000
AXPZ20 KNHC 301527
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 30 2012

CORRECTED TO INCLUDE MENTION OF ASCAT WINDS ASSOCIATED WITH 
SPECIAL FEATURE LOW UNDER DISCUSSION SECTION

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 FEATURE...
TROPICAL STORM ROSA CENTERED NEAR 14.5N 116.5W AT 1500 UTC 
MOVING WNW OR 290 DEGREES AT 6 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 1004 MB. MAXIMUM SUSTAINED WINDS ARE 35 KT GUSTS TO 
45 KT. NUMEROUS STRONG CONVECTION E OF THE TROPICAL STORM FROM 
11N-16N BETWEEN 113W-117W. SEE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 9N84W TO 8N95W TO LOW PRES AT 14N107W TO 
T.S. ROSA AT 14.5N 116.4W CONTINUES TO 10N130W. ITCZ 10N130W TO 
8N140W. SCATTERED MODERATE ISOLATED STRONG FROM 5N-8N BETWEEN 
78W-83W.

...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 14N125W 
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.

SURFACE HIGH PRES RIDGE IS ANALYZED FROM 32N130 SE TO NEAR 
23N115W. NE TRADE WINDS REMAIN RATHER LIGHT TO THE S AND SW OF 
THE RIDGE WITH SPEEDS OF 10-15 KT. SEAS TO 9 FT IN NW SWELLS 
STILL LINGER OVER A SMALL AREA FROM 10N-15N W OF 130W. 

COLD FRONT IS FORECAST TO MOVE ACROSS THE NW PORTION OF THE AREA 
LATE TONIGHT EXTENDING FROM 30N137W TO 28N140W WED. THE FRONT 
EXTEND FROM 30N129W TO 26N140W THU THEN DISSIPATE. NW SWELL IN 
THE WAKE OF THE FRONT WILL RAISE SEAS 8 TO 10 FT.

A 1010 MB LOW PRES IS ANALYZED ALONG THE MONSOON TROUGH CENTERED 
NEAR 14N107W. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 100 
NM SW SEMICIRCLE OF LOW.

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.

$$
DGS