000
AXPZ20 KNHC 222123
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU NOV 22 2012

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.

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

THE MONSOON TROUGH IS ALONG 07N78W TO 06N85W TO 07N90W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N90W TO 
06N105W TO 09N115W TO 10N140W. SCATTERED MODERATE CONVECTION 
NOTED IN GULF OF PANAMA WITHIN 90 NM EITHER SIDE OF MONSOON 
TROUGH AXIS. SCATTERED MODERATE CONVECTION WITHIN 120 NM N OF 
MONSOON TROUGH AXIS BETWEEN 85W AND 90W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION WITHIN 120 NM S OF ITCZ AXIS AND AND 
90 NM N OF ITCZ AXIS BETWEEN 120W AND 135W.

...DISCUSSION...

GULF OF TEHUANTEPEC...WHILE HIGH PRES OVER THE NORTHERN GULF OF 
MEXICO CONTINUES TO SHIFT EAST...THE PRES GRADIENT BETWEEN THE 
SW GULF OF MEXICO THE GULF OF TEHUANTEPEC IS STILL STRONG ENOUGH 
TO SUPPORT FRESH TO STRONG GAP FLOW. THESE WINDS FLOWING THROUGH 
THE GULF OF TEHUANTEPEC ARE AT A DIURNAL MINIMUM 
CURRENTLY...WITH WIND SPEEDS LIKELY 20 TO 25 KT. THIS WILL 
INCREASE TO 30 KT OVERNIGHT WITH CONTRIBUTIONS FROM DRAINAGE 
EFFECTS. WINDS WILL AGAIN DIMINISH SLIGHTLY BY MIDDAY FRI...BUT 
A REINFORCING SURGE OF COOLER AND DRIER AIR WILL PUSH ACROSS THE 
WESTERN GULF OF MEXICO THROUGH THE CHIVELA PASS AND INTO THE 
GULF OF TEHUANTEPEC BY LATE FRI NIGHT INTO EARLY 
MORNING...INDUCING ANOTHER GALE EVENT COMMENCING AROUND 06 UTC 
SAT AND PERSISTING THROUGH SAT NIGHT INTO EARLY SUN MORNING.

GULF OF PAPAGAYO...ANOTHER GAP WIND EVENT IN THE GULF OF 
PAPAGAYO CONTINUES TO PRODUCE STRONG BREEZE CONDITIONS. AN ASCAT 
PASS FROM 16 UTC INDICATED 20 KT WINDS REACHING AS FAR AS 360 NM 
W OF THE GULF OF PAPAGAYO. THIS EVENT SHOULD CONTINUE FOR THE 
NEXT COUPLE OF DAYS WITH LITTLE CHANGE...BUT WITH THE TYPICAL 
DIURNAL VARIABILITY WITH WEAKER WINDS AND LOWER SEAS DURING THE 
AFTERNOON AND EARLY EVENING.

CLUSTERS OF CONVECTION PERSIST ALONG THE MONSOON TROUGH FROM THE 
GULF OF PANAMA THROUGH 90W. AN ASCAT PASS FROM 1430 UTC 
INDICATED SW WINDS CONVERGING INTO THE MONSOON TROUGH HAVE 
DIMINISHED SLIGHTLY...TO GENERALLY 10 TO 15 KT...ALLOWING THE 
CONVECTION TO DECREASE AS WELL. GLOBAL MODEL CONSENSUS CONTINUES 
TO SHOW A BROAD LOW FORMING ALONG THE MONSOON TROUGH ALONG 08N 
BETWEEN 90W AND 100W THROUGH FRI...BOTH A CAUSE AND AN ENHANCER 
OF OF THE PAPAGAYO PULSES JUST TO THE NORTH OF THIS AREA.  

FURTHER WEST...SCATTEROMETER PASSES FROM EARLIER TODAY INDICATED 
TRADE WINDS HAVE DIMINISHED SLIGHTLY FROM THE LAST COUPLE OF 
DAYS...WITH MAINLY 15 TO 20 KT NOTED FROM 10N TO 20N W OF 125W. 
1025 MB HIGH PRES IS CENTERED NEAR 31N132W WITH A RIDGE 
EXTENDING TO A SE TERMINUS NEAR 20N112W. THE PRES GRADIENT S OF 
THE RIDGE AND N OF THE ITCZ WILL CONTINUE TO SUPPORT THESE WINDS 
ACROSS THE SAME GENERAL AREA THROUGH SAT.

LONG-PERIOD...12-14 SECOND NW SWELL WITH SIGNIFICANT WAVE 
HEIGHTS OF UP TO 12 FEET CONTINUE TO PROPAGATE INTO THE NW 
PORTION OF THE AREA AS MEASURED BY AN OVERNIGHT ALTIMETER PASS. 
THIS SET OF NW SWELL WILL CONTINUE TO PROPAGATE TO THE 
SE...GRADUALLY DECAYING DURING THE NEXT FEW DAYS. THE NEXT 
NOTEWORTHY LONG-PERIOD SWELL EVENT MAY OCCUR BEGINNING NEXT 
WEDNESDAY.

$$
CHRISTENSEN