000
AXPZ20 KNHC 030250
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT NOV 3 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURE...

TROPICAL STORM ROSA CENTERED NEAR 12.7N 119.4W AT 0300 UTC MOVING
WSW 4 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM 
SUSTAINED WINDS 40 KT GUSTS TO 50 KT. PERSISTENT WESTERLY SHEAR 
CONTINUES TO DISPLACE THE CONVECTION E OF THE LOW-LEVEL CENTER. 
NUMEROUS MODERATE TO STRONG CONVECTION LOCATED WITHIN 75 NM NE 
SEMICIRCLE. THE STORM IS EXPECTED TO DRIFT SLOWLY W-NW AND WEAKEN
THROUGH MON...BECOMING A POST-TROPICAL 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...

THE MONSOON TROUGH EXTENDS FROM 09N85W TO 08N95W TO 11N110W... 
THEN RESUMES W OF T.S. ROSA FROM 12N120W TO 10N127W. THE ITCZ 
EXTENDS FROM 10N127W TO 09N133W TO 11N140W. SCATTERED MODERATE 
CONVECTION WITHIN 60 NM S OF TROUGH BETWEEN 89W AND 102W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 14N TO 16N 
BETWEEN 104W AND 111W. SCATTERED MODERATE CONVECTION WITHIN 90 S 
OF BOUNDARY BETWEEN 121W AND 131W.

...DISCUSSION...

BROAD SUBTROPICAL RIDGE ANCHORED BY 1019 MB HIGH CENTERED NEAR 
28N132W EXERTS ITS INFLUENCE OVER LARGE PORTION OF THE DISCUSSION
AREA N OF 18N W OF 110W. ASCAT SCATTEROMETER DATA SHOWS LIGHT TO 
MODERATE WINDS N OF 20N...AND MODERATE TO FRESH WINDS BETWEEN 20N
AND THE ITCZ/MONSOON TROUGH DUE TO A STRONGER PRES GRADIENT N OF 
THE CONVERGENCE ZONE. EARLIER ASCAT PASS AT 1805 UTC SHOWED FRESH
TO STRONG NE WINDS ON THE NW PERIPHERY OF T.S. ROSA EXTEND ABOUT 
150 FROM THE CENTER...WITH MODERATE TO FRESH WINDS EVIDENT 
CLOSER TO THE CENTER IN THE SW QUADRANT.

1623 UTC ASCAT PASS SHOWED FRESH TO STRONG N-NE WINDS DOWNSTREAM 
FROM THE GULF OF TEHUANTEPEC IN A NARROW SWATH ABOUT 40 NM WIDE 
EXTENDING FROM THE COASTLINE NEAR 16N95W TO 14.5N96W. WINDS IN 
THE SW GULF OF MEXICO ARE ANTICYCLONIC AROUND A HIGH NEAR 27N89W 
WHICH DOES NOT SUPPORT A SIGNIFICANT GAP WIND EVENT OTHER THAN 
DIURNAL EPISODES OF GUSTY WINDS SPILLING THROUGH THE ISTHMUS DUE 
TO HIGH PRES NE AND LOWER PRES SW ACROSS THE AREA. EXPECT THIS 
TREND TO CONTINUE THROUGH SAT NIGHT WHILE HIGH PRES REMAINS 
STATIONARY OVER THE NE GULF OF MEXICO...BUT COMBINED SEAS WILL 
BE WELL BELOW 8 FT IN TEHUANTEPEC THROUGH THE WEEKEND...WITH A 
MAX OF ABOUT 6-7 FT DURING PEAK WINDS.

BROAD AREA OF LOW PRES ASSOCIATED WITH AN ACTIVE NEAR-EQUATORIAL 
CONVERGENCE ZONE WILL PERSIST THROUGH MON FROM THE WEST COAST OF 
MEXICO NEAR 20N105W W-SW TO AROUND 10N130W...ANCHORED BY REMNANT 
LOW POST-TROPICAL ROSA. THIS WILL ALLOW MODERATE TO FRESH E-NE 
TRADE WINDS TO PERSIST WITHIN 200 NM N OF THE CONVERGENCE ZONE...
AND LIGHT TO MODERATE CROSS-EQUATORIAL SOUTHERLY FLOW SOUTH OF 
THE BOUNDARY. A FRONTAL BOUNDARY WILL BECOME STATIONARY NW OF 
THE AREA SUN. LONG PERIOD NW SWELL ASSOCIATED WITH THE FRONT WILL
REACH FAR NW PORTION BY SAT NIGHT WITH SEAS BUILDING TO 10 FT MON
N OF 28N BETWEEN 125W AND 135W. LITTLE CHANGE EXPECTED ELSEWHERE.

$$
MUNDELL