Hurricane Iota satellite image
Infrared satellite image of Tropical Storm Iota at 10:40 a.m. EST Saturday, November 14. (Image credit: RAMMB/CIRA/Colorado State University)

Tropical Storm Iota formed in the central Caribbean Friday afternoon, becoming the 30th named storm of this record-busy 2020 Atlantic hurricane season. The previous record for most named storms in a season was 28, set in 2005.

Iota is predicted to rapidly intensify and be close to major hurricane strength on Monday night, when it will be approaching landfall near the Nicaragua/Honduras border. Iota will likely bring catastrophic rains of 8-16 inches, with isolated amounts of 20-30 inches, to portions of Central America still recovering from devastating Hurricane Eta, which hit northern Nicaragua as a category 4 storm with 140 mph winds on November 3.

At 1 p.m. EST Saturday, Iota was 375 miles south of Kingston, Jamaica, headed west-southwest at 5 mph. Iota had top winds of 50 mph, with a central pressure of 1002 mb. Satellite imagery showed Iota’s heavy thunderstorms mostly confined to the south and east sides of the center of circulation, but they were steadily becoming more organized, and were beginning to move over the center of circulation. Upper-level winds out of the northwest were creating about 10 knots of wind shear, restricting heavy thunderstorm activity on Iota’s northwest side.

The first Hurricane Hunter mission into Iota is scheduled for Saturday afternoon.

Record late-season activity

Iota’s formation in November gives the 2020 Atlantic hurricane two records for late-season activity: five Caribbean named storms since October 1 (tying with 2005 for most Caribbean named storm formations after October 1), and three November named storms (tying with 1931, 1961, 2001 and 2005 for most Atlantic named storms to form in November). As measured by accumulated cyclone energy (ACE), Atlantic hurricane activity since October 20 has been more akin to what is seen in an average September – typically the peak month of hurricane season. (Thanks go to Dr. Phil Klotzbach for these stats.)

Figure 1
Figure 1. Track forecasts out to seven days for Iota from the 6Z (1 a.m. EST) Saturday, November 14, run of the GFS ensemble model (GEFS). The black line is the mean of the 31 ensemble members; individual ensemble member forecasts are the thin lines, color-coded by the central pressure they predict for Iota, which is expected to move mostly westward and be a significant threat to Nicaragua and Honduras. (Image credit: Tropical Tidbits)

Track forecast for Iota

A ridge of high pressure to Iota’s northwest will slide to the east on Saturday afternoon, resulting in a more westerly to west-northwesterly motion of Iota until landfall occurs near the Nicaragua/Honduras border on Monday night.

As a result of a relocation of Iota’s center to the south on Saturday morning, which put the center near the most intense thunderstorms, a more southerly path for the storm is now predicted. This shift should help Iota avoid a worst-case scenario for Honduras: Had the storm moved parallel to and just offshore of the coast, it could maintain its strength longer, subjecting the region to much higher rainfall totals. This scenario is looking much less likely than it did 24 hours ago, with only the 6Z Saturday run of the HWRF model and a few of the members of the GFS ensemble predicting it.

Once Iota makes landfall, steering currents are predicted to shift, putting Iota on a more west-southwesterly path deep into Central America. Dissipation is expected to occur about two days after landfall, when Iota will be close to emerging into the Pacific Ocean near the El Salvador coast. There continues to be almost no model support for the idea that Iota might move northward into the Gulf of Mexico and threaten the U.S., as so many other storms this year have done.

Figure 2
Figure 2. Predicted wind speed (colors) and sea level pressure (black lines) for Iota at 1 a.m. EST (6Z) Tuesday, November 17, from the 1 a.m. (6Z) Saturday, November 14, run of the GFS model. The model predicted Iota would be approaching landfall near the Nicaragua/Honduras border as a high-end category 2 hurricane with 110 mph winds and a central pressure of 951 mb. (Image credit: Tropical Tidbits)

Intensity forecast for Iota

The intensity forecast from the National Hurricane Center continues to be aggressive, calling for Iota to intensify from 40 mph to 110 mph – to the brink of category 3 status – in just 60 hours. Keep in mind, though, that NHC and the intensity models tend to under-predict rapid intensification events in the western Caribbean, and it would not be surprising for Iota to become a category 4 storm with 130 mph winds or higher at its peak.

