000
AXPZ20 KNHC 300306
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
 
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC SUN JUN 30 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 
0315 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION FOUR CENTERED AT 13.7N 103.0W 1006 MB HAS
JUST FORMED 300 NM SW OF ACAPULCO MEXICO.  THE PREVIOUS LOW PRES
CENTER HAD BEEN SLOWLY PULLING CONVECTION CLOSER TO ITS CENTER 
WITH BETTER BANDING AND CURVATURE.  WHILE STILL NOT LARGE BY ANY
MEANS IT IS EXPECTED TO CONTINUE ITS INTENSIFICATION TO TROPICAL
STORM BY DAYBREAK SUNDAY AND DRIFT N CLOSER TO AND THREATEN THE
COAST OF MEXICO WITHIN NEXT 24 HRS.  CONDITIONS ALOFT AND AT
LOWER LEVELS REMAINS FAVORABLE AND IT WOULD TAKE VERY LITTLE TO 
BECOME A TROPICAL STORM.  THE UPPER LEVEL CYCLONE TO THE NW OF 
LOW PRES THAT MAY HAVE BEEN CURTAILING THE OUTFLOW AND SLOWING
DEVELOPMENT BY ADDING UNFORESEEN SHEAR IS MOVING W DIMINISHING 
UPPER LEVEL SHEAR SIGNIFICANTLY.  OVERALL ENVIRONMENT REMAINS
FAVORABLE FOR CONTINUED DEVELOPMENT WITH SEA SURFACE TEMPERATURES
ABOVE 28 DEG AND WARM MOIST AIR MASS SURROUNDING LOW PRES. MODEL
GUIDANCE FAVOR ITS DEVELOPMENT WITH MOST SOLUTIONS POINTING TO A
N DRIFT APPROACHING THE COAST OF MEXICO THEN TURNING NW PARALLEL
TO IT AND EVENTUALLY TURNING W ALONG 20N AWAY FROM COAST. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
MONSOON TROUGH AXIS FROM TROPICAL DEPRESSION FOUR AT 13.7N 103.0W
TO 09N114W TO 10N120W THEN ITCZ TO 11N130 TO BEYOND 07N140W.
SCATTERED MODERATE CONVECTION WITHIN 120 NM OF AXIS FROM 103W TO
133W.  

...DISCUSSION... 
UPPER LEVEL RIDGE CENTERED OVER EL SALVADOR ADVECTS ABUNDANT WARM
TROPICAL AIR MASS UNTO E PAC ALONG MONSOON TROUGH AND THE 
AFOREMENTIONED TROPICAL DEPRESSION. REMNANT CIRCULATION OF COSME
DRIFT W WITHOUT ANY SIGNIFICANT CONVECTION AND EXPECTED TO BE OUT
OF THE AREA EARLY MON.  FRESH TO STRONG WINDS AND 8-10 FT SEAS 
REMAIN OVER ITS N SEMICIRCLE THROUGH ITS PATH OVER E PAC AS 1020
MB HIGH PRES CENTER N OF AREA KEEPS A TIGHT PRES GRADIENT.   

$$
WALLY BARNES