Tag Archives: Hurricane Otto

Hurricane Otto Strengthens As It Nears Nicaragua and Costa Rica

Hurricane Otto strengthened quickly on Thursday morning as it neared the coast of Nicaragua and Costa Rica.  At 7:00 a.m. EDT on Thursday the center of Hurricane Otto was located at latitude 11.0°N and longitude 82.9°W which put it about 90 miles (150 km) southeast of Bluefields, Nicaragua.  Otto was moving toward the west at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 105 m.p.h. (170 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 976 mb.

A Hurricane Warning is in effect for the portion of the coast from Limon, Costa Rica to Bluefields, Nicaragua.  A Hurricane Watch has been issued for the portions of the coast from Bluefields to Sandy Bay Sirpi, Nicaragua and from the Panama/Costa Rica border to Limon, Costa Rica.  Tropical Storm Warnings are in effect for the portions of the coast from Bluefields to Sandy Bay Sirpi, Nicaragua and from Puntarenas, Costa Rica to Puerto Sandino, Nicaragua.

An Air Force Reserve Hurricane Hunter aircraft found that Hurricane Otto strengthened quickly during the overnight hours.  The reconnaissance plane found a circular eye with a diameter of 23 miles (37 km).  The eye is surrounded by a ring of strong thunderstorms.  Additional bands of thunderstorms are occurring north and west of the center of circulation.  Thunderstorms in the core of Hurricane Otto are generating upper level divergence which is pumping mass away from the center.

Hurricane Otto is a small hurricane.  Winds to hurricane force extend out about 20 miles (32 km) from the center of circulation.  Winds to tropical storm force extend out about 70 miles (110 km) from the center.  The Hurricane Intensity Index (HII) is 17.8.  The Hurricane Size Index (HSI) is 8.4 and the Hurricane Wind Intensity Size Index (HWISI) is 26.2.  These indices indicate that Hurricane Otto is capable of causing localized serious wind damage.

Hurricane Otto is moving through a favorable environment and it could strengthen further before it reaches the coast of Nicaragua and Costa Rica.  Otto is moving over water where the Sea Surface Temperature is near 29°C.  The upper level winds are weak and there is little vertical wind shear.

A ridge of high pressure north of Otto is steering the hurricane toward the west and that general motion is expected to continue today.  On its anticipated track the center of Hurricane Otto will make landfall over southern Nicaragua or northern Costa Rica later today.

In addition to localized serious wind damage Hurricane Otto will produce a storm surge along the coast of Nicaragua and Costa Rica.  The surge will be highest north of where the center makes landfall because that is where the wind will push the water toward the coast.  Hurricane Otto will produce very heavy rain over parts of Nicaragua and Costa Rica.  The heavy could cause serious flooding and mudslides in some locations.  Outer rainbands could also produce heavy rain over portions of Honduras and El Salvador.

Hurricane Otto Approaching Nicaragua and Costa Rica

After weakening to a tropical storm earlier on Wednesday Hurricane Otto intensified as it approached the border between Nicaragua and Costa Rica.  At 10:00 p.m. EST on Wednesday the center of Hurricane Otto was located at latitude 11.2°N and longitude 82.2°W which put it about 120 miles east-southeast of Bluefields, Nicaragua.  Otto was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 85 m.p.h. (140 km/h) and there were wind gusts to 100 m.p.h. (160 km/h).  The minimum surface pressure was 981 mb.

A Hurricane Warning is in effect for the portion of the coast from Limon, Costa Rica to Bluefields, Nicaragua.  Hurricane Watches have been issued for the portions of the coast from Bluefields to Sandy Bay Sirpi, Nicaragua and from the Panama/Costa Rica border to Limon, Costa Rica.  Tropical Storm Warnings are in effect for the  portions of the coast from Bluefields to Sandy Bay Sirpi, Nicaragua, from Puntarenas, Costa Rica to Puerto Sandino, Nicaragua and for San Andres Island.

Hurricane Otto had meandered over the same water long enough to mix cooler water to the surface.  The cooler water reduced the energy transfer to the atmosphere and the inner core of Otto weakened.  The eye disappeared and Otto weakened below hurricane intensity.  When Otto began to move west, the core of the circulation moved away from the cooler water.  Thunderstorms developed rapidly near the center of circulation and the inner core began to redevelop.  A reconnaissance plane found that the wind speed had increased above hurricane intensity again.

Hurricane Otto has a very small circulation.  Winds to hurricane force only extend out about 12 miles (19 km) from the center of circulation.  Winds to tropical storm force extend out about 70 miles (110 km) from the center.  The Hurricane Intensity Index (HII) is 12.7.  The Hurricane Size Index (HSI) is 4.7 and the Hurricane Wind Intensity Size Index (HWISI) is 17.4.  These indices indicated that Hurricane Otto is capable of causing localized minor wind damage.

