000
AXPZ20 KNHC 152215
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN SEP 15 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...SPECIAL FEATURE... 

TROPICAL STORM MANUEL HAS MOVED INLAND NEAR MANZANILLO 
MEXICO...AND WAS LOCATED NEAR 19.2N 104.3W AT 2100 UTC MOVING NW 
OR 320 DEG AT 8 KT. MAXIMUM SUSTAINED WINDS HAS DECREASED TO 40 
KT WITH GUSTS TO 55 KT. ESTIMATED MINIMUM PRESSURE IS 998 MB. 
TROPICAL STORM FORCE WINDS ARE OCCURRING ONLY WITHIN 90 NM SE 
QUADRANT OF CENTER. MANUEL IS EXPECTED TO CONTINUE MOVING NW AND 
WEAKEN QUICKLY AS IT INTERACTS WITH THE MOUNTAINOUS TERRAIN OF 
THIS REGION OF MEXICO...WITH THE REMNANTS MOVING OUT OVER WATER 
EAST OF LAS TRES MARIAS ISLANDS BY 24 HOURS. SHOWERS AND TSTORMS 
ASSOCIATED WITH MANUEL HAVE SPREAD WELL INTO AS FAR NORTH AS 
ZACATECAS AND NORTHEASTWARD TO MEXICO CITY. ELSEWHERE SCATTERED 
TO NUMEROUS STRONG EXTENDED SOUTH OVER WATERS FROM 16.5N TO 19N 
BETWEEN 101.5W AND 106W. 

ALTHOUGH THE LOW LEVEL CIRCULATION OF MANUEL WILL WEAKEN QUICKLY 
TONIGHT...THE MIDDLE LEVEL CIRCULATION OF MANUEL REMAINS 
EMBEDDED WITHIN A CYCLONIC GYRE ALIGNED NE TO SW THAT EXTENDS 
ACROSS S CENTRAL MEXICO AND INTO THE SW GULF OF MEXICO. THIS 
BROAD CYCLONIC CIRCULATION WILL CONTINUE TO TRANSPORT ABUNDANT 
TROPICAL MOISTURE FROM THE TROPICAL EPAC NORTHEASTWARD INTO 
SOUTH AND SOUTH CENTRAL PORTIONS OF MEXICO DURING THE NEXT 24 
HOURS...ALLOWING FOR ADDITIONAL SHOWER AND TSTORM ACTIVITY TO 
PERSISTS ACROSS THESE AREAS. RAINFALL OF FOUR TO TEN INCHES ARE 
ESTIMATED TO HAVE FALLEN ACROSS THE PACIFIC COASTS AND SLOPES OF 
THE SIERRA MADRES DEL SUR...WITH AN ADDITIONAL FOUR TO TEN 
INCHES POSSIBLE DURING THE NEXT 24 HOURS. THIS HAS RESULTED IN 
POTENTIALLY A LIFE-THREATENING SCENARIO...WITH WIDESPREAD AREAS 
OF FLASH FLOODS AND MUD SLIDES POSSIBLE...ESPECIALLY IN REGIONS 
OF MOUNTAINOUS TERRAIN. RAINFALL MAY CONTINUE ACROSS THE REGION 
FOR ANOTHER FEW DAYS. PLEASE SEE WMO HEADER/AWIPS HEADERS WTPZ23 
KNHC/MIATCMEP3 FOR ADDITIONAL DETAILS.  

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
            
MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 07N74W TO 
10.5N81.5W TO INTERIOR HONDURAS NEAR 14.5N87W WHERE IT REMAINS 
FRACTURED...THEN RESUMES FROM 15.5N105W TO 09N121W TO 08N134W TO 
07N140W....WHERE IT TRANSITIONS TO ITCZ. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION NOTED N OF 05N E OF 87W. SCATTERED 
MODERATE TO STRONG CONVECTION NOTED WITHIN 100 NM EITHER SIDE OF 
LINE FROM 17N101W TO 15N103.5W TO 11.5N111.5W. 

...DISCUSSION...

AN UPPER TROUGH EXTENDING N TO S OVER N CENTRAL MEXICO ROUGHLY  
ALONG 105W CONTINUES TO PROVIDE DECENT OUTFLOW TO BOTH MANUEL 
AND HURRICANE INGRID IN THE SW GULF OF MEXICO. DRY AND SUBSIDENT 
NW FLOW BETWEEN THE UPPER TROUGH AND AN UPPER ANTICYCLONE 
CENTERED NEAR 22N123W IS SUPPRESSING CONVECTION W OF 105W 
ALLOWING FOR VERY DEEP ATMOSPHERIC MOISTURE AND ASSOCIATED 
CONVECTION CONFINED TO MANUEL AND VICINITY AND WITH THE VERY WELL 
PRONOUNCED MONSOONAL FLOW TO ITS SW. SW WINDS OF 20-30 KT WITH 
SEAS TO 15 FT ARE WITHIN THE MONSOON GYRE OVER THE AREA DEPICTED 
BY A LINE FROM 16.5N104W TO 16N100W TO 10N108W TO 12N111W TO 
16.5N104W. THIS PATTERN HAS PERSISTED FOR THE PAST SEVERAL DAYS 
AS MANUEL HAS DEVELOPED WITHIN THE GYRE. THE LONG FETCH OF SW 
WINDS AND DURATION OF THIS EVENT IS CAUSING ROUGH AND CONFUSED 
SEAS ALONG MUCH OF THE MEXICAN COAST FRONT THE GULF OF 
TEHUANTEPEC TO MANZANILLO...ALONG LARGE AND ROUGH SURF...WHICH 
IS CREATING HIGH POTENTIAL FOR COASTAL FLOODING AND RIP CURRENTS 
ALONG THE COAST. LOOKING AHEAD...GLOBAL MODELS CONTINUE TO 
INDICATE THAT THE SW FLOW WILL GRADUALLY BEGIN TO WEAKEN 
MON INTO WED WITH SEAS SLOWLY SUBSIDING.

ELSEWHERE AT THE SURFACE...A WEAK SURFACE HIGH PRES AREA IS 
CENTERED NW OF THE AREA WITH RIDGE EXTENDING W TO THE COAST OF 
THE BAJA PENINSULA. SCATTEROMETER DATA THIS AFTERNOON INDICATED 
NW TO N AROUND 15 KT WINDS OFF THE SOUTHERN COAST OF BAJA 
PENINSULA. IN ADDITION...FRESH TO STRONG NW WINDS WERE NOTED OF 
THE COAST OF SOUTHERN CALIFORNIA...THOUGH THESE WINDS ARE 20 KT 
OR LESS S OF 30N. NO SIGNIFICANT CHANGES ARE EXPECTED THROUGH 
MID WEEK.
 
$$
STRIPLING