000
AXPZ20 KNHC 160911
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC SAT MAR 16 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0700 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE ITCZ AXIS WAS ANALYZED FROM 06N87W TO 06N92W TO 02N99W TO 
03N103W THEN CONTINUES FROM 03N113W TO 04N130W TO 04N140W. 
SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM S OF AXIS 
BETWEEN 87W AND 89W.

...DISCUSSION...                                                 
GULF OF TEHUANTEPEC...THE GALE CONDITIONS IN THE GULF OF 
TEHUANTEPEC ARE EXPECTED TO DIMINISH AFTER SUNRISE AS THE WINDS 
IN THE SW GULF OF MEXICO CONTINUE TO WEAKEN AND SHIFT MORE 
EASTERLY...CUTTING OFF THE FLOW THROUGH THE ISTHMUS OF 
TEHUANTEPEC. NE SWELL FROM THE GULF OF TEHUANTEPEC IS MIXING 
WITH CROSS-EQUATORIAL SW SWELL TO PRODUCE AN IMPRESSIVE AREA OF 
8-11 FT SEAS S OF 13N BETWEEN 90W AND 110W. THIS AREA OF SWELL 
WILL SUBSIDE OVER THE WEEKEND AS THE WINDS IN THE GULF 
DIMINISH...WITH SEAS LESS THAN 8 FT EXPECTED BY MON MORNING.

GULF OF PAPAGAYO...THE 0236 UTC ASCAT PASS SHOWED WINDS TO 25 KT 
NEAR THE GULF OF PAPAGAYO WHILE SHIP ZCDG4 REPORTED 30 KT JUST S 
OF THE MOUTH OF THE GULF OF PAPAGAYO AT 0500 UTC. OVERNIGHT SAT 
NIGHT...WINDS WILL BEGIN TO DIMINISH IN THE GULF OF PAPAGAYO. 
THEY ARE EXPECTED TO FALL BELOW A STRONG BREEZE BY SUN 
AFTERNOON. 

GULF OF PANAMA...A FRESH TO OCCASIONALLY STRONG N BREEZE WILL 
CONTINUE IN THE GULF OF PANAMA THROUGH THIS MORNING WITH SEAS TO 
8 FT. WINDS WILL DIMINISH AND SEAS WILL SUBSIDE BY THIS 
AFTERNOON. 

AN UPPER-LEVEL LOW CENTERED NEAR GUADALAJARA MEXICO WILL WEAKEN 
TODAY AS IT IS PICKED UP BY A WEAK TROUGH ALOFT PASSING THROUGH 
THE SOUTHWEST UNITED STATES. PRECIPITABLE WATER IMAGERY SHOWS 
PLENTIFUL LOW-LEVEL TROPICAL MOISTURE EXTENDING NORTHWARD INTO 
SOUTHERN MEXICO ON THE E SIDE OF THE UPPER LOW. SCATTERED 
SHOWERS LIE OVER PORTIONS OF CENTRAL MEXICO AS OBSERVED BY THE 
MEXICO CITY RADAR AND SEEN ON INFRARED SATELLITE IMAGERY. 
OFFSHORE...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE 
NOTED FROM 14N TO 18N BETWEEN 99W AND 106W AND FROM 11N TO 14N 
BETWEEN 103W AND 117W. CONDITIONS SHOULD BECOMES LESS FAVORABLE 
FOR PRECIPITATION HERE OVER THE NEXT FEW DAYS AS THE UPPER LOW 
DISSIPATES AND ITS REMNANTS MOVE NORTHEASTWARD.

THE 1027 MB SUBTROPICAL HIGH LIES NEAR 35N133W. THE PRESSURE 
GRADIENT IS WEAK BETWEEN THE SUBTROPICAL HIGH AND THE ITCZ OVER 
WESTERN WATERS. TRADE WINDS HAVE BEEN REDUCED TO A MODERATE TO 
FRESH NE BREEZE OVER MOST OF THE AREA. THE SMALL AREA OF FRESH 
TO STRONG TRADES MAINLY FROM 10N-20N BETWEEN 115W AND 130W 
OBSERVED BY THE 0600 UTC ASCAT PASS AND AN UNKNOWN SHIP NEAR 
13N116W IS EXPECTED TO DIMINISH AS THE SUBTROPICAL RIDGE WEAKENS 
TODAY. A WARM FRONT IS IMPEDING ON THE SUBTROPICAL HIGH FROM THE 
NW. THIS BOUNDARY EXTENDS FROM A DEEP LAYER LOW FOUND N OF THE 
HAWAIIAN ISLANDS. THE LOW WILL GRADUALLY EDGE EASTWARD...BUT 
REMAIN W OF THE FORECAST AREA THROUGH MON MORNING. THE 
SUBTROPICAL HIGH IS EXPECTED TO REORGANIZE N OF THE WARM FRONT 
BY SUN. 

$$ 
SCHAUER