000
AXPZ20 KNHC 191650 RRA
TWDEP 

TROPICAL WEATHER DISCUSSION...RESENT 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI AUG 19 2011

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 FEATURE...
GREG HAS WEAKENED TO A TROPICAL STORM. AT 19/1500 UTC...IT IS 
CENTERED NEAR 19.1N 115.7W MOVING W OR 275 DEGREES AT 8 KT. THIS 
GENERAL MOTION IS EXPECTED TO CONTINUE FOR THE NEXT COUPLE OF 
DAYS. MAXIMUM SUSTAINED WINDS ARE 55 GUSTS TO 65 KT. RAPID 
WEAKENING IS FORECAST DURING THE NEXT 48 HOURS AS GREG MOVES 
OVER COOLER WATERS. THE SYSTEM IS EXPECTED TO BECOME A 
POST-TROPICAL REMNANT LOW PRESSURE SYSTEM BY SUNDAY. ESTIMATED 
MINIMUM CENTRAL PRES IS 991 MB. NUMEROUS MODERATE TO STRONG 
CONVECTION IS WITHIN 60 NM N OF CENTER. REFER TO FORECAST 
ADVISORIES ISSUED UNDER WMO HEADER WTPZ22 KNHC AND AWIPS HEADER 
MIATCMEP2 FOR FURTHER DETAILS.

...ITCZ/MONSOON TROUGH...
MONSOON TROUGH FROM 10N85W TO 1008 MB LOW PRES NEAR 12N100W THEN 
RESUMES FROM 16N119W TO 11N140W. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS WITHIN 150 NM S OF TROUGH BETWEEN 117W AND 
123W. SCATTERED MODERATE CONVECTION IS ALSO NOTED FROM 06N TO 
09N BETWEEN 82W AND 88W.

...DISCUSSION...
WEAK SURFACE RIDGE DOMINATES THE NW CORNER OF THE FORECAST AREA. 
WINDS AND SEAS ASSOCIATED WITH THE MONSOON TROUGH ARE FAIRLY 
BENIGN EXCEPT FOR A SWATH OF HIGHER WINDS EXTENDING SW FROM GREG 
TO AROUND 10N121W DEPICTED BY EARLIER SCATTEROMETER PASS. EXPECT 
THIS TAIL OF HIGHER WINDS AND SEAS TO PROPAGATE WESTWARD ALONG 
WITH GREG OVER THE NEXT 24-36 HOURS. 

AN AREA OF DISTURBED WEATHER...ANALYZED 1008 MB LOW PRES ON THE 
1200 UTC SURFACE MAP...HAS DEVELOPED ALONG THE MONSOON TROUGH 
AND IS LOCATED NEAR 12N110W OR ABOUT 275 NM SOUTH OF ACAPULCO 
MEXICO. SOME SLOW DEVELOPMENT OF THIS LARGE DISTURBANCE IS 
POSSIBLE OVER THE NEXT FEW DAYS AS IT MOVES TOWARD THE WEST- 
NORTHWEST AT 10 TO 15 MPH. THIS SYSTEM HAS A LOW CHANCE OF 
BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. SCATTERED 
MODERATE CONVECTION IS NOTED WITHIN 60 NM E SEMICIRCLE OF LOW 
CENTER. SIMILAR CONVECTION IS ALSO OBSERVED IN A BAND ON THE 
WEST SIDE OF THE LOW PRES FROM 12N TO 18N BETWEEN 102W AND 104W. 

VERY LITTLE CROSS EQUATORIAL SWELL IN EXPECTED THROUGH THE 
WEEKEND. 

$$
GR