Rina rapidly intensifies into a hurricane

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

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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

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Quoting Saltydogbwi1:


2 days ago the gfs had a strong storm in the nw carib but then dropped it for some reason and hasnt really shown it since dunno why


Yeah, a couple days ago GFS was predicting a hurricane crossing Cuba. Then it just dropped it. Ever since its been way off the mark with development.
Member Since: September 16, 2007 Posts: 0 Comments: 8248
Hurricane RINA
...RINA TURNS WEST-NORTHWESTWARD...EXPECTED TO STRENGTHEN...
5:00 PM EDT Mon Oct 24
Location: 17.1°N 83.1°W
Max sustained: 75 mph
Moving: WNW at 3 mph
Min pressure: 989 mb
Member Since: Posts: Comments:
HURRICANE RINA ADVISORY NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL182011
500 PM EDT MON OCT 24 2011

...RINA TURNS WEST-NORTHWESTWARD...EXPECTED TO STRENGTHEN...


SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...17.1N 83.1W
ABOUT 195 MI...315 KM SW OF GRAND CAYMAN
ABOUT 355 MI...570 KM ESE OF CHETUMAL MEXICO
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...989 MB...29.21 INCHES
Member Since: July 12, 2007 Posts: 0 Comments: 6065
Quoting TropicalAnalystwx13:

"B" is a possibility, but "A" is more likely, at least, IMO. I could be wrong though. We'll see in the next 15 minutes. ;)

I said C because of the rate it is going, there is a huge chance that I could be wrong though.
Also it is moving into an area where the TCHP is high.
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Quoting angelafritz:
Our Head of Meteorological Operations, Shaun Tanner, is on a flight home from Cancun today. In the nick of time! This is the second time this year one of our meteorologists have had close calls with hurricanes.


Remind me to not travel with the meteorologist there. ;-)
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Quoting Speeky:
Looks like HWRF forecast from yesturday seems to be spot on for Rina. A rare occasion. By the way does Rina kind of give you a Wilma feel. Its oddly fishy how the time of year, location and rapid intesification are somewhat similar.

Does anyone else have that Wilma feel with Rina?


completely... the similarities are there but rina is a different name and essentially a different box, whatever she decides to pull out of that box is a different thing. she has already pulled out some crazy things and who knows what there is to come. The similarities are uncannily like wilma though.
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Quoting sdcbassman:


Excitement?


As in a storm to track, after the death of the season at the peak.

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Quoting Sfloridacat5:
GFS models has done a terrible time with Rina.


2 days ago the gfs had a strong storm in the nw carib but then dropped it for some reason and hasnt really shown it since dunno why
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HURRICANE RINA DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL AL182011
500 PM EDT MON OCT 24 2011

VISIBLE SATELLITE IMAGES SHOW SEVERAL BANDS OF DEEP CONVECTION
WRAPPING AROUND THE CENTER OF RINA AND A SMALL CENTRAL DENSE
OVERCAST FEATURE. THE HURRICANE HUNTER AIRCRAFT HAS NOT REPORTED
ANY STRONGER WINDS SINCE THEIR INITIAL PASS INTO THE CENTER JUST
BEFORE 1800 UTC...AND BASED ON THE EARLIER DATA THE INITIAL
INTENSITY WILL REMAIN 65 KT.

RINA WILL BE TRAVERSING VERY WARM WATER AND REMAIN IN A LOW SHEAR
ENVIRONMENT DURING THE NEXT COUPLE OF DAYS. THE ONLY NEGATIVE
FACTOR FOR INTENSIFICATION IS AN AREA OF DRY AIR TO THE NORTHWEST
OF THE CYCLONE. SO FAR...RINA HAS REMAINED WELL INSULATED FROM THE
DRY AIR AND THE OFFICIAL FORECAST ASSUMES THAT THE DRY AIR WILL NOT
REACH THE CORE DURING THE NEXT COUPLE OF DAYS. AFTER THAT...
SOUTHERLY SHEAR IS FORECAST TO INCREASE AND RINA IS ALSO EXPECTED
TO INTERACT WITH A FRONTAL BOUNDARY THAT MOVES INTO THE
SOUTHEASTERN GULF OF MEXICO NEAR THE END OF THE FORECAST PERIOD.
THE INTENSITY FORECAST IS VERY SIMILAR TO THE ONE ISSUED IN THE
SPECIAL ADVISORY AND IS NEAR THE GFDL AND HWRF GUIDANCE THROUGH 48
HOURS. AFTER THAT TIME...IT IS CLOSER TO A BLEND OF THE STATISTICAL
AND DYNAMICAL MODEL GUIDANCE. GIVEN THE RELATIVELY SMALL SIZE OF
THE HURRICANE...IT WOULD NOT BE SURPRISING TO SEE RAPID CHANGES
BOTH UP AND DOWN IN ITS INTENSITY.

