000
AXPZ20 KNHC 230925
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE OCT 23 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.

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

THE MONSOON TROUGH EXTENDS FROM 13N87W TO 13N100W TO 09N130W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 45 NM N 
AND 120 NM S OF THE TROUGH E OF 115W. CLUSTERS OF MODERATE TO 
STRONG CONVECTION WITHIN 60 NM OF CENTRAL AMERICA COAST BETWEEN 
81W AND 88W.

...DISCUSSION...

A WEAK COLD FRONT ACROSS THE NORTHERN PORTION OF THE AREA FROM 
31N121W TO 26N140W WILL DISSIPATE TONIGHT AND WED WEST OF 
NORTHERN BAJA CALIFORNIA. STRONG HIGH PRES WILL BUILD BEHIND THE 
FRONT NEAR 31N140W TONIGHT THEN SHIFT EASTWARD THROUGH WED NIGHT 
TO NEAR 30N130W...WHICH TIGHTEN THE PRES GRADIENT ACROSS THE NE 
PORTION OF THE AREA AND INCREASE N-NW WINDS ALONG THE WEST COAST 
OF THE BAJA PENINSULA. EXPECT FRESH TO STRONG WINDS N OF 24N E OF
120W WED MORNING THROUGH EARLY FRI. BUILDING HIGH PRES ALONG 30N 
WILL ALSO STRENGTHEN NE TRADE WINDS N OF THE CONVERGENCE ZONE W 
OF 120W THROUGH THE END OF THE WEEK. 

INTENSIFYING CIRCULATION ASSOCIATED WITH TROPICAL STORM SANDY IN 
THE SW CARIBBEAN IS ACTING TO STRENGTHEN W-SW WIND FLOW S OF THE 
MONSOON TROUGH WHICH EXTENDS ACROSS NICARAGUA INTO THE CARIBBEAN.
EXPECT MOIST CONVERGENT MONSOONAL FLOW TO PRODUCE WIDESPREAD RAIN
AND OCCASIONAL MODERATE TO HEAVY SHOWERS ACROSS PANAMA AND COSTA 
RICA...GRADUALLY SHIFTING NORTHWARD INTO NICARAGUA THROUGH THU...
WITH STRONG GUSTY WINDS POSSIBLE IN HEAVIER DOWNPOURS. 

SCATTEROMETER DATA SHOWS LIGHT TO MODERATE WINDS ACROSS MOST OF 
THE DISCUSSION AREA EXCEPT FOR MODERATE TO FRESH W-SW WINDS JUST 
S OF THE MONSOON TROUGH E OF 110W. A TINY AREA OF 20 KT WINDS IS 
DEPICTED NEAR THE COAST IN THE GULF OF TEHUANTEPEC...ASSOCIATED 
WITH GAP WINDS SPILLING THROUGH THE ISTHMUS DUE TO STRONG HIGH 
PRES IN THE NE GULF OF MEXICO. EXPECT GAP WINDS TO INCREASE LATE 
TONIGHT...REACHING 20-25 KT AND POSSIBLY TO 30 KT AT TIMES EARLY 
WED...N OF 15N IN THE GULF OF TEHUANTEPEC. THE DOWNSTREAM EFFECTS
OF THIS ONGOING WIND EVENT MAY INDUCE A CYCLONIC CIRCULATION TO 
DEVELOP S OF TEHUANTEPEC. GFS HAS BACKED OFF CONSIDERABLY FROM 
PREVIOUS MODEL RUNS AND NOW AGREES VERY CLOSELY WITH ECMWF MODEL.
BOTH SHOW A WEAK LOW DEVELOPING ROUGHLY NEAR 10N95W BETWEEN WED 
AND FRI AS THE TEHUANTEPEC WINDS ADD VORTICITY N OF THE SYSTEM.

$$
MUNDELL