May 2021 Tropical Cyclones Report

Summary

The most significant tropical cyclone in May was Cyclone Tauktae in the Arabian Sea. Tauktae reached category 4 intensity with winds of 135 mph as it paralleled the west coast of India. The strongest winds remained offshore as it passed Mumbai, but it still made landfall in Gurajat as a category-3 tropical cyclone. It also brought torrential rain and flooding throughout the west coast of India. The impacts were amplified by the storm occurring during a surge of COVID-19 cases in India.

In the Western Hemisphere, Tropical Storm Ana was the first storm of the 2021 Atlantic hurricane season. This marked the seventh year in a row with at least one named storm developing in the Atlantic before the official start of the hurricane season on June 1. Ana was weak and remained at sea, so its impacts were limited. The East Pacific had two tropical storms in May, which was the seventh time since records began in 1949 that two storms formed before June. Both were weak and short-lived.

North Atlantic

May 2021 North Atlantic Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Ana	TS	May 22May 22-23	45 mph	1006 mb

North Atlantic Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1851-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	1	0.3 (3 in 10 Mays)	3rd (tied with 7 other Mays)	2 (1887, 2012, 2020)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.0 (0 in 10 Mays)	1st (tied with 40 other Mays)	1 (1889, 1908, 1951, 1970)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	1st (tied with 40 other Mays)	0
Accumulated Cyclone Energy ACE×10⁴ kt²	0.8	0.4 (4 in 10 Mays)	6th	16.1 (1951)

North Atlantic Tropical Cyclone Season Counts January-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1851-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	1	0.5 (5 in 10 seasons)	4th (tied with 10 other seasons)	2 (6 seasons)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.0 (0 in 10 seasons)	2nd (tied with 39 other seasons)	2 (1908)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 seasons)	1st (tied with 40 other seasons)	0
Accumulated Cyclone Energy ACE×10⁴ kt²	0.8	0.9 (9 in 10 seasons)	10th	21.6 (1951)

East Pacific

May 2021 East Pacific Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Andres	TS	May 9May 9-10	40 mph	1005 mb
Blanca	TS	May 31-June 2May 31-Jun 2	60 mph†	998 mb†
†Value occurred in June

East Pacific Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1949-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	2	0.7 (7 in 10 Mays)	1st (tied with 4 other Mays)	2 (6 Mays)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.3 (3 in 10 Mays)	13th (tied with 28 other Mays)	1 (15 Mays)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.2 (2 in 10 Mays)	6th (tied with 35 other Mays)	1 (5 Mays)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.7	3.1	20th	18.6 (2014)

East Pacific Tropical Cyclone Season Counts January-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1949-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	2	0.8 (8 in 10 seasons)	1st (tied with 5 other seasons)	2 (7 seasons)
Hurricane Winds ≥ 74 mph (64 kts)	0	0.3 (3 in 10 seasons)	15th (tied with 26 other seasons)	1 (17 seasons)
Major Hurricane Winds ≥ 111 mph (96 kts)	0	0.2 (2 in 10 seasons)	7th (tied with 34 other seasons)	1 (6 seasons)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.7	3.8	23rd	18.6 (2014)

West Pacific

May 2021 West Pacific Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Not_Named	TS	May 13May 13	40 mph	1004 mb
Choi-Wan	TS	May 30-June 5May 30-Jun 5	60 mph	986 mb

West Pacific Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1945-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	2	1.2	5th (tied with 8 other Mays)	6 (1971)
Typhoon Winds ≥ 74 mph (64 kts)	0	0.7 (7 in 10 Mays)	24th (tied with 17 other Mays)	3 (1971, 2008)
Major Typhoon Winds ≥ 111 mph (96 kts)	0	0.5 (5 in 10 Mays)	17th (tied with 24 other Mays)	2 (1976, 2008, 2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	1.6	13.4	26th	59.6 (2015)

West Pacific Tropical Cyclone Season Counts January-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1945-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	4	2.9	6th (tied with 9 other seasons)	9 (1971)
Typhoon Winds ≥ 74 mph (64 kts)	1	1.4	19th (tied with 13 other seasons)	5 (2015)
Major Typhoon Winds ≥ 111 mph (96 kts)	1	0.9 (9 in 10 seasons)	8th (tied with 18 other seasons)	4 (2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	45.9	26.5	8th	109.2 (2015)

