000
AXPZ20 KNHC 302159
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE OCT 30 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.

...SPECIAL FEATURE...
TROPICAL STORM ROSA CENTERED NEAR 14.4N 116.7W AT 2100 UTC 
MOVING W OR 280 DEGREES AT 5 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 1003 MB. MAXIMUM SUSTAINED WINDS ARE 40 KT GUSTS TO 
50 KT. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION E OF THE 
TROPICAL STORM FROM 11N TO 17N BETWEEN 113W AND 118W. SEE LATEST 
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 
KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 07N78W TO 09N100W TO LOW PRES AT 15N108W 
1011 MB. ITCZ FROM 11N135W TO 10N140W. SCATTERED MODERATE FROM 
05N TO 08N BETWEEN 79W AND 85W...AND FROM 11N TO 15N BETWEEN 
105W AND 108W.

...DISCUSSION...
UPPER LEVEL TROUGH ACROSS THE FAR NW PORTION OF THE DISCUSSION 
AREA FROM 32N131W TO 25N140W. DOWNSTREAM UPPER LEVEL RIDGE 
EXTENDS FROM AN ANTICYCLONIC CIRCULATION CENTERED NEAR 11N130W
THEN NE ACROSS THE BAJA PENINSULA INTO THE SOUTHWESTERN UNITED 
STATES. THE RIDGE DOMINATES MOST OF THE DISCUSSION AREA. 
MODERATE TO STRONG SUBSIDENCE WITH DRY AND STABLE AIR AT THE 
MIDDLE AND UPPER LEVELS IS N OF 20N...INCLUDING THE BAJA 
CALIFORNIA PENINSULA AND NORTH-CENTRAL MEXICO.

1021 MB SURFACE HIGH IS ANALYZED NEAR 30N128. A SURFACE RIDGE 
AXIS EXTENDS SE TO NEAR 25N113W. NE TRADE WINDS REMAIN RATHER 
LIGHT TO THE S AND SW OF THE RIDGE WITH SPEEDS OF 10-15 KT.  

COLD FRONT IS FORECAST TO MOVE ACROSS THE NW PORTION OF THE AREA 
WED MORNING EXTENDING FROM 30N135W TO 28N140W WED. THE FRONT 
WILL MOVE N OUT OF THE AREA THU THEN DISSIPATE. NW SWELL IN THE 
WAKE OF THE FRONT WILL RAISE SEAS TO 9 FT.

A 1011 MB LOW PRES IS ANALYZED ALONG THE MONSOON TROUGH CENTERED 
NEAR 15N108W. SCATTERED MODERATE CONVECTION IS FROM 11N TO 15N 
BETWEEN 105W AND 108W. 

A 1011 MB LOW IS ANALYZED W OF ROSA AT 14N125W WITH NO 
SIGNIFICANT CONVECTION.
 
ANOTHER 1010 MB LOW IS ANALYZED FURTHER W AT 11N130W WITH NO 
SIGNIFICANT CONVECTION. 

NLY WINDS 20-25 KT CONTINUE TO BLOW THROUGH THE GULF OF 
TEHUANTEPEC...HOWEVER THE PRES GRADIENT IS FORECAST TO RELAX AND 
WINDS WILL DECREASE TO LESS THAN 20 KT WED.

$$
FORMOSA