000
AXPZ20 KNHC 070924
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
                
...SPECIAL FEATURES...                                     

TROPICAL DEPRESSION LORENA NEAR 23.2N 111.6W AT 07/0900 UTC OR 
110 NM W OF CABO SAN LUCAS MEXICO AND 120 NM SSE OF CABO SAN 
LAZARO MEXICO MOVING WNW AT 7 KT. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 1007 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH 
GUSTS TO 40 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. VERY SPORADIC 
DEEP CONVECTION IS PRESENT WITH LORENA. LORENA IS FORECAST TO 
BECOME A REMNANT LOW BY LATE TONIGHT...DISSIPATING BY LATE MON 
NIGHT. ASSOCIATED SEAS WILL SUBSIDE TO LESS THAN 8 FT BY LATE 
SUN NIGHT.

...TROPICAL WAVES...

THE FAR SOUTHERN EXTENT OF A TROPICAL WAVE IS N OF 11N ALONG 
88W. ASSOCIATED CONVECTION IS DESCRIBED BELOW. THE NORTHERN 
PORTION IS IN THE PROCESS OF MOVING FROM THE GULF OF HONDURAS TO 
THE W OVER THE YUCATAN. THIS TROPICAL WAVE IS FORECAST TO BECOME 
ILL-DEFINED DURING THE NEXT 24 HOURS WITH LITTLE DIRECT IMPACT 
ON WINDS AND SEAS IN THE NE PACIFIC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 12N92W TO 11N97W 
...THEN RESUMES FROM 15N118W TO 08N140W. NO ITCZ IS PRESENT E OF 
140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 150 NM E OF A LINE FROM 10N87W TO 07N89W...AND ALSO N OF 
THE MONSOON TROUGH TO CENTRAL AMERICA E OF 91W. SCATTERED 
MODERATE CONVECTION IS WITHIN 120 NM S OF THE MONSOON TROUGH 
BETWEEN 130W AND 134W.   

SCATTERED MODERATE CONVECTION IS WITHIN 180 NM S OF A LINE FROM 
13N98W TO 11N104W TO 13N111W...WHERE THE MONSOON TROUGH APPEARS 
TO BECOMING RE-ESTABLISHED IN THE WAKE OF LORENA. ALSO... 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 90 NM S OF THE 
COAST OF MEXICO BETWEEN 100W AND 105W...WHICH IS CONVECTION THAT 
IS IN THE PROCESS OF MOVING OFFSHORE FROM EARLIER TSTMS THAT 
DEVELOPED OVER THE TOPOGRAPHY OF SW MEXICO.

...DISCUSSION... 

AN UPPER LEVEL ANTICYCLONE AT 24N132W IS MAINTAINING DRY AND 
STABLE AIR OVER THE BASIN N OF 16N W OF 115W. A SECOND UPPER 
LEVEL ANTICYCLONE IS JUST TO THE S OF LORENA NEAR 21N111W. THIS 
FEATURE HAD BEEN AIDING LORENAS OUTFLOW WHILE ALSO PROVIDING 
SUPPORT FOR CONVECTION TO THE S ALONG A REFORMING PORTION OF THE 
MONSOON TROUGH OVER THE CENTRAL WATERS AS IS DESCRIBED ABOVE.

ELSEWHERE AT THE SURFACE...1027 MB HIGH PRES IS WELL N OF THE 
BASIN NEAR 10N136W WITH A RIDGE EXTENDING TO THE S THROUGH 
32N137W THEN SE TO 22N121W. FRESH NORTHERLY WINDS W OF THE 
CALIFORNIA COAST ARE FORECAST TO DIMINISH WHILE ASSOCIATED 
SWELLS OF 5 TO 7 FT PROPAGATE INTO THE FAR N CENTRAL PART OF THE 
WATERS.

MODEL GUIDANCE STRENGTHENS SW FLOW S OF THE MONSOON TROUGH BY 
EARLY SUN MORNING. FRESH SOUTHERLY WINDS WILL ALLOW FOR SEAS TO 
BUILD TO 8 TO 9 FT OVER THE AREA FROM 10N TO 13N BETWEEN 100W 
AND 104W BY LATE SUN NIGHT.
 
ELSEWHERE...A RATHER LOOSE PRES GRADIENT IS INDUCING MAINLY 
LIGHT TO MODERATE WINDS AND 4 TO 6 FT SEAS...EXCEPT 2 TO 3 FT 
NEAR CENTRAL AMERICA.

$$
LEWITSKY