THE AIRCRAFT FIXES SHOW THAT THE HURRICANE HAS SLOWED DOWN. A
BUILDING HIGH PRESSURE RIDGE OVER THE NORTHERN GULF OF MEXICO IS
EXPECTED TO STEER RINA WESTWARD DURING THE NEXT 24 TO 36 HOURS.
AS THE RIDGE SLIDES EASTWARD THE HURRICANE SHOULD TURN
NORTHWESTWARD...THEN NORTHWARD IN 2 TO 3 DAYS. AFTER THAT...THE
TRACK GUIDANCE BECOMES QUITE DIVERGENT WITH THE GFDL AND HWRF
TAKING THE CYCLONE NORTHEASTWARD...AND THE GFS SHOWING AN
EASTWARD OR EAST-SOUTHEASTWARD MOTION. FOR NOW...THE NHC FORECAST
REMAINS BETWEEN THESE TWO EXTREMES AND SHOWS A SLOW EAST-NORTHEAST
MOTION NEAR THE END OF THE PERIOD.

GIVEN THE EXTREMELY LARGE SPREAD IN THE GUIDANCE...AND THE POOR RUN
TO RUN CONSISTENCY...THERE IS MUCH LOWER THAN NORMAL CONFIDENCE IN
THE LONG-RANGE TRACK FORECAST OF RINA.


FORECAST POSITIONS AND MAX WINDS

INIT 24/2100Z 17.1N 83.1W 65 KT 75 MPH
12H 25/0600Z 17.2N 83.7W 75 KT 85 MPH
24H 25/1800Z 17.3N 84.4W 90 KT 105 MPH
36H 26/0600Z 17.6N 85.2W 100 KT 115 MPH
48H 26/1800Z 18.1N 86.0W 105 KT 120 MPH
72H 27/1800Z 19.8N 87.2W 95 KT 110 MPH
96H 28/1800Z 21.0N 87.0W 85 KT 100 MPH
120H 29/1800Z 21.5N 85.0W 75 KT 85 MPH

$$
FORECASTER BROWN
Member Since: July 6, 2010 Posts: 113 Comments: 32531
Quoting Articuno:
What do you think Rina will be at 5:00 EST?
A. 75
B. 80
C. 85
D. Higher
E. other


80 miles per hour.
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Quoting Articuno:
What do you think Rina will be at 5:00 EST?
A. 75
B. 80
C. 85
D. Higher
E. other

"B" is a possibility, but "A" is more likely, at least, IMO. I could be wrong though. We'll see in the next 15 minutes. ;)
Member Since: July 6, 2010 Posts: 113 Comments: 32531
GFS models has done a terrible time with Rina.
Member Since: September 16, 2007 Posts: 0 Comments: 8248
Quoting jfm1975:
I would like to ask those of you on this blog that are serious and know what you are talking about. Rina really grabbed my attention bigtime this afternnon and honestly as a long time south florida resident feel like I have seen this movie before...itlike Wilma part 2..anyone have feedback on this ? Thanks.


South Florida is definitely in play now that the storm has become stronger. I do not believe that Rina would impact the area as strong as Wilma though.
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Quoting Speeky:
Looks like HWRF forecast from yesturday seems to be spot on for Rina. A rare occasion. By the way does Rina kind of give you a Wilma feel. Its oddly fishy how the time of year, location and rapid intesification are somewhat similar.

Does anyone else have that Wilma feel with Rina?

I do.
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What do you think Rina will be at 5:00 EST?
A. 75
B. 80
C. 85
D. Higher
E. other
Member Since: Posts: Comments:
Quoting jfm1975:
I would like to ask those of you on this blog that are serious and know what you are talking about. Rina really grabbed my attention bigtime this afternnon and honestly as a long time south florida resident feel like I have seen this movie before...itlike Wilma part 2..anyone have feedback on this ? Thanks.

