000
AXPZ20 KNHC 102217
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE SEP 10 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 
2145 UTC.

...TROPICAL WAVES... 

A WEAK TROPICAL WAVE MOVING SLOWLY WWD ACROSS THE BAY OF 
CAMPECHE...SOUTHERN MEXICO...AND THE ADJACENT TROPICAL PACIFIC 
DURING THE PAST 36 HOURS APPEARS TO HAVE BEEN ABSORBED WITHIN 
THE BROAD CYCLONIC LOW LEVEL CIRCULATION ACROSS THE REGION...AND 
HAS BEEN DROPPED FROM THE 1800 UTC SURFACE MAP. 
 

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

MONSOON TROUGH AXIS BEGINS ACROSS CENTRAL AMERICA AS A BROAD 
CYCLONIC CIRCULATION ACROSS NICARAGUA...HONDURAS AND THE GULF OF 
HONDURAS AND MEANDERS SW TO NEAR 14N94W TO 17N104W TO 13N107W TO 
13N126W TO BEYOND 10N140W. SCATTERED MODERATE TO STRONG 
CONVECTION NOTED FROM 04.5N TO 07.5N BETWEEN 80W AND 85.5W. 
SCATTERED STRONG CONVECTION NOTED FROM 10N TO 13N BETWEEN 93.5W 
AND 99W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED 
ELSEWHERE FROM 07N TO 13.5N BETWEEN 91W AND 100W. 

...DISCUSSION...

AN UPPER TROUGH IS BECOMING NEARLY STATIONARY JUST TO THE NW OF 
THE DISCUSSION AREA...WHILE A DEEP LAYERED CYCLONE ENCOMPASSED 
THE SOUTHWESTERN U.S. BETWEEN 111W AND 125W AND EXTENDED S INTO 
THE AREA ALONG 28.5N118W. UPPER LEVEL RIDGING PREVAILED TO THE 
SW OF THIS CYCLONE TO 140W...AND WAS AIDING IN PRODUCING A BROAD 
ZONE OF GENERALLY DRY AND STABLE ATMOSPHERIC CONDITIONS ACROSS 
THE NW ONE-THIRD OF THE AREA. SOUTHEAST OF THE DEEP LAYERED 
TROUGH IS A BROAD UPPER RIDGE COVERING ALL BUT NW MEXICO...AND 
EXTENDING FROM AN ANTICYCLONE NEAR 23N105W W-SW TO NEAR 19N125W. 
ANTICYCLONIC FLOW GENERALLY RESIDES ELSEWHERE TO THE E...AS 
SCATTERED MODERATE TO STRONG CONVECTION ACROSS THE REGION 
CONTINUE TO INDUCE ZONES OF DIVERGENCE ALOFT. 

ELSEWHERE AT LOW LEVELS...A BROAD TROUGH EXTENDS FROM THE GULF 
OF CALIFORNIA S-SE TO OFFSHORE OF MANZANILLO MEXICO NEAR 
18N106.5W...WHERE ISOLATED MODERATE TO STRONG CONVECTION IS 
OBSERVED. MID DAY SCATTEROMETER PASSES ACROSS THE AREA SHOWED A 
BROAD ZONE OF MODERATE SW WINDS S OF THE MONSOON TROUGH FROM 
02.5N TO 10N BETWEEN E OF 112W...AND AN AREA OF 20-25 KT SW 
WINDS FROM 02N TO 08N BETWEEN 80W AND 89W...WHICH WAS FUELING A 
LARGE CLUSTER OF DEEP CONVECTION. 

GLOBAL MODELS INDICATE THAT THE SW MONSOONAL FLOW WILL 
STRENGTHEN BETWEEN 92W AND 105W DURING THE NEXT FEW DAYS AND 
GRADUALLY LEAD TO THE DEVELOPMENT OF A SURFACE LOW OFFSHORE AND 
TO THE SOUTHWEST OF THE GULF OF TEHUANTEPEC...WHERE IT MAY  
MEANDER FOR SEVERAL DAYS. THIS INCREASED SW FLOW WILL LEAD TO 
VERY ACTIVE CONVECTION ACROSS THIS AREA...AND LOCAL SEAS 
BUILDING 7-10 FT WITHIN 48 HOURS.

$$
STRIPLING