North Indian

May 2021 North Indian Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Tauktae	4	May 14May 14-19	135 mph	935 mb
Yaas	1	May 24May 24-26	75 mph	974 mb

North Indian Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1972-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	2	0.9 (9 in 10 Mays)	2nd (tied with 6 other Mays)	3 (2010)
Cyclone Winds ≥ 74 mph (64 kts)	2	0.5 (5 in 10 Mays)	1st	2 (1975, 2021)
Major Cyclone Winds ≥ 111 mph (96 kts)	1	0.3 (3 in 10 Mays)	1st (tied with 10 other Mays)	1 (11 Mays)
Accumulated Cyclone Energy ACE×10⁴ kt²	13.9	5.1	7th	20.6 (1975)

North Indian Tropical Cyclone Season Counts January-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1972-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	2	1.2	2nd (tied with 13 other seasons)	3 (2010)
Cyclone Winds ≥ 74 mph (64 kts)	2	0.6 (6 in 10 seasons)	1st	2 (1975, 2021)
Major Cyclone Winds ≥ 111 mph (96 kts)	1	0.3 (3 in 10 seasons)	1st (tied with 12 other seasons)	1 (13 seasons)
Accumulated Cyclone Energy ACE×10⁴ kt²	13.9	6.8	9th	22.2 (2019)

South Indian

No South Indian Tropical Cyclones occurred during May 2021.

South Indian Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1956-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.3 (3 in 10 Mays)	13th (tied with 28 other Mays)	2 (1979)
Cyclone Winds ≥ 74 mph (64 kts)	0	0.1 (1 in 10 Mays)	7th (tied with 34 other Mays)	1 (6 Mays)
Major Cyclone Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	1st (tied with 40 other Mays)	0
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	1.0	13th (tied with 28 other Mays)	8.2 (1993)

South Indian Tropical Cyclone Season Counts July 2020-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1956-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	12	10.4	8th (tied with 2 other seasons)	16 (1997)
Cyclone Winds ≥ 74 mph (64 kts)	5	6.0	24th (tied with 6 other seasons)	11 (2019)
Major Cyclone Winds ≥ 111 mph (96 kts)	2	3.4	27th (tied with 8 other seasons)	9 (2019)
Accumulated Cyclone Energy ACE×10⁴ kt²	99.3	94.0	17th	186.9 (1994)

Australia

No Australia Tropical Cyclones occurred during May 2021.

Australia Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1956-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.4 (4 in 10 Mays)	16th (tied with 25 other Mays)	4 (1963)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	0	0.1 (1 in 10 Mays)	5th (tied with 36 other Mays)	2 (1986)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	2nd (tied with 39 other Mays)	1 (1997)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	1.0 (10 in 10 Mays)	16th (tied with 25 other Mays)	12.5 (1986)

Australia Tropical Cyclone Season Counts July 2020-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1956-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	10	10.4	24th (tied with 2 other seasons)	19 (1999)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	3	4.8	27th (tied with 10 other seasons)	9 (1992, 1996)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	2	2.4	16th (tied with 8 other seasons)	6 (2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	32.0	59.5	33rd	111.3 (1999)

Southwest Pacific

No Southwest Pacific Tropical Cyclones occurred during May 2021.

Southwest Pacific Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1956-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	0	0.2 (2 in 10 Mays)	9th (tied with 32 other Mays)	2 (1989, 1997, 2017)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	0	0.1 (1 in 10 Mays)	4th (tied with 37 other Mays)	2 (2017)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	0	0.0 (0 in 10 Mays)	2nd (tied with 39 other Mays)	1 (2017)
Accumulated Cyclone Energy ACE×10⁴ kt²	0.0	1.2	9th (tied with 32 other Mays)	28.6 (2017)

Southwest Pacific Tropical Cyclone Season Counts July 2020-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1956-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	9	6.9	11th (tied with 2 other seasons)	17 (1998)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	4	3.7	14th (tied with 4 other seasons)	11 (1998)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	2	1.9	13th (tied with 6 other seasons)	6 (2003)
Accumulated Cyclone Energy ACE×10⁴ kt²	41.4	49.9	21st	139.9 (1998)