Figure 3
Figure 3. Predicted seven-day rainfall ending at 1 a.m. EST Saturday, November 21, from the 6Z (1 a.m. EST) Saturday, November 14, run of the GFS model. The model predicted that Iota would dump widespread rainfall amounts in excess of five inches (orange colors) to portions of the Caribbean, with over 20 inches (pink colors) falling in northern Honduras, Guatemala, and Nicaragua. (Image credit: NOAA/AOML)

Conditions for development will be favorable for development of Iota through landfall, with the SHIPS model predicting light wind shear less than 10 knots, warm sea surface temperatures of 29 degrees Celsius (84°F), and a moist atmosphere with a mid-level relative humidity of 70%. The 12Z Saturday SHIPS model gave a 52% chance that Iota would follow the NHC intensity forecast, and increase its winds by 75 mph in 72 hours. This probability is 10 times higher than the climatological mean.

Climate change is causing more rapid intensification of Atlantic hurricanes

These conditions are very similar to what Hurricane Eta experienced during its rapid intensification episode as it approached landfall in Nicaragua nearly two weeks ago. Although Iota will be passing over the same part of the Caribbean traversed by Eta, the sea surface temperature has not cooled much, remaining about 0.5°C above average.

Iota is a significant threat to intensify into a major hurricane that will affect the same areas of the Caribbean impacted by Hurricane Eta. In particular, Nicaragua and Honduras, which were devastated by flooding from Hurricane Eta’s torrential rains of over 20 inches, appear at great risk of receiving similar rains from Iota, beginning on Sunday night or Monday morning.

Figure 4
Figure 4. Visible satellite image of category 3 Typhoon Vamco approaching Vietnam (upper right). Tropical Storm Alicia, the first tropical cyclone of the 2020-2021 Southern Hemisphere tropical cyclone season, is visible at lower left. The image is from 4 a.m. EST November 14, 2020. (Image credit: UK Met Office)

Typhoon Vamco approaching landfall in typhoon-weary Vietnam

Long-suffering Vietnam – which has already been affected by 10 tropical cyclones this year – is now bracing for number 11.

Typhoon Vamco surged from category 1 to category 4 strength in just 12 hours on Friday, peaking with top winds of 130 mph at 1 p.m. EST November 13, according to the Joint Typhoon Warning Center. As Vamco moved toward Vietnam Friday night and Saturday morning, the typhoon moved over cool waters of 26 degrees Celsius (79°F), weakening it to 110 mph winds at 7 a.m. EST Saturday, November 14. Vamco is expected to weaken further, to a category 1 typhoon with 80 mph winds, on Saturday night (U.S. EST), as it makes landfall over northern Vietnam.

Vamco clobbered the Philippines on Wednesday as a category 2 storm with 110 mph winds, killing at least 53 people.

Theta almost dead

Tropical Storm Theta was barely clinging to tropical storm status on Saturday morning, with 40 mph winds, as it headed east at 8 mph over the waters about 600 miles southeast of the Azores Islands. Dry air, high wind shear, and cold waters are predicted to reduce Theta to a remnant low on Saturday night.

Editor’s note: The headline on this post was revised at 6:25pm EST on November 14. 

Bob Henson contributed to this post.


Website visitors can comment on “Eye on the Storm” posts (see below). Please read our Comments Policy prior to posting. (See all EOTS posts here. Sign up to receive notices of new postings here.)

Posted on November 14, 2020(1:27pm EST)

Topics: Weather Extremes
19 Comments
Inline Feedbacks
View all comments
Amature Met
Amature Met
13 days ago

Do you change your user name every week?

Dirk
Dirk
13 days ago
Reply to  Amature Met

At least twice a day i guess.

Amature Met
Amature Met
13 days ago

This is plain wrong! No yellow on top of a current cane please.

two_atl_5d0.png
Tim Krantzhoef
Tim Krantzhoef
13 days ago

We’d rather hear from them than you, and this isn’t the place to air such thoughts.

Last edited 13 days ago by Tim Krantzhoef
Amature Met
Amature Met
13 days ago
Reply to  Tim Krantzhoef

I would rather not hear from them or him! Weather please.

Kevin
13 days ago

The location and diameter of this storm’s wind field is causing it to suck in dust from the Amazon, from the Pacific across the isthmus of Panama, and from a significant Sahara dust cloud moving across the Atlantic. This is good news, no doubt.

