AXPZ20 KNHC 250347

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sun Feb 25 2018

Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis.

Based on 0000 UTC surface analysis and satellite imagery through 0345 UTC.

...SPECIAL FEATURE...The Fuego Volcano inland over Southern Guatemala near at 14.5N 90.9W is erupting. A plume of volcanic ash may reach to the surface across the Pacific waters N of 14N and E of 93W. Low level visibilities may be reduced to 6 nm or less. Mariners should exercise caution. If mariners encounter volcanic ash, they are encouraged to report the observation to the National Weather Service by calling 305-229-4425. Please refer to the East Pacific High Seas Forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details on the ashfall advisory.


A surface trough extends SW from the Pacific coast of Costa Rica at 09N84W to 03N100W where scatterometer winds indicate a transition to an ITCZ, which continues NW to 08N123W to beyond 05N140W. Scattered moderate isolated strong convection is observed along the ITCZ within 120 nm either side of a line from 00N100W to 03N108W and within 150 nm either side of a line from 15N120W to 08N130W.



Pacific waters w of the Baja Peninsula: A W to E ridge extends across the offshore waters from 20N116W to 14N97W. Moderate NW to N winds, with 5 to 8 ft seas will continue with the seas gradually subsiding to less than 8 ft by Sun evening. Another round of NW swell in the form of 7 to 10 ft seas will reach 30N120W on Mon morning with fresh to strong NW winds arriving on Mon night. Expect fresh NW winds and 8 to 14 ft seas N of 24N on Tue night, and moderate N winds and 7 to 10 ft seas w of the entire Baja Peninsula on Wed night. Expect seas to subside to less than 8 ft briefly on Thu with another round of NW swell reaching 30N120W on Fr morning.

Gulf of Tehuantepec: Gentle onshore flow expected during the daylight hours with gentle offshore during the overnight hours through Mon. Moderate to locally fresh northerly drainage flow forecast on Mon night. Model guidance is suggesting the next strong event will occur on thu night.

Gulf of California: Strong NW winds currently across central gulf waters between 24N and 28N will diminish to a fresh breeze around sunrise on Sun. The pressure gradient will quickly relax on Sun and Mon, with gentle winds gradually clocking to S by Mon evening, then increasing to a strong SW breeze along 30N on Mon night ahead of the next cold front sweeping across the northern gulf waters on Tue.


Gulf of Papagayo: Fresh to locally strong NE winds will continue to pulse through and downstream of the Gulf of Papagayo through Fri, with seas building to 7 ft.

Gulf of Panama: Mostly moderate nocturnal drainage flow is then forecast overnight and on Sun night with fresh winds expected to resume on Mon and Tue nights.

Elsewhere, gentle to moderate offshore flow will prevail N of 08N while light to gentle SW winds are forecast S of 08N.


Strong high pressure well NW of the area will continue to support fresh to locally strong NE trades, and 7 to 11 ft seas, across the tropical waters N of the convergence zone and W of 115W with the pressure gradient is forecast to further tighten on Mon. Expect a strong NE breeze, with 8 to 12 ft seas, across the Pacific waters from 08N to 24N W of 129W by early Tue. Model guidance indicates that the pressure gradient will begin to relax on Thu.

Northerly swell, in the form of 6 to 9 ft seas, will continue to propagate S across the waters from 28N to 32N between 120W and 127W through Mon. Around round of strong northerly winds will reach along 32N between 120W and 130W on Mon evening. These winds will diminish to a fresh N breeze on Tue, but expect 8 to 15 ft seas across the Pacific waters from 22N to 32N between 117W and 130W on Tue night, with the seas quickly subsiding on Wed.

$$ Nelson