000
AXPZ20 KNHC 090241
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED OCT 9 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 FEATURE... TROPICAL DEPRESSION NARDA AT 16.9N 128.2W
AT 0300 UTC MOVING W-NW OR 295 DEG AT 10 KT.  MAXIMUM SUSTAINED 
WIND CONTINUE TO DIMINISH NOW AT 30 GUSTING TO 40 KT AND CENTRAL
PRES OF 1008 MB.  CONVECTION HAS DIMINISHED SIGNIFICANTLY IN 
LAST 12 HRS WITH ONLY SCATTERED MODERATE CONVECTION WITHIN 45 NM
S SEMICIRCLE.  NARDA APPROACHING VERY DRY AIR MASS AND LOST ITS
OUTFLOW.  NARDA IS DOWNGRADED TO TROPICAL DEPRESSION AND EXPECTED
TO BECOME POST TROPICAL LOW PRES WITHIN THE NEXT 12-24 HRS.
REFER TO FORECAST ADVISORY UNDER WMO/AWIPS HEADERS WTPZ24
KNHC/MIATCMEP4 FOR ADDITIONAL DETAILS. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH EXTENDS FROM 15N92W TO LOW PRES 1009 MB AT 12N98W
TO LOW PRES 1009 MB AT 12N108W TO 11N115W TO 16N119W THEN RESUME
FROM 13N129W TO BEYOND 10N140W.  SCATTERED MODERATE ISOLATED
STRONG CONVECTION WITHIN 180 NM N OF AXIS E OF 92W AND FROM 109W
TO 118W.

...DISCUSSION...
STRONG UPPER TROUGH FROM 32N124W TO BEYOND 30N140W BRINGS ZONAL
AND VERY DRY AND STABLE AIR MASS INTO BASIN N OF 17N W OF 109W...
INCLUDING EFFECTS OVER T.D. NARDA.  BROAD UPPER LEVEL RIDGE
CENTERED AT 19N111W BRINGS ABUNDANT TROPICAL MOISTURE INTO E PAC S OF 14N
E OF 118W...ENOUGH TO SUSTAIN PLENTY OF MODERATE TO STRONG
CONVECTION ALONG MONSOON TROUGH. 

...ELSEWHERE AT LOWER LEVELS...
BROAD AND HEALTHY 1034 MB HIGH PRES CENTER AT 40N144W EXTEND
SURFACE RIDGE TO 25N116W AND SUPPORT FRESH NE TRADES N OF 15N
W OF 125W.  HIGH PRES MOVES W AND TIGHTENS PRES GRADIENT WITH
WEAK SURFACE TROUGH OVER CENTRAL CALIFORNIA INCREASING WINDS AND 
BRINGING NW SWELLS INTO N PART OF BASIN.  

MODEL GUIDANCE PAYS ATTENTION TO INTENSITY OF CURRENT LOW PRES 
1009 MB EMBEDDED IN MONSOON TROUGH THAT EVENTUALLY BREAKS OFF
AND MOVES W-NW.  UPPER LEVEL CONDITIONS ARE FAVORABLE FOR SLOW
INTENSIFICATION AND WILL BE MONITORED FOR SIGNS OF TROPICAL
ORGANIZATION. 

GULF OF TEHUANTEPEC...WINDS DIMINISHING SIGNIFICANTLY AS COLD
FRONT OVER GULF OF MEXICO MOVES FURTHER E AND WINDS VEER E-SE 
OVER BAY OF CAMPECHE.  WINDS EXPECTED TO BECOME UNDER 20 KT WED.  
 
GULF OF CALIFORNIA...LIGHT SW WINDS EXPECTED TO INCREASE LATE
WED OR THU BUT DIMINISH BY END OF FORECAST PERIOD.

WALLY BARNES