000
AXPZ20 KNHC 170332
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
0405 UTC TUE SEP 17 2013

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 
0200 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
            
MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 08N74W TO 12N82W 
TO 14.5N88W WHERE IT REMAINS FRACTURED...THEN RESUMES FROM 
17N104W TO 10N120W TO LOW PRES NEAR 08N132W 1010 MB TO 
07N135W... WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON BEYOND 
06N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 
180 NM SW OF COASTLINE FROM 80W TO 93W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION NOTED FROM 11.5N TO 18.5N BETWEEN 
101W AND 107W. 

...DISCUSSION...

THE REMNANT LOW PRES CENTER OF MANUEL WAS CENTERED JUST OFFSHORE 
OF THE COAST OF WESTERN MEXICO NEAR SAYULITA...LOCATED JUST 
SOUTH OF LAS TRES MARIAS ISLANDS...DRIFTING NW. ESTIMATED 
CENTRAL PRESSURE WAS 1004 MB. SHOWERS AND TSTORMS HAVE CONTINUED 
TO DIMINISH IN INTENSITY AND COVERAGE OVER THE WATERS ACROSS 
THIS AREA...WITH A SIGNIFICANT CLUSTER OF STRONG TSTORMS 
OCCURRING WITHIN 180 NM ACROSS THE NE QUADRANT SHIFTING W OFF 
THE COAST. ALTHOUGH A MID LEVEL CIRCULATION REMAINS EVIDENT IN 
SATELLITE IMAGERY THIS EVENING...VERY DRY AND STABLE AIR IS 
BEING PULLED INTO THIS CIRCULATION FROM THE WATERS OFFSHORE OF 
BAJA CALIFORNIA...AND WILL ACT TO WEAKEN THIS SYSTEM OVER THE 
NEXT 24 TO 48 HOURS. THE REMNANTS OF MANUEL ARE EXPECTED TO 
DRIFT NW AND MEANDER ABOUT THE SOUTHERN WATERS OF THE GULF OF 
CALIFORNIA FOR THE NEXT FEW DAYS. SOUTHWESTERLY LOW LEVEL WINDS 
OCCURRING WELL TO THE SOUTHEAST OF MANUEL THE PAST FEW DAYS 
CONTINUE TO WEAKEN ACROSS THE TROPICAL EPAC EXTENDING NE TO 
COASTAL ZONES OF OAXACA...GUERRERO AND MICHOACAN...AND ARE 
AIDING IN REDUCING THE AMOUNT OF SHOWER AND THUNDERSTORM 
ACTIVITY PERSISTING ACROSS THOSE STATES. HOWEVER...THIS WEAKENED 
SOUTHWEST FLOW WILL CONTINUE TO ALLOW FOR THE FORMATION OF 
SHOWERS AND TSTORMS ACROSS THE REGIONAL WATERS AND SPREAD INLAND 
ACROSS THESE STATES...WHERE FLASH FLOODING AND MUDSLIDES HAVE 
RECENTLY OCCURRED.

IN THE MID TO UPPER LEVELS...A SHARP TROUGH THAT REACHED FROM 
THE GREAT BASIN ACROSS THE SOUTHERN ROCKIES AND NW MEXICO TO THE 
SOUTHERN GULF OF CALIFORNIA IS WEAKENING. THIS TROUGH HAD BEEN 
PROVIDING CONSIDERABLE UPPER SUPPORT TO THE CONVECTION E OF 105W 
ASSOCIATED WITH MANUEL OVER THE PAST COUPLE OF DAYS. A WEAK LOW 
TO MID LEVEL TROUGH IS EXPECTED TO REMAIN IN PLACE OVER THIS 
AREA THROUGH MID WEEK...ENHANCING COASTAL CONVECTION MAINLY AT 
NIGHT.

THE WEAKENING SWATH OF FRESH SW WINDS AT THE SURFACE CONTINUES 
TO DIMINISH IN SIZE AND STRENGTH...AND WAS WITHIN 90 NM SE OF 
THE MONSOON TROUGH BETWEEN 100W TO 105W. THE WINDS AND SEAS WILL 
DIMINISH TO 20 KT OR BELOW AND LESS THAN 8 FT WITHIN 24 HOURS AS 
THE OVERALL CYCLONIC CIRCULATION DOMINATING THE REGION CONTINUES 
TO WEAKEN AND REORIENT TO THE NORTHWEST. 

FARTHER WEST...1029 MB HIGH PRES IS CENTERED NEAR 37N154W WITH A 
RIDGE EXTENDING E TO THE COAST OF BAJA CALIFORNIA NEAR 28N117W. 
ASCAT DATA FROM THIS AFTERNOON INDICATED 15 TO 20 KT NW FLOW 
ALONG THE COAST OF THE BAJA PENINSULA AND S OF THE SOUTHERN TIP 
OF THE PENINSULA TO 21.5N...MAINTAINING SEAS 6-7 FT.

ELSEWHERE...LIGHT TO MODERATE WINDS AND SLIGHT SEAS PREVAIL WITH 
NO SIGNIFICANT CONVECTION NOTED.
 
$$
STRIPLING