000
AXPZ20 KNHC 102118
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED DEC 10 2008

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...06N77W TO 
06N100W TO 08N120W TO 07N140W. SCATTERED MODERATE WITH ISOLATED 
STRONG CONVECTION IS WITHIN 60 NM OF THE POINT 07N81W. SCATTERED 
MODERATE CONVECTION IS WITHIN 75 NM OF THE POINT 06N86W. A LARGE 
AREA OF SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 200 NM 
OF THE POINT 11N113.5W.

...DISCUSSION...

DEEP LAYER TROUGH IS OVER MEXICO. THE GULF OF MEXICO COASTAL 
PLAINS OF EAST MEXICO ARE BEING AFFECTED BY A STRONG COLD FRONT 
WITH STRONG NORTHERLY WINDS AND OVERCAST COLD AIR STRATOCUMULUS.
A SMALL AREA OF BROKEN HIGH CLOUDS ARE ALONG THE RIDGE OF THE 
SIERRA MADRE OCCIDENTAL. OTHERWISE THE AREA UNDER THE TROUGH 
IS DRY IN LOWER AND MIDDLE AND UPPER LEVELS AND CLOUD FREE. THE 
TROUGH IS EXPECTED TO CONTINUE THROUGH 24 HOURS THEN WEAKEN AND 
MOVE EAST.

A DEEP LAYER TROUGH IS OVER THE NORTHWEST PART OF THE AREA 
CENTERED NEAR 26N130W. THE NORTHEAST SEMICIRCLE OF THE 
CIRCULATION IS MOIST AND DIFLUENT ALOFT WITH A LARGE AREA OF 
MULTI LEVEL CLOUDS WITHIN 600 NM IN THE NORTHEAST SEMICIRCLE.  

A MAINLY UPPER LEVEL TROUGH IS ALONG THE LINE FROM 23N120W TO 
03N128W. THE AREA EAST OF THIS AXIS OUT TO 105W N OF 08N AND TO 
120W S OF 08N IS MOIST IN THE MIDDLE AND UPPER LEVELS WITH MULTI 
LEVEL OVERCAST CLOUDS.  A LARGE AREA OF PERSISTENT CONVECTION IS 
STILL PRESENT WITHIN 200 NM OF THE POINT 11N113.5W. THE 
CONVECTION BEGAN ABOUT 24 HOUR AGO. A TROUGH IS ANALYZED AT THE 
SURFACE NEAR THE CONVECTION BUT NO DEVELOPMENT OF THIS FEATURE 
IS FORECAST.

REMAINDER OF THE MIDDLE AND UPPER LEVELS IS BROAD ANTICYCLONIC 
FLOW.

MODERATE SURFACE RIDGE IS NORTH OF 15N WEST OF 110W. REMAINDER 
OF THE AREA IS ANALYZED AS BROAD TROUGH.

GAP WINDS IN THE GULF OF TEHUANTEPEC WILL BEGIN THIS EVENING 
AND WILL RAPIDLY INCREASE TO GALE FORCE TONIGHT. THESE GALE 
CONDITION WILL CONTINUE THROUGH 36 TO 48 HOURS THEN SLOWLY 
DIMINISH.
 
$$
LL