000
AXPZ20 KNHC 010246
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC THU AUG 01 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 FEATURES...
HURRICANE GIL AT 14.0N 121.2W AT 01/0300 UTC MOVING W-NW OR 285 
DEGREES AT 10 KT.  MAXIMUM SUSTAINED WIND 70 GUSTS TO 85 KT.
NUMEROUS STRONG WITHIN 120 NM OF N AND 90 NM S SEMICIRCLES.  
SCATTERED MODERATE ISOLATED STRONG ELSEWHERE WITHIN 150 NM OF 
CENTER.  GIL TRACKS W-NW ALONG SOUTHERN PERIPHERY OF LARGE UPPER
LEVEL RIDGE WHICH PROVIDES FAVORABLE CONDITIONS FOR FURTHER 
INTENSIFICATION. TRACK ALSO ACROSS WARM SEAS SURFACE TEMPERATURES
FOR THE NEXT 48 HOURS SO GIL IS FORECAST TO INTENSIFY SLIGHTLY...
AFTER WHICH IT ENTERS A REGION OF UNFAVORABLE UPPER WINDS AND 
COOLER SEA SURFACE TEMPERATURES WHICH ARE EXPECTED TO WEAKEN THE
SYSTEM.  SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMEP2/WTNT22 KNHC FOR ADDITIONAL DETAILS.

LOW PRES CENTER 1009 MB AT 13N113W MOVES W AT 10 KT WITH
SCATTERED CONVECTION WITHIN 120 NM OF CENTER.  LOW PRES FOLLOWS
IN THE WAKE OF HURRICANE GIL AND ANY INTENSIFICATION...IF ANY...
WILL BE SLOW TO OCCUR.  THERE IS A 50 PERCENT CHANCE THIS SYSTEM
MAY REACH TROPICAL CYCLONE STRENGTH WITHIN NEXT 48 HOURS.  EVEN
IF NOT...MARINE CONDITIONS ARE EXPECTED TO DETERIORATE 
TEMPORARILY IN ITS VICINITY DUE TO GUSTY WINDS AND SCATTERED
MODERATE AND ISOLATED STRONG CONVECTION.  
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS FROM 09N84W TO 10N104W TO 1009 MB LOW PRES
13N113W.  ITCZ AXIS FROM 12N124W TO 11N130W TO 09N140W. 
SCATTERED MODERATE TO STRONG CONVECTION FROM 06N-10N E OF 89W.
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 240 NM N
AND 75 NM S OF AXIS FROM 127W TO 132W.
   
...DISCUSSION...  
WELL DEFINED UPPER LEVEL CYCLONE AT 26N138W BRINGS LARGE AREA
OF DRY STABLE AIR MASS INTO NW PART OF BASIN N OF 18N W OF 116W.
ASSOCIATED TROUGH ALOFT TO 17N140W INCREASES SW FLOW WHICH WILL
EVENTUALLY IMPACT HURRICANE GIL BY FRI INCREASING ITS SW SHEAR
AND LITERALLY DECOUPLING LOWER AND UPPER CENTERS...AFTER WHICH 
CYCLONE WEAKENS INTO OBLIVION.  

MEANTIME E-W UPPER LEVEL RIDGE MAINTAINS GOOD OUTFLOW FEATURE
OVER HURRICANE GIL ALLOWING GOOD OUTFLOW FOR FURTHER
STRENGTHENING WITHIN NEXT TWO DAYS.  WHILE SECOND SURFACE LOW
PRES CENTER NOW AT 13N113W SHARE SAME CONDITIONS ALOFT...OUTFLOW
FROM GIL MAY CAUSE DISRUPTION IN ITS DEVELOPMENT. OVERALL REGION
STILL CONTAINS ABUNDANT WARM TROPICAL MOISTURE AND SEAS REMAIN 
WARM SO SHORT-TERM INTENSIFICATION CANNOT BE TOTALLY ELIMINATED. 

...AT THE LOWER LEVELS...
HEALTHY HIGH PRES CENTER 1029 MB AT 34N142W MAINTAINS STEADY 
FRESH NE TRADES OVER WESTERN BOUNDARIES OF BASIN FROM 12N-18N
W OF 130W WITH MIXING NE AND SE SWELL RESULTING IN COMBINED SEAS
TO 10 FT. CONDITIONS FORECAST TO REMAIN FOR NEXT 36 TO 48 HOURS
THEN SUBSIDE AS HIGH PRES CENTER DRIFTS SW AS TROPICAL CYCLONE
GIL ADVANCES W. 

$$
WALLY BARNES