000
AXPZ20 KNHC 161515
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED NOV 16 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 10N86W TO LOW PRES NEAR 9N91W 1008 MB TO 8N100W 
9N110W. ITCZ FROM 9N110W 12N117W 8N130W 7N140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM S OF AXIS FROM 
90W-97W. SCATTERED MODERATE TO STRONG CONVECTION WITHIN 150 NM S 
OF AXIS FROM 115W-135W AND WITHIN 90 NM S OF AXIS FROM 131W-134W.

...DISCUSSION...
UPPER LEVEL RIDGE ACROSS THE NW PORTION OF THE DISCUSSION AREA 
WITH AXIS FROM 32N130W TO 20N130W. HIGH LEVEL MOISTURE IS MOVING 
INTO THE AREA W OF THE RIDGE AXIS. A BROAD UPPER LEVEL TROUGH
OVER THE GREAT PLAINS EXTENDS SOUTHWARD ACROSS NORTHERN MEXICO.
HOWEVER MOSTLY WLY ZONAL UPPER LEVEL FLOW IS E OF THE RIDGE WITH 
WINDS 45-50 KT INCREASING TO 75 KT OVER NE MEXICO. STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS IS 
ACROSS THE AREA N OF 20N E OF 130W. AN UPPER LEVEL ANTICYCLONIC 
CIRCULATION SW OF MEXICO NEAR 15N98W. DIFFLUENCE ALOFT IS 
ENHANCING CONVECTION ALONG THE MONSOON TROUGH FROM 90W-97W.

IN THE DEEP TROPICS AN UPPER LEVEL CYCLONIC CIRCULATION IS 
CENTERED NEAR THE EQUATOR AT 117W. NW OF THE CYCLONIC 
CIRCULATION IS AN UPPER LEVEL ANTICYCLONIC CIRCULATION NEAR 
11N125W.

SURFACE RIDGE IS N OF 18N W OF 115W. SURFACE ELY WINDS TO 20 KT 
ARE FROM 10N-16N W OF 120W WITH SEAS TO 9 FT IN NW SWELL. 
ANOTHER AREA OF NW SWELL IS N OF 26N BETWEEN 118W AND 129W. A 
1008 MB LOW PRES IS ANALYZED ALONG THE MONSOON TROUGH NEAR 9N91W 
IS DRIFTING W. A COUPLE OF SURFACE TROUGHS ARE ANALYZED ALONG 
THE ITCZ. THE FIRST EXTENDS FROM 16N117W TO 8N119W. SCATTERED 
MODERATE TO STRONG CONVECTION ASSOCIATED WITH THE TROUGH AND THE 
ITCZ IS AS DESCRIBED ABOVE. ANOTHER TROUGH WITH AXIS FROM 
12N133W TO 6N133W.

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 THU EVENING.

$$
DGS