Rina rapidly intensifies into a hurricane
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
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yes stormpetrol stand up for you right and safty the \
NHC needs to start reading the full data from the HH
YAY! WINTER! (does that mean SE TX gets rain?)
If you are driving west on I-10, and change lanes, does that mean you are suddenly are going WNW or even NW?
I actually got to sit next to Bill Reed on a flight out of Tampa back to Fort Lauderdale. Didn't recognize him but noticed his bag with the logo so asked him about it and that's when he introduced himself. Nice guy and we all joked about getting the generator AFTER Wilma and how we've been good since.
correct Tropical storms and hurricanes wobble all the time imagine how many course changes they would need if they adjusted every hour instead of 6. Right now this system is pretty much stationary
OMG, they are the experts and their confidence is very low !!! Oh Wow !!!
So... if the upper trough lags, Rina can push more west before recurving out to the NE. If the trough is weak, the turn won't be as sharp. If the trough has more time to deepen, the turn can be sharper, and the forward motion will be faster, too. Oh... and the deeper the trough, the greater the shear.
Lots of moving parts. If you can do better, I'm sure the NWS and NHC would love to hire you.
Thank you Dr. Jeff for your update... always appreciated!
000
URNT12 KNHC 242104
VORTEX DATA MESSAGE AL182011
A. 24/20:42:20Z
B. 17 deg 09 min N
083 deg 03 min W
C. 850 mb 1310 m
D. 60 kt
E. 162 deg 10 nm
F. 272 deg 74 kt
G. 162 deg 10 nm
H. 987 mb
I. 17 C / 1523 m
J. 22 C / 1525 m
K. 14 C / NA
L. NA
M. NA
N. 12345 / 8
O. 0.02 / 2 nm
P. AF306 0218A RINA OB 19
MAX FL WIND 74 KT S QUAD 20:39:00Z
Strong banding around center from 300 to 020 degrees
;
We knew it had the potential...
Yeah, but that doesn't fit the WU Model AKA "It's going to absolutely destroy X!"
12.1n60.1w, 12.1n61.4w, 12.1n62.5w are now the most recent positions
Starting 23Oct_6pmGMT and ending 24Oct_6pmGMT
The 4 line-segments represent Invest97L's now eastward path.
Copy&paste gnd, uvf, 12.1n57.6w-12.1n59.0w, 12.1n59.0w-12.1n60.1w, 12.1n60.1w-12.1n61.4w, 12.1n61.4w-12.1n62.5w, lrv, bon, cur into the GreatCircleMapper for more info
The previous mapping for 24Oct_12pmGMT
I've got my 3D glasses and candy.
Very true. The WU model is a big reason I stopped coming by all the time, and trying to help.
yes I read your post and I still say: Oh Wow !!!
Not even close, 20% at the absolute highest.
However, now that I have said that it will probably dissipate. Not likely unfortunately, she's on a run for sure. Rina seems to have that against all odds attitude observed in only a small percentage of cyclones per year.
Popcorn is horrible.
a: east back into the carribean
b: ene towards cuba
c: ne/ene towards the Florida keys
d: South florida
im thinking C or D and intensity should be around 80mph as the Subtropical jet rips her apart
bet you have no reason to say that
I say 40% the highest
and rapid strengthening.
Be sure to cover all bases ;)
I go with the Euro which deepens it further east.
I wouldn't be surprised if it reached Cat. 4 status before it starts to wind down.
Or the dreaded Cat. 5
The system is very elongated, with a broad area of low pressure. There is no way this is getting even an Orange Circle at the 8PM or even 2AM TWO.
I agree.
Eye seems to be clearing possibly?
Same here, but I'm thinking more with the NAM, which tends to do very well during the winter. (which also speeds it up, but with a little less deepening)
I disagree.
:P
I say A as I said just a few mins ago forecast will lie between the OFCI and the AVNO/GFS
3 words:
Wilma-like intensification.
Viewing: 101 - 151
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