000
AXPZ20 KNHC 171519
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU NOV 17 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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH 10N85W TO LOW PRES 1009 MB NEAR 9N94W TO 9N110W. 
ITCZ 9N110W 11N120W 8N140W. SCATTERED MODERATE TO STRONG CONVECTION 
FROM 7N-13N BETWEEN 93W-96W AND WITHIN 120 NM S OF AXIS FROM 
117W-123W AND WITHIN 90 NM N OF AXIS FROM 129W-139W.

...DISCUSSION...
AN UPPER LEVEL CYCLONIC CIRCULATION HAS MOVED INTO THE FAR NW 
PORTION OF THE DISCUSSION AREA NEAR 31N139W. ASSOCIATED UPPER TROUGH 
IS N OF 24N W OF 136W. AN UPPER LEVEL RIDGE IS E OF THE TROUGH WITH 
AXIS FROM 32N130W TO AN ANTICYCLONIC CIRCULATION NEAR 11N123W. HIGH 
LEVEL MOISTURE IS MOVING INTO THE AREA W OF 130W. MOSTLY WLY ZONAL 
UPPER LEVEL FLOW IS E OF THE RIDGE WITH WINDS 45-55 KT. STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS 
ACROSS THE AREA N OF 15N E OF 120W. AN UPPER LEVEL RIDGE EXTENDS 
FROM THE AN ANTICYCLONIC CIRCULATION OVER THE YUCATAN CHANNEL ACROSS 
SOUTHERN MEXICO TO 16N101W TO 12N110W.

IN THE DEEP TROPICS THE UPPER LEVEL CYCLONIC CIRCULATION HAS MOVED S 
INTO THE SOUTHERN HEMISPHERE WITH TROUGH FROM EQUATOR AT 120W TO 
10N113W.

SURFACE RIDGE IS N OF 15N W OF 115W. AN AREA OF NW SWELL IS N OF 27N 
BETWEEN 120W-129W WITH SEAS TO 9 FT. THE SWELL IS FORECAST TO 
SUBSIDE WITHIN THE NEXT 24 HOURS. A 1009 MB LOW PRES IS ANALYZED 
ALONG THE MONSOON TROUGH NEAR 9N94W IS DRIFTING W. SCATTERED 
MODERATE TO STRONG CONVECTION IS FROM 7N-13N BETWEEN 93W AND 96W. A 
SURFACE TROUGH IS ANALYZED ALONG THE ITCZ FROM 14N120W TO 7N122W. 
SCATTERED MODERATE TO STRONG CONVECTION ASSOCIATED WITH THE TROUGH 
AND THE ITCZ IS AS DESCRIBED ABOVE.

HIGH PRES WILL BUILD BEHIND A COLD FRONT MOVING THROUGH THE GULF 
OF MEXICO TIGHTENING THE PRES GRADIENT ACROSS SOUTHERN MEXICO. 
THIS WILL RESULT IN WINDS INCREASING TO GALE FORCE THROUGH THE GULF 
OF TEHUANTEPEC STARTING THIS EVENING. THE WINDS ARE FORECAST TO 
DECREASE TO BELOW GALE FORCE FRI AFTERNOON.

$$
DGS