Katrina was a tropical depression that briefly became a 35-knot tropical storm while moving onshore on the Caribbean coast of Nicaragua.
a. Synoptic history
Satellite imagery suggests that the remnants of a cold front moved slowly southward across the western Caribbean Sea beginning on 22 October. A broad area of low pressure gradually formed over much of the Caribbean during this time and cloudiness and thunderstorms became concentrated over the southwestern Caribbean Sea on the 26th of October. On the 27th, low-level cloud lines began to show a circulation just north of Panama. On the 28th, a reconnaissance aircraft reported a well-defined low-level circulation about 150 n mi east of Bluefields, Nicaragua and tropical depression fifteen had formed. The best track begins at 1800 UTC on the 28th as indicated in Table 1, which is a listing, every six hours, of best track positions, maximum one-min surface wind speeds, and minimum central surface pressure. A map of the best track positions is shown in Figure 1.
Katrina was a tropical storm for about six hours from 1800 UTC on the 29th to 0000 UTC on the 30th, while making landfall on the coast of Nicaragua just south of Puerto Cabezas. For the rest of its four days of existence, Katrina was a tropical depression that moved on a generally northwestward track across Nicaragua and Honduras, back over the water of the northwest Caribbean, and then across northern Belize and the Yucatan Peninsula. The depression dissipated on the 1st just north of the Yucatan Peninsula as it was absorbed by a cold front.
b. Meteorological statistics
The best track pressure and wind speed time series curves are shown in Figure 2 and Figure 3, along with plots of the data on which the curves are based. The system was monitored by reconnaissance aircraft on the 28th and 29th of October while located in the southwestern Caribbean Sea. The basis for naming Katrina a tropical storm was a 43-knot, 1500-feet flight level wind observation at 1824 UTC on the 29th.
Satellite-based rainfall estimates suggest that 10 to 15 inches of rain may have ocurred over portions of Nicaragua and Honduras and lesser amounts for the Yucatan Peninsula. A report of 3.58 inches of rain in six hours was received on the 28th from San Andres, Colombia, an island about 100 n mi east of the coast of Nicaragua.
c. Casualties and damages
It is possible that the rainfall described above caused some flash flooding over mountainous terrain over portions of Central America. No reports of damage or casualties have been received.
d. Forecast and warning critique
A tropical storm warning was issued for the east coast of Nicaragua at 0000 UTC on the 29th and for the San Andres Islands at 0300 UTC. This was a lead time of 24 hours for the Nicaragua coast, as Katrina made landfall as a tropical storm at 0000 UTC on the 30th. The warnings for San Andres and for the east coast of Nicaragua south of Bluefields were discontinued on 1500 UTC on the 29th. The warnings for the remainder of the east coast of Nicaragua were discontinued at 0300 UTC on the 30th.
Statistics of track and intensity forecasts are calculated only for forecasts when the tropical cyclone is a tropical storm or hurricane. Since Katrina was a tropical storm very briefly, there are no meaningful statistics of track and wind speed forecast errors to report on.
Figure 1. Best track positions for Tropical Storm Katrina, 28 October-01 November 1999.
Figure 2. Best track maximum-one-min-surface-wind-sped vs. time curve for Tropical Storm Katrina, 28 October-01 November 1999.
Figure 3. Best track minimum-central-surface-pressure vs. time curve for Tropical Storm Katrina, 28 October-01 November 1999.
Table 1. Preliminary Best Track, Tropical Storm Katrina, 28 October-1 November 1999. Date/Time
Stage Lat. (°N) Lon. (°W) 28/1800 11.4 80.9 1001 30 tropical depression 29/0000 11.6 81.6 1001 30 " 0600 12.0 82.0 1001 30 " 1200 12.6 82.6 1000 30 " 1800 13.2 82.9 1000 35 tropical storm 30/0000 13.8 83.4 999 35 " 0600 14.1 84.0 1000 30 tropical depression 1200 14.3 84.5 1001 25 " 1800 14.7 85.2 1003 25 " 31/0000 16.0 86.6 1005 25 " 0600 17.2 87.4 1007 25 " 1200 18.4 88.0 1008 25 " 1800 19.4 88.7 1009 25 " 01/0000 19.9 89.6 1010 20 " 0600 20.4 89.8 1011 20 " 1200 21.2 89.8 1011 20 " 1800 dissipated 30/0000 13.8 83.4 999 35 landfall just south of Puerto Cabezas, Nicaragua 30/0000 13.8 83.4 999 35 minimum pressure