000
AXPZ20 KNHC 141558
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC MON OCT 14 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES...

TROPICAL STORM OCTAVE NEAR 22.6N 113.7W AT 14/1500 UTC OR 150 NM 
SSW OF CABO SAN LAZARO MEXICO MOVING N AT 11 KT. ESTIMATED 
MINIMUM CENTRAL PRESSURE 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 
50 KT WITH GUSTS TO 60 KT. SEE LATEST NHC FORECAST/ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS. 
NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION IS OBSERVED 
WITHIN 120 NM IN THE NE QUADRANT. SCATTERED MODERATE CONVECTION 
IS ELSEWHERE WITHIN 180 NM IN THE N AND NE QUADRANTS. OCTAVE IS 
FORECAST TO WEAKEN AS IT MOVES OVER COOLER SEA SURFACE 
TEMPERATURES WHILE ALSO ENCOUNTERING INCREASING SHEAR ALOFT WITH 
THE OFFICIAL FORECAST BRINGING OCTAVE DOWN TO A TROPICAL 
DEPRESSION BY TUE AFTERNOON...THEN TO A REMNANT LOW BY LATE TUE 
NIGHT. EVEN THOUGH OCTAVE IS FORECAST TO WEAKEN AS IT MOVES 
CLOSER THE SOUTHERN BAJA CALIFORNIA PENINSULA...LOCALLY HEAVY 
RAINFALL IS SPREADING ACROSS THE SOUTHERN PENINSULA AND WILL 
CONTINUE TO DO SO DURING THE NEXT DAY OR TWO.

TROPICAL STORM PRISCILLA NEAR 15.2N 115.5W AT 14/1500 UTC OR 560 
NM SW OF THE SOUTHERN TIP OF BAJA CALIFORNIA MOVING N AT 9 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE 1001 MB. MAXIMUM SUSTAINED 
WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC 
FOR MORE DETAILS. NUMEROUS MODERATE AND SCATTERED STRONG 
CONVECTION IS OBSERVED WITHIN 150 NM IN THE W SEMICIRCLE. 
PRISCILLA IS FORECAST TO MOVE TO THE N THEN NW WHILE 
STRENGTHENING SLIGHTLY OVER THE NEXT 36 HOURS...THEN IS FORECAST 
TO WEAKEN AS IT ENCOUNTERS COOLER SEA SURFACE TEMPERATURES AND A 
MORE STABLE AIRMASS. THE OFFICIAL FORECAST HAS OCTAVE WEAKENING 
TO A REMNANT LOW BY FRI.

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

THE MONSOON TROUGH MONSOON TROUGH FROM 08N82W TO LOW PRES NEAR 
11N103W THEN RESUMES FROM 12N116W TO 09N119W. NO SIGNIFICANT 
CONVECTION NOTED DIRECTLY RELATED TO THE MONSOON TROUGH OR ITCZ 
IS NOTED...HOWEVER SCATTERED MODERATE CONVECTION IS N OF 05N E 
OF 80W...INCLUDING THE GULF OF PANAMA.

...DISCUSSION...

AN UPPER LEVEL TROUGH REMAINS IN PLACE FROM SOUTHERN CALIFORNIA 
THROUGH 32N125W TO 25N125W WITH LITTLE TO NO EASTWARD PROGRESS 
BEING MADE DUE TO A DOMINATE UPPER LEVEL ANTICYCLONE WHICH 
REMAINS ANCHORED OVER CENTRAL MEXICO NEAR 23N100W. DRY AND 
STABLE AIR IS BETWEEN 116W AND 130W IN THE VICINITY OF THE 
TROUGH AXIS WHILE THE ANTICYCLONE CONTINUES TO PROVIDE UPPER 
LEVEL SUPPORT FOR BOTH OCTAVE AND PRISCILLA WHICH ARE ON THE SW-
W PERIPHERY OF IT. 

A SURFACE RIDGE EXTENDS FROM 32N133W TO NW OF OCTAVE NEAR 
25N120W. MODERATE TO FRESH WINDS AND 4-7 FT SEAS DOMINATE THE 
WATERS N OF 10N W OF 120W...EXCEPT FROM 14N TO 18N W OF 136W 
WHERE LINGERING 8 FT SEAS IN NE SWELL ARE GRADUALLY DECAYING IN 
THE WAKE OF THE REMNANT TROUGH OF NARDA WHICH HAVE FINALLY 
SHIFTED W OF 140W.

WINDS ARE FORECAST TO INCREASE TO MODERATE TO FRESH IN THE 
NORTHERN GULF OF CALIFORNIA WITH SEAS BUILDING TO 4-6 FT AFTER 
OCTAVE DISSIPATES WITH A TIGHTENING PRES GRADIENT SETTING UP 
ACROSS THE NW MEXICO REGION.

GULF OF TEHUANTEPEC...THE REMNANTS OF A TROPICAL WAVE ALONG WITH 
HIGH PRES RIDGING OVER THE FAR W GULF OF MEXICO SUPPORTED FRESH 
TO STRONG NORTHERLY WINDS AND RESULTANT SEAS TO 8 FT IN THE GULF 
OF TEHUANTEPEC OVER THE PAST SEVERAL HOURS. WHILE A BRIEF LULL 
IN THESE CONDITIONS LIKELY TODAY TODAY...EXPECT ANOTHER ROUND OF 
FRESH TO STRONG WINDS AND SEAS TO 8 FT IN THE IMMEDIATE GULF OF 
TEHUANTEPEC WATERS IN 24 HOURS BEFORE DIMINISHING DURING THE DAY 
ON TUE.
 
$$
LEWITSKY/CHRISTENSEN