000
AXPZ20 KNHC 161520
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC MON DEC 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1400 UTC.

...SPECIAL FEATURE...

GULF OF TEHUANTEPEC...THE 0636 UTC OSCAT PASS SHOWED 45 KT 
NORTHERLY FLOW IN THE GULF OF TEHUANTEPEC THIS MORNING...BUT THE 
PASS ONLY CAPTURED THE WESTERN HALF OF THE AREA OF HIGHEST 
WINDS. STORM CONDITIONS ARE BELIEVED TO HAVE OCCURRED AT 1200 UTC 
BUT ARE EXPECTED DIMINISH BACK TO GALE FORCE THIS MORNING ONCE 
THE PERIOD OF PEAK DIURNAL DRAINAGE FLOW IS OVER. THE GALE EVENT 
IS EXPECTED TO CONTINUE THROUGH AT LEAST THE END OF THE FORECAST 
PERIOD ON WED MORNING. NE SWELL FROM THE EVENT WILL PROPAGATE 
WELL SW OF TEHUANTEPEC...WITH THE AREA FROM 04N TO 14N BETWEEN 
92W AND 110W EXPECTED TO SEE SEAS OVER 8 FT BY TUE MORNING 
BEFORE THE SWELL STARTS TO SUBSIDE. 

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

THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 07N80W TO 08N85W 
TO 06N107W. THE ITCZ AXIS AXIS EXTENDS FROM 06N107W TO 08N126W 
TO 06N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION 
WAS WITHIN 120 NM N OF THE AXIS BETWEEN 101W AND 108W AND 
BETWEEN 110W AND 114W. SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION WAS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 123W 
AND 132W.

...DISCUSSION... 

A 1030 MB HIGH PRESSURE CENTER NEAR 39N134W SENDS A RIDGE AXIS 
SOUTHEASTWARD TO 20N110W. THE MOST RECENT ASCAT AND OSCAT PASSES 
SHOWED AN AREA OF MODERATE TO FRESH TRADE WINDS SW OF THE RIDGE 
GENERALLY WITHIN 300 NM EITHER SIDE OF A LINE FROM 25N140W TO 
10N125W. THIS AREA OF TRADES IS FORECAST TO SHRINK THROUGH TUE 
AS THE DRIVING HIGH PRESSURE CENTER WEAKENS...LOOSENING THE 
PRESSURE GRADIENT BETWEEN IT AND THE ITCZ/MONSOON TROUGH AXIS. 
LONG PERIOD NW SWELL IS MIXING WITH THE ASSOCIATED NE TRADE WIND 
SWELL AND WITH LONG PERIOD CROSS-EQUATORIAL SOUTHERLY SWELL. THE 
RESULT IS COMBINED SEAS OF 7-11 FT WITHIN THIS AREA THAT ARE 
EXPECTED TO SHIFT SOUTHEASTWARD AND GRADUALLY DIMINISH. THE 
LEADING EDGE OF THE NW SWELL HAS PERIODS IN THE 18-20 SECOND 
RANGE AND WILL PASS S ALONG THE BAJA CALIFORNIA COAST TODAY AND 
THE SE MEXICAN COAST BETWEEN CABO CORRIENTES AND THE GULF OF 
TEHUANTEPEC TUE. 

GULF OF CALIFORNIA...THE 0640 UTC OSCAT PASS SHOWS WINDS TO 20 
KT PERSISTING IN THE GULF N OF 25N THIS MORNING...WITH A STRONG 
BREEZE CONTINUING TO SPILL THROUGH SOME OF THE MOUNTAIN PASSES 
OF THE BAJA CALIFORNIA PENINSULA INTO THE OPEN PACIFIC WATERS 
CLOSE TO THE COAST. THE TIGHT PRESSURE GRADIENT BETWEEN RIDGING 
EXTENDING FROM STRONG HIGH PRESSURE OVER THE U.S. GREAT BASIN 
REGION AS WELL AS FROM THE EASTERN PACIFIC AND PRONOUNCED 
TROUGHING ACROSS NW MAINLAND MEXICO IS DIMINISHING AS BOTH THE 
RIDGING AND THE TROUGHING WEAKENS. WINDS IN THE GULF ARE 
EXPECTED TO GRADUALLY DIMINISH TO 20 KT OR LESS BY THIS EVENING. 
      
GULF OF PAPAGAYO...NE-E WINDS ARE EXPECTED TO PULSE AT 20-25 KT 
DURING THE PERIOD MAXIMUM NOCTURNAL DRAINAGE THROUGH THE END OF 
THE FORECAST PERIOD WED MORNING. NE WIND WAVES FROM PAPAGAYO 
WILL COMBINE WITH NW SWELL FROM THE GULF OF TEHUANTEPEC EVENT TO 
BUILD SEAS TO 9 FT TUE MORNING AND WED MORNING.

$$
SCHAUER