000
AXPZ20 KNHC 161613
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JUN 16 2008

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 
1600 UTC.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE (ITCZ) IS CENTERED ALONG 07N78W 
7N83W 10N96W 7N112W 6N120W 7N128W 5N140W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM S OF THE 
AXIS E OF 80W...AND ALSO BETWEEN 94W-99W. SCATTERED MODERATE 
CONVECTION IS WITHIN 180 NM N OF THE AXIS BETWEEN 128W-131W...
AND ALSO BETWEEN 136W-140W.

...DISCUSSION...

E OF 120W...
A NEARLY STATIONARY MID/UPPER LEVEL ANTICYCLONE IS OVER N/CENTRAL
MEXICO NEAR 27N104W...WITH A RIDGE EXTENDING SW TO 20N114W TO
12N116W. MODERATE TO STRONG SUBSIDENCE IS EVIDENT OVER MUCH OF 
THIS AREA...EXCEPT ACROSS A SWATH FROM 5N-13N E OF 115W WHICH
INCLUDES THE ITCZ. A MID/UPPER LEVEL TROUGH EXTENDS FROM 15N100W
NE ACROSS SE MEXICO AND TO THE GULF OF MEXICO. ISOLATED TSTMS
ARE WITHIN 3014N97W. THE MID/UPPER LEVEL TROUGH IS FORECAST TO 
MOVE NE OF THE AREA DURING THE NEXT 3-4 DAYS. THE TROUGH 
PRESENTLY SEPARATES TWO AREAS OF MID/UPPER LEVEL RIDGING...ONE 
TO ITS NW ASSOCIATED WITH THE MID/UPPER LEVEL ANTICYCLONE OVER 
NRN MEXICO AND THE OTHER TO ITS SE ALONG THE ISTHMUS OF CENTRAL 
AMERICA. A SURFACE TROUGH MOVING W ABOUT 10-15 KT EXTENDS FROM 
12N108W TO 6N109W. IT IS UNDER AN AREA OF DIFFLUENT FLOW LOCATED 
TO THE SW OF THE MID/UPPER LEVEL TROUGH...AND W OF THE MID/UPPER 
RIDGE OVER CENTRAL AMERICA.

DUE TO THE LOCATIONS OF THE MID/UPPER TROUGH AND MID/UPPER 
RIDGE...THE UPPER FLOW IS E-SE N OF 8N E OF 90W AND NE THE
S OF 8N. BECAUSE THE FLOW BECOMES DIFFLUENT BETWEEN 92W-100W
...CONVECTION ALONG THE ITCZ IN THAT AREA REMAINS ACTIVE. A
SURFACE TROUGH MAY BE FORMING THERE AS WELL. THIS UPPER FLOW
CONTINUES TO TRANSPORT UPPER LEVEL ITCZ MOISTURE NEWD TO E OF 
THE AREA AND INTO THE WRN CARIBBEAN SEA. 

W OF 120W...  
A SMALL MID/UPPER LEVEL LOW MOVING NE 15 KT IS OVER THE FAR NW 
CORNER NEAR 31N140W. A PERSISTENT TROUGH EXTENDS SE FROM THE LOW
THROUGH 26N136W TO 22N132W TO 18N128W TO NEAR 11N120W. A SPLIT 
FLOW PATTERN IS OBSERVED W OF THE TROUGH. N OF 13N THE FLOW IS 
SW TO W...WHILE S OF 13N THE FLOW PATTERN IS RATHER ZONAL 
BECOMING MORE BROADLY ANTICYCLONIC TO THE S OF 7N. MODERATE 
SUBSIDENCE PERSISTS TO THE E OF THE TROUGH N OF 18N. THE TROUGH 
IS FORECAST TO LIFT N AND GRADUALLY DAMPEN OUT OVER THE NEXT 
48 HOURS. UPPER MODEL GUIDANCE SUGGESTS THAT A SHORTWAVE TROUGH 
MAY SWEEP THROUGH THE NW CORNER OF THE AREA ON THU.

AT THE SURFACE...A RIDGE EXTENDS SE INTO THE AREA AT 32N140W 
...AND REACHES TO 21N128W. HIGH PRES COVERS THE AREA THE AREA N 
OF 19N AND W OF 123W. PATCHES OF BROKEN TO OVERCAST STRATOCUMULUS
CLOUDS WITH POSSIBLE ISOLATED SHOWERS MOVING WWD ARE PRESENT N 
OF 14N. A WEAK SURFACE TROUGH MOVING W AROUND 10 KT IS ALONG 
15N122W 9N126W...AND IS DEPICTED WELL IN THE LOW LOW-LEVEL CLOUD 
MOTION IN ITS VICINITY. A QUIKSCAT PASS FROM THIS MORNING AGAIN
SHOWED A SUBTLE WIND NNE TO NE WINDS SHIFT WITH THIS TROUGH ALONG
WITH A SLIGHT CHANGE IN THE WIND SPEEDS.

$$
AGUIRRE