Hurricane Imelda (2019/MO)

Hurricane Imelda was the strongest, most destructive and deadliest hurricane in the 2019 Atlantic hurricane season.

Meteorological history
The National Hurricane Center (NHC) began monitoring a strong tropical wave on September 14 as it moved off of the coast of Africa. The showers and thunderstorms associated with the system gradually coalesced into a low pressure area. Gradually consolidating and organizing, the low pressure acquired a burst of deep convection and became Tropical Depression 10 on September 17. The depression formed at an area of stable atmosphere and dry air, but it gradually organized, aiding from the warm sea surface temperatures below it. The system moved on a west-southwestward position under the influence of an unusually strong subtropical ridge to its north. The depression was forecast to turn north and dissipate, but a break in the subtropical ridge to the north of the system that was forecast to happen due to a trough didn't materialize. The Azores High remained very strong and the depression moved into an environment that is more favorable.

Lowering wind shear, moist air and fairly warm waters aided the system. Satellite images indicated a rigid structure and a strong convection. The Dvorak estimates also indicate that the system has achieved winds of at least 40 mph, and it was assigned the name "Imelda" at 2100 UTC on September 19. A weak trough weakened the influence of the Azores High as Imelda turned to the north and executed a general west-northwestward track. Imelda was forecast to organize and strengthen despite being in an environment with a lack of upper-level-divergence and dry air.

Nearly halfway between the Leeward Islands and Cape Verde, Imelda was upgraded to a hurricane due to the storm's strong poleward and equatorial outflow, organization, and banding at 1900 UTC on September 21. Moving into an area of low wind shear and anomalously high sea surface temperatures, Imelda strengthened. At this point, the only factor preventing Imelda from undergoing rapid intensification is the presence of dry air.

As the Saharan Air Layer weakened, Imelda started to undergo a period of rapid intensification at 1300UTC on September 23. With a very prominent central dense overcast and towering cloud tops with a temperature of around -76 °C, Imelda was upgraded to a Category 2 hurricane just hours later, and then a Category 3 hurricane in the next warning. A pinhole eye appeared on Imelda as the hurricane's periphery drastically increased in size; the convection on top of the central dense overcast cooled as well.

TBA