000
AXPZ20 KNHC 181005
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JUN 18 2006

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.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 93W N OF 5N MOVING W 10 KT. SCATTERED 
CONVECTION WITHIN 5 DEGREES W OF AXIS BUT NO ORGANIZATION.  

TROPICAL WAVE ALONG 104W FROM 5N TO 15N MOVING W 10 KT. A WEAK 
LOW PRES CENTER NEAR 12N108W MAY BE ASSOCIATED WITH THIS WAVE. 

TROPICAL WAVE ALONG 123W FROM 6N TO 15N MOVING W 15 KT. ITCZ IS 
BOWED NWD ALONG THE WAVE AXIS. ONLY ISOLATED CONVECTION AT THIS 
TIME.
 
TROPICAL WAVE ALONG 134W FROM 5N TO 13N MOVING W 10 KT. NO 
INDICATION OF WAVE PRESENCE AT THIS TIME. ISOLATED CONVECTION ON 
ITCZ. CIRRUS CLOUDS INDICATE 40 KT WLY WINDS AT 200 MB LEVEL 
OVER WAVE. 

..ITCZ...
AXIS ALONG...6N77W 5N85W 8N98W 6N106W 13N123W 7N140W. ISOLATED 
MODERATE CONVECTION NEAR 3N79W. SCATTERED MODERATE FROM 6N TO 
10N BETWEEN 95W AND 100W. SCATTERED MODERATE WITHIN 45 NM OF A 
LINE FROM 10N112W TO 10N117W. 

OTHER MODERATE CONVECTION NOTED WITHIN 120 NM NW QUADRANT OF A 
WEAK LOW CENTER NEAR 12N108W.

...DISCUSSION...

UPPER LEVEL FEATURES...

UPPER RIDGE ALONG 30N TONIGHT BULGING NWD OVER NW MEXICO 
ACCORDING TO LATEST WATER VAPOR IMAGERY. STRONG SUBSIDENCE AREA 
OVER NRN BAJA COINCIDES WITH ERN CENTER OF RIDGE. WRN CENTER 
BACK NEAR 30N145W. RIDGE SEPARATES WESTERLIES N OF 34N AND 
EASTERLIES S OF 22N. A WEAK SHORTWAVE TROUGH ALONG 130W S OF 20N 
CONTINUES TO SHOW SOME AMPLIFICATION TONIGHT AND THE LATEST 
IMAGERY SHOWS THE ITCZ BOWING NWD IN THAT AREA.

LATER DAY 1 THE GFS MODEL SHOWS THE ERN CENTER OF THE RIDGE 
GETTING LARGER OVER NRN MEXICO. ALSO MID LEVEL HEIGHTS BEGIN TO 
FALL BETWEEN THE TWO CENTERS BETWEEN 120W AND 135W. THE 
SHORTWAVE IN THE EASTERLIES REMAINS ALONG 130W BUT THE MODEL 
WANTS TO DEVELOP IT SLOWLY. 

FOR DAY 2 THE TWO RIDGE CENTERS REMAIN STATIONARY BUT CONTINUE 
TO SHOW SOME AMPLIFICATION. A SHORTWAVE IN THE WESTERLIES DROPS 
INTO THE WEAKNESS BETWEEN 115W AND 130W LOWERING HEIGHTS FURTHER 
N OF 25N. THE EASTERLIES BEGIN TO GET DIVERTED NW AROUND THE 
SHORTWAVE THAT SLOWLY MOVES TO 135W. STILL AN OPEN WAVE BUT 
BEING INFLUENCED BY THE WEAKNESS BETWEEN 120W AND 130W.

SURFACE FEATURES...

THE PACIFIC RIDGE APPEARS TO BE ABOUT THE SAME STRENGTH TONIGHT 
AS LAST NIGHT. NE TRADES 20 TO 25 KT ARE CONFINED N OF 20N W OF 
125W ACCORDING TO THE GFS MODEL. SSMI IS MOSTLY BLANK ACROSS 
THIS AREA AND QUIKSCAT IS NO HELP EITHER. PRESSURE GRADIENT E OF 
120W IS WEAK TONIGHT AND WINDS ALONG THE BAJA COAST ARE LIGHT 
NWLY. 

LATER DAY 1 LITTLE CHANGE TO THE PACIFIC RIDGE PRESSURE PATTERN 
WITH NE TRADES REMAINING STRONGEST N OF 20N AND W OF 125W. 
PRESSURE GRADIENT E OF 120W REMAINS WEAK WITH LIGHT WINDS. SWLY 
SWELL CONTINUES TO WORK IT'S WAY NWD E OF 120W. LONG PERIOD SW 
SWELL OF 9 TO 12 FT WORKS N TO 12N BETWEEN 90W AND 120W.

FOR DAY 2 THE PACIFIC RIDGE CHANGES LITTLE AND NE TRADES W OF 
130W REMAIN ABOUT THE SAME. NLY WINDS N OF 25N E OF 130W BEGIN 
TO EXPAND EWD TOWARD THE UPPER BAJA COAST AND NLY SWELL 
INCREASES A LITTLE. WINDS S OF 15N E OF 120W REMAIN LIGHT BUT SW 
SWELL CONTINUES N AND NE WITH LONG PERIOD SWELL OF 9 TO 11 FT 
MOVING TO THE CENTRAL AMERICAN COAST. AFTER DAY 2 THE SWELL 
HEIGHT SHOULD GRADUALLY DECREASE. 

$$
RRG