The small circulation of Hurricane Otto is more symmetrical.   There are indications that a circular eye and eyewall could be reforming at the center of the hurricane.  Several bands of thunderstorms are rotating around the core of Otto.  Thunderstorms at the core were generating upper level divergence which pumped out mass and allowed the surface pressure to decrease on Wednesday evening.

Hurricane Otto will be moving through an environment that is favorable for intensification until it makes landfall.  Otto will be moving over water where the Sea Surface Temperature is near 29°C.  An upper level ridge east of the hurricane is producing southeasterly winds which are flowing near the top of the circulation.  However, those winds are weaker than they were yesterday and the vertical wind shear is less.  Hurricane Otto could strengthen further during the next few hours.

A ridge to the north of Otto is steering the hurricane toward the west and that general motion is expected to continue for another day or two.  On its anticipated track Hurricane Otto will make a landfall on the coast between the Nicaragua/Costa Rica border and Monkey Point, Nicaragua.  Winds blowing toward the coast will produce a storm surge along the southern coast of Nicaragua.  Otto could drop heavy rain over Nicaragua and Costa Rica.  Outer bands may also produce locally heavy rain over parts of Honduras and El Salvador.  The rain may be heavy enough to cause flooding and mudslides.

Otto Becomes a Hurricane, Watches and Warnings Issued

Tropical Storm Otto intensified into a hurricane on Tuesday as it meandered over the southwestern Caribbean Sea.  At 4:00 p.m. EST on Tuesday the center of Hurricane Otto was located at latitude 10.5°N and longitude 79.6°W which put it about 235 miles (375 km) east of Limon, Costa Rica.  Otto was moving toward the west at 2 m.p.h. (3 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 984 mb.

Hurricane Watches have been issued for the portion of the coast from the Costa Rica/Panama border to Bluefields, Nicaragua.  Tropical Storm Warnings have been issued for the portion of the coast from Nargana to Colon, Panama and for San Andres Island, Colombia.  Tropical Storm Watches have been issued for the portions of the coast from Colon, Panama to the Panama/Costa Rica border and from Bluefields to Sandy Bay Sirpi, Nicaragua.

The inner core of Hurricane Otto became more circular and symmetrical on Tuesday.  An eyelike feature appeared on microwave satellite imagery and hints of an eye were seen intermittently on visible imagery during the day.  There appeared to be breaks in the eyewall on the southeast side of the eye.  Most of the stronger thunderstorms are forming northwest of the eye.  Convective activity outside the core of Hurricane Otto is more asymmetrical.  There are some thinner rainbands north and west of the center where winds from a high pressure system are converging into the circulation of Otto.  There are fewer showers and thunderstorms in the southeastern quadrant of the circulation.  Thunderstorms around the center of the hurricane are generating upper level divergence at the very top of the circulation.

Hurricane Otto has a very small circulation.  Winds to hurricane force only extend out about 10 miles (15 km) from the center of circulation.  Winds to tropical storm force only extend out about 70 miles (110 km) from the center.  The Hurricane Intensity Index (HII) for Otto is 10.4.  The Hurricane Size Index (HSI) is 3.2 and the Hurricane Wind Intensity Size Index (HWISI) is 13.6.

Hurricane Otto will be moving through an environment that will be favorable for intensification.  It will move over water where the Sea Surface Temperature is 29°C.  An upper level ridge located east of Otto is generating southeasterly winds which are blowing against the upper portion of the circulation of the hurricane.  Those winds appear to be hitting Otto just under the level of upper level divergence at the top of the circulation.  So, the upper level winds and vertical wind shear appear to be restricting upper level divergence to the south of the circulation, but they do not appear to be completely blocking divergence.  The speed of the upper level winds is forecast to decrease.  If the vertical shear decreases, then Hurricane Otto could strengthen.

A ridge of high pressure is forecast to build north of Hurricane Otto.  That ridge will steer Otto toward the west and the hurricane could start to move faster on Wednesday.  On its anticipated track Hurricane Otto could approach the coast of Costa Rica and Nicaragua on Thursday.

Hurricane Otto is a small hurricane, but it could cause localized minor wind damage.  Heavy rain, flash floods and mudslides are a much greater threat.  Hurricane Otto could bring flooding rains to portions of Nicaragua, Honduras, Panama, Costa Rica, Guatemala and El Salvador.

On a historical note Hurricane Martha formed during this time of year in 1969 in almost exactly the same area where Hurricane Otto formed.  Hurricane Martha moved southward and weakened.  Martha officially made landfall in Panama as a tropical storm, but it did cause flooding rains and fatalities in parts of Costa Rica.