HadesGodWyvern
HadesGodWyvern
13 days ago

Mauritius Meteorological Services
Tropical Cyclone Advisory #12 – 10:00 AM RET November 15 2020
FORTE TEMPETE TROPICALE ALICIA (01-20202021)
================================================
South Southeast of Diego Garcia

At 6:00 AM UTC, Severe Tropical Storm Alicia (990 hPa) located at 12.8S 74.2E has 10 minute sustained winds of 50 knots with gusts of 70 knots. The cyclone is reported as moving southwest at 15 knots.

Storm Force Winds
===================
Extending up to 30 nm in the southwestern and northeastern quadrants, and up to 35 nm in the southeastern quadrant

Gale Force Winds
==================
60 nm radius from the centre, extending up to 70 nm in the northwestern quadrant and up to 80 nm in the eastern semi-circle

Near Gale Force Winds
======================
90 nm radius from the centre, extending up to 110 nm in the eastern semi-circle

Dvorak Intensity: T3.5/3.5/S0.0/12 HRS

Forecast and Intensity
===========================
12 HRS: 14.8S 73.4E – 65 knots (Cyclone Tropical)
24 HRS: 16.3S 73.2E – 65 knots (Cyclone Tropical)
48 HRS: 18.2S 72.4E – 35 knots (Tempête Tropicale Modérée)
72 HRS: 20.0S 70.9E – 20 knots (Depression Residuelle)

Additional Information
===========================
Over the last 6 hours, the curved band cloud pattern has been maintained but is gradually evolving in the last few moments towards a central dense overcast (cdo) pattern. This evolution suggests that Alicia will intensify in the near future. The intensity estimation according to Dvorak allows to estimate maximum winds of about 50kt.

No change in terms of track : Alicia keeps on heading south southwestward movement on the north-western side of the mid-level subtropical ridge. With the arrival of a deep trough from the southwest, the ridge shifts eastward and should soon let alicia dive southward during the day. Available guidance is in good agreement on this scenario. From Tuesday, the uncertainty is greater with two possible scenario suggested by the ensemble guidance : the persistence of a south to southeastward motion or the capture of the remnant low by the trade winds. The present forecast of the RSMC opts for the second option.

Environmental conditions are rather conducive until this evening, as the system should soon track under the upper ridge axis. Alicia should still benefit from an excellent divergence, relatively weak wind shear and a very strong oceanic energy content. The system could still reach the tropical cyclone stage by this evening. Under these conditions, Alicia generates a very marked high altitude flow which induces a strong nefast wind shear to the cyclogenesis of a second system located northwest of Alicia. After, conditions should begin to quickly deteriorate with insufficient sea temperatures south of 17.0S, a strengthening shear constraint, gradually associated to mid-level dry intrusions. These conditions announce a clear weakening of the intensity of Alicia, which at the 84-hour period will only have residual circulation.

HadesGodWyvern
HadesGodWyvern
13 days ago

Japan Meteorological Agency
Tropical Cyclone Advisory #55 – 15:00 PM JST November 15 2020
SEVERE TROPICAL STORM VAMCO (T2022)
=============================================
Gulf of Tonkin

At 6:00 AM UTC, Severe Tropical Storm Vamco (996 hPa) located at 17.9N 106.6E has 10 minute sustained winds of 50 knots with gusts of 70 knots. The cyclone is reported as moving west northwest at 12 knots.

Gale Force Winds
=================
130 nm from the center in northern quadrant
60 nm from the center in southern quadrant

Dvorak Intensity:

Forecast and Intensity
=========================
12 HRS: 18.7N 105.4E – Tropical Depression over land Vietnam
24 HRS: 18.8N 104.1E – Tropical Depression over land Laos

Dirk
Dirk
13 days ago

User indeed is ruined.

HadesGodWyvern
HadesGodWyvern
13 days ago

Japan Meteorological Agency
Tropical Cyclone Advisory #53 – 9:00 AM JST November 15 2020
TYPHOON VAMCO (T2022)
=============================================
South China Sea

At 0:00 AM UTC, Typhoon Vamco (980 hPa) located at 17.2N 108.0E has 10 minute sustained winds of 65 knots with gusts of 95 knots. The cyclone is reported as moving west northwest at 8 knots.

Storm Force Winds
===================
50 nm from the center

Gale Force Winds
=================
180 nm from the center in northern quadrant
150 nm from the center in southern quadrant

Dvorak Intensity: T4.5-

Forecast and Intensity
=========================
12 HRS: 17.5N 105.8E – Tropical Depression over land Laos
24 HRS: 17.6N 103.7E – Tropical Depression over land Thailand

Dirk
Dirk
13 days ago

Thanks Bob Henson and Dr.Jeff for this update.

