000
AXPZ20 KNHC 221459
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC SUN DEC 22 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.

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC...A COLD FRONT IS MOVING ACROSS THE GULF OF 
MEXICO. THE FRONT WILL REACH THE BAY OF CAMPECHE OVERNIGHT. COLD 
DENSE AIR BEHIND THE FRONT WILL FUNNEL THROUGH THE CHIVELA PASS 
INTO THE GULF OF TEHUANTEPEC. WINDS WILL RAPIDLY INCREASE TO 
NEAR GALE FORCE BY MON MORNING...AND REACH GALE FORCE BY MON 
AFTERNOON. WINDS WILL CONTINUE TO INCREASE MON NIGHT...AND WITH 
THE ADDED COMPONENT OF NOCTURNAL DRAINAGE FLOW DURING THE 
OVERNIGHT HOURS...WINDS ARE EXPECTED TO INCREASE TO STORM FORCE 
LATE MON INTO EARLY TUE. SEAS IN THE GULF OF TEHUANTEPEC WILL 
RAPIDLY BUILD TO 10 FT BY MON AFTERNOON...TO 15 FT MON 
EVENING...17-19 FT MON NIGHT AND REACHING AS HIGH AS 18-20 FT BY 
TUE MORNING. FRESH TO STRONG WINDS WILL EXTEND WESTWARD TO REACH 
AS FAR AS 105W WITH SEAS TO 8 FT. WINDS ARE FORECAST TO DIMINISH 
BELOW STORM FORCE BY TUE EVENING...THEN BELOW GALE FORCE BY WED 
AFTERNOON.

PLEASE REFER TO THE LATEST NHC/TAFB HIGH SEAS FORECAST UNDER 
AWIPS/WMO HEADERS MIAHSFEP2/FZPN03 KNHC FOR MORE DETAILS.

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

THE MONSOON TROUGH EXTENDS FROM 09N83W TO 07N99W WHERE LOW LEVEL 
WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 07N120W TO 
05N125W TO BEYOND 05N140W. SCATTERED MODERATE CONVECTION 
WAS NOTED WITHIN 90 NM OF ITCZ BETWEEN 110W AND 113W. 

...DISCUSSION... 

HIGH PRESSURE OF 1030 MB CENTERED N OF THE AREA NEAR 39N136W 
EXTENDS A RIDGE SE ACROSS THE NORTH WATERS TO NEAR THE 
REVILLAGIGEDO ISLANDS. THE PRES GRADIENT BETWEEN THE RIDGE AND 
LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS MAINTAINING A 
SMALL AREA OF FRESH TO STRONG TRADES FROM 11N TO 15N W OF 132W. 
THE HIGH PRESSURE CENTER WILL REMAIN N OF THE AREA OVER THE NEXT 
COUPLE OF DAYS TO MAINTAIN THE SMALL AREA OF FRESH TO STRONG 
TRADES.

LONG PERIOD NW SWELLS...WITH WAVE PERIODS BETWEEN 19-21 SEC 
ALONG THE LEADING EDGE...ARE MOVING ACROSS THE WESTERN PORTION 
OF THE FORECAST AREA. THESE SWELLS WILL CONTINUE TO PROPAGATE 
SOUTHEASTWARD COVERING MUCH OF THE FORECAST AREA W OF 110W BY 
MON MORNING...AND W OF 100W BY TUE MORNING. 

GULF OF PAPAGAYO...WINDS WILL PULSE OVER THE NEXT COUPLE OF DAYS 
OVER THE GULF OF PAPAGAYO. WINDS WILL PEAK NEAR 25 KT DURING THE 
OVERNIGHT AND EARLY MORNING HOURS WITH THE COMBINATION OF 
NOCTURNAL DRAINAGE FLOW AND TRADES FROM THE CARIBBEAN FUNNELING 
THROUGH THE GAP IN TOPOGRAPHY OF CENTRAL AMERICA.

GULF OF CALIFORNIA...HIGH PRES WILL BUILD ACROSS THE GREAT BASIN 
REGION THROUGH MON WHILE INTENSIFYING. THE PRES GRADIENT BETWEEN 
THE HIGH PRES AND TROUGHING OVER MEXICO WILL STRENGTHEN WINDS 
OVER THE GULF OF CALIFORNIA BY SUN NIGHT WITH NW FLOW OF 20-25 
KT COVERING THE GULF WATERS BETWEEN 23N AND 29N. BY MON 
AFTERNOON...THE NW WINDS ARE FORECAST TO AFFECT THE GULF WATERS 
N OF 24N WITH SEAS BUILDING TO AROUND 6 FT. HIGH PRESSURE OVER 
THE GREAT BASIN REGION WILL START TO WEAKEN MON NIGHT. THIS WILL 
LOOSEN THE PRESSURE GRADIENT OVER THE GULF OF CALIFORNIA AND 
WINDS WILL DIMINISH BELOW 25 KT BY TUE MORNING.
 
$$
AL