000
AXPZ20 KNHC 072109
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC SAT DEC 07 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURE...
GULF OF TEHUANTEPEC...DENSE COLD AIR BEHIND A STALLED FRONT OVER 
THE GULF OF MEXICO IS FUNNELING THROUGH THE CHIVELA PASS INTO 
THE GULF OF TEHUANTEPEC. THIS IS PRODUCING NEAR GALE WINDS OVER 
THE GULF OF TEHUANTEPEC...AND WINDS WILL INCREASE TO GALE FORCE 
THIS EVENING. A GALE WARNING IS IN EFFECT STARTING AT 08/0000 
UTC AND PERSISTING THROUGH EARLY SUNDAY MORNING WHEN OVERNIGHT 
DRAINAGE EFFECTS WILL CONTRIBUTE TO THE WIND SPEEDS NEAR THE 
COAST. SEAS WILL BUILD TO 11 FT OVERNIGHT. WINDS AND SEAS WILL 
DIMINISH THROUGH SUNDAY AS THE AIRMASS N OF THE AREA MODIFIES... 
WITH WINDS DIMINISHING BELOW 25 KT BY SUN EVENING. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 05N100W WHERE LOW 
LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 
09N125W TO BEYOND 09N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WAS NOTED N OF 04N E OF 83W. SCATTERED MODERATE 
CONVECTION WAS NOTED WITHIN 60 NM OF TROUGH BETWEEN 88W AND 95W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 60 NM S OF ITCZ 
BETWEEN 125W AND 129W. 

...DISCUSSION... 
HIGH PRESSURE OF 1028 MB IS CENTERED JUST N OF THE AREA NEAR 
31N131W WITH RIDGE EXTENDING SE TO NEAR 19N110W. THE PRESSURE 
GRADIENT BETWEEN THE AREA OF HIGH PRESSURE AND LOWER PRESSURE IN 
THE VICINITY OF THE ITCZ IS SUPPORTING A LARGE AREA OF FRESH TO 
STRONG TRADES N OF THE ITCZ TO NEAR 22N AND W OF 120W WITH SEAS 
TO 10 FT. STRONG HIGH PRESSURE WILL REMAIN IN THIS AREA OVER THE 
NEXT COUPLE OF DAYS. THIS WILL MAINTAIN THE TIGHT PRESSURE 
GRADIENT AND THE LARGE AREA OF FRESH TO STRONG TRADES N OF THE 
ITCZ THROUGH MON. 

GULF OF CALIFORNIA...HIGH PRES WILL BUILD OVER THE GREAT BASIN 
OF THE WESTERN UNITED STATES. THIS WILL SET UP A STRONG GRADIENT 
FOLLOWED BY 20 TO 25 KT WINDS FUNNELING INTO THE NORTHERN GULF 
OF CALIFORNIA BY MONDAY. THE STRONG NW WINDS WILL PUSH DOWN THE 
LENGTH OF THE GULF THROUGH LATE MONDAY AND TUESDAY...WITH SEAS 
REACHING 8-9 FT.

GAP WINDS... 
GULF OF PAPAGAYO...WINDS WILL PULSE TO 25 KT...PRIMARILY IN 
OVERNIGHT AND EARLY MORNING HOURS. 

LOOKING AHEAD FOR THE GULF OF TEHUANTEPEC...A STRONGER COLD 
FRONT IS EXPECTED TO MOVE ACROSS THE GULF OF MEXICO MID WEEK. 
WINDS OVER THE GULF OF TEHUANTEPEC WILL INCREASE TO GALE FORCE 
EARLY WED.

$$
AL