000
AXPZ20 KNHC 232204
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON JUL 23 2012

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 
2145 UTC.

...SPECIAL FEATURES...
A 1008 MB LOW PRESSURE EMBEDDED IN THE MONSOON TROUGH NEAR 
10N112W IS THE RESULT OF THE INTERACTION OF A TROPICAL WAVE 
EXTENDING FROM 16N112W TO LOW CENTER AND THE MONSOON TROUGH. 
CONVECTION HAS SLIGHTLY INCREASED THIS MORNING AND IS EXHIBITING 
CYCLONIC CURVATURE. SATELLITE IMAGERY INDICATES THAT SCATTERED 
MODERATE TO STRONG CONVECTION IS WITHIN 150 NM NE SEMICIRCLE OF 
LOW CENTER. THIS FEATURE CONTINUES TO SHOW SIGNS OF 
ORGANIZATION...AND ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR A 
TROPICAL DEPRESSION TO FORM AT ANY TIME DURING NEXT DAY OR SO. 
THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE 
DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD OR W-NW AT 5-10 
KT. 

...TROPICAL WAVES...
ANOTHER TROPICAL WAVE EXTENDS FROM THE GULF OF TEHUANTEPEC TO 
NEAR 10N97W. THE WAVE COINCIDES WITH A BULGE OF MOISTURE AS
DEPICTED IN THE MIMIC/TPW ANIMATION. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 180 NM ON EITHER SIDE 
OF THE WAVE AXIS. THE WAVE WILL CONTINUE SHIFTING WESTWARD OVER 
THE NEXT COUPLE OF DAYS. LATEST GUIDANCE DOES NOT SUGGEST 
TROPICAL CYCLONE DEVELOPMENT WITH THIS FEATURE.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM 07N78W TO 10N93W TO 08N104W 
TO A 1008 MB LOW PRES NEAR 10N112W TO 09N124W. ITCZ AXIS EXTENDS 
FROM 07N129W TO BEYOND 07N140W. SCATTERED MODERATE TO STRONG 
CONVECTIVE PRECIPITATION IS WITHIN 60 TO 90 NM ON EITHER SIDE OF 
12N112W 09N109W 06N113W...AND FROM 04N TO 05N BETWEEN 116W AND 
118W. SCATTERED MODERATE TO

...DISCUSSION...
1036 MB HIGH PRESSURE CENTERED NW OF THE FORECAST AREA NEAR 
42N143W EXTENDS A RIDGE SE TO NEAR 22N112W. THE PRESSURE 
GRADIENT BETWEEN THIS FEATURE AND LOWER PRES ALONG THE MONSOON 
TROUGH AND IN THE VICINITY OF THE ITCZ IS MAINTAINING FRESH 20 
KT TRADE WINDS FROM 10N TO 18N W OF 120W AS DEPICTED BY THE MOST 
RECENT SCATTEROMETER PASSES. THE AREA OF FRESH TRADES WILL 
SLIGHTLY DECREASE IN ABOUT 24 HOURS BUT WILL INCREASE AGAIN IN 
48 HOURS AND THE LOW PRES CURRENTLY NEAR 1ON112W CONTINUES TO 
MOVE WWD. PRES GRADIENT IS FORECAST BY THE COMPUTER MODELS TO 
INCREASE BETWEEN THIS LOW AND THE RIDGE TO THE N. 

THREE SHIP OBSERVATIONS OVER THE NW CORNER OF THE AREA REPORTED 
WINDS BETWEEN 15-25 KT WITH SEAS OF 8-10 FT. THESE CONDITIONS 
ARE FORECAST TO PERSIST OVER THE NEXT 24 TO 48 HOURS AS HIGH 
PRES NW OF THE AREA CONTINUES TO INTENSIFY. IN FACT...THIS 
SYSTEM IS ALREADY PRODUCING GALE FORCE WINDS NEAR THE COAST OF 
CALIFORNIA.

WEAK E GULF OF PAPAGAYO AND NE GULF OF TEHUANTEPEC GAP WIND 
EVENTS ARE OCCURRING...BUT WILL REMAIN AT OR BELOW 20 KT FOR THE 
NEXT COUPLE OF DAYS. 

$$
GR