000
AXPZ20 KNHC 150919
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE DEC 15 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
AXIS IS ALONG 5N77W 4N85W 5N115W 8N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 60 NM N OF AXIS FROM 131W-134W 
AND WITHIN 120 NM N OF AXIS W OF 135W.

...DISCUSSION...
A MID TO UPPER LEVEL TROUGH IS APPROACHING THE FAR NW CORNER
OF THE DISCUSSION AREA. A 95-100 KT JETSTREAM IS S OF THE TROUGH 
FROM 25N140W TO 25N135W. MID TO UPPER LEVEL RIDGE IS E OF THE 
TROUGH WITH AXIS FROM 32N123W TO 17N 135W. MODERATE TO STRONG
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER LEVELS
OF THE ATMOSPHERE COVERS THE AREA N OF THE ITCZ TO 25N W OF
120W. 

A SHARP MID TO UPPER LEVEL TROUGH EXTENDS FROM NW MEXICO THROUGH 
SOUTHERN BAJA CALIFORNIA TO 15N120W. A 95-115 KT JETSTREAM IS
SE OF THE TROUGH FROM 18N115W ACROSS MEXICO TO THE BIG BEND OF
TEXAS. OVERCAST HIGH CLOUDS ARE WITHIN 500 NM SE OF THE JET W OF 
107W. A WEAK UPPER LEVEL RIDGE IS S OF THE JET FROM SOUTHERN
MEXICO NEAR 18N97W TO 7N103W. MODERATE TO STRONG SUBSIDENCE IS
E OF 100W. THE SUBSIDENCE SUPPRESSED ANY SIGNIFICANT CONVECTION
ALONG THE ITCZ...WITH ONLY ISOLATED AREAS OF SHOWERS.

A 1023 MB HIGH PRES IS CENTERED NEAR 31N123W. A BROAD AREA OF 
MODERATE TO STRONG TRADE WINDS ON THE SOUTHERN PERIPHERY OF THE 
HIGH PRES...MAINLY FROM 08N TO 20N W OF 115W. COLD FRONT WILL 
ENTER THE FAR NW PORTION OF THE DISCUSSION LATER TODAY. A 
COUPLE OF TROUGH ARE ANALYZED ALONG THE ITCZ. THE FIRST ONE 
EXTENDS FROM 12N-4N ALONG 104W. SCATTERED SHOWERS ARE NEAR THE 
INTERSECTION OF THE TROUGH AXIS AND THE ITCZ. THE SECOND TROUGH
WITH AXIS FROM 13N122W TO 5N124W. A 1008 MB LOW IS ALONG THE 
TROUGH NEAR 8N124W. SCATTERED SHOWERS ARE NEAR THE LOW PRES
CENTER.

SEA HEIGHTS ARE BEGINNING TO INCREASE ACROSS THE NW PORTION OF 
THE AREA AS ANOTHER SET OF NW SWELL MOVES INTO THE DISCUSSION 
AREA. SEAS OF UP TO 16 FT ARE EXPECTED OVER THE NW PORTION OF THE
AREA WED EVENING.

NE WINDS 20 KT CONTINUE THROUGH THE GULF OF TEHUANTEPEC. MODEL 
GUIDANCE SUGGESTS THAT THIS WIND EVENT WILL CONTINUE AND THEN 
BECOME STRONGER WED INTO THU AS A COLD FRONT PUSHES INTO THE SW 
GULF WED.

NE TO E WINDS OF 20 TO 25 KT ARE STILL BLOWING ACROSS THE 
GULF OF PAPAGAYO AS A TIGHT PRES GRADIENT ACROSS THE WESTERN 
CARIBBEAN IS ALLOWING ELY TRADE WINDS TO FUNNEL ACROSS COSTA 
RICA AND NICARAGUA INTO THE EASTERN PACIFIC. THESE WINDS ARE 
EXPECTED TO SLIGHTLY DIMINISH DURING THE NEXT 24 TO 48 HOURS. 


FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE
  
$$
DGS