Summary

Twenty named storms occurred across the globe in September, which was the third most on record. Twelve of those reached tropical cyclone strength (≥74 mph), and six reached major tropical cyclone strength (≥111 mph). These counts are all above the 1991-2020 averages for September. The global accumulated cyclone energy (ACE: an integrated metric of the strength, frequency, and duration of tropical storms) was also above normal in September. The 66 named storms during January-September is near normal, but all other global metrics remain below normal for January-September.

Six named storms occurred in the Atlantic during September, which was near normal. However, four of these became hurricanes, including two major hurricanes, both of which were above normal. The Atlantic tropical cyclone activity in September was particularly noteworthy following the complete lack of tropical storms in August. All metrics have returned to near normal for January-September after being below normal for January-August.

Hurricane Fiona was the first major hurricane of the 2022 Atlantic season. It caused widespread flooding and power outages over Puerto Rico. Fiona also made landfall in the Dominican Republic and the Turks and Caicos Islands as a hurricane. After its extratropical transition, Fiona ultimately made landfall in Nova Scotia as the strongest and costliest post-tropical cyclone on record for Canada.

Hurricane Ian formed and rapidly intensified into a major hurricane in the western Caribbean as it made landfall in Cuba. Ian rapidly intensified again leading up to its landfall in southwestern Florida. Its peak intensity before landfall was 155 mph, just shy of Category 5 strength (≥157 mph). Ian weakened to a tropical storm as it crossed the Florida Peninsula but regained hurricane strength before making landfall in South Carolina. Ian was one of the strongest and costliest storms to make landfall in Florida.

The East Pacific had six named storms in September, which was above normal. However, only one of them, Hurricane Kay, reached hurricane strength during September. Kay brought heavy rains and flooding to southwestern Mexico and the Baja peninsula. A second storm, Orlene, formed in September and became a major hurricane in October. The one hurricane and zero major hurricanes during September were both below normal, and the ACE for September was about half of its climatological value. The East Pacific tropical activity for January-September is near normal by most metrics except for the two major hurricanes, which is below normal.

Seven named storms occurred in the West Pacific during September, which was above normal. That includes Super Typhoon Hinnamnor, which formed in August. All seven named storms reached typhoon strength during September, which ties 1956 and 1996 for the most typhoons in September. Four of those also reached major typhoon strength, which is the second most since 1981. The ACE was above normal for September. However, the 2022 typhoon season before September had been so inactive that most metrics are still below normal for January-September.

Several of the typhoons in September had significant impacts. In August, Hinnamnor became the first Category 5 tropical cyclone of 2022 on the Saffir-Simpson hurricane wind scale globally for 2022. It weakened as it approached South Korea but still made landfall as a Category 2 typhoon and one of the strongest in history there. Typhoon Muifa made landfall near Shanghai as a Category 1 storm and was one of the strongest storms to affect that metro region. The post-tropical remnants of Typhoon Merbok caused hurricane strength winds and coastal flooding in the Aleutians and western Alaska. Super Typhoon Nanmandol rapidly intensified to Category 4 strength before rapidly weakening as it made landfall in southern Japan with torrential rains and flooding. Super Typhoon Noru rapidly intensified into the second Category 5 tropical cyclone of 2022 before making landfall in the northern Philippines as a Category 4 storm. Noru weakened as it crossed Luzon but reintensified to Category 4 over the South China Sea. It brought heavy rain to Southeast Asia after making landfall as a Category 2 storm in Vietnam.

All other basins were inactive during September except for a weak tropical storm, Ashley, in the South Indian Ocean. This lack of activity in these basins is typical for September.

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.