000
AXPZ20 KNHC 101554
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 09 2007

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 1515 UTC.
  
...TROPICAL WAVE...
A TROPICAL WAVE IS ABOUT TO MOVE W OF THE AREA ALONG 
140W...MOVING W NEAR 15 KT. THERE ARE A FEW SWIRLS OF LOW LEVEL 
CYCLONIC TURNING IN THE VICINITY...NONE OF WHICH ARE PRODUCING 
VERY ORGANIZED CONVECTION. SCATTERED MODERATE CONVECTION IS 
EMBEDDED IN THE ITCZ JUST TO THE E OF THE WAVE...FROM 8N-14N 
BETWEEN 131W-137W.  

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS CENTERED ALONG 13N87W 
11N100W 12N110W 11N120W 10N140W. BESIDES FOR THE CONVECTION 
DESCRIBED ABOVE WITH THE TROPICAL WAVE...SCATTERED MODERATE TO 
STRONG IS WITHIN 210 NM N OF THE AXIS BETWEEN 87W-102W. THIS 
UNORGANIZED ACTIVITY IS JUST OFF THE COAST OF NICARAGUA...EL 
SALVADOR...GUATEMALA...AND SE MEXICO. A WEAK TROUGH EMBEDDED IN 
THE ITCZ ALONG 112W IS ALSO SUPPORTING SCATTERED 
SHOWERS/ISOLATED TSTMS FROM 12N-15N BETWEEN 108W-116W. 

...DISCUSSION...

W OF 110W...
A WEAK COLD FRONT IS PUSHING THROUGH THE NW PORTION OF THE AREA 
ALONG 30N127W 27N140W. THE FRONT IS CHARACTERIZED BY A BROKEN UP 
LINE OF BROKEN TO OVERCAST LOW CLOUDS...PERHAPS PRODUCING LIGHT 
RAINFALL WITHIN 60NM EITHER SIDE OF THE BOUNDARY. MODERATE TO 
STRONG MEDIUM PERIOD (10-14S) NW SWELL ASSOCIATED WITH WINDS 
BEHIND THE FRONT WILL SPREAD THROUGH THE AREA OVER THE NEXT 
COUPLE DAYS...AS THE FRONT ITSELF BECOMES DIFFUSE. A 1021 MB 
HIGH IS AHEAD OF THE FRONT NEAR 27N125W...PRODUCING MODERATE NW 
WINDS ALONG THE COAST OF BAJA. 

ALOFT...A SHORTWAVE TROUGH IS OVER THE NW PORTION OF THE 
DISCUSSION AREA. WV IMAGERY SHOWS THAT MID TO UPPER VORTICITY IS 
MAXIMIZED NEAR 24N134W. SW/WSW FLOW AHEAD OF THIS IS SPREADING A 
SMALL PLUME OF UPPER MOISTURE TOWARDS CENTRAL BAJA. AN UPPER 
HIGH IS CENTERED NEAR THE SRN GULF OF CALIFORNIA NEAR 25N110W 
THAT HAS RIDGING SPREADING SW OVER MUCH OF THE REMAINDER OF THE 
AREA. AN EMBEDDED INVERTED UPPER TROUGH IS ALONG 110W PRODUCING 
INCREASED MOISTURE IN THE VICINITY. 

E OF 110W...
BROAD SFC TROUGHING CONTINUES TO DOMINATE THE FAR NE PACIFIC. A 
RECENT QUIKSCAT PASS SHOWED MODERATE MONSOON-LIKE SW FLOW OVER 
MUCH OF THE AREA E OF 105W TO THE COAST OF CENTRAL AMERICA AND 
MEXICO. THIS IS EXPECTED TO PERSIST OVER THE NEXT COUPLE OF 
DAYS...AND WILL ALLOW MODERATE...SHORT PERIOD SW WIND WAVES TO 
MIX WITH SMALL LONGER PERIOD BACKGROUND ENERGY FROM THE SOUTHERN 
HEMISPHERE. THE MOIST ONSHORE FLOW WILL ALSO ASSIST IN KEEPING 
SCATTERED SHOWERS/TSTMS LINGERING NEAR THE COAST OF CENTRAL 
AMERICA/SRN MEXICO.   

BROAD LOW PRES OVER THE YUCATAN PENINSULA AT 19N89W IS EXPECTED 
TO REMAIN QUASI-STATIONARY OVER THE NEXT COUPLE OF DAYS. THIS IN 
TURN IS CONTINUING THE NW TO N LOW LEVEL FLOW IN THE BAY OF 
CAMPECHE. THEREFORE...EXPECT INTERMITTENT BRIEF N SURGES INTO 
GULF OF TEHUANTEPEC...MOSTLY NEAR 15 KT...FOR THE NEXT FEW DAYS. 

ALOFT...LARGE SCALE UPPER E TO NE FLOW COVERS MUCH OF THE AREA S 
OF RIDGING FROM ANTICYCLONES OVER MEXICO AND THE CENTRAL 
CARIBBEAN. THERE ARE A FEW SMALLER SCALE INVERTED UPPER TROUGHS 
EMBEDDED IN THIS FLOW.

$$
WILLIS