000
AXPZ20 KNHC 092148
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON SEP 09 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES... 
SOUTHERN EXTENT OF WEAK TROPICAL WAVE MOVES INTO GULF OF 
TEHUANTEPEC AND SOUTHERN MEXICO TONIGHT WHERE POOL OF ABUNDANT
TROPICAL MOISTURE SITS.  THIS LIKELY TO FIRE OFF NEW CONVECTION
OVER GUATEMALA...YUCATAN AND FAR SE MEXICO...INCLUDING GULF OF
TEHUANTEPEC AND ADJACENT WATERS.  WAVE EXPECTED TO WEAKEN A IT
MOVES FURTHER W INTO ADVERSE UPPER LEVEL ENVIRONMENT AND INTO 
MUCH DRIER AIR MASS. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 11N86W TO 15N102W TO 13N113W TO 13N135W
TO BEYOND 11N140W.  SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION S OF AXIS TO 04N E OF 85W.  SCATTERED MODERATE
CONVECTION WITHIN 30 NM OF AXIS FROM 113W TO 116W.

...DISCUSSION...
COMPLEX STRUCTURE OF ANTICYCLONES...AS MANY AS FOUR...COVER MOST
OF BASIN ALOFT WITH DRY SUBSIDING AIR N OF 17N W OF 112W. ON THE
EASTERN SIDE OF 110W...ABUNDANT DEEP LAYERS OF TROPICAL MOISTURE
QUICKLY RESPONDING TO UPLIFTING TRIGGERS TO PRODUCE CONVECTION.
WHETHER IT IS A TROPICAL WAVE ALONG 92W OVER SOUTHEASTERN MEXICO
...MID-LEVEL TROUGH NEAR 103W OR DIVERGENT FLOW ALOFT E OF 90W...
CONVECTION POPS UP AND DIES DOWN SOON.  A STEADY FLOW OF E-NE 
UPPER LEVEL WINDS S OF 14N IS CURRENTLY ALMOST FREE OF ANY 
PERTURBATIONS.  

...ELSEWHERE IN THE LOWER LEVELS...
HIGH PRES CENTER 1023 MB REMAINS WELL N OF BASIN NEAR 43N136W 
MAINTAINING FLAT PRES GRADIENT AND KEEPING LIGHT TO GENTLE TRADES
N OF MONSOON TROUGH W OF 120W.

AFOREMENTIONED TROPICAL WAVE CURRENTLY ALONG 92W BRINGS UPLIFTING
MECHANISM TO FIRE UP SCATTERED CONVECTION OVER YUCATAN PENINSULA
E OF ITS AXIS AND SIMILAR WEATHER E OF AXIS N OF 20N. UPPER LEVEL
FLOW REMAINS UNFAVORABLE TO FURTHER ORGANIZATION OF SYSTEM.
GLOBAL MODELS CONTINUE IN AGREEMENT SHOWING A LOW PRES CENTER
FORMS...IT WOULD BE N OF E PAC BASIN. BUT FRESH SW FLOW DOES 
CONVERGE INTO MONSOON TROUGH COVERING AREA S OF 12N FROM 95W TO
115W.   

ELSEWHERE LIGHT TO MODERATE TRADE WINDS PERSIST WITH SEAS 3-5 FT.
SWELL FROM SOUTHERN HEMISPHERE CROSSES EQUATOR TONIGHT REACHING
AS FAR N AS 05N BETWEEN 100W AND 120W EARLY TUE. 

LOOKING AHEAD...CONDITIONS AROUND BASIN REMAIN USUALLY QUIET FOR
THE PEAK OF HURRICANE SEASON.  NO OUTSTANDING FEATURE APPEARS TO 
ATTRACT THE ATTENTION FOR TROPICAL DEVELOPMENT THROUGH THE REST
OF THE WEEK. 

$$
WALLY BARNES