000
AXPZ20 KNHC 250914
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE SEP 25 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0915 UTC.
  
...TROPICAL WAVES...
TROPICAL WAVE ALONG 90W/91W N OF 6N TO THE COAST OF EL SALVADOR 
MOVING W 10-15 KT. ALTHOUGH AIR MASS IS VERY MOIST...CONVECTION 
IS LIMITED DUE TO STRONG UPPER LEVEL NELY WINDS WHICH SHOULD 
CONTINUE FOR NEXT 48 HRS.   SCATTERED MODERATE TO STRONG 
CONVECTION IS OVER THE NORTHERN PORTION OF THE WAVE AXIS INLAND 
OVER EL SALVADOR...GUATEMALA AND WRN HONDURAS.  

TROPICAL WAVE ALONG 109W FROM 5N TO 16N MOVING W 10 KT. A WEAK 
1010 MB LOW IS EMBEDDED ON THE WAVE AXIS NEAR 12N. WAVE IS 
EMBEDDED IN AN ENVIRONMENT OF NORTHEASTERLY SHEAR. NO 
SIGNIFICANT CONVECTION EXISTS ALONG THE WAVE AXIS ALTHOUGH A 
PATCH OF SCATTERED MODERATE CONVECTION IS NOTED FROM 10N TO
12N BETWEEN 112W AND 116W...WELL DISPLACED FROM THE WAVE AXIS.  

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N78W 10N88W 14N92W 12N110W 15N129W 
9N140W. WIDELY SCATTERED MODERATE WITHIN 90-120 NM OF THE AXIS 
BETWEEN 112W AND 118W...AND BETWEEN 128W AND 140W. WIDELY 
SCATTERED MODERATE N OF 11N TO THE COAST OF MEXICO BETWEEN 95W 
AND 100W.  

...DISCUSSION...
W OF 110W...
LARGE AMPLITUDE MID/UPPER TROUGH DIGS S ALONG 132W FROM A MID TO 
UPPER LEVEL CYCLONIC VORTEX NEAR 30N132W WITH STRONG SUBSIDENCE 
WITHIN 240 NM OF THE TROUGH AXIS AND ELSEWHERE NW OF JTST AXIS 
SLICING THROUGH 14N135W 23N125W ACROSS NRN BAJA CALIFORNIA TO NW 
MEXICO. JET ALSO ADVECTING LARGE AMOUNTS OF TROPICAL MOISTURE 
FROM ITCZ NE ACROSS NW MEXICO INTO SW CONUS. TROUGH EXPECTED TO 
SWING NE AS LARGE WELL ANCHORED ANTICYCLONE NEAR 23N110W BLOCKS 
ANY FURTHER EWD MOTION. HIGH IS ALSO PRODUCING MODERATE NE FLOW 
ALOFT TO 15N110W E OF THE AXIS BRINGING IN MID LEVEL DRY AIR AND 
NE SHEAR WHICH IS INHIBITING CONVECTION ALONG TROPICAL WAVE AT 
109W.

E OF 110W...
RIDGE AXIS EXTENDING FROM CENTRAL GULF OF MEXICO NEAR 24N92W 
SWWD ACROSS THE ISTHMUS OF TEHUANTEPEC TO 12N104W IS ACCOMPANIED 
BY MODERATE BUT MOIST NE FLOW AT THE UPPER LEVELS ACROSS CENTRAL 
AMERICA INTO THE TROPICAL E PACIFIC...BUT WITH CONVECTION 
LIMITED TO INLAND AREAS OF EL SALVADOR AND GUATEMALA. 

QUASI-STATIONARY 1009 MB LOW SW OF THE GULF OF TEHUANTEPEC NEAR 
12N957 MOVING W AT 10 KT. SHEARING NE FLOW ALOFT IS LIMITING 
CONVECTION AROUND THE LOW. 

REMNANT LOW OF T.D. THIRTEEN HAS OPENED UP INTO A SURFACE TROUGH 
WHICH EXTENDS FROM 14N TO 21N ALONG 130W. THIS TROUGH IS 
ENHANCING SOME ELY TRADE WINDS OVER THE FAR W PORTION OF THE 
AREA. 

HIGH PRES 1030 MB WELL N OF AREA FORCING TRADES ALONG CALIFORNIA 
COAST WITH MODERATE SWELLS ENCROACHING FROM 22N TO 31N E OF 
117W. LARGER CROSS EQUATORIAL SWELLS AFFECT SEAS S OF 10N W OF 
80W.  

$$
COBB