000
AXPZ20 KNHC 111521
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT AUG 11 2012

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 
1515 UTC.

...SPECIAL FEATURES...

GILMA HAS BEEN DOWNGRADED TO A TROPICAL DEPRESSION AND WAS 
CENTERED NEAR 20.2N 120.1W AT 11/1500 UTC MOVING NNW OR 335 DEG 
AT 4 KT WITH MAXIMUM SUSTAINED WINDS OF 30 KT GUSTING TO 40 KT. 
ESTIMATED MINIMUM CENTRAL PRESSURE IS 1004 MB. THE SYSTEM IS 
VOID OF ANY DEEP CONVECTION...CONSISTING OF A SWIRL OF LOW AND 
MID LEVEL CLOUDS. GILMA IS EXPECTED TO WEAKEN TO A REMNANT LOW
LATER TODAY. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

THE CIRCULATION OF FORMER ATLANTIC TROPICAL CYCLONE ERNESTO IS 
NOW ANALYZED AS A SURFACE LOW PRESSURE NEAR 17N105W WITH AN 
ESTIMATED CENTRAL PRESSURE OF 1002 MB. CURRENTLY NUMEROUS STRONG 
CONVECTION IS OCCURRING BETWEEN 180 NM AND 480 NM IN THE NW 
QUADRANT OF THE LOW WITH SCATTERED MODERATE ISOLATED STRONG 
CONVECTION OCCURRING WITHIN 90 NM SE AND 180 NM IN THE NW 
SEMICIRCLE. ENVIRONMENTAL CONDITIONS ARE FAVORABLE FOR CONTINUED 
DEVELOPMENT AND THERE IS A HIGH CHANCE...90 PERCENT...OF THE
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 13N88W TO LOW PRES NEAR 17N105W 
TO 11N111W TO 13N122W TO 11N130W TO 09N140W. SCATTERED MODERATE 
CONVECTION WAS INDICATED WITHIN 450 NM S OF AXIS BETWEEN 88W 
AND 100W AND WITHIN 75 NM EITHER SIDE OF AXIS BETWEEN 100W AND 
102W. SCATTERED MODERATE ISOLATED STRONG WITHIN 90 NM EITHER 
SIDE OF AXIS BETWEEN 106W AND 110W. SCATTERED MODERATE WITHIN 90 
NM N AND 180 NM S OF AXIS BETWEEN 124W AND 139W.

...DISCUSSION...

A SPRAWLING ANTICYLONE IS CENTERED OVER THE SW CONUS WITH THE 
ASSOCIATED FLOW DOMINATING NORTHERN MEXICO AND RIDGE AXIS 
EXTENDING SW TOWARD T.D. GILMA. THE EASTERLY FLOW S OF THE 
ANTICYCLONE WAS PROVIDING EXCELLENT OUTFLOW OVER THE LOW 
PRESSURE NEAR 17N105. A SMALLER UPPER ANTICYLONE IS CENTERED 
NEAR 23N131W WITH ITS ENVELOPE OF ANTICYCLONIC FLOW AND 
ACCOMPANYING VERY DRY UPPER AIR DOMINATING THE UPPER LEVELS FROM 
20N TO 32N BETWEEN 128W AND 142W.  A SHARP UPPER TROUGH IS 
OBSERVED BETWEEN THESE TWO ANTICYCLONES EXTENDING SW FROM A 
SMALL UPPER LEVEL CYCLONE NEAR 31N119W TO 21N125W. DEBRIS 
MOISTURE FROM GILMA IS ADVECTED NE ALONG THE W PERIPHERY OF THE 
RIDGE...BUT EVAPORATES NEAR 26N118W. BROAD ANTICYCLONIC FLOW 
DOMINATES THE UPPER LEVELS FROM 10N TO 22N BETWEEN 90W AND 114W 
WHILE LOW LEVEL SOUTHWESTERLY FLOW S OF THE PREVIOUSLY DESCRIBED 
MONSOON TROUGH IS SUPPORTING THE INTENSE CONVECTION NOTED ABOVE 
NEAR THE REDEVELOPING REMNANTS OF ERNESTO NEAR 17N105W...AND THE 
OTHER CONVECTION NOTED BETWEEN 90W AND 100W. 

NE WINDS AT 20 KT...WITH MERGING N AND NE SWELL RESULTING IN 
COMBINED SEAS TO 9 FT...IS FORECAST OVER THE AREA N OF 25N 
BETWEEN 120W AND 135W THROUGH SUN...WITH WINDS DIMINISHING TO 20 
KT OR LESS AND SEAS SUBSIDING TO LESS THAN 8 FT ON MON.

$$
COBB