000
AXPZ20 KNHC 020914
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI NOV 02 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...

TROPICAL STORM ROSA CENTERED NEAR 13.3N 118.5W AT 0900 UTC IS 
NEARLY STATIONARY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 
MB. MAXIMUM SUSTAINED WINDS ARE 40 KT GUSTS TO 50 KT. PERSISTENT 
WESTERLY SHEAR CONTINUES TO DISPLACE THE CONVECTION E-SE OF THE 
LOW-LEVEL CENTER. NUMEROUS MODERATE TO STRONG CONVECTION IS 
WITHIN 120 NM SE SEMICIRCLE. THE STORM IS EXPECTED TO REMAIN 
NEARLY STATIONARY AND THROUGH LATE FRIDAY. A LARGE UPPER-LEVEL 
TROUGH IS EXPECTED TO INCREASE VERTICAL SHEAR IN ABOUT 48 HOURS 
AND CAUSE ROSA TO TRANSITION INTO A REMNANT LOW BY EARLY SUN. 
SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/ WMO HEADERS 
MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

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

MONSOON TROUGH FROM 08N82W TO 09N100W TO LOW PRES NEAR 15N110W 
1010 MB. MONSOON TROUGH RESUMES FROM 10N120W TO 11N128W TO LOW 
PRES NEAR 14N130W 1011 MB. ITCZ FROM LOW PRES NEAR 14N130W TO 
11N140W.

...DISCUSSION...

A SHORT WAVE MID LEVEL TROUGH CONTINUES TO PUSH EAST INTO THE 
NORTHERN COAST OF BAJA CALIFORNIA. AN ASSOCIATED SURFACE TROUGH 
N OF 25N BETWEEN 125W AND 130W IS FOLLOWING THE SUPPORTING UPPER 
FEATURE...SLOWLY ERODING A WEAK 1018 MB SURFACE HIGH PRES AREA 
CENTERED NEAR 27N125W. THE SURFACE TROUGH WILL DISSIPATE LATER 
TODAY AS THE SUPPORTING UPPER TROUGH EXITS THE AREA TO THE 
EAST...AND AS ANOTHER WEAK SURFACE HIGH PRES AREA BUILDS NEAR 
26N135W IN THE WAKE OF THE SURFACE TROUGH. 

A FAIRLY ZONAL MID TO UPPER PATTERN THAT FOLLOWS IN THE WAKE OF 
THE SHORT WAVE TROUGH WILL START TO AMPLIFY A LITTLE MORE BY 48 
HOURS AHEAD OF A DEEP LAYER TROUGH DIGGING THROUGH THE N CENTRAL 
PACIFIC. THIS WILL ALLOW THE SURFACE HIGH PRES TO STRENGTHEN 
SOME...BUT ALSO SHIFT NORTH. AREAS OF MOSTLY 15 TO 20 KT TRADE 
WINDS WILL PERSIST S OF THE HIGH PRES...GENERALLY FROM 10N TO 
20N W OF 130W. A COLD FRONT ASSOCIATED WITH THE APPROACHING MID 
TO UPPER LEVEL TROUGH WILL STALL JUST W OF THE DISCUSSION AREA 
BY SUN. LONG PERIOD NW SWELL ASSOCIATED WITH THE FRONT WILL 
REACH A OF 30N AND E OF 140W BY SAT NIGHT WITH SEAS BUILDING TO 
10 FT MON N OF 28N BETWEEN 125W AND 135W.

FURTHER EAST...MODERATE TO FRESH SW FLOW S OF THE MONSOON TROUGH 
ALONG WITH DIVERGENT FLOW ALOFT E OF ROSA IS AIDING SCATTERED 
MODERATE CONVECTION FROM 08N TO 13N BETWEEN 105W AND 110W. 

$$
CHRISTENSEN