| Category 3 major hurricane (SSHWS/NWS) | |
 Hurricane Lee near peak intensity in the Central Atlantic on September 27 | |
| Formed | September 14, 2017 |
|---|---|
| Dissipated | October 1, 2017 |
| (Extratropical after September 30) | |
| Highest winds | 1-minute sustained: 115 mph (185 km/h) |
| Lowest pressure | 962 mbar (hPa); 28.41 inHg |
| Fatalities | None |
| Damage | Minimal |
| Areas affected | Cape Verde |
| Part of the 2017 Atlantic hurricane season | |
Hurricane Lee was a long-lived and unusual Category 3 hurricane that remained far from any land areas. The twelfth named storm, seventh hurricane, and fifth major hurricane of the 2017 Atlantic hurricane season, Lee developed from a tropical wave west of the Cape Verde islands on September 15. Lee intensified little due to dry air and northerly wind shear, with its center of circulation exposed at times. Despite only marginally favorable conditions, Lee strengthened into a tropical storm on September 16. Conditions became unfavorable for development the following day, causing Lee to weaken, and on September 19 it opened up into a trough after succumbing to the effects of wind shear.
The mid-level remnants of Lee interacted with the remnant trough, leading to a burst of convection and the formation of a new circulation, and on September 22 Lee regenerated into a tropical depression. Located within a more favorable environment, Lee steadily strengthened, and it reached hurricane strength on September 24 as a mid-level eye developed. The compact storm executed a tight cyclonic loop, and it strengthened into a Category 2 hurricane on September 26. Lee reached its peak intensity the following day as it turned northeastward. The hurricane began to weaken late on September 27 as it encountered strong wind shear and increasingly colder sea surface temperatures, and it weakened to a tropical storm on September 29. Early the next day, Lee degenerated into a post-tropical cyclone and was absorbed by a larger extratropical system on October 1.
Meteorological history edit
Tropical storm (39–73 mph, 63–118 km/h)
Category 1 (74–95 mph, 119–153 km/h)
Category 2 (96–110 mph, 154–177 km/h)
Category 3 (111–129 mph, 178–208 km/h)
Category 4 (130–156 mph, 209–251 km/h)
Category 5 (≥157 mph, ≥252 km/h)
Unknown
Extratropical cyclone, remnant low, tropical disturbance, or monsoon depressionThe National Hurricane Center began tracking two tropical waves for possible tropical cyclone formation on September 13.[1] The second wave developed into Tropical Depression Fourteen on September 14, while the other wave became what would eventually become Hurricane Maria two days later.[2][3] The newly-formed tropical depression struggled to strengthen, however, due to moderate northerly wind shear and the presence of dry air in the mid-levels.[4] Despite the somewhat unfavorable environment, the depression strengthened into Tropical Storm Lee at approximately 12:00 UTC on September 16.[5] Due to impending strong westerly shear, the NHC forecasted little strengthening of the system, expecting it to degenerate into a remnant low within a few days.[6] As forecast, Lee struggled to intensify, with its circulation sheared away from the center of the system.[7] The environment turned unfavorable for strengthening on September 17, and Lee weakened to a tropical depression at 12:00 UTC that day.[5] Periodic bursts of convection formed near the center of the system, and Lee restrengthened into a tropical storm on September 19 and reached an initial peak intensity with winds of 45 mph (65 km/h).[5] The cyclone turned northwestward after interacting with a trough, although this also caused a notable increase in wind shear. On September 20, Lee opened up into a trough as its remnants decoupled, with the mid-level circulation rapidly accelerating north-northeastward.[5]
Despite the interaction with the trough, which usually proves to be fatal to tropical cyclones, Lee's remnant mid-level circulation maintained deep convection as it moved northwest around the mid-level trough, and on September 21, satellite imagery revealed that a low-level circulation was beginning to form beneath the mid-level center.[5] Early the next day, convection increased as the remnant disturbance entered a more favorable environment, and Lee regenerated into a tropical depression at 12:00 UTC.[5]
- ^ Michael Brennan (September 13, 2017). "Tropical Weather Outlook". National Hurricane Center. Retrieved April 8, 2018.
- ^ Daniel P. Brown (September 14, 2017). "Tropical Weather Outlook". National Hurricane Center. Retrieved April 8, 2018.
- ^ Robbie Berg (September 13, 2017). "Tropical Weather Outlook". National Hurricane Center. Retrieved April 8, 2018.
- ^ Daniel P. Brown (September 15, 2017). "Tropical Depression Fourteen Discussion Number 4". National Hurricane Center. Retrieved April 8, 2018.
- ^ a b c d e f Eric S. Blake (February 13, 2018). Hurricane Lee (AL142017) (PDF) (Report). Tropical Cyclone Report. National Hurricane Center. Retrieved April 8, 2018.
- ^ Robbie Berg (September 16, 2017). "Tropical Depression Lee Discussion Number 8". National Hurricane Center. Retrieved April 8, 2018.
- ^ Jack Beven (September 16, 2017). "Tropical Storm Lee Discussion Number 9". National Hurricane Center. Retrieved April 8, 2018.