000
AXPZ20 KNHC 072202
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
2205 UTC SAT SEP 07 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.
                
...SPECIAL FEATURES...                                     
TROPICAL DEPRESSION LORENA AT 23.9N 111.9W AT 2100 UTC MOVING
W-NW AT 3 KT WITH CENTRAL PRES 1008 MB.  MAXIMUM SUSTAINED WIND
SPEED 25 GUSTS TO 35 KT.  SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION WITHIN 30 NM OF CENTER HAS DIMINISHED CONSIDERABLY IN
LAST 6 HOURS.  LORENA EXPECTED TO BECOME REMNANT LOW TONIGHT...
AND DISSIPATE BY LATE SUN.  ASSOCIATED SEAS SUBSIDE BELOW 8 FT
LATE SUN NIGHT.  SEE LATEST NHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXITS COSTA RICA LATE TONIGHT INTO E PAC WITH
SCATTERED MODERATE CONVECTION ALONG IT AXIS N OF 08N.  MODEL 
GUIDANCE FOLLOWS WAVE THROUGH SUN AND INCREASES SW WINDS S OF
MONSOON TROUGH...BUT WAVE ITSELF BECOMES ILL-DEFINED BY THEN.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 14N91W TO LOW PRES 1010 MB AT 12N97W TO
15N110W TO 12N124W TO BEYOND 11N140W. SCATTERED MODERATE ISOLATED
STRONG CONVECTION WITHIN 180 NM S OF AXIS FROM 104W TO 120W.

...DISCUSSION... 
WEAKENING UPPER LEVEL ANTICYCLONE AT 25N132W BECOMING PART OF 
EXPANDING SECOND ANTICYCLONE CURRENTLY AT 23N114W...JUST SW OF
T.D. LORENA.  BOTH GYRES MAINTAIN VERY DRY SUBSIDING AIR MASS
OVER E PAC N OF 14N W OF 114W.  THIS DRY AIR INTRUDING INTO
LORENA AND HAS DIMINISHED ITS CONVECTION CONSIDERABLY WITHIN
LAST 6 HOURS.  ANTICYCLONIC CIRCULATION ALSO BRINGS INTO E PAC
CONVECTIVE DEBRIS FROM SURFACE TROUGH ALONG 97W IN BAY OF
CAMPECHE.  MOISTURE ADVECTING INTO REGION WHERE ABOVE MENTIONED
TROPICAL WAVE IS MOVING INTO. WITH WARM SEA SURFACE 
TEMPERATURES...ABUNDANT TROPICAL MOISTURE AND MECHANICAL UPLIFT 
BY THE WAVE...ONLY UPPER LEVEL INGREDIENTS ARE NEEDED TO 
DETERIORATE WEATHER IN THIS AREA.    

HIGH PRES CENTER 1025 MB WELL N OF BASIN NEAR 41N137W AND SECOND
ONE AT 28N146W MAINTAIN FLAT PRES GRADIENT WITH GENTLE TO
MODERATE NE TRADES N OF MONSOON TROUGH W OF 125W.  

CROSS-EQUATORIAL SOUTHERLY SWELL WITH SEAS TO 8 FT WILL PUSH AS
FAR N AS 03N EARLY MON.

$$
WALLY BARNES