000
AXPZ20 KNHC 130930
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT OCT 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURES...

A BROAD AREA OF LOW PRESSURE EMBEDDED IN THE MONSOON TROUGH IS 
CENTERED NEAR 15N110W MOVING W AT AROUND 15 KT WITH ESTIMATED 
MINIMUM PRES OF 1008 MB. THIS SYSTEM CONTINUES TO PRODUCE POORLY 
ORGANIZED SCATTERED MODERATE TO STRONG CONVECTION WITHIN 120 NM 
W AND NW OF THE LOW CENTER. UPPER-LEVEL WINDS ARE EXPECTED TO 
WEAKEN...ALLOWING VERTICAL SHEAR TO DIMINISH...AND ENVIRONMENTAL 
CONDITIONS WILL BECOME MORE FAVORABLE FOR DEVELOPMENT DURING THE 
NEXT COUPLE OF DAYS. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING 
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. EXPECT WINDS NEAR 
THE CENTER TO INCREASE TO 25 KT LATER TODAY MAINLY IN SE QUADRANT
OF LOW CENTER WITH SEAS BUILDING TO AROUND 10-11 FT BY SUN.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM 10N85W TO 07N91W TO 13N99W TO 
LOW PRES NEAR 15N110W TO 10N124W TO 10N136W TO 08N140W. CLUSTERS 
OF SCATTERED MODERATE ISOLATED STRONG CONVECTION ARE WITHIN 45 
NM OF 07N92W...14N102W AND 11.5N130W. SCATTERED MODERATE 
CONVECTION IS WITHIN 60 NM N OF THE TROUGH BETWEEN 108W AND 120W.

...DISCUSSION...

WEAKENING STATIONARY FRONT IS ACROSS NW CORNER OF DISCUSSION AREA
FROM 32N132W TO 25N143W. WEAK HIGH PRES CENTERED NEAR 28N127W. 
SUBTROPICAL RIDGE EXTENDS OVER MOST OF THE AREA N OF 18N W OF 
112W EXCEPT TROUGHING N OF 24N W OF 133W ASSOCIATED WITH FRONT. 
SCATTEROMETER DATA SHOWS SMALL AREA OF 20-25 KT NE WINDS FROM 
14N TO 17N BETWEEN 125W AND 130W. MODERATE NE TRADE WINDS PREVAIL
ELSEWHERE POLEWARD OF THE MONSOON TROUGH TO AROUND 23N W OF 110W.
LIGHT TO MODERATE S-SW WINDS PREVAIL EQUATORWARD OF THE MONSOON 
TROUGH W OF 100W. EXPECT TRADE WINDS TO WEAKEN SLIGHTLY AS THE 
SUBTROPICAL RIDGE SHIFTS N OF THE AREA. SW MONSOON WINDS ARE 
EXPECTED TO STRENGTHEN THROUGH MON AS THE LOW PRES CURRENTLY NEAR
15N110W INTENSIFIES NEAR 16N114W SUN THEN MOVES NORTH ALONG WITH 
THE STRONGER MONSOON FLOW. THIS WILL EXPAND AREA OF FRESH TO 
STRONG WINDS AND HIGH SEAS MAINLY IN SW SEMICIRCLE OUT TO 300 NM.

PERSISTENT STRONG HIGH PRES OVER THE GULF OF MEXICO CONTINUES TO 
ALLOW FRESH TO STRONG GAP WIND FLOW TO PULSE THROUGH THE GULF OF 
TEHUANTEPEC...PRIMARILY DURING OVERNIGHT AND EARLY MORNING HOURS.

HIGH PRES BUILDING ACROSS THE GREAT BASIN AND INTERMOUNTAIN WEST 
WILL ENHANCE NW WINDS IN THE GULF OF CALIFORNIA THIS WEEKEND WITH
20 TO 25 KT WINDS EXPECTED BETWEEN 24N AND 27N THROUGH TONIGHT.

$$
MUNDELL