000
AXPZ20 KNHC 240323
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI AUG 24 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 
0215 UTC.

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

MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO 12N102W TO 1011 MB 
LOW PRES NEAR 12N109W TO 13N134W THEN ITCZ AXIS CONTINUES TO 
BEYOND 11N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED FROM 06N TO 10N BETWEEN 81W AND 90W...FROM 07N TO 11N 
BETWEEN 90W AND 94W AND WITHIN 150 NM S OF TROUGH AXIS BETWEEN 
120W AND 128W. SCATTERED MODERATE CONVECTION CAN BE FOUND WITHIN 
90 NM N SEMICIRCLE OF LOW PRES NEAR 12N109W...AND WITHIN 60 NM N 
OF ITCZ AXIS W OF 136W. 

...DISCUSSION...

A BROAD ANTICYCLONE ALOFT NEAR 27N116W HAS A RIDGE EXTENDING WWD 
ACROSS THE N WATERS TO NEAR 135W. ANOTHER RIDGE EXTENDS FROM THE 
SAME ANTICYCLONE TO THE E AND THEN SE OVER NORTH-CENTRAL MEXICO. 
AN INVERTED TROUGH HAS DEVELOPED S OF THE RIDGE AND RUNS FROM 
20N110W TO 14N116W. BROADLY DIFFLUENT 25 TO 30 KT E-NE FLOW IS 
NOTED S OF THE ANTICYCLONE AND W OF THE TROUGH. WATER VAPOR 
IMAGERY SHOWS MODERATE TO STRONG SUBSIDENCE AND IMPLIED DRY AIR 
MASS N OF 15N W OF 120W. 

A 1010 MB SURFACE LOW PRES SYSTEM LIES NEAR 20N111W WHILE THE 
REMNANTS OF HECTOR ARE STILL SEEN ON SATELLITE IMAGERY NEAR 
19N115W. IN BETWEEN THESE LOWS...A NARROW LINE OF SCATTERED 
MODERATE TO ISOLATED STRONG CONVECTION IS OBSERVED. AN EARLIER  
ASCAT PASS DEPICTED A CLOSED CIRCULATION AROUND THE LOW CENTER 
NEAR 20N111W...WITH WINDS REMAINING AT 10 TO 15 KT. THIS LOW IS 
FORECAST TO GRADUALLY OPEN UP INTO A TROUGH OVER THE NEXT 36-48 
HOURS AS THE SHEAR ALOFT TAKES ITS TOLL ON THE SYSTEM. 

HIGH PRESSURE 1030 MB IS CENTERED NEAR 45N140W WITH WEAK RIDGE 
EXTENDING SE TO NEAR 24N115W. TRADEWINDS ACROSS THE AREA ARE 
GENERALLY IN THE 10 TO 15 KT RANGE...WITH A FRESH BREEZE FOUND 
JUST N OF THE ITCZ AXIS WHERE THE PRESSURE GRADIENT IS TIGHTEST. 
THE LOW PRES THAT WAS EMBEDDED IN THE ITCZ DURING THE PREVIOUS 
DAYS HAS DISSIPATED.

SHOWERS AND THUNDERSTORMS CONTINUE NEAR AN AREA OF DISTURBED 
WEATHER LOCATED A FEW HUNDRED MILES SOUTH-SOUTHWEST OF THE COAST 
OF GUATEMALA.  DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE 
NEXT COUPLE OF DAYS AS IT MOVES GENERALLY WESTWARD AT 10 TO 15 
MPH. THIS SYSTEM HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE 
DURING THE NEXT 48 HOURS.

CROSS-EQUATORIAL SE TO S SWELL WITH COMBINED SEAS TO 8 FT WILL 
PREVAIL OVER THE FORECAST AREA GENERALLY S OF 04N W OF 130W 
THROUGH FRI. A SECOND AREA OF 8 FT SEAS WILL MOVE INTO THE AREA 
S OF 03N BETWEEN 92W AND 115W SAT. 20 KT SE TO S WINDS ARE NOTED 
PER SCATTEROMETER DATA S OF 06N BETWEEN 100W AND 110W AND S OF 
06N W OF 138W.

$$
GR