000
AXPZ20 KNHC 021523
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1605 UTC FRI AUG 02 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES...                                  
HURRICANE GIL CENTERED NEAR 14.6N 128.4W AT 02/1500 UTC MOVING W 
OR 270 DEG AT 8 KT. ESTIMATED MINIMAL CENTRAL PRESSURE IS 990 
MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT GUSTS TO 80 KT.  
NUMEROUS STRONG CONVECTION IS NOTED WITHIN 60 NM THE CENTER. GIL 
HAS BECOME LESS ORGANIZED DURING THE LAST FEW HOURS WITH THE 
COVERAGE OF DEEP CONVECTION DIMINISHING. CURRENTLY...IT IS A 
MINIMAL HURRICANE AND THE INTENSITY FORECAST CALLS FOR A GRADUAL 
WEAKENING AS GIL MOVES OVER PROGRESSIVELY COOLER WATER AND INTO 
AN ENVIRONMENT OF SLIGHTLY STRONGER SHEAR. SEE LATEST NHC 
FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTNT22 KNHC 
FOR ADDITIONAL DETAILS.

IN THE WAKE OF GIL...THERE IS A LOW PRES LOCATED NEAR 13N118W 
1009 MB. THIS SYSTEM CONTINUES TO PRODUCE DISORGANIZED SHOWERS 
AND THUNDERSTORMS. ENVIRONMENTAL CONDITIONS COULD BECOME 
CONDUCIVE FOR DEVELOPMENT IF HURRICANE GIL WEAKENS OR THE 
DISTANCE BETWEEN THE SYSTEMS INCREASES. THIS SYSTEM STILL HAS A 
MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 
HOURS. CURRENTLY...A 60 NM WIDE BAND OF SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS NOTED S OF CENTER FROM 11N TO 13N 
BETWEEN 118W AND 119W. MODEL GUIDANCE SUGGESTS THAT WINDS SHOULD 
REMAIN BELOW TROPICAL STORM FORCE IN ASSOCIATION WITH THIS 
SYSTEM. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH EXTENDS FROM 10N85W TO 08N95W TO 1009 MB LOW PRES 
AT 13N118W. ITCZ IS FROM 12N131W TO 1009 MB LOW PRES AT 12N138W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 10N 
TO 13N BETWEEN 91W AND 94W AND FROM 10N TO 13N BETWEEN 105W AND 
110W.

...DISCUSSION...                                       
ALOFT...AN UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC 
CIRCULATION NEAR 31N131W TO BEYOND 30N140W. UPPER LEVEL RIDGE 
EXTENDS TO THE N FROM AN ANTICYCLONIC CIRCULATION CENTERED OVER 
HURRICANE GIL NEAR 14N127W TO ABOUT 27N125W. ANOTHER RIDGE 
EXTENDS EWD FROM THE SAME ANTICYCLONE TO NEAR 13N113W. MODERATE 
TO STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS IS NOTED MAINLY N 
OF 20N W OF 120W. ANOTHER UPPER LEVEL LOW NEAR 22N117.5W HAS A 
TROUGH EXTENDING SE TO NEAR 20N107W. 

A SECOND LOW PRES IS CENTERED NEAR 12N138W 1009 MB. NUMEROUS 
MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 90 NM SW 
SEMICIRCLE. ALTHOUGH THE DISTURBANCE IS CURRENTLY POORLY 
ORGANIZED...THERE IS A CHANCE THAT THE LOW MAY DEVELOP INTO A 
TROPICAL CYCLONE DURING THE NEXT 48 HOURS...HOWEVER IT WILL 
LIKELY BE W OF THE DISCUSSION AREA.

A SURFACE RIDGE IS N OF HURRICANE GIL AND THE LOWS N OF 18N W OF 
110W. PRES GRADIENT BETWEEN THE RIDGE AND THE LOW PRES LOCATED 
NEAR 12N138W...WHICH IS EMBEDDED IN THE ITCZ...MAINTAINS AN AREA 
OF NE WINDS OF 20-25 KT FROM 12N TO 18N W OF 135W. MIXING NE AND 
SW SWELL IS RESULTING IN COMBINED SEAS OF 8-10 FT. THESE 
CONDITIONS ARE FORECAST TO REMAIN IN PLACE ACROSS THE TROPICAL 
WATERS OVER THE NEXT 36 TO 48 HOURS. THE AREA OF SEAS HIGHER 
THAN 8 FT WILL INCREASE IN ADVANCE OF TROPICAL CYCLONE GIL... 
PARTICULARLY BETWEEN 10N AND 20N W OF 130W. HOWEVER...THE AREA 
OF FRESH TO STRONG NE WINDS IS FORECAST TO MOVE WWD IN TANDEM 
WITH THE LOW PRES NEAR 12N138W.  

$$ 
GR