000
AXPZ20 KNHC 192142
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED SEP 19 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 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 09N84W TO 1010 MB LOW PRES AT 
12N97W TO 13N104W TO 09N118W.  ITCZ AXIS EXTENDS FROM 08N124W TO 
06N135W TO BEYOND 07N140W.  SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 120 NM S OF AXIS FROM 124W TO 131W.  SCATTERED 
MODERATE CONVECTION WITHIN 90 NM OF AXIS FROM 95W TO 102W.
 
...DISCUSSION...
BROAD UPPER LEVEL ANTICYCLONE AT 17N127W DOMINATES DRY AIR MASS 
N OF 11N W OF 122W...CONTINUING STRONG SW WIND SHEAR OVER 
REMNANTS OF TROPICAL CYCLONE LANE.  WEAK DEEP LAYER CYCLONE AT 
19N119W EXTENDS DRY SLOT FURTHER E TO 110W.  MOISTURE REMAINS 
CONFINED TO S OF 20N E OF 110W.  SECOND ANTICYCLONE ALOFT JUST 
SW OF GULF OF TEHUANTEPEC ENHANCES MOISTURE FLOW INTO MONSOON 
TROUGH AND BRINGS LIGHT SHEAR TO REGION THAT ALLOWS WEAK 
CIRCULATION TO LOWER PRES IN AREA AND POSSIBLY INTENSIFY IN THE 
NEXT 24-48 HRS.   

ELSEWHERE IN THE LOWER LEVELS...
TWO OTHER SURFACE LOW PRES CENTERS...REMNANTS OF TROPICAL 
CYCLONES KRISTY 1014 MB AT 23N117W AND LANE 1012 MB AT 21N132W 
...HAVE BECOME COMPLETELY DEVOID OF DEEP CONVECTION AND ARE NO 
LONGER CONSIDERED AS POTENTIAL TROPICAL THREATS.  BOTH ARE 
EXPECTED TO DISSIPATE WITHIN THE NEXT TWO DAYS UNDER SUCH A DRY 
AND STABLE ATMOSPHERE. 

HIGH PRES CENTER 1025 MB AT 34N136W KEEP TIGHT GRADIENT AGAINST 
REMNANTS OF LANE WITH STRONG GUSTY NE WINDS IN NW QUADRANT OF 
LANE AND SUBSIDING LINGERING SEAS TO 13 FT.

GAP WINDS...BUILDING HIGH PRES IN WAKE OF GULF OF MEXICO COLD 
FRONT THAT STALLS NEAR BAY OF CAMPECHE FORCE STRONG N BREEZE 
ACROSS CHIVELAS PASS INTO GULF OF TEHUANTEPEC.  LATE NIGHT 
DRAINAGE WINDS MAY ENHANCE GUSTS TO NEAR GALE FORCE IN EARLY 
MORNINGS THROUGH FORECAST PERIOD.
 
$$
WALLY BARNES