North of the Yucatan Channel, conditions become very unfavorable for tropical cyclones to thrive on. Yesterday, it appeared that Rina would be nothing more than a remnant low by the time it reached Florida. However, with the recent burst of intensification, and the fact that it is likely to reach Category 3 status, or even Category 4 status, over the coming days, means that Florida may get more than a remnant low. However, I wouldn't worry about it right now...My best advice to you is to monitor the situation closely, and act accordingly. But the good news is, Rina will not be a serious hurricane by the time it gets to the state.

Hope that helps.
Member Since: July 6, 2010 Posts: 113 Comments: 32531
Looks like HWRF forecast from yesturday seems to be spot on for Rina. A rare occasion. By the way does Rina kind of give you a Wilma feel. Its oddly fishy how the time of year, location and rapid intesification are somewhat similar.

Does anyone else have that Wilma feel with Rina?
Member Since: Posts: Comments:
.
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I would like to ask those of you on this blog that are serious and know what you are talking about. Rina really grabbed my attention bigtime this afternnon and honestly as a long time south florida resident feel like I have seen this movie before...itlike Wilma part 2..anyone have feedback on this ? Thanks.
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Is anyone here?
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Quoting Ameister12:

Hot towers?
Eye looks like it might form.
Rina has acne.
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Quoting TropicalAnalystwx13:

It doesn't have to sound scary to be scary.
Exactly. Irene isn't a scare name, but it was for most of the East Coast. Gert on the other hand, is a scary name. ;)
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Quoting yqt1001:
And the term "Beware of the R storms" lives on... (though Richard could've been way worse)

If you think that's bad check out the I storms.
:P
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After the tree leaf shredding, branch breaking, ignored unnamed, finger in their ears, "La, La, La, I can't hear you" subtropical storm of 2011, I hope all of this "not another Wilma" cocky talk is correct. For my part, I will be paying special attention around Dmax tonight.
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Quoting Sfloridacat5:
Yikes
And our local meteorologist, Channel 2 if your in the Ft. Myer area -Robert Van Winkle was just saying this morning that "Rina wouldn't affect Florida."

We'll have to wait and see.

Local meteorologists need to follow the official forecast from the NHC and NOT go out on a limb like that. They could find themselves without a job. This almost happened to one of the locals here in Palm Beach County many years ago. I think it was Hurricane Erin in 1995. The local guy said Palm Beach County wouldn't get the storm. He was right, but almost lost his job.
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Quoting nrtiwlnvragn:
Gulfstream IV research mission tomorrow:

Mission Plan :

NOAA 49RF will fly an HRD-tasked Rapid Intesification mission around Hurricane Rina. The G-IV will leave MacDill AFB, FL 1730 UTC and will recover back at MacDill AFB, FL by 0200 UTC next day.






The G-IV was a huge help in the forecast of Hurricane Irene, so I'm very much looking forward to what they find tomorrow.
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Quoting HurricaneVSafety:
Rina does not sound like a threating name.

Wilma does.

It doesn't matter...
A hurricane is a hurricane no matter what the name, even if the name ISN'T threatening, doesn't mean it won't be a threat.
BTW
(kat+rina=katrina)
^^not to scare ppl
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Quoting HurricaneVSafety:
Rina does not sound like a threating name.

Wilma does.

It doesn't have to sound scary to be scary.
Member Since: July 6, 2010 Posts: 113 Comments: 32531
35. wpb
Quoting SunnyDaysFla:
Do they put any of the info from the research mission into the models?
yes they intake all the data
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Meanwhile 97L seems to be trying to organize.



If it does develop we should see a very nice dance in the W.Caribbean.
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And the term "Beware of the R storms" lives on... (though Richard could've been way worse)
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17.0n82.6w has been re-evaluated&altered for H.Rina's_6pmGMT_ATCF
17.0n82.7w, 17.1n83.0w are now the most recent positions
Starting 23Oct_6pmGMT and ending 24Oct_6pmGMT

The 4 eastern line-segments represent HurricaneRina's path,
the westernmost line-segment is the straightline projection for 24Oct_6pmGMT,
the sea-to-island dumbbell at 21.52n86.364w-ISJ is the endpoint of the straightline projection connected to its nearest airport for the 24Oct_12pmGMT*mapping,
and the sea-to-island dumbbell at 21.871n85.558w-SNJ is the same for 24Oct_6amGMT but to the 2nd nearest airport.

