Tropical Weather Discussion

axpz20 knhc 170947

Tropical weather discussion
NWS National Hurricane Center Miami FL
1005 UTC Fri Nov 17 2017

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 0600 UTC surface analysis and satellite imagery through 
0945 UTC.

Intertropical convergence zone/monsoon trough... 

The monsoon trough extends W off the coast of Costa Rica at 
10n85w to 11n89w, then turns SW to 09n123w where scatterometer 
winds indicate a transition to an ITCZ which continues W to 
beyond 09n140w. Isolated moderate to strong convection is noted 
within 90 nm either side of a line from 07n80w to 08n101w.
Scattered moderate isolated strong convection is noted within 
120 nm either side of a line from 08n112w to 09n132w.


Offshore waters within 250 nm of Mexico...

A ridge will extend se across the far offshore waters to the W 
of 100w through sun. This will result in gentle to locally 
moderate N breezes across the waters W of Baja California 
through today. Expect moderate to locally fresh NW flow N of 25n 
within 90 nm of the Pacific coast of baja beginning tonight, 
with these conditions spreading S across all waters W of baja by 
late Sat and continuing into early sun when the pressure 
gradient will begin to relax.  

Gulf of tehuantepec: pulses of strong to near gale force 
northerly drainage flow, with seas building to a Max of 10 ft, 
are forecast through sunrise on Sat with winds becoming light 
and variable on Sat afternoon. Strong to near gale force 
conditions will resume late Sat night in the wake of a cold 
front in the Gulf of Mexico, and then increase to gale force on 
Sun morning through about sunrise on Mon morning, with seas 
building to a Max of 16 ft downstream of the Gulf waters near 
14n95.5w on Sun night. 

Gulf of california: light and variable winds expected through 
sunrise on Sat. Strong N winds will develop across the Gulf 
waters N of 30n later on Sat morning in the wake of a cold 
front. Strong NW winds will shift S across the central Gulf 
waters on Sat night through sunrise on sun with seas building to 
7 ft. Light NW winds forecast across the entire Gulf waters on 

Offshore waters within 250 nm of Central America, Colombia, and 
within 750 nm of Ecuador...

Gulf of papagayo:  moderate to locally fresh NE drainage winds 
are forecast during the overnight hours through the middle of 
next week with seas building to 5 ft downstream near 10n87w. 

Light and variable winds, and 3 to 5 ft seas, are expected 
elsewhere to the N of 09n, while moderate to locally fresh 
southerly winds, and 4 to 7 ft seas, are forecast S of 09n 
through the middle of next week. 

Remainder of the area...

A 1011 mb surface low is centered near 30n134w with a weakening 
cold front extending SW to 20n140w. Long-period NW-N swell in 
the form of 7 to 9 ft seas currently W of the low and front will 
subside to less than 8 ft today. The low will shift slow E and 
wash out by late Sat night. 

Strong se return flow will develop N of 22n W of 137w on Sat 
night, with these strong southerly winds spreading E across the 
waters N of 26n to the W of 130w on Mon night with seas of 7 to 
11 ft, all ahead of a cold front reaching from 32n137w to 
28n140w late Wed with seas building 12 to 16 ft W of the front. 

Gentle to moderate trade winds and 4 to 6 ft seas will persist 
farther S through Sat, with moderate to locally fresh 
anticyclonic flow on Sat night into sun.



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