000
AXPZ20 KNHC 291520
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC TUE SEP 29 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.               

...SPECIAL FEATURES...

TROPICAL STORM MARTY CENTERED NEAR 16.2N 101.6W AT 29/1500 UTC 
MOVING ESE AT 3 KT. ESTIMATED MINIMUM CENTRAL PRESSURE 996 MB. 
MAXIMUM SUSTAINED WINDS 50 KT GUSTS TO 60 KT. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS PULSING EVERY FEW HOURS WITHIN 75 
NM OF THE CENTER. MARTY IS WEAKENING AND IS EXPECTED TO BECOME A 
TROPICAL DEPRESSION BY WED EVENING AND DISSIPATE SW OF THE COAST 
OF MEXICO SHORTLY AFTERWARDS. DEEP TROPICAL MOISTURE AND HEAVY 
RAIN SPREADING INLAND ACROSS SW MEXICO MAY PRODUCE LOCALIZED 
FLASH FLOODING AND MUDSLIDES. LARGE SWELL FROM MARTY MAY CAUSE 
DANGEROUS SURF CONDITIONS AND RIP CURRENTS. REFER TO LATEST NHC 
FORECAST/ADVISORY AND PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP2/WTPZ22 KNHC MIATCPEP2/WTPZ32 KNHC FOR MORE DETAILS.

A 1006 MB LOW...POSSIBLE TROPICAL CYCLONE...IS EMBEDDED IN THE 
MONSOON TROUGH NEAR 12N119W. IT IS EXPECTED TO DRIFT SLOWLY NNE 
IN ENHANCED MONSOONAL FLOW THROUGH WED WITH LITTLE CHANGE IN 
INTENSITY. BY THU...ENVIRONMENTAL CONDITIONS WILL BECOME MORE 
FAVORABLE FOR TROPICAL CYCLONE DEVELOPMENT. CROSS-EQUATORIAL S 
SWELL MIXING WITH SW WIND WAVES S OF THE MONSOON TROUGH AXIS 
WILL PRODUCE 8-9 FT SEAS ROUGHLY FROM 05N-12N BETWEEN 110W-122W 
ACROSS S CENTRAL WATERS THE NEXT COUPLE OF DAYS. GFS NUMERICAL 
MODEL INDICATES THE LOW WILL MOVE NE LATER IN THE WEEK TOWARD 
SOUTHERN BAJA CALIFORNIA. 

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

A DISCONTINUOUS MONSOON TROUGH EXTENDS FROM 06N77W TO 08N88W TO 
07N102W...THEN CONTINUES SW OF TS MARTY FROM 15N103W TO LOW PRES 
NEAR 12N119W TO 06N127W TO 13N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF AXIS E OF 87W. 
SCATTERED MODERATE CONVECTION FROM 06N-11N BETWEEN 113W-124W.

...DISCUSSION...

A STATIONARY FRONT EXTENDING FROM 30N129W TO 22N138W WILL BECOME 
DIFFUSE DURING THE NEXT 24 HOURS. 7-8 FT SEAS IN NW CORNER OF 
DISCUSSION AREA WILL SLOWLY SUBSIDE THROUGH WED NIGHT AS WELL. A 
TIGHTENING PRES GRADIENT WSW OF BAJA CALIFORNIA FROM A TROUGH 
ACROSS THE GULF OF CALIFORNIA AND A RIDGE SLOWLY BUILDING ACROSS 
NORTHERN WATERS N OF 20N BETWEEN 115W-130W TO INCREASE NW WINDS 
IN NE PORTION OF DISCUSSION AREA N OF 27N E OF 120W...AND SEAS 
BUILDING TO 7 FT WED AND THU.

GULF OF TEHUANTEPEC...THE PRES GRADIENT IS EXPECTED TO TIGHTEN 
ACROSS THE AREA AS HIGH PRES STRENGTHENS IN EASTERN MEXICO...AND 
RESULT IN A SURGE OF FRESH TO STRONG NE WINDS IN THE GULF LATE 
WED NIGHT...WITH SEAS BUILDING TO 7-8 FT THU MORNING.
  
$$
MUNDELL