Tropical Weather Discussion

axpz20 knhc 260920

Tropical weather discussion
NWS National Hurricane Center Miami FL
1005 UTC Fri may 26 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 
0900 UTC.

...Tropical waves...

The southern portion of a tropical wave moving into Central 
America is along 84w. Scattered moderate to strong convection is 
observed within 240 nm west of the wave. The wave is under upper 
level diffluent flow which is maintaining the active convection. 
This wave will move slowly westward through the weekend.

A weak tropical wave extends from the Yucatan Peninsula to 
08n94w, with active convection inland over Guatemala. This wave 
is expected to become diffuse and ill-defined through Saturday.

...Intertropical convergence zone/monsoon trough... 

The monsoon trough axis extends northwestward across Central 
America from an area of low pressure in northern Colombia near 
09n75w to 15n90w then westward to the coast of southern Mexico 
near 16n98w. From there it extends southwestward through a 1009 
mb low near 08n117w then westward to 08n130w, where it becomes 
the ITCZ which extends beyond 07n140w. Clusters of scattered 
moderate isolated strong convection associated with the oceanic 
low are within 45 nm either side of the trough axis between 114w 
and 119w, with minimal convection elsewhere along the boundary.


Offshore waters within 250 nm of Mexico...

A 1006 mb low is analyzed along a trough across the western part 
of the Gulf of California from 32n114w to 25n111w. Scatterometer 
data at 0427 UTC showed 25-30 kt SSW winds north of 30n associ-
ated with the low and trough, which is in agreement with model 
guidance the past few days. Expect strong SW winds and seas to 8 
ft to continue north of 30n today, then diminish late tonight. 
Latest scatterometer data shows gentle to moderate northerly 
winds west of Baja California, and gentle westerly winds south 
of 17n. Light and variable winds are expected in the Gulf of 
California this weekend, as well as south of Tehuantepec, where 
a weak low is expected to develop near 13n98w. Gentle NW winds 
and 4-6 ft seas will prevail elsewhere through Sunday.

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

Gentle southwest to west winds prevail between the papagayo 
region and Tehuantepec, with seas of 4 to 5 ft in SW swell. 
Expect gentle westerly monsoonal winds to spread across the 
coastal waters today as the tropical wave mentioned above moves 
across the area. Nocturnal offshore winds will pulse to fresh 
levels in the Gulf of papagayo Saturday night and Sunday night 
behind the wave. Moderate southwest winds will continue south of 
09n through Thursday night. Otherwise, little change is forecast 
this weekend.

Remainder of the area...

weak troughing prevails the forecast area north of 22n. The lack 
of a strong ridge is also reflected in gentle to moderate trade 
winds north of the ITCZ indicated in recent scatterometer data. 
Slightly stronger high pressure northwest of the area will build 
southward by the end of the weekend and into early next week, 
supporting increasing trades to moderate to fresh levels and 
building seas to 5-8 ft across the waters north of the ITCZ.



View All Hurricanes and Tropical Cyclones

Category 6

Welcome to Category 6. This is the collective home for Weather Underground's featured writeups by Dr. Jeff Masters (right), Bob Henson (left), Chris Burt, and other regular contributors.

Learn more about and the hurricane season in our hurricane archive.

View All Hurricanes and Tropical Cyclones

Hurricane Archive

All Atlantic Storms (1851-2017)

Named Storms for 2016

Historical Hurricane Statistics

Articles of Interest