000
AXPZ20 KNHC 200321
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN NOV 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURE...
TROPICAL DEPRESSION THIRTEEN-E CENTERED NEAR 10.3N 102.1W 1006 
MB MOVING W 10 KT WITH MAXIMUM SUSTAINED WINDS 30 KT GUST TO 40 
KT AT 0300 UTC. TROPICAL DEPRESSION THIRTEEN-E IS FORECAST TO TO 
INTENSIFY INTO A TROPICAL STORM EARLY SUN. MODERATE TO STRONG 
CONVECTION IS WITHIN 220 NM NE SEMICIRCLE. OVERALL THE SYSTEM IS 
UNDER VERY CONDUCIVE ANTICYCLONIC FLOW ALOFT WITH LOW VERTICAL 
SHEAR SO THE SYSTEM IS FORECAST TO CONTINUE TO INTENSIFY AS IT 
MOVES W OVER THE NEXT FEW DAYS

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH 10N85W 8N90W TO TROPICAL DEPRESSION THIRTEEN-E 
10.1N101.5W TO 09N123W. INTERTROPICAL CONVERGENCE ZONE 9N123W 
10N130W 8N140W. SCATTERED MODERATE CONVECTION WITHIN 170 NM S 
OF AXIS FROM 125W-128W.

...DISCUSSION...
A BROAD UPPER LEVEL TROUGH COVERS THE AREA N OF 20N W OF 115W. A 
75-95 KT JETSTREAM ENTERS THE AREA NEAR 25N140W THEN WINDS 
INCREASE TO 100-105 KT AT 24N121W THE JETSTREAM CONTINUES NE TO 
CENTRAL BAJA CALIFORNIA INTO THE SW U.S.. BROKEN/OVERCAST CIRRUS
CLOUDS ARE WITHIN 240 NM SE OF THE JETSTREAM FROM 118W THROUGH 
CENTRAL BAJA CALIFORNIA INTO ARIZONA AND NEW MEXICO. A BROAD 
ANTICYCLONIC CIRCULATION IS CENTERED OVER TROPICAL DEPRESSION 
THIRTEEN-E PROVIDING FOR GOOD OUTFLOW. ANTICYCLONIC FLOW COVERS 
THE AREA N OF 8N E OF 115W. MODERATE TO STRONG SUBSIDENCE WITH 
DRY AND STABLE AT THE MIDDLE AND UPPER LEVELS N OF 15N E OF 110W.

SURFACE HIGH PRES RIDGE IS N OF 15N W OF 105W. LARGE NLY SWELLS 
PROPAGATING THROUGH THE AREA N OF 26N W OF 120W. THESE LARGE 
SWELLS ARE FORECAST TO CONTINUE TO MOVE S THROUGH THE NEXT 
FEW OF DAYS.

TWO SURFACE TROUGHS ARE ANALYZED ALONG THE ITCZ. THE FIRST FROM 
12N126W TO 10N129W. A FEW SHOWERS ARE ALONG THE TROUGH AXIS.
ANOTHER TROUGH EXTENDS FROM 12N134W TO 9N136W. SCATTERED SHOWERS 
ARE WITHIN 140 NM E OF TROUGH AXIS FROM 9N-11N.

THE PRES GRADIENT WEAKENED OVER SOUTHERN MEXICO AND NLY WINDS 
HAVE DECREASED THROUGH THE GULF OF TEHUANTEPEC. N WINDS OF 20 KT 
WILL THEN RESTART THROUGH THE GULF SUN NIGHT.

$$
DGS