000
AXPZ20 KNHC 200915
TWDEP 

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1005 UTC Tue Mar 20 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...

Gale Warning: A weakening cold front from 30N127W to 20N140W is 
preceded by strong southerly flow north of 26N within 180 nm E 
of the front, with seas to 12 ft. A deepening surface low pres 
system NW of the area near 32N143W will drop SE this morning 
behind the cold front, dragging a second cold front into the 
discussion area accompanied by near gale force westerly winds. 
The pressure gradient will tighten in the southern semicircle of 
the low, with winds increasing to minimal gale force near 0900 
UTC today, with associated seas of 15 to 17 ft. The low pres 
will lift north of the area later today with winds diminishing 
to 20-30 kt, becoming 20 kt or less by early Wed. Large NW swell 
will propagate southeastward through Sat. Please refer to the 
Pacific high seas forecast for more details on this upcoming 
event under AWIPS/WMO headers MIAHSFEP2/FZPN03.

Gulf of Tehuantepec Gale Warning: Strong to near-gale north flow 
will surge into the gulf early Wed morning, then increase to 
minimal gale force Wed night. Gale conditions are then expected 
to continue through Fri morning, with seas building to a maximum 
of around 12 ft. 

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

A surface trough extends from 09N83W to 04N97W to 05N108W. The 
ITCZ axis continues from 05N108W to 07N140W. Scattered moderate 
isolated strong convection is noted within 60 nm north of the 
ITCZ axis between 117W and 123W.

...DISCUSSION...

OFFSHORE WATERS WITHIN 250 NM OF MEXICO...

Weak high pressure W of the northern Baja Peninsula extends a 
ridge axis S to near 18N. The ridge will shift southeast through 
tonight, supporting fresh to locally strong northerly winds on 
Jalisco, Mexico offshore waters between 105W and 107W. Gentle to 
moderate northerly winds in the Baja offshore waters will become 
light to gentle by tonight as the ridge weakens.
  
Gulf of California: Fresh to locally strong northwest flow is 
forecast across the southern half of the gulf waters through 
this evening accompanied by 5-6 ft seas.

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

Gulf of Papagayo: Fresh to strong northeast winds will develop 
downstream of the Gulf of Papagayo tonight, with seas building 
to 7 ft. Stronger winds are expected Wed night through Sat night 
with seas building to 11 ft. 

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

REMAINDER OF THE AREA... 

Please see see Special Features Section above for details on 
gale force winds expected to affect the NW portion of the area.

A progressive pattern will continue to impact the the northwest 
portion of the area well into the weekend. A deep layer low pres 
system located NW of the area is preceded by deep mid to upper 
level moisture. Clouds and precipitation associated the the low 
pres system will advance eastward towards southern California 
and the northern and central Baja California through Wed.

$$
Mundell