000
AXPZ20 KNHC 220918
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE DEC 22 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 9N84W 3N100W 9N135W 7N140W. NO SIGNIFICANT 
CONVECTION.

...DISCUSSION...
AN UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 30N137W 
WITH A TROUGH S TO 25N240W. A MID/UPPER LEVEL SHORTWAVE TROUGH
IS APPROACHING WITH CALIFORNIA COAST WITH AXIS S TO 32N122W
TO 29N127W. OTHERWISE A LARGE UPPER LEVEL RIDGE DOMINATES MUCH 
OF THE AREA W OF AROUND 100W,..WITH AXIS FROM NORTHERN MEXICO 
ACROSS SOUTHERN GULF OF CALIFORNIA TO 5N119W. A 95-115 KT 
JETSTREAM ENTERS THE AREA AT 22N140W THEN NE TO 32N121W THEN 
ACROSS THE ARIZONA/MEXICO BORDER THEN SE ACROSS EASTERN MEXICO. 
THE SW WINDS BETWEEN THE RIDGE AND UPPER LEVEL TROUGH IS 
ADVECTING TROPICAL MOISTURE NWD ACROSS THE RIDGE. A SHARP UPPER 
LEVEL TROUGH EXTENDS FROM THE YUCATAN PENINSULA TROUