000
AXPZ20 KNHC 140923
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON DEC 14 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 7N78W 6N105W 9N115W 6N130W 8N140W. NO SIGNIFICANT 
CONVECTION.

...DISCUSSION...
MID TO UPPER LEVEL RIDGE IS MOVING INTO THE NW PORTION OF THE
DISCUSSION AREA...N OF 15N W OF 135W. AN UPPER LEVEL TROUGH IS E 
OF THE RIDGE FROM 32N118W TO 23N126W. A JET STREAM BRANCH WITH 
CORE WINDS OF 90-95 KT ENTERING THE DISCUSSION AREA NEAR 22N140W 
TO 18N125W TO SOUTHERN BAJA CALIFORNIA. SOME MID/UPPER LEVEL 
MOISTURE IS NOTED ON WATER VAPOR IMAGERY N OF 25N WHILE MODERATE 
TO STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS OF THE ATMOSPHERE DOMINATES THE AREA N OF THE ITCZ W OF 
105W.

AN UPPER ANTICYCLONE LOCATED OVER THE NW CARIBBEAN WITH A RIDGE 
EXTENDING ACROSS SE MEXICO AND MOST OF CENTRAL AMERICA WHERE IT 
IS PRODUCING MODERATE TO STRONG SUBSIDENCE MAINLY E OF 100W. THE 
SUBSIDENCE IS LIMITING CONVECTION ALONG THE ITCZ.

A 1021 MB HIGH PRES IS CENTERED NEAR 30N129W. MODERATE TO STRONG 
TRADE WINDS ON THE SOUTHERN PERIPHERY OF THIS HIGH IN THE 20-25 
KT RANGE. THIS WEATHER PATTERN WILL PERSIST OVER THE NEXT COUPLE 
OF DAYS AS THE HIGH MOVES EWD. THE NEXT COLD FRONT IS EXPECTED 
TO REACH THE FAR NW PORTION OF THE AREA IN ABOUT 48 HOURS.

A COUPLE OF TROUGHS ARE ANALYZED ALONG THE ITCZ. THE FIRST 
TROUGH IS FROM 11N117W TO 05N118W. ONLY A FEW SHOWERS ALONG THE 
TROUGH. A SECOND TROUGH WITH AXIS FROM 10N138W TO 5N138W. NO 
SIGNIFICANT WEATHER ASSOCIATED WITH THE TROUGH.

LARGE AND LONG PERIOD NW SWELL CONTINUES TO SPREAD ACROSS THE 
REGION BEYOND THE EQUATOR. A NEW BATCH OF NW SWELL WITH WAVE 
PERIODS BETWEEN 14 TO 15 SECONDS IS NOW ENTERING THE N WATERS 
RAISING SEAS UP TO 12 FT. 

WINDS IN THE GULF OF PAPAGAYO ARE EXPECTED TO OSCILLATE BETWEEN 
20 TO 25 KT OVER THE NEXT 48 HOURS 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.

NLY WINDS OF 20 KT ARE STILL BLOWING ACROSS THE GULF OF 
TEHUANTEPEC. THE WINDS SHOULD DECREASE BY 24 HOURS...BUT ARE 
EXPECTED TO INCREASE AGAIN ABOUT MID WEEK.
  
$$
DGS