000
AXPZ20 KNHC 052130
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC SAT APR 05 2014

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.                           

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
 
THE ITCZ AXIS EXTENDS FROM 07N85W TO 04N105W TO 03N114W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 04N TO 
07N BETWEEN 85W AND 93W...AND FROM 02N TO 04N BETWEEN 108W AND 
114W.
 
...DISCUSSION...                                                

ALOFT...AN UPPER LEVEL RIDGE IS ACROSS THE FAR NW CORNER OF THE 
FORECAST AREA PRODUCING MODERATE TO STRONG SUBSIDENCE MAINLY N 
OF 20N W OF 130W. E OF THE RIDGE...THERE IS AN UPPER LEVEL 
TROUGH EXTENDING FROM 31N114W TO 25N135W. A 90-110 KT JETSTREAM 
EXTENDS FROM 24N117W TO SOUTHERN BAJA CALIFORNIA AND NW 
MEXICO...WHERE WINDS INCREASE TO 120-140 KT. BROKEN HIGH CLOUDS 
ARE NOTED S OF THE JETSTREAM AXIS. A LARGE ANTICYCLONIC 
CIRCULATION IS CENTERED NEAR 13N95W WITH A RIDE EXTENDING NE 
OVER SE MEXICO AND THE YUCATAN PENINSULA AS WELL AS OVER MOST OF 
CENTRAL AMERICA WHERE STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS 
IS OBSERVED ON WATER VAPOR IMAGERY. 

A 1029 MB SURFACE HIGH PRES CENTERED NEAR 32N135W EXTENDS A 
RIDGE SE ACROSS THE FORECAST REGION TO NEAR 17N114W. THIS SYSTEM 
WILL MAINTAIN LIGHT TO MODERATE EASTERLY WINDS TO PERSIST INTO 
EARLY NEXT WEEK ACROSS WATERS N OF 20N. SEAS WILL REMAIN JUST AT 
OR BELOW 8 FT IN LINGERING NW SWELL. HOWEVER...THE PRESSURE 
GRADIENT BETWEEN THE ITCZ AND THE HIGH PRES IS PRODUCING A BROAD 
AREA OF FRESH TO STRONG TRADE WINDS MAINLY FROM 09N TO 22N W OF 
130W AND FROM 11N TO 18N BETWEEN 118W AND 130W WITH SEAS TO 11 
FT IN A MIX OF LONGER PERIOD NW SWELL AND SHORTER PERIOD NE 
SWELL DUE TO TRADE WINDS. LATEST SCATTEROMETER DATA CONFIRMED 
THE PRESENCE OF THESE WINDS AND ALTIMETER PASS INDICATED SEAS TO 
11 FT NEAR 16N137W. THESE STRONG TRADE WINDS WILL GRADUALLY 
DIMINISH LATE TONIGHT THROUGH EARLY NEXT WEEK AS HIGH PRES TO 
THE N MOVES NE AND WEAKENS. 

A PAIR OF SHIP OBSERVATIONS ALONG WITH THE 1720 UTC ASCAT PASS 
INDICATE FRESH TO STRONG NW WINDS JUST W OF THE BAJA CALIFORNIA 
PENINSULA PARTICULARLY N OF 25N E OF 116W. SEAS ARE BUILDING TO 
11-12 FT NEAR 30N IN NW SWELL. THESE WINDS ARE THE RESULT OF A 
TIGHT PRES GRADIENT BETWEEN LOWER PRESSURE OVER MEXICO AND THE 
ABOVE MENTIONED HIGH PRES. THIS NW FLOW WILL GRADUALLY DIMINISH 
BY SUN. THEN...WINDS ARE FORECAST TO INCREASE TO 20 KT ACROSS 
THE CENTRAL GULF OF CALIFORNIA OR SEA OF CORTEZ BY SUN EVENING 
WITH BUILDING SEAS OF 4-5 FT...AND WILL FURTHER INCREASE TO 25 
KT BY MON EVENING. 

ATTENTION REMAINS FOCUSED ON THE NEXT GULF OF TEHUANTEPEC GAP 
WIND EVENT. GLOBAL MODELS ARE IN GOOD AGREEMENT WITH GOOD RUN TO 
RUN CONSISTENCY SHOWING A GALE BY TUE AT 1800 UTC...WITH A STORM 
BY WED AT 0600 UTC. THE STRONGEST WINDS WILL BUILD SEAS UP TO 22-
23 FT ACCORDING TO WAVEWATCH GUIDANCE BY TODAY. BASED ON THE 
MODEL GUIDANCE...A WARNING WILL LIKELY BE ISSUED ON SUN. THIS 
LATE SEASON GULF OF TEHUANTEPEC WIND EVENT WILL BE INDUCED BY A 
STRONG COLD FRONT PASSING THROUGH THE BAY OF CAMPECHE EARLY NEXT 
WEEK. 

$$
GR