000
AXPZ20 KNHC 150248
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
0405 UTC TUE OCT 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURES... 
TROPICAL STORM OCTAVE NEAR 24.6N 112.8W AT 0300 UTC MOVING N-NE
AT 10 KT WITH CENTRAL PRES 1002 MB AND WINDS 35 GUSTS TO 45 KT.
NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION WITHIN 120 NM
IN NE QUADRANT.  SCATTERED MODERATE CONVECTION ELSEWHERE WITHIN
120 NM N AND NE QUADRANTS.  OCTAVE EXPECTED TO CONTINUE ITS 
WEAKENING TREND AND BECOME TROPICAL DEPRESSION WITHIN NEXT 12
HOURS.  INCREASING UPPER LEVEL SHEAR...COOLER SST AND INTRUSION
OF DRY AIR INTO SYSTEM HAS FINALLY SPELLED ITS DOOM. SIGNIFICANT
RAINFALL IS EXPECTED OVER SOUTHERN HALF OF BAJA CALIFORNIA AND
NW MEXICO AS OCTAVE CONVECTIVE DEBRIS ADVECTS OVER REGION.  
SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMEP5/WTPZ25 KNHC FOR MORE DETAILS.

TROPICAL STORM PRISCILLA AT 16.2N 116.1W AT 0300 UTC MOVING N AT
7 KT WITH CENTRAL PRES 1003 MB AND WINDS 35 GUSTS TO 45 KT.
NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION WITHIN 150 NM
W SEMICIRCLE.  PRISCILLA STILL REMAINS OVER WARM WATERS AND 
EXPECTED TO HOLD ITS STRENGTH DURING NEXT 12 HOURS BEFORE 
STARTING ITS DOWNWARD TREND.  MODEL GUIDANCE NOW KEEPS PRISCILLA
DRIFTING NW OVER COOLER WATERS WEAKENING TO TROPICAL DEPRESSION
BY WED.  SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH FROM 09N84W TO 07N92W TO 1007 MB LOW PRES AT 11N104W
THEN RESUMES FROM 13N118W TO BEYOND 09N140W.  SCATTERED MODERATE CONVECTION
WITHIN 90 NM OF AXIS E OF 85W.

...DISCUSSION...
ALTHOUGH UPPER LEVEL TROUGH HAS BEEN BEING ABLE TO MOVE STUBBORN
ANTICYCLONE FROM CENTRAL MEXICO...THE DRY STABLE AIR MASS HAS
REACHED NORTHERN PORTIONS OF BAJA CALIFORNIA PENINSULA AND IS
INTRUDING INTO OCTAVE AND EVENTUALLY PRISCILLA THWARTING ANY
CHANCE OF EITHER REACHING HURRICANE STRENGTH.  DRY AND STABLE
AIR ALSO ENTERS E PAC FROM THE E DRYING OUT MONSOON TROUGH AND
HINDERING DEVELOPMENT OF WEAK LOW PRES WHICH FORMED NEAR 11N103W.

...ELSEWHERE AT THE LOWER LEVELS...
HIGH PRES CENTER 1033 MB WELL N OF AREA HAS RIDGE EXTENDING
RIGHT TO THE WESTERN FRINGES OF T.S OCTAVE.  RIDGE MAINTAINS
GENTLE TO MODERATE NE BREEZE AND SEAS 5-6 FT ACROSS BASIN N OF
MONSOON TROUGH W OF 120W.  

WEAK LOW PRES CENTER 1009 MB JUST ANALYZED AT 11N103W WAS
ORIGINALLY FAVORED BY MODEL GUIDANCE FOR POSSIBLE DEVELOPMENT...
HAS NOW FALLEN INTO UNFAVORABLE UPPER LEVEL ENVIRONMENT AND DRY
LOW LEVEL AIR MASS.  ITS CHANCES OF DEVELOPMENT NOW REMAIN 
UNCERTAIN.
 
$$
WALLY BARNES