Tropical Storm Rina forms
Tropical Storm Rina formed in the Western Caribbean Sea just off the coast of Honduras last night, and is headed north-northwest towards Mexico's Yucatan Peninsula. Rina's formation brings this year's tally of named storms to 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 29% of this year's named storms have made it to hurricane strength (five), 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.
Visible satellite loops show that Rina has had a respectable burst of thunderstorm activity with high, cold cloud tops this morning. This "Central Dense Overcast" (CDO) is characteristic of intensifying tropical storms that are a threat to reach hurricane strength. Rina has been bringing sporadic heavy rain squalls to the Cayman Islands over the past day; George Town on Grand Cayman Island had received 2.28" of rain and a peak wind gust of 31 mph as of 9 am EDT from the storm. 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. We don't have any surface wind reports from the vicinity of Rina; the closest buoy is Western Caribbean buoy 42057, about 60 miles east of Rina's center, which had top sustained winds out of the ESE at 29 mph this morning. We'll have to wait for the next hurricane hunter flight, scheduled for 2 pm this afternoon, to get a better idea of Rina's intensity.
Figure 1. Morning satellite image of Rina.
Forecast for Rina
The intensity forecast for Rina has a high amount of uncertainty. Rina should be able to slowly intensify through Tuesday, becoming a strong tropical storm. On Wednesday, Rina will be approaching a dry airmass with high wind shear that lies over the extreme northwestern Caribbean. Since Rina is a small storm, these hostile conditions could cause the storm to dissipate on Wednesday as it nears landfall over the Yucatan Peninsula, as predicted by the ECMWF and NOGAPS models. The completely opposite scenario is predicted by the GFDL and HWRF models, which forecast Rina will stay just south of the high shear/dry air region, and attain major hurricane status. The official NHC forecast of a Category 1 Hurricane Rina late this week is a reasonable compromise between these extremes. The track forecast for Rina also presents difficulties. A west-northwest to northwest motion towards the Yucatan Peninsula is likely through Wednesday. A trough of low pressure is predicted to pass to the north of Rina late this week, but the models are increasingly suggesting that Rina will not be far enough north to get caught up in the trough, but instead will remain trapped in the Western Caribbean. None of the latest 06Z (2 am EDT) model runs of the GFS, NOGAPS, GFDL, or HWRF models are predicting that Rina's center will make it north of Cuba during the next five days. In any case, heavy rains from Rina should begin affecting Mexico's Yucatan Peninsula, northern Belize, and extreme Western Cuba on Wednesday.
97L
A broad region of low pressure about 300 miles west of the southern Lesser Antilles Islands (Invest 97L), is moving west-northwest at 10 mph through the Caribbean Sea. This low has very limited heavy thunderstorm activity, due to dry air, and no signs of a surface circulation. NHC is giving 97L just a 10% chance of developing into a tropical depression by Wednesday. 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. The NOGAPS model predicts 97L could develop into a tropical depression by Saturday.
Jeff Masters
Reader Comments
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I have no idea where those guys are...im just saying no wat rina reached major hurricane status.cozumel and the tucatan are in line for whatever rina has in store and rina will die there..south florida is lucky to see any rain from rina at all..they will see some rain from the cold front on friday though..rina will be crushed if it tries to make it into the se gom..IMHO
busy cooking a big batch of crow to a crow feast later tonight when Rina become a Hurricane.
Not seeing an upper level anticyclone over Rina at the moment.
I didn't say by tonight I said later tonight.
P.S. I only drink after 5 p m on week days.
Happy Hour?
No AC over Rina, Nice one over 97L though.
lol
Recon flying at FL260.
Got any Mid-Level Shear maps?
Not sure about you guys but the front will plow through Central Florida by Friday afternoon/evening.
Don't forget, she's going to move over some hypo-energized water soon, she could blow up.
HUGE IMAGE
I think both will get absorbed into the EC trough. Though I have a feeling 97L might pull a Noel on us.
and then another one with 97l getting interesting
Blog update:
Tropical Tidbit for Monday, October 24th, with Video
Throw out the GFS, it's totally wrong already on 97L
Yeah, could stop her from becoming a major. maybe not a cat 1 or cat 2 though. Dry air has been a major contributor to most storms being so week this year, I wouldn't be surprised if Rina get sucked dry also.
Almost seems like it's building an eye
Interested to see what the storm does with it. It will be a good bellwether to see if Rina can efficiently mix out the dry air. A storm that has relatively good conditions otherwise "Should" be able to over come it.
Was going to comment on that myself. I wouldn't be surprised to see mention of an eye feature in the Recon.
Remarks Section - Additional Remarks...
NW ENTRY POINT
SFC NOT VISIBLE
IN CLOUDS
Beautiful Tropical Storm.
000
URNT15 KNHC 241736
AF306 0218A RINA HDOB 20 20111024
172700 1740N 08336W 8433 01563 0090 +176 +122 030034 035 041 003 00
172730 1739N 08334W 8432 01562 0091 +174 +117 030036 037 039 002 00
172800 1737N 08333W 8429 01566 0091 +173 +120 030037 037 040 002 00
172830 1736N 08332W 8429 01564 0092 +166 +125 032036 037 041 007 00
172900 1735N 08331W 8427 01562 0098 +149 +133 027036 036 042 009 00
172930 1734N 08329W 8431 01556 0091 +155 +132 023036 036 042 006 00
173000 1733N 08328W 8432 01551 0093 +148 +134 023038 039 043 010 00
173030 1731N 08327W 8426 01557 0096 +139 +138 020040 041 043 018 00
173100 1730N 08325W 8438 01541 0094 +134 //// 022043 047 050 013 01
173130 1729N 08324W 8430 01545 0089 +136 //// 026048 050 050 013 01
173200 1728N 08323W 8434 01537 0082 +142 //// 034047 048 051 014 01
173230 1726N 08322W 8431 01540 0077 +142 //// 034048 049 050 012 01
173300 1725N 08320W 8427 01535 0074 +139 //// 032048 049 050 012 01
173330 1724N 08319W 8439 01516 0070 +136 //// 033050 051 052 013 01
173400 1723N 08318W 8425 01525 0060 +141 //// 030055 059 053 014 01
173430 1722N 08317W 8443 01502 0058 +139 //// 034057 062 052 015 05
173500 1721N 08315W 8437 01505 0053 +135 //// 044058 059 059 018 01
173530 1719N 08314W 8434 01501 0055 +123 //// 034060 062 054 032 05
173600 1718N 08313W 8426 01502 0045 +125 //// 034061 063 061 029 01
173630 1717N 08312W 8430 01482 //// +132 //// 031063 067 064 029 01
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