Global

May 2021 Global Tropical Cyclones

Name	Maximum CategoryMax Cat	Dates >39 mph	Maximum Sustained Winds	Minimum Central Pressure
Andres	TS	May 9May 9-10	40 mph	1005 mb
Not_Named	TS	May 13May 13	40 mph	1004 mb
Tauktae	4	May 14May 14-19	135 mph	935 mb
Ana	TS	May 22May 22-23	45 mph	1006 mb
Yaas	1	May 24May 24-26	75 mph	974 mb
Choi-Wan	TS	May 30-June 5May 30-Jun 5	60 mph	986 mb
Blanca	TS	May 31-June 2May 31-Jun 2	60 mph†	998 mb†
†Value occurred in June

Global Tropical Cyclone May Counts

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1972-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	7	3.9	1st (tied with 4 other Mays)	7 (5 Mays)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	2	1.8	11th (tied with 10 other Mays)	4 (1986, 1997, 2008, 2015)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	1	1.0	8th (tied with 19 other Mays)	3 (2008, 2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	17.1	25.1	26th	71.9 (2015)

Global Tropical Cyclone Season Counts January-May 2021

Storm Type	Count	1981-2010 Mean	1981-2021 Rank*	1972-2021 Record
Tropical Storm Winds ≥ 39 mph (34 kts)	29	24.9	7th (tied with 3 other seasons)	36 (1986)
Tropical Cyclone Winds ≥ 74 mph (64 kts)	11	13.2	30th (tied with 3 other seasons)	19 (1989, 1994)
Major Tropical Cyclone Winds ≥ 111 mph (96 kts)	6	7.4	21st (tied with 4 other seasons)	13 (2015)
Accumulated Cyclone Energy ACE×10⁴ kt²	196.2	202.9	19th	325.2 (1994)

Data Description

The data in this report are derived from NCEI's IBTrACS dataset (Knapp et al. 2010; Schreck et al. 2014). IBTrACS tropical cyclone track and intensity data from agencies and sources around the globe. In this report, data from NOAA's National Hurricane Center (NHC) are used for the North Atlantic and East Pacific. The other basins use data from the U.S. Military's Joint Typhoon Warning Center (JTWC).

Historical values use the "best track" data that have been analyzed by forecasters after the season using all available data. Operational procedures and observing systems have changed with time and between regions, which makes these data heterogeneous. Intensity data are generally the most reliable since the early 1970s in the Atlantic (Landsea and Franklin 2013) and since the mid-1980s in other regions (Chu et al. 2002). The number of short-lived storms (≤2 days) has also increased since around 2000 due to improvements in observations and analysis techniques (Landsea et al. 2010).

Values for the current year are provisional values from the operational forecast advisories. IBTrACS obtains these from NCEP's TC Vitals, the NCAR Tropical Cyclone Guidance Project, and NHC provisional data. These values are subject to change during the post-season best track analysis. They also only include 6-hourly storm fixes, which means they may miss special advisories at landfall, peak intensity, etc.

The tropical cyclone seasons in the Southern Hemisphere begin in July and end in June, while the Northern Hemisphere seasons are counted from January to December. Storms are counted in all basins, months, and years in which they occur, which means some storms may appear more than once. However, the global totals only include each storm one time.

References

• Chu, J.-H., C. R. Sampson, A. S. Levine, and E. Fukada, 2002: The joint typhoon warning center tropical cyclone best-tracks, 1945–2000. Naval Research Laboratory, Reference Number NRL/MR/7540-02-16, 22 pp., https://www.metoc.navy.mil/jtwc/products/best-tracks/tc-bt-report.html.
• Knapp, K. R., M. C. Kruk, D. H. Levinson, H. J. Diamond, and C. J. Neumann, 2010: The International Best Track Archive for Climate Stewardship (IBTrACS). Bull. Amer. Meteor. Soc., 91, 363–376, https://doi.org/10.1175/2009BAMS2755.1.
• Landsea, C. W., and J. L. Franklin, 2013: Atlantic Hurricane database uncertainty and presentation of a new database format. Mon. Wea. Rev., 141, 3576–3592, https://doi.org/10.1175/MWR-D-12-00254.1.
• ——, G. A. Vecchi, L. Bengtsson, and T. R. Knutson, 2010: Impact of duration thresholds on Atlantic tropical cyclone counts. J. Climate, 23, 2508–2519, https://doi.org/10.1175/2009JCLI3034.1.
• Schreck, C. J., K. R. Knapp, and J. P. Kossin, 2014: The Impact of Best Track Discrepancies on Global Tropical Cyclone Climatologies using IBTrACS. Mon. Wea. Rev., 142, 3881–3899, https://doi.org/10.1175/MWR-D-14-00021.1.