000
AXPZ20 KNHC 120917
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC FRI DEC 12 2014

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 
0900 UTC.  
       
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
           
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 05N110W. THE ITCZ AXIS 
CONTINUES FROM 05N110W TO 05N120W TO LOW PRES 1010 MB NEAR 
09135W TO 07N140W. A CLUSTER OF MODERATE TO ISOLATED STRONG 
CONVECTION IS WITHIN 180 NM N OF MONSOON TROUGH BETWEEN 100W AND 
105W.

...DISCUSSION...

A COLD FRONT EXTENDING FROM SOUTHERN CALIFORNIA TO 30N125W TO 
22N130W WILL CONTINUE TO MOVE EASTWARD AND THROUGH THE BAJA 
PENINSULA BY EARLY SUNDAY. STRONG WINDS ARE NOTED IN RECENT 
SCATTEROMETER SATELLITE DATA SHOWED STRONG SW WINDS WITHIN 240 
NM AHEAD OF THE FRONT N OF 25N...AND A BROAD AREA OF STRONG NW 
WINDS BEHIND N OF 25N AS FAR WEST AS 135W. THE LONG FETCH AND 
DURATION OF THE NW WINDS HAS GENERATED SEAS AS HIGH AS 21 FT N 
OF 28N W OF THE FRONT...AS VERIFIED BY RECENT SHIP REPORTS. THE 
WINDS WILL DIMINISH QUICKLY THROUGH THE NEXT 12 TO 18 HOURS AS 
WEAK HIGH PRES BEHIND THE FRONT BUILDS EASTWARD. THE HIGH SEAS 
WILL PERSIST WITH NW SWELL IN EXCESS OF 12 FT ENCOMPASSING MUCH 
OF THE AREA N OF 18N W OF 120W WITHIN 24 HOURS WITH PERIODS OF 
12 TO 15 SECONDS. SOME OF THIS SWELL IS STARTING TO REACH THE 
COAST OF BAJA CALIFORNIA NORTE THIS MORNING. SHOWERS MAY DEVELOP 
ALONG THE BAJA CALIFORNIA NORTE COAST LATER TODAY AS THE 
SOUTHERN EXTENT OF THE NEGATIVELY TILTED TROUGH NORTH OF 
THE AREA MOVES INLAND.
 
LOOKING AHEAD...ANOTHER COLD FRONT WILL MOVE E OF 140W N OF 22N 
BY LATE SAT/EARLY SUN. GLOBAL MODELS INDICATE THIS WILL BE 
WEAKER THAN THE CURRENT SYSTEM WITH WINDS REMAINING 20 KT OR 
LESS JUST AHEAD AND BEHIND THE FRONT. ANOTHER NW SWELL TRAIN 
WITH COMBINED SEAS REACHING NEAR 20 FT WILL FOLLOW HOWEVER. 
GLOBAL MODELS 

FARTHER TO THE SOUTH...A WEAK BUT WELL DEFINED 1010 MB LOW PRES 
IS CENTERED ALONG THE ITCZ NEAR 09N135W. CONDITIONS ARE VERY DRY 
OVER WEST OF 115W N OF THE ITCZ DUE TO SUBSIDENT NW FLOW ALOFT 
AND NO SIGNIFICANT CONVECTION IS OBSERVED WITH THIS LOW PRES. 
EARLIER SCATTEROMETER PASSES INDICATED WINDS TO 20 KT WERE 
ACTIVE ON THE NORTHERN PERIPHERY OF THIS LOW. THE LOW IS 
EXPECTED TO WEAKEN TO A TROUGH WITHIN 24 HOURS...BUT FRESH TRADE 
WILL COVER MUCH OF THE AREA W OF 130W N OF THE ITCZ AS RIDGING 
BUILDS N OF THE AREA BEHIND THE FRONT.

A CLUSTERS OF THUNDERSTORMS IS NOTED NEAR 16N1150W...AT THE BASE 
OF A SHARP UPPER TROUGH REACHING FROM THE SOUTHERN TIP OF THE 
BAJA CALIFORNIA PENINSULA TO 17N113W. A FEW MORE SHOWERS AND 
THUNDERSTORMS ARE NOTED ON SATELLITE IMAGERY N OF THE MONSOON 
TROUGH NEAR 08N101W...RELATED DIVERGENCE ALOFT BETWEEN AN UPPER 
TROUGH LOCATED W OF THE AREA AND UPPER RIDGING OVER THE SW 
CARIBBEAN. MODEL OUTPUT INDICATES CONDITIONS SUPPORTING PULSES 
OF CONVECTION IN THIS AREA WILL REMAIN IN PLACE FOR ANOTHER 24 
TO 36 HOURS.

GULF OF TEHUANTEPEC...FRESH TO STRONG NE WINDS WILL CONTINUE TO 
PULSE MAINLY N OF 14N IN THE REGION THROUGH SUN FROM A MODERATE 
PRES GRADIENT ACROSS SOUTHERN MEXICO ASSOCIATED WITH HIGHER 
PRESSURE OVER THE WESTERN GULF OF MEXICO. PEAK WINDS WILL BE IN 
EXCESS OF 25 KT IN LATE NIGHT AND EARLY MORNING HOURS...AIDED BY 
NOCTURNAL DRAINAGE FLOW. SEAS WILL BE 8-10 FT AT TIMES. 

GULF OF PAPAGAYO...FRESH TO STRONG NE TO E GAP WINDS WILL 
CONTINUE TO PULSE THE NEXT FEW DAYS...PEAKING IN THE EARLY 
MORNING DURING MAX NOCTURNAL DRAINAGE FLOW. SEAS WILL BUILD TO 7 
FT DOWNSTREAM OF THE GULF REGION.
   
$$
CHRISTENSEN