000
AXPZ20 KNHC 201543
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC TUE OCT 20 2015

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.               

...SPECIAL FEATURES...

NEWLY-FORMED TROPICAL DEPRESSION 20-E LOCATED SOUTH OF THE GULF 
OF TEHUANTEPEC NEAR 13.3N 94.4W MOVING SLOWLY W 280 DEG AT 2 KT. 
MAXIMUM SUSTAINED WINDS ARE 30 KT GUSTS 40 TO KT. ESTIMATED MSLP 
IS 1006 MB. NUMEROUS MODERATE TO STRONG CONVECTION WITHIN 120 NM 
E OF THE CENTER AND SCATTERED MODERATE ISOLATED STRONG ELSEWHERE 
WITHIN 150 NM OF THE CENTER. NEAR GALE-FORCE WINDS AS EVIDENCED 
BY RECENT ASCAT SCATTEROMETER PASS FUNNELING THROUGH THE GULF OF 
TEHUANTEPEC IS ENHANCING CYCLONIC VORTICITY NW OF T.D. 20-E AND 
HELPING SPIN UP THE CIRCULATION. ENVIRONMENTAL CONDITIONS ARE 
FAVORABLE FOR THE CYCLONE TO INTENSIFY DURING THE NEXT 2-3 DAYS 
AND IT IS EXPECTED TO BECOME A HURRICANE BEFORE MOVING INLAND 
ALONG THE COAST OF MEXICO BETWEEN MANZANILLO AND ACAPULCO. HEAVY 
RAIN AND FLOODING IS POSSIBLE IN THIS AREA PRIOR TO LANDFALL. 
SEE LATEST FORECAST AND PUBLIC ADVISORIES ISSUED BY THE NATIONAL 
HURRICANE CENTER UNDER AWIPS/WMO HEADERS MIATCMEP5/WTPZ25 KNHC 
AND MIATCPEP5/WTPZ35 FOR MORE DETAILS.

HURRICANE OLAF IS W OF 140W AND MOVING AWAY FROM THE DISCUSSION 
AREA. TROPICAL STORM FORCE WINDS AND LARGE SEAS ARE STILL 
AFFECTING A PORTION OF THE AREA W OF 137W. SCATTERED MODERATE TO 
STRONG CONVECTION OVER FORECAST WATERS FROM 05N-14N W OF 136W. 
PLEASE SEE LATEST FORECAST ADVISORY UNDER AWIPS/WMO HEADERS 
HFOTCMCP5/WTPA25 PFHO FOR MORE DETAILS ON OLAF.  
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
MONSOON TROUGH AXIS EXTENDS FROM TROPICAL DEPRESSION TWENTY-E TO 
10N98W TO 08N120W TO 07N129W. SCATTERED MODERATE TO STRONG 
CONVECTION FROM 08N TO 11N BETWEEN 94W AND 100W. SCATTERED 
MODERATE TO STRONG CONVECTION WITHIN 60 NM OF 07N111W. SCATTERED 
MODERATE CONVECTION WITHIN 75 NM OF TROUGH AXIS BETWEEN 119W AND 
128W. SCATTERED MODERATE TO STRONG CONVECTION ELSEWHERE FROM 05N 
TO 10N BETWEEN 85W AND 88W.

...DISCUSSION... 

A 1027 MB SUBTROPICAL HIGH PRESSURE CENTER NEAR 35N137W EXTENDS 
A RIDGE AXIS SOUTHWARD TO AROUND 20N W OF 122W. THE PRESSURE 
GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURE OVER THE SW UNITED 
STATES IS PRODUCING FRESH TO STRONG NW WINDS OFF THE COAST OF 
SOUTHERN CALIFORNIA. NW SWELL ASSOCIATED WITH THESE WINDS IS 
PROPAGATING INTO NORTHEASTERN WATERS N OF 28N BETWEEN 116W AND 
124W...WITH SEAS IN THE 7-9 FT RANGE. THE WINDS N OF THE AREA 
WILL DIMINISH BY TONIGHT AND THE SWELL WILL SUBSIDE TO 6-7 FT 
OVER FORECAST WATERS BY WED AFTERNOON.
                                                    
A DEEP-LAYER TROUGH SWEEPING THROUGH THE GULF OF CALIFORNIA THIS 
MORNING SUPPORTED STRONG WESTERLY WINDS IN THE NORTHERN GULF. 
MODEL GUIDANCE INDICATES WINDS WILL RAPIDLY DIMINISH LATER TODAY 
AS THE LEADING EDGE OF THE TROUGH MOVES FURTHER EAST. EXPECT 
SEAS TO SUBSIDE FROM 6-7 FT TO 3-5 FT DURING THE NEXT 6-12 HOURS.

$$ 
MUNDELL