after the first advisory was issued for it as a tropical depression. This is the second fastest such intensification since record keeping began in 1851.


I have a bad feeling about this

Member Since: Posts: Comments:
When its off this much the run is kinda useless.
Member Since: Posts: Comments:
Quoting barotropic:

only about 30mb...off LOL Also never shows Rina getting stronger than 996 - 1000mb.


I've seen the GFS have its issue before. I recall once in 2007, it showed Felix (Cat 5) as an open wave.
Member Since: Posts: Comments:
Quoting BenBIogger:
Wonder why the GFS is initializing Rina as a 1008Mb storm...

only about 30mb...off LOL Also never shows Rina getting stronger than 996 - 1000mb.
Member Since: Posts: Comments:
Recon heading north at FL102, and descending.

Last recon pass for tonight.
Member Since: Posts: Comments:
Wonder why the GFS is initializing Rina as a 1008Mb storm...
Member Since: Posts: Comments:
Quoting 7544:


agree she just might inch alittle more north tonight and into tomorow the ? is could the new gfdl be right / im 50/50 on that one


I see that.....pics I looked at may have been several hours old.....sorry! To tired to go back and check! Think Recon info is as good as it gets.
Member Since: Posts: Comments:
H.Rina's_6amGMT_ATCF : Starting 24Oct_6amGMT and ending 25Oct_6amGMT

The 4 eastern line-segments represent HurricaneRina's path,
the westernmost line-segment is the straightline projection for 25Oct_6amGMT,
the sea-to-island dumbbell at 17.545n83.894w-MHIC is the endpoint of the 25Oct_12amGMT
straightline projection connected to its nearest airport,
and the dot at MHIC is the same for 24Oct_6pmGMT.

Using straightline projection of the travel-speed&heading derived from the
ATCF coordinates spanning the 6hours between 12amGMT then 6amGMT :
H.Rina's travel-speed was 3.5mph(5.6k/h) on a heading of 289.2degrees(WNW)
H.Rina was headed toward passing ~1mile(~1.7kilometres) north of the SwanIslands*Honduras ~6hours from now (though I wouldn't count on Rina continuing to move that slowly)

For more info and a more detailed view of the SwanIsland area, copy&paste
17.545n83.894w-mhic, 16.5n82.2w-17.0n82.7w, 17.0n82.7w-17.1n83.0w, 17.1n83.0w-17.2n83.2w, 17.2n83.2w-17.3n83.5w, 17.2n83.2w-17.431n83.894w into the GreatCircleMapper

The previous mapping for 25Oct_12amGMT

* In October 1998, Hurricane Mitch passed over the SwanIslands with winds of 180mph.
Member Since: August 21, 2007 Posts: 0 Comments: 4860
968. 7544
Quoting barotropic:
Checked SSMIS...looks like eye wall pretty well closed off. Just little weak on north side. Rina slowly getting stronger.


agree she just might inch alittle more north tonight and into tomorow the ? is could the new gfdl be right / im 50/50 on that one
Member Since: Posts: Comments:
Quoting barotropic:
Checked SSMIS...looks like eye wall pretty well closed off. Just little weak on north side. Rina slowly getting stronger.


According to recon, the southeast part of the eye wall is still open.
Member Since: Posts: Comments:
Checked SSMIS...looks like eye wall pretty well closed off. Just little weak on north side. Rina slowly getting stronger.
Member Since: Posts: Comments:
965. JLPR2
Quoting Bordonaro:

Hurricane force winds are only about 10-15 NM from the center. They may have hit "Rina'a sweet spot".


What I meant is that the surface winds where much higher than flight level winds, which is weird. But Rina is at least a 90mph hurricane, would even dare to say 95mph.
Member Since: Posts: Comments:
964. 7544
hmmmm new run here Link
Member Since: Posts: Comments:

Viewing: 1014 - 964

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron