000
AXPZ20 KNHC 120308
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC WED JUN 12 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE OVER THE SW CARIBBEAN ALONG 78W EXTENDS FARTHER 
S INTO THE EPAC THROUGH PANAMA TO NEAR 03N78W. THE WAVE IS 
HELPING TO INDUCE SCATTERED TO NUMEROUS SHOWERS AND TSTMS OVER 
PANAMA AND REGIONAL WATERS...INCLUDING THE PANAMA CANAL. THIS 
WAVE COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE PRESENT IN 
TOTAL PRECIPITABLE WATER...AND IS FORECAST TO MOVE THROUGH THE 
SW CARIBBEAN TONIGHT AND WED AND INTO CENTRAL AMERICA WED NIGHT.

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

THE MONSOON TROUGH IS ALONG 07N81W TO 10N100W TO A 1009 MB LOW 
PRES NEAR 11N109W TO 09N125W. THE ITCZ EXTENDS FROM 09N125W TO 
07N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS 
NOTED FROM 07N TO 11N BETWEEN 90W AND 94W. SIMILAR CONVECTION IS 
FROM 11N TO 15N BETWEEN 108W AND 113W.

...DISCUSSION... 

AS PREVIOUSLY MENTIONED...A 1009 MB LOW PRES IS EMBEDDED WITHIN 
THE MONSOON TROUGH NEAR 11N109W MOVING W-NW AT 9 KT. THIS SYSTEM 
IS PRODUCING A DISORGANIZED AREA OF SHOWERS AND ISOLATED TSTMS. 
CONVECTION IS MINIMAL NEAR THE LOW CENTER. HOWEVER...A BROKEN 
BAND OF MODERATE CONVECTION IS NOTED TO THE WEST. ONLY A SLOW 
DEVELOPMENT IS ANTICIPATED BEFORE ENVIRONMENTAL CONDITIONS 
BECOME EVEN LESS FAVORABLE IN THE NEXT FEW DAYS. THIS SYSTEM HAS 
A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 
HOURS. FARTHER NW...THERE IS ANOTHER WEAK 1010 MB LOW PRES 
LOCATED NEAR 14N115. A SWIRL OF MAINLY LOW CLOUDS IS ASSOCIATED 
WITH THIS SECOND LOW.

STRONG HIGH PRES SITUATED NW OF AREA EXTENDS A RIDGE SE OVER THE 
N WATERS TO NEAR 20N115W. THIS SYSTEM IS PRODUCING NE WINDS OF 
20 KT OVER THE NW CORNER OF THE FORECAST AREA PER AN EARLIER  
ASCAT PASS. WINDS ARE EXPECTED TO INCREASE TO 20-25 KT WED NIGHT 
AS PRES GRADIENT SLIGHTLY TIGHTENS THERE. A WEAK SURFACE 
TROUGH...ASSOCIATED WITH AN UPPER LEVEL TROUGH OVER THE NW PART 
OF THE AREA...GOES FROM 30N123W TO 23N131W. THE EDGE OF THE MOST 
RECENT ASCAT PASS SHOWED THE WIND SHIFT ASSOCIATED WITH THE 
TROUGH AXIS. THIS TROUGH WILL DISSIPATE LATER TONIGHT INTO WED 
AS HIGH PRES CONTINUES TO BUILD ACROSS THE N WATERS.

ALOFT...A MIDDLE TO UPPER LEVEL TROUGH IS OVER THE NW PART OF 
THE FORECAST REGION. AN ANTICYCLONE LOCATED NEAR 18N141W EXTENDS 
A RIDGE ENE TO NEAR 20N123W THEN NE TO OVER NORTHERN BAJA 
CALIFORNIA AND NW MEXICO. TO THE EAST OF THE RIDGE...THERE IS 
ANOTHER UPPER LEVEL TROUGH EXTENDING FROM N-CENTRAL MEXICO TO A 
LOW NEAR 21N111W TO 16N120W. MODERATE TO STRONG SUBSIDENCE AND 
IMPLIED DRY AIR MASS COVERS MUCH OF THE AREA N OF 16N W OF 110W. 
AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE BAY OF CAMPECHE 
IN THE GULF OF MEXICO WITH MOISTURE SPREADING WESTWARD ON THE 
SOUTHERN PERIPHERY OF THE RIDGING. EAST-NORTHEASTERLY WINDS 
ALOFT DOMINATE THE REMAINDER OF THE DISCUSSION AREA...MAINLY  
EAST OF 103W WITH AN OVERALL DIFFLUENT ENVIRONMENT SUSTAINING 
CONVECTION NEAR THE TROPICAL WAVE AND ALONG THE MONSOON TROUGH. 

CURRENTLY...NLY SWELLS ACROSS THE N WATERS ARE RAISING SEAS TO 
ABOUT 10 FT BASED ON THE MOST RECENT ALTIMETER PASS. THIS SWELL 
EVENT WILL CONTINUE TO AFFECT THE AREA WITH SEAS SUBSIDING TO 8-
9 FT IN ABOUT 48 HOURS. FINALLY...LONG PERIOD CROSS EQUATORIAL 
SW SWELLS...WITH WAVE PERIOD OF 16-18 SECONDS WILL CONTINUE TO 
IMPACT THE WATERS E OF 115W. A NEW SW SWELL TRAIN WITH LEADING 
EDGE PERIOD OF 17-19 SECONDS IS FORECAST TO SPREAD ACROSS THE 
SOUTH-CENTRAL WATERS ON WED REACHING THE COASTLINE THU NIGHT. 

$$
GR