000
AXPZ20 KNHC 131516
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                       
1605 UTC SUN JUL 13 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURE...

GULF TEHUANTEPEC...THE COMBINATION OF GAP WIND FLOW INDUCED BY A 
TROPICAL WAVE ALONG WITH NOCTURNALLY ENHANCED WINDS HAVE 
RESULTED IN MINIMAL GALE CONDITIONS OVER THE GULF OF TEHUANTEPEC 
AS DEPICTED ON THE OVERNIGHT ASCAT PASS. WINDS WILL DIMINISH 
BELOW GALE FORCE EARLY TODAY AS THE TROPICAL WAVE SHIFTS W OF 
THE GAP OVER SOUTHERN MEXICO AND THE ADDED COMPONENT OF 
NOCTURNAL DRAINAGE FLOW SHUTS OFF. WINDS WILL FURTHER DIMINISH 
TO NEAR 25 KT THIS AFTERNOON. A SECOND TROPICAL WAVE WILL 
APPROACH THE AREA TONIGHT. WINDS MAY REACH NEAR GALE FORCE 
DURING THE OVERNIGHT HOURS...HOWEVER...THIS TROPICAL WAVE HAS 
NOT BEEN INDUCING AS STRONG GAP WIND FLOW AS THE PREVIOUS ONE. 
WINDS OVER THE GULF OF TEHUANTEPEC WILL DIMINISH TO 20 KT OR 
LESS BY MON AFTERNOON. 
     
...TROPICAL WAVES...                           

TROPICAL WAVE AXIS EXTENDS FROM THE SW GULF OF MEXICO ACROSS S 
MEXICO INTO THE AREA NEAR 16N95W TO 06N96W MOVING W AT AROUND 20 
KT. ACTIVE CONVECTION ASSOCIATED TO THIS WAVE IS SEEN OVER THE 
SOUTHERN PORTION OF THE WAVE WHERE IT IS INTERACTING WITH THE 
MONSOON TROUGH. THIS WAVE HAS HELPED FOR STRONG GAP WIND EVENTS 
OVER THE GULF OF TEHUANTEPEC...REACHING GALE FORCE AS DISCUSSED 
ABOVE...AND THE GULF OF PAPAGAYO WHICH REACHED NEAR GALE FORCE 
FRI NIGHT. 

TROPICAL WAVE AXIS FROM 18N129W TO 09N130W MOVING W AT AROUND 20 
KT. THIS WAVE WAS REPOSITIONED BACK TO THE EAST A LITTLE BIT AS 
PREVIOUS MOVEMENT WAS TOO QUICK. THE WAVE IS RESPONSIBLE FOR A 
NORTHWARD PERTURBATION TO THE ITCZ. ACTIVE CONVECTION ASSOCIATED 
TO THE WAVE IS NOTED NEAR THE SOUTHERN PORTION OF THE WAVE IN 
THE VICINITY OF THE ITCZ. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...  
 
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 05N96W TO 05N100W 
WHERE LOW LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS 
TO 08N105W TO 07N120W TO 12N130W TO 08N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 240 NM OF THE 
MONSOON TROUGH BETWEEN 91W AND 100W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WAS NOTED WITHIN 150 NM N OF THE ITCZ BETWEEN 
100W AND 108W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 
150 NM OF THE ITCZ BETWEEN 126W AND 133W. 
        
...DISCUSSION...                                                

HIGH PRESSURE OF 1026 MB CENTERED N OF THE AREA NEAR 35N135W 
EXTENDS A RIDGE SE TO NEAR 21N113W. THE PRESSURE GRADIENT 
BETWEEN THIS AREA OF HIGH PRESSURE AND LOWER PRESSURE IN THE 
VICINITY OF THE ITCZ AND A TROPICAL WAVE IS MAINTAINING MODERATE 
TO LOCALLY FRESH TRADEWINDS OVER THE WESTERN WATERS. SEAS ARE 
EXPECTED TO INCREASE TO NEAR 8 FT THIS AFTERNOON FROM 13N TO 17N 
BETWEEN 127W AND 130W IN A MIX OF SOUTHERLY SWELL WITH NE SWELL. 
THIS AREA OF 8 FT SEAS IS EXPECTED TO SHIFT WESTWARD AS FRESH 
TRADES INDUCED FROM THE PRESSURE GRADIENT BETWEEN THE TROPICAL 
WAVE AND THE AREA OF HIGH PRESSURE HELPS BUILD SEAS. 

A TROPICAL WAVE MOVING ACROSS CENTRAL AMERICA INTO THE FAR 
EASTERN NORTH PACIFIC IS HELPING INDUCE FRESH TO STRONG GAP 
WINDS INTO THE GULF OF PAPAGAYO. THIS WAVE IS NOT PRODUCING AS 
STRONG A GAP WIND FLOW AS THE PREVIOUS TROPICAL WAVE...AND WINDS 
IN THE GULF OF PAPAGAYO ARE EXPECTED TO DIMINISH TO 20 KT OR 
LESS THIS AFTERNOON. 
        
$$ 
AL