000
AXPZ20 KNHC 120914
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAY 12 2007

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS ALONG 7N77W 10N91W 8N103W 
11N118W 7N132W 6N140W. ISOLATED STRONG CONVECTION NEAR 7N79W AND 
5N84W. SCATTERED MODERATE TO STRONG WITHIN AN AREA FROM 6N TO 
10N BETWEEN 93W AND 111W. OTHER SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION FROM 7N TO 11N BETWEEN 116W AND 126W.

OTHER STRONG CONVECTION ALONG THE COLOMBIAN COAST FROM 2N80W TO 
4N77W TO 6N77W.

...DISCUSSION...

A PERSISTING MID LEVEL TROUGH HANGES ON TONIGHT W OF 120W N OF 
20N. STRONGEST CENTER IS ALONG 130W WELL N OF THE REGION WHILE A 
SECONDARY SHORTWAVE MOVES E ALONG 135W. LOOKING UPSTREAM..A 
STRONGER UPPER LEVEL TROUGH IS BARRELING ESE OVER THE N PACIFIC 
PUMPING A RIDGE AHEAD OF IT ALONG 145W WHICH WILL PUSH THIS 
TROUGH EWD. A FLAT MID LEVEL RIDGE COVERS THE REMAINDER OF THE 
REGION TONIGHT BULGING NWD ALONG 110W. WEAK IMPULSES FROM THE S 
CENTRAL PACIFIC CONTINUE TO MOVE ENE IN THE SRN BRANCH OF THE 
WESTERLIES. ONE IS OVER THE CENTRAL BAJA COAST ANOTHER BACK NEAR 
20N137W. ON THE SURFACE TONIGHT THE PACIFIC RIDGE IS SLOWLY 
STRENGTHENING WITH A SLIGHT INCREASE IN NE TRADES S OF 20N W OF 
125W. ALSO NW WINDS ALONG THE BAJA COAST ARE INCREASING TO 20 
KT. OTHERWISE GAP WINDS REMAIN LIGHT WITH WEAK PRESSURE 
GRADIENTS OVER THE SRN GULF OF MEXICO AND WRN CARIBBEAN. 

LATER DAY 1 AS SHOWN IN LAST NIGHTS MODEL RUN..THE MID LEVEL 
FLOW BEGINS TO BECOME MORE WLY AS THE LATEST SHORTWAVE MOVES E 
ALONG 130W. THE FLAT MID LEVEL RIDGE CHANGES LITTLE AND STILL 
NOSES NWD OVER THE SW CONUS. ON THE SURFACE LATER DAY 1 THE 
PACIFIC RIDGE REMAINS ABOUT THE SAME WITH NE TRADES TO 20 KT AND 
SEAS TO 8 FT BETWEEN 10N AND 22N W OF 125W. NW WINDS ALONG THE 
BAJA COAST CONTINUE AT 15 TO 20 KT WITH SEAS TO 8 FT. SOME 
SLIGHT INCREASE IN N AND NE WINDS THROUGH TEHUANTEPEC WITH WEAK 
HIGH PRES OVER THE GULF OF MEXICO..OTHERWISE GAP WINDS REMAIN 
LIGHT. 

FOR DAY 2 AS THE LAST OF THE SHORTWAVES MOVES INLAND OVER 
CA..THE MID LEVEL HEIGHT FIELD BEGINS TO RISE ALONG 135W JUST N 
OF 30N IN RESPONSE TO THE STRONGER UPPER TROUGH MOVING E FROM 
THE N PACIFIC. THE GENERAL MID LEVEL FLOW N OF 20N W OF 120W 
REMAINS SWLY WITH WEAK IMPULSES CONTINUING TO MOVE ENE..ONE OF 
WHICH WILL LIE ALONG 120W. THE MID LEVEL RIDGE COVERING THE AREA 
E OF 120W SHOWS SIGNS OF WEAKENING OVER THE SW CONUS AS THE LAST 
SHORTWAVE MOVES INLAND OVER CA. THE RIDGE AXIS HAS BEEN BLOCKED 
THE PAST FEW DAYS BY A PERSISTENT TROUGH OVER THE GULF OF 
MEXICO. ON THE SURFACE DAY 2 THE PACIFIC RIDGE STRENGTHENS 
SLIGHTLY KEEPING NE TRADES TO 20 KT N OF 8N W OF 125W. N TO NW 
WINDS N OF 20N E OF 120W SHOULD BE 15 TO 20 KT WITH NW SWELL OF 
8 FT. GAP WINDS MOSTLY LIGHT EXCEPT FOR TEHUANTEPEC WHERE A 
LIGHT TO MODERATE N TO NE FLOW WILL CONTINUE THANKS TO A 1018 MB 
HIGH SITTING OVER THE WRN GULF OF MEXICO.  

$$
RRG