000
AXPZ20 KNHC 151526
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC FRI MAR 15 2013

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE ITCZ AXIS WAS ANALYZED FROM 02N120W TO 04N130W TO 02N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 60 NM EITHER SIDE 
OF ITCZ W OF 130W. 

...DISCUSSION...                                               
GULF OF TEHUANTEPEC...A GALE WARNING CONTINUES IN THE GULF OF 
TEHUANTEPEC THIS MORNING. RECENT LAND BASED OBSERVATIONS FROM 
IXTEPEC (MMIT)HAVE BEEN 25 KT SUSTAINED WITH GUSTS TO 35 KT AND 
PEAK WINDS TO 40 KT. THIS IS INDICATIVE OF STRONG GALE 
CONDITIONS OVER THE WATERS DUE TO HIGHER MOMENTUM AIR MIXING TO 
THE OCEAN SURFACE. AN OSCAT PASS FROM 0630 UTC ALSO SHOWED WINDS 
TO 40 KT WITH A PLUME OF WINDS IN EXCESS OF 25 KT REACHING AS 
FAR AS 240 NM DOWNSTREAM OF THE GULF OF TEHUANTEPEC TO THE S AND 
SW. SEAS ARE ESTIMATED TO BE AS HIGH AS 15 FT WITHIN 75 NM 
OFFSHORE. THE GALES ARE DUE TO A LARGE MASS OF COLD AIR OVER THE 
GULF OF MEXICO FILTERING THROUGH THE GAP. THE AIRMASS WILL 
MIGRATE EASTWARD ALLOWING WINDS OVER THE SW GULF TO VEER MORE 
SE. THIS ALONG WITH THE FACT THAT THE AIRMASS WILL MODIFY WILL 
ALLOW WINDS TO DIMINISH BELOW GALE FORCE THROUGH THE GULF OF 
TEHUANTEPEC SAT. WHILE GLOBAL MODELS INDICATE THE WINDS 
DIMINISHING BELOW GALE FORCE TONIGHT...THE OFFICIAL FORECAST 
WILL HOLD THE WINDS TO GALE FORCE THROUGH EARLY SAT DUE TO 
LOCAL NOCTURNAL DRAINAGE EFFECTS.

GULF OF PAPAGAYO AND FONSECA...ENHANCED TRADE WIND FLOW OVER THE 
SW CARIBBEAN WILL ALLOW FRESH TO STRONG GAP FLOW TO PERSIST 
THROUGH THE GULF OF PAPAGAYO MAINLY IN THE EARLY MORNING HOURS 
THROUGH SAT. EARLIER SCATTEROMETER ALSO INDICATED FRESH TO 
STRONG N TO NE FLOW OFF THE GULF OF FONSECA.

THE COMBINED EFFECT OF THESE GAP WINDS HAS PRODUCED A LARGE AREA 
OF NE TO E SWELL AS FAR W AS 110W S OF 14N.

GULF OF PANAMA...SHIP OBSERVATIONS FROM THE CANAL AND NEAR ITS 
CARIBBEAN TERMINUS INDICATE FRESH N FLOW FROM THE SW CARIBBEAN 
INTO THE GULF OF PANAMA. 

DIVERGENCE ALOFT ASSOCIATED WITH AN UPPER-LEVEL LOW OVER THE 
SOUTHERN TIP OF THE BAJA PENINSULA IS ENHANCING CLUSTERS OF 
CONVECTION OVER THE AREA FROM 11N TO 14N BETWEEN 100W AND 110W. 
A SURFACE RIDGE CENTERED NEAR 33N130W IS MAINTAINING AN AREA OF 
FRESH TRADE WINDS NEAR THE ITCZ W OF 135W. A TIGHT PRES GRADIENT 
ON THE EAST SIDE OF THE RIDGE IS PRODUCING A BROAD AREA OF FRESH 
TO STRONG NW TO N WINDS OFF SOUTHERN CALIFORNIA N OF THE 
DISCUSSION AREA...WHICH IS PRODUCING SWELL TO 7 FT OVER THE AREA 
N OF 27N BETWEEN 118W AND 125W...BUILDING TO 8 FT IN N SWELL BY 
LATE SUN.

$$ 
CHRISTENSEN