000
AXPZ20 KNHC 241528
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON SEP 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES...
HURRICANE MIRIAM CENTERED NEAR 17.7N 112.9W AT 1500 UTC MOVING 
NW OR 305 DEGREES AT 10 KT. THIS GENERAL MOTION WITH A REDUCTION 
IN FORWARD SPEED IS EXPECTED DURING THE NEXT COUPLE OF DAYS. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 958 MB. MAXIMUM SUSTAINED 
WIND SPEED IS 105 KT GUSTS TO 125 KT. ADDITIONAL STRENGTHENING 
IS FORECAST THIS EVENING. NUMEROUS STRONG CONVECTION IS NOTED 
FROM 15N-21N BETWEEN 110W-114W. SEE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 10N85W TO 11N100W TO 9102W...THEN RESUMES 
FROM 13N117W TO 10N130W. ITCZ FROM 10N130W TO 7N140W. SCATTERED 
STRONG CONVECTION WITHIN 200 NM N OF AXIS FROM 92W-97W. 
SCATTERED MODERATE CONVECTION WITHIN 60 NM S OF AXIS FROM
132W-137W.

...DISCUSSION...
UPPER LEVEL RIDGE EXTENDS FROM 25N129W TO 32N132W. AN UPPER 
LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 12N138W. EXCEPT FOR 
SCATTERED HIGH CLOUDS N OF 25N W OF 134W STRONG SUBSIDENCE WITH 
DRY STABLE AIR AT MID AND UPPER LEVELS IS N OF 15N W OF 120W.  
BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION NEAR 18N105W RIGHT 
NEXT TO HURRICANE MIRIAM MAINTAINS LIGHT UPPER LEVEL WIND SHEAR 
AND GOOD DIVERGENT OUTFLOW FOR MIRIAM TO CONTINUE TO DEVELOP.

HIGH PRES RIDGE COVERS AREA N OF 20N W OF 125W. ELY TRADE WINDS 
AROUND 15 KT ON SOUTHEASTERN PERIPHERY OF RIDGE. NW SWELL 
GENERATED BEHIND FRONT NW OF THE AREA BUILD SEAS TO 11 FT ACROSS 
WESTERN PORTIONS OF THE DISCUSSION AREA. 

NLY WINDS 20 KT CONTINUE TO BLOW THROUGH THE GULF OF 
TEHUANTEPEC. WINDS EXPECTED TO DIMINISH TO BELOW 20 KT TUE.

$$
DGS