000
AXPZ20 KNHC 210921
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Wed Mar 21 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 0600 UTC surface analysis and satellite imagery through 
0900 UTC. 

...SPECIAL FEATURES...

Gulf of Tehuantepec Gale Warning: High pressure building into 
southern Mexico behind a cold front in the western Gulf of 
Mexico will induce strong to near-gale north winds surging into 
the gulf this morning, then increase to minimal gale force this 
evening. Gale conditions are then expected to continue through 
Fri morning, with seas building to a max of 13-14 ft. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

A surface trough extends from 09N79W to 05N90W to 06N104W. The 
ITCZ axis continues from 06N104W to 08N140W. Scattered moderate 
and isolated strong convection is within 45 nm S and 75 nm N of 
the ITCZ axis between 118W and 133W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Please see see Special Features Section above for details on 
gale force winds expected to affect the Gulf of Tehuantepec.

Weak high pressure is centered W of the Baja peninsula near 27N 
121W. The high will support gentle northerly winds in the Baja 
offshore waters through Thursday. Moderate northerly winds will 
develop Fri morning as a strong ridge builds NW of the forecast 
area behind a cold front moving into southern California.
  
Gulf of California: Scatterometer data shows moderate NW winds 
across the southern half of the gulf. These winds are forecast 
to gradually diminish through Thursday along with 3-4 ft seas.

OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND 
WITHIN 750 NM OF ECUADOR... 

Gulf of Papagayo: Scatterometer data indicates light winds in 
the region this morning. Fresh to locally strong northeast winds 
will develop downstream from the Gulf of Papagayo later today, 
with seas building to 7 ft. Stronger winds are expected early 
Thu morning through Sun with max seas building to 10-11 ft. 

Fresh to strong northerly winds are also expected downstream of 
the Gulf of Panama early Thu morning through Sat night. Light to 
gentle offshore flow will prevail elsewhere.

REMAINDER OF THE AREA... 

A 997 mb surface low pres system N of the area near 34N135W 
extends a cold front from 30N131W to 22N140W. Fresh W winds are 
N of 28N west of the cold front. Large seas to 14-15 ft and long 
period NW swell are in the NW part of forecast waters. The low 
will lift northward away from the area today, and winds will 
diminish to 20 kt or less by afternoon. Large NW swell will 
propagate southeastward through Sat.

A progressive pattern will affect the northeast portion of the 
area through Thu night. A deep layer low pres system located NW 
of the area is preceded by deep mid to upper level moisture that 
will support clouds and precipitation streaming into southern 
California.

$$
Mundell