000
AXPZ20 KNHC 070338
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.
                
...SPECIAL FEATURES...                                     
TROPICAL STORM LORENA AT 23.2N 111.0W AT 0300 UTC MOVING W-NW AT
8 KT.  CENTRAL PRESSURE IS 1006 MB WITH MAXIMUM WIND SPEED OF 35
GUSTS TO 45 KT.  NUMEROUS MODERATE TO STRONG CONVECTION WITHIN
90 NM NW SEMICIRCLE AND NUMEROUS MODERATE TO ISOLATED STRONG
CONVECTION WITHIN 45 NM SE SEMICIRCLE.  LORENA IS JUST W OF THE
TIP OF SOUTHERN BAJA CALIFORNIA PENINSULA WITH LITTLE CHANGE IN
INTENSITY.  ALTHOUGH UPPER LEVEL CONDITIONS REMAIN FAVORABLE FOR
CONTINUED INTENSIFICATION...LORENA HAS BEGUN INTERACTING WITH
DRY STABLE AIR TO ITS NW AND WARMER SEA SURFACE TEMPERATURES. 
ADDITIONALLY...INTERACTION WITH LAND EFFECTIVELY DISTURB ITS
CYCLONIC ORGANIZATION.  LORENA EXPECTED TO PRODUCE COPIOUS 
RAINFALL AND LIFE-THREATENING FLASH FLOODS OVER SOUTHERN
PORTIONS OF BAJA CALIFORNIA.  SEE LATEST NHC FORECAST/ADVISORY
UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
MONSOON TROUGH AXIS EXTENDS FROM 10N86W TO 11N95W TO 10N102W  
THEN RESUME FROM 15N117W TO BEYOND 08N140W.  SCATTERED
MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM OF AXIS E OF
87W AND FROM 95W TO 103W.  SCATTERED MODERATE CONVECTION WITHIN
75 NM OF AXIS FROM 128W TO 133W.    

...DISCUSSION... 
UPPER LEVEL ANTICYCLONE AT 23N132W MAINTAIN A DRY STABLE CANOPY
OVER BASIN N OF 17N W OF 114W.  SECOND ANTICYCLONE...THIS ONE
NEARLY OVER LORENA HELPING ITS OUTFLOW...BRINGS ABUNDANT
TROPICAL MOISTURE WELL INTO AND ALONG THE MONSOON TROUGH
ENHANCING MODERATE CONVECTION.    

ELSEWHERE AT THE LOWER LEVELS...
HIGH PRES CENTER 1028 MB N OF BASIN HAS RIDGE EXTEND TO 25N115W.
FRESH NORTHERLY BREEZE RUNNING PARALLEL TO CALIFORNIA COAST
BRINGING N SWELL INTO NE CORNER OF BASIN SOME OF IT INTERACTING
WITH WIND WAVES CAUSED BY LORENA.  

MODEL GUIDANCE STRENGTHENS SW WINDS S OF MONSOON TROUGH ALONG
TROPICAL WAVE ENTERING E PAC AT THIS TIME BY LATE SAT AND BRING
IT TO A STRONG SW BREEZE BY LATE SUN.  GIVEN THE EXISTING
FAVORABLE CONDITION...REGION BEARS MONITORING. 
 
ELSEWHERE...LOOSE PRES GRADIENT PROMPTS LIGHT TO MODERATE BREEZE
AND SLIGHT SEAS IN REMAINDER OF BASIN.

$$
WALLY BARNES