000
AXPZ20 KNHC 132158
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC SUN OCT 13 2013

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 FEATURES...
TROPICAL STORM OCTAVE AT 19.2N112.7W AT 2100 UTC MOVING N-NW OR
335 DEGREES AT 11 KT WITH CENTRAL PRES 995 MB.  WINDS 55 GUSTS
TO 65 KT.   UPPER LEVEL WIND HAS TURNED MORE FAVORABLE...WARM
SST AND ABUNDANT WARM TROPICAL MOISTURE...OCTAVE MAY INTENSIFY
FURTHER AS IT DRIFT JUST OFF SOUTHERN BAJA CALIFORNIA PENINSULA
W COAST.  BANDS AND CLUSTER OF STRONG CONVECTION HAS IMPACTED 
LAND SECTIONS.  OCTAVE IS EXPECTED TO WEAKEN AFTER 48 HOURS AND
SLOWLY TURN N AND NE BEFORE MOVING INLAND.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH EXTENDS FROM 10N85W TO 110N97W TO 15N106W THEN
RESUME FROM LOW PRES AT 12N117W TO 10N131W THEN ITCZ TO BEYOND
09N140W.  SCATTERED MODERATE CONVECTION WITHIN 180 NM S OF AXIS
E OF 92W.

...DISCUSSION...
UPPER LEVEL TROUGH REMAINS IN PLACE FROM SOUTHERN CALIFORNIA 
THROUGH 32N120W TO 14N130W...MAKING LITTLE EASTWARD PROGRESS AS 
A BROAD AND DOMINANT UPPER LEVEL ANTICYCLONE ANCHORED OVER 
CENTRAL MEXICO. THE UPPER LEVEL TROUGH CONTINUES TO MAINTAIN A 
VERY DRY...STABLE...AND SUBSIDING AIR MASS OVER THE BASIN W OF 
ITS AXIS W OF 120W.

MONSOON TROUGH HAS BEEN BREAKING DOWN BETWEEN 110W AND 120W 
WITH THE DEVELOPMENT OF OCTAVE...AND THE DEVELOPMENT OF SECOND 
LOW PRES AREA NEAR 13N117W. CONVECTION IS A LITTLE MORE ACTIVE 
NEAR THIS LOW THAN NEAR OCTAVE AT THE MOMENT LARGELY DUE TO 
SUPPORT FROM FRESH TO STRONG SW FLOW INTO THE SYSTEM. HOWEVER 
DUE THE PROXIMITY OF THE LOW TO OCTAVE...LITTLE SIGNIFICANT 
DEVELOPMENT IS EXPECT OVER THE NEXT 48 HOURS AS THE LOW DRIFTS 
NE IN THE WAKE OF OCTAVE. ASIDE FROM PERIODIC FLARE UPS OF 
CONVECTION...THE MAIN IMPACT OVER THE NEXT 24 TO 36 HOURS WILL 
REMAIN BROAD 20 TO 25 KT SURGES OF SW FLOW WITHIN 270 NM ON THE 
SE SIDE OF THE LOW CONVERGING TO THE NORTH INTO OCTAVE WITH SEAS
BUILDING TO 10 FT. 

FARTHER W...WEAK REMNANT LOW PRES OF NARDA PERSISTS AT 12N135W.
FRESH WINDS ON NORTHERN SIDE OF CENTER...BUT RESIDUAL MIXED N
AND NE SWELL WITHIN 180 NM ON NW SEMICIRCLE PERSISTS.  LOW PRES
CONTINUE TO WEAKEN OVER NEXT 24 HOURS...EVENTUALLY OPENING INTO
WEAK TROUGH...AS IT DRIFTS SW WITH SEAS SUBSIDING BELOW 8 FT.

MODERATE TO FRESH NW TO N FLOW ALONG PAC COAST OF BAJA 
CALIFORNIA PERSIST TONIGHT BETWEEN HIGH PRES WELL NW OF AREA AND
TROUGH OVER NW MEXICO/SW UNITED STATES. 
 
GULF OF TEHUANTEPEC...REMNANTS OF TROPICAL WAVE OVER W CENTRAL
AMERICA ALONG WITH WEAK HIGH PRES OVER CENTRAL MEXICO HELP USHER
IN FRESH TO STRONG NORTHERLY WINDS AND RESULTANT SEAS TO 8 FT IN
GULF OF TEHUANTEPEC TONIGHT.  CONDITIONS PERSIST THROUGH MON...
DIMINISHING MON NIGHT.
 
$$
WALLY BARNES