Tropical Storm Katrina (1999) - Meteorological History

Meteorological History

Tropical Storm Katrina originated out of the remnants of a cold front tracking southward through the Caribbean Sea on October 22. By October 26, a broad area of low pressure, associated with disorganized shower and thunderstorm activity, developed over the southwestern Caribbean Sea. The following day, a surface low pressure became apparent after the system showed signs of rotation near the northern Panama coastline. On October 28, a hurricane hunter flight into the circulation revealed a well-defined low pressure system and resulting in the system being declared Tropical Depression Fifteen while situated roughly 175 mi (280 km) east of Bluefields, Nicaragua. The center of the newly classified depression was situated on the western edge of deep convection. The depression tracked slowly towards the northeast in response to the mid-level flow it was embedded within.

By the morning of October 29, a tropical wave, tracking towards the west, began to interact with the depression and leading to forecasters discussing a possible merger of the two systems. An upper-level anticyclone over the eastern Caribbean produced significant wind shear over the depression, preventing the center from moving under the deep convection. However, a large convective banding feature developed to the north of the system. Several hours later, hurricane hunters flew through the storm and recorded surface winds of 40 mph (65 km/h) and a barometric pressure of 999 mbar (hPa; 29.5 inHg), leading to the upgrade of the depression to a tropical storm. At this time, the storm received the name Katrina and peaked in intensity. By 0000 UTC on October 30, the center of Katrina made landfall near Puerto Cabezas, Nicaragua at peak intensity. Within three hours, the storm weakened to a depression due to interaction with the mountains of Nicaragua and convection was limited to a small area on the western side of the center of circulation.

Katrina continued to track over Central America for most of October 30 and began to accelerate. Roughly 24 hours after landfall, the depression moved back over water, in the Gulf of Honduras; however, by this time, there was no convection remaining around the system. The acceleration of the storm was due to a regeneration of the low-level circulation northward. Due to unfavorable conditions, the weakened system failed to regenerate convection before moving back over land near the northern Belize-Mexico border. Around this time, forecasters reported that the depression would re-intensify once in the Gulf of Mexico before transitioning into an extratropical cyclone. Although situated over land, the depression began to regenerate convection, leading to increased rainfall over the Yucatan Peninsula. By the evening of November 1, the depression weakened again and moved into the Gulf of Mexico; however, unlike previous forecasts, the circulation was absorbed by a cold front hours later.