Using straightline projection of the travel-speed&heading derived from the
ATCF coordinates spanning the 6hours between 12pmGMT then 6pmGMT :
H.Rina's travel-speed was 3.5mph(5.6k/h) on a heading of 289.2degrees(WNW)
H.Rina was headed toward passage over GreatSwanIsland^Honduras ~16hours from now
(though I wouldn't count on Rina continuing to move that slowly)

Copy&paste 21.871n85.558w-snj, 21.52n86.364w-isj, 15.5n81.7w-16.0n81.9w, 16.0n81.9w-16.5n82.2w, 16.5n82.2w-17.0n82.7w, 17.0n82.7w-17.1n83.0w, 17.0n82.7w-mhic into the GreatCircleMapper for more info

The previous mapping for 24Oct_12pmGMT

* The alteration of the endpoint of a TropicalCyclone's previous path also changes its previous travel-speed&heading, and the endpoint of its previous straightline projection...
...but I'm choosing to preserve the historicity of the previous straightline projections.

^ "In October 1998, Hurricane Mitch moved over Swan Island with winds of 180 mph."
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Do they put any of the info from the research mission into the models?
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Rina does not sound like a threating name.

Wilma does.
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Quoting HurricaneVSafety:
Rina

???
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Quoting HurricaneVSafety:
Rina

Yes...Rina :P
Member Since: July 6, 2010 Posts: 113 Comments: 32531
Gulfstream IV research mission tomorrow:

Mission Plan :

NOAA 49RF will fly an HRD-tasked Rapid Intesification mission around Hurricane Rina. The G-IV will leave MacDill AFB, FL 1730 UTC and will recover back at MacDill AFB, FL by 0200 UTC next day.




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Rina
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24. DDR
Heavy rains with flash flooding hit Parts of Trinidad today,just over 2 inches here after 4 days of sunshine.
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2nd fastest in history!
Member Since: September 16, 2007 Posts: 0 Comments: 8248
Repost

A stall typically precedes a track change but not always. The high to the West might serve as a blocker to progress in that direction unless it can build over the top of the hurricane fairly soon.

It looks as if the influence of the steering from the East is about equal to that from the West with the shortwave trying to exert some pull on Rina.

Some motion to the N NNE or NNW would not be out of the realms of possibility now. Let's see what the HH finds on the next pass near the centre but probably very little if any movement since the last pass.

Will be back later
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Quoting Thundercloud01221991:
How fast can she make it to major status

I say tomorrow is possible.
Member Since: July 6, 2010 Posts: 113 Comments: 32531
Quoting JLPR2:
What the....

6th hurricane of the season.
17-6-3

The NHC was greatly underestimating Rina.

Very.
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Yikes
And our local meteorologist, Channel 2 if your in the Ft. Myer area -Robert Van Winkle was just saying this morning that "Rina wouldn't affect Florida."

We'll have to wait and see.

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Quoting TropicalAnalystwx13:

No, you're getting big and small confused with tropical and subtropical. SUBTROPICAL systems (Lee) deal with dry air and wind shear better than tropical systems. Dry air can weaken a system faster, and so can wind shear. However, because of their small size, they can ramp up really quickly (Rina).
oh yeah i forgot lee was turning subtropical :P anyways if rina makes it to SW florida what do u think her intensity will be? im think cat 1 about 80mph
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How fast can she make it to major status
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What the....

6th hurricane of the season.
17-6-3

The NHC was greatly underestimating Rina.
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Quoting wunderweatherman123:
actually smaller storm take dry air much less than larger ones. remember ts lee? he was huge and half of his side was all dry air :P i could see rina a cat 1 hitting sw florida as long as it dosent interact with W. cuba and the yucatan

No, you're getting big and small confused with tropical and subtropical. SUBTROPICAL systems (Lee) deal with dry air and wind shear better than tropical systems. Dry air can weaken a system faster, and so can wind shear. However, because of their small size, they can ramp up really quickly (Rina).
Member Since: July 6, 2010 Posts: 113 Comments: 32531
Thanks for the update Dr. Masters.

My weekend better not get ruined...

• 12z HWRF & GFDL.

Both models have the cyclone reaching a peak intensity in the 2-3 day time frame (sub-945mb pressure).



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