000
AXPZ20 KNHC 230319
TWDEP 

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

...SPECIAL FEATURES...
A 1008 MB LOW PRESSURE EMBEDDED IN THE MONSOON TROUGH NEAR 
10N111W IS THE RESULT OF THE INTERACTION OF A TROPICAL WAVE 
EXTENDING FROM 16N110W TO LOW CENTER AND THE MONSOON TROUGH. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS PRESENT WITHIN 
180 NM E SEMICIRCLE OF THE LOW AND SCATTERED MODERATE EXISTS 
WITHIN 120 NM W SEMICIRCLE OF THE LOW.  EASTERLY VERTICAL SHEAR 
SHOULD REMAIN WEAK TO MODERATE...SEA SURFACE TEMPERATURES VERY 
WARM...AND LOWER LEVEL MOISTURE QUITE ABUNDANT DURING THE NEXT 
COUPLE OF DAYS.  THUS ENVIRONMENTAL CONDITIONS ARE BECOMING MORE 
CONDUCIVE FOR A TROPICAL DEPRESSION TO FORM AND THE SYSTEM HAS 
A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 
HOURS.  OF THE GLOBAL MODELS...ONLY THE GFS SHOWS STRONG 
DEVELOPMENT IN THE NEXT TWO DAYS...WHILE THE OTHER MODELS 
SUGGEST ONLY MODEST INTENSIFICATION.

...TROPICAL WAVES...
ANOTHER TROPICAL WAVE EXTENDS FROM 16N94W TO THE MONSOON TROUGH 
NEAR 09N95W. THE WAVE IS EMBEDDED WITHIN A LARGE AREA OF 
MOISTURE AS DEPICTED ON THE TPW ANIMATION. SCATTERED MODERATE 
AND ISOLATED STRONG CONVECTION EXISTS WITHIN 180 NM OF THE 
MONSOON TROUGH AXIS...THOUGH NO COHERENT CONVECTION IS DIRECTLY 
ASSOCIATED WITH THE LOW AS OF YET.  THE WAVE IS EQUATORWARD OF A 
RATHER LARGE TROPICAL UPPER TROPOSPHERIC TROUGH CENTERED OVER 
CENTRAL AMERICA.  THIS UPPER LOW HAS BEEN PRODUCING MODERATE 
WESTERLY VERTICAL SHEAR OVER THE WEAK LOW.  THE GLOBAL MODELS 
SUGGEST THAT THIS SHEAR SHOULD WEAKEN AND BE REPLACED BY WEAK TO 
MODERATE EASTERLY SHEAR.  CORRESPONDINGLY...SOME TROPICAL 
DEVELOPMENT IS SEEN IN ALL OF THE GLOBAL MODELS THOUGH ONLY THE 
NOGAPS MODEL INDICATES GENESIS AND INTENSIFICATION AS A TROPICAL 
CYCLONE IN THE NEXT TWO DAYS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...THE MONSOON 
TROUGH AXIS EXTENDS FROM 08N77W TO A 1008 MB LOW PRES NEAR 
10N111W AND EXTENDS TO 08N126W THEN ITCZ TO BEYOND 09N140W. 
SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM OF MONSOON 
TROUGH BETWEEN 95W AND 105W.

...DISCUSSION...
1034 MB HIGH PRESSURE CENTERED NW OF THE FORECAST AREA NEAR 
41N143W EXTENDS TO A RIDGE SE TO NEAR 20N112W. 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 17N W OF 125W. THIS AREA OF TRADES 
WILL CONTINUE THROUGH THE FORECAST PERIOD BUT WILL SHRINK TO A 
NEGLIGIBLE AREA OF 20 KT WINDS IN ABOUT A DAY.

WEAK E GULF OF PAPAGAYO AND NE GULF OF TEHUANTEPEC GAP WIND 
EVENTS ARE OCCURRING...BUT REMAIN AT OR BELOW 20 KT FOR THE NEXT 
COUPLE OF DAYS.  THUS THESE ARE NOT INCLUDED WITHIN THE HIGH 
SEAS FORECASTS.  THE NEXT SIGNIFICANT GAP WIND EVENT MAY OCCUR 
NEXT WEEKEND...PRIMARILY IN THE GULF OF PAPAGAYO.  IT IS NOTED 
THAT SHIP PHIN REPORTED 33 KT AT 00Z...THOUGH THIS WOULD APPEAR 
TO BE SUBSTANTIALLY TOO HIGH TO BE CONSIDERED VALID.

NO SIGNIFICANT LONG PERIOD SWELL SHOULD BE REACHING OUR AREA OF 
RESPONSIBILITY FOR AT LEAST THE NEXT SEVERAL DAYS.

$$
LANDSEA