Stevettocs
Stevettocs
13 days ago

today’s look

gfs_world-ced_t2anom_1-day.png
SunnyDaysFl
SunnyDaysFl
13 days ago

When will this season end? Enough already.

Dirk
Dirk
13 days ago
Reply to  SunnyDaysFl

31-12-2020. 😉

Federweißer
Federweißer
13 days ago
Reply to  Dirk

Nearly right… Season will end when the last storm that formed bevor 01.01.2021 dissipates…

Amature Met
Amature Met
13 days ago
Reply to  Federweißer

Now thats on heck of a thought!

Dirk
Dirk
13 days ago
Reply to  Federweißer

When you want to be that specific yes your right. 🙂

HadesGodWyvern
HadesGodWyvern
14 days ago

Mauritius Meteorological Services
Tropical Cyclone Advisory #10 – 22:00 PM RET November 14 2020
FORTE TEMPETE TROPICALE ALICIA (01-20202021)
================================================
Southeast of Diego Garcia

At 18:00 PM UTC, Severe Tropical Storm Alicia (992 hPa) located at 10.2S 76.3E has 10 minute sustained winds of 50 knots with gusts of 70 knots. The cyclone is reported as moving west southwest at 12 knots.

Storm Force Winds
===================
extending up to 30 nm in the southwestern quadrant and up to 35 nm in the south-eastern quadrant

Gale Force Winds
==================
extending up to 20 nm in the northeastern quadrant, up to 50 nm in the south-eastern quadrant and up to 60 nm in the southwestern quadrant

Near Gale Force Winds
======================
45 nm radius from the centre, extending up to 150 nm in the southwestern quadrant and up to 200 nm in the southeastern quadrant

Dvorak Intensity: T3.5/3.5/S0.0/12 HRS

Forecast and Intensity
===========================
12 HRS: 12.4S 74.5E – 60 knots (Forte Tempête Tropicale)
24 HRS: 14.6S 73.7E – 70 knots (Cyclone Tropical)
48 HRS: 17.5S 72.9E – 45 knots (Tempête Tropicale Modérée)
72 HRS: 20.6S 72.4E – 30 knots (Depression se Comblant)

Additional Information
===========================
Over the last 6 hours, a strong convective burst has triggered near the circulation center. The 1515z ASCAT-B swath suggests that the circulation center is located near the northeastern border of the central dense overcast, confirming a sheared pattern under a weak to moderate east northeasterly upper constraint. The associated Dvorak analysis is in agreement with the ADT estimate. Consistently, the ASCAT data show storm-force winds within the southern semi-circle. The 89ghz 1332z SSMIS image shows a still ill-defined internal structure, with the main convection limited to the western semi-circle.

Alicia keeps on heading southwestward at a quick pace on the northwestern side of the mid-level subtropical ridge. With the arrival of a deep trough from the southwest, the ridge shifts eastward and will let Alicia dive southward tomorrow. Available guidance is in good agreement on this scenario. From Tuesday, the uncertainty is greater with two possible scenario : the persistence of a south to southeastward motion or the capture of the remnant low by the trade winds.

Environmental conditions are rather conducive until Sunday night, despite the weak shear constraint currently affecting the storm. Alicia should still benefit from an excellent divergence, relatively weak wind shear and a very strong oceanic energy content. The system could thus still reach the tropical cyclone stage tomorrow. Sunday night, conditions should begin to quickly deteriorate with insufficient sea temperatures south of 17.0S, a strengthening shear constraint, gradually associated to mid-level dry intrusions.

HadesGodWyvern
HadesGodWyvern
14 days ago

Japan Meteorological Agency
Tropical Cyclone Advisory #51 – 3:00 AM JST November 15 2020
TYPHOON VAMCO (T2022)
=============================================
South China Sea

At 18:00 PM UTC, Typhoon Vamco (960 hPa) located at 16.6N 108.7E has 10 minute sustained winds of 80 knots with gusts of 115 knots. The cyclone is reported as moving west northwest at 9 knots.

Storm Force Winds
===================
50 nm from the center

Gale Force Winds
=================
180 nm from the center in northern quadrant
150 nm from the center in southern quadrant

Dvorak Intensity: T5.5-

Forecast and Intensity
=========================
12 HRS: 17.4N 106.5E – 40 knots (CAT 1/Tropical Storm) Over land Vietnam
24 HRS: 17.6N 104.2E – Tropical Depression over land Thailand