000
AXPZ20 KNHC 021631
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN SEP 02 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...SPECIAL FEATURES...

TROPICAL LOW...BROAD LOW PRESSURE AND ACTIVE CONVECTION ALONG 
THE MONSOON TROUGH NEAR 108W THIS MORNING CONTINUES TO ATTEMPT 
TO COALESCE INTO AN ORGANIZED TROPICAL CYCLONE. SATELLITE 
IMAGERY AND ASCAT WIND VECTORS YESTERDAY AFTERNOON SUGGESTED TWO 
LOW PRES CENTERS OCCURRING WITHIN A BROAD CYCLONIC 
ENVELOPE...WHILE AN OVERNIGHT ASCAT PASS AT 0445 UTC SUGGESTED 
THESE TWO CENTER MOVING CLOSER TOGETHER AS THE ENTIRE CYCLONIC 
ENVELOPE DRIFTED WNW. BOTH OF THESE TWO LOWS HAVE BEEN TRACKED 
OVERNIGHT AS POTENTIAL TROPICAL SYSTEMS...A SOUTHERN-MOST LOW 
ALONG THE MONSOON TROUGH...WHICH HAD REORGANIZED THIS MORNING 
NEAR 17N108W...AND A MORE NORTHERN LOW EMBEDDED IN STRONG E-SE 
WIND FLOW...WHICH WAS LOCATED NEAR 19N108W. THESE TWO FEATURES 
ARE EXPECTED TO MERGE INTO ONE LOW PRES CENTER IN THE NEXT 24-36 
HOURS. SCATTERED MODERATE TO STRONG CONVECTION WAS NOTED WITHIN 
180 NM NW AND 270 NM SE SEMICIRCLES OF THE SOUTHERN CENTER.... 
WHICH IS ASSUMED TO CURRENTLY BE THE MEAN CENTER. CONVECTION HAS 
BEEN FORMING INTO WELL DEFINED BUT SHORT BANDING SEGMENTS...BUT 
THE STRONGEST CONVECTION HAS SHIFTED TOWARD THE NORTH PORTION OF 
THE SYSTEM...AND THE NORTHER-MOST LOW...IN THE PAST FEW HOURS. A 
TROPICAL CYCLONE COULD FORM WITH THIS SYSTEM WITHIN THE NEXT 24 
HOURS. REGARDLESS...AN ELONGATED BAND OF 20 TO 30 KT E TO SE 
WINDS WILL REMAIN ACROSS THE NE SEMICIRCLE OF THIS SYSTEM AS IT 
SHIFTS WNW AROUND 15 KT DURING THE NEXT 24-48 HOURS. THIS WILL 
COMBINE WITH MODERATE SW LONG PERIOD SWELL TO MAINTAIN SEAS 9 TO 
15 FT WITHIN THIS AREA OF STRONG WINDS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N72W TO 07.5N85W TO 
NEAR 11N96W...WHERE IT BREAKS...THEN RESUMES FROM NEAR 15N102W 
TO COMPLEX LOW PRES NEAR 17N108W TO 09N127W TO BEYOND 10N140W. 
SCATTERED MODERATE TO STRONG CONVECTION WITHIN 210 NM EITHER 
SIDE OF TROUGH E OF 96W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION FROM 08N TO 23N BETWEEN 100W AND 113W. 

...DISCUSSION...
BROAD UPPER TROUGHING ACROSS N PORTIONS OF THE DISCUSSION AREA N 
OF 25N AND W OF 119W THIS MORNING...WITH ELONGATED UPPER RIDGING 
ACROSS TEXAS AND N MEXICO EXTENDING WSW TO THE REMNANTS OF T.D. 
ILEANA NEAR 22N122W...WITH NARROW RIDGE TO THE W OF ILEANA 
REMNANTS EXTENDING WSW TO 145W. ILEANA HAS CONTINUED TO WEAKEN 
TO A REMNANT LOW PRES CENTER...AND NOW CONSISTS OF A WELL 
DEFINED LOW TO MID LEVEL CLOUD SWIRL DEVOID OF CONVECTIVE 
CLOUDS. SOUTH THROUGH SOUTHEAST OF THE RIDGING...NE TO ELY FLOW 
GENERALLY PREVAILS ACROSS THE TROPICS W OF 90W...WHILE AN 
INVERTED UPPER TROUGH WAS LONG ABOUT 88W-89W...SHIFTING W.
  
...ELSEWHERE AT THE LOW LEVELS...
SURFACE HIGH PRES CENTER 1030 MB NW OF AREA NEAR 38N148W IS 
DOMINATED THE REGION NW OF ILEANA REMNANTS...PRODUCING MODERATE 
NE TRADES...WITH N TO NE WINDS 20-25 OCCURRING WITHIN 42O NM NW 
OF THIS LOW.

CROSS EQUATORIAL SW TO S SWELL CONTINUES TO PROPAGATE N AND NE  
INTO THE BASIN TODAY AND IS TO SUBSIDE BY MON.

$$
STRIPLING