000
AXPZ20 KNHC 142157
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURES... 
TROPICAL STORM OCTAVE NEAR 24.1N 113.4W AT 2100 UTC MOVING N-NE 
AT 8 KT WITH CENTRAL PRES 999 MB AND WINDS 45 GUSTS TO 55 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 24
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 TWO THIRDS 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 15.7N 115.8W AT 2100 UTC MOVING N AT
8 KT WITH CENTRAL PRES 1001 MB AND WINDS 40 GUSTS TO 50 KT.
NUMEROUS MODERATE AND SCATTERED STRONG CONVECTION WITHIN 150 NM
W SEMICIRCLE.  PRISCILLA STILL REMAINS OVER WARM WATERS AND 
EXPECTED TO STRENGTHEN SLIGHTLY DURING NEXT 24-36 HOURS BEFORE 
STARTING ITS DOWNWARD TREND.  MODEL GUIDANCE NOW KEEPS PRISCILLA
DRIFTING NW OVER COOLER WATERS AFTER 12 HOURS AND WEAKENING TO 
TROPICAL DEPRESSION BY THU.  SEE LATEST NHC FORECAST/ADVISORY
UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS.

...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...
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