000
AXPZ20 KNHC 242317 AAA
TWDEP 

TROPICAL WEATHER DISCUSSION...AMENDED                            
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC WED JUL 24 2013

...AMENDED FOR HIGH TROPICAL CYCLONE FORMATION

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.

...SPECIAL FEATURES...                                          
A 1006 MB SURFACE LOW IS CENTERED NEAR 14N120W MOVING W-NW AT 15 
KT AND IS SLOWLY BECOMING DETACHED FROM THE MONSOON TROUGH. OVER 
THE PAST 6 TO 12 HOURS CONVECTION HAS BECOME BETTER ORGANIZED 
AND IS ARRANGED IN TWO BANDS...ONE EXTENDING IN THE NW 
SEMICIRCLE WITHIN NE FLOW...AND THE OTHER IN THE SE SEMICIRCLE 
WITHIN S-SW FLOW. A RECENT ASCAT-B SCATTEROMETER PASS SHOWED THE 
STRONGEST WINDS WITH THE SYSTEM WITHIN 45 NM OF THE POINT 
15N118.5W. THIS AREA EXHIBITED WINDS IN THE 25 TO 30 KT RANGE 
WITH HIGHER GUSTS LIKELY. THE CONVECTION EXHIBITS VERY COLD 
CLOUD TOPS WITH TEMPERATURES OF -75C TO -80C NOTED. THE LOW IS 
FORECAST TO TRACK W-NW OVER THE NEXT SEVERAL DAYS AND HAS A HIGH 
CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE MONSOON TROUGH EXTENDS FROM 09N79W TO 08N89W TO 10N98W TO 
LOW PRES NEAR 09N108W TO 14N114W. AXIS RESUMES NEAR 12N124W TO 
10N140W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 05N TO 07N 
BETWEEN 79W AND 90W...AND FROM 08N TO 12N BETWEEN 130W AND 140W. 
SCATTERED MODERATE CONVECTION IS FROM 11N TO 19N BETWEEN 100W 
AND 106W...AND FROM 11N TO 15N BETWEEN 106W AND 111W.

...DISCUSSION...                                                

A NORTHEASTWARD DRIFTING 1025 MB HIGH PRESSURE CENTER IS LOCATED 
WELL N OF THE DISCUSSION AREA NEAR 42N139W WITH A SURFACE RIDGE 
EXTENDING SOUTHEASTWARD. THE RIDGE CONTINUES TO INFLUENCE THE NW 
PORTION OF THE AREA N OF 18N W OF 132W. A VERY WEAK PRESSURE 
GRADIENT DOMINATES THE REMAINDER OF THE N PORTION OF THE AREA... 
PARTICULARLY N OF 20N E OF 130W. A WEAK SURFACE TROUGH IS 
ANALYZED FROM 26N130W TO 30N128W. THE TROUGH IS EXPECTED TO 
WEAKEN AS A HIGH PRESSURE CENTER FORMS IN THE VICINITY OF 
29N124W BY EARLY THURSDAY. TRADE WINDS IN THE RANGE OF 15 TO 20 
KT ARE NOTED SOUTH OF THE RIDGE AND NORTH OF THE MONSOON TROUGH 
ELSEWHERE W OF 125W.

E WINDS OF 15 TO 20 KT CONTINUE ACROSS THE GULF OF PAPAGAYO AND 
INTO THE ADJACENT COASTAL WATERS TO THE WEST. THE WINDS ARE 
GREATEST DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE 
ASSISTANCE OF THE NOCTURNAL DRAINAGE FLOW.

CROSS EQUATORIAL S AND SW SWELLS TO 8 FT ARE FORECAST TO MOVE 
INTO THE AREA S OF 03N BETWEEN 105W AND 123W WITHIN 36 HOURS AND 
SPREAD SLOWLY N INTO FRIDAY. 

$$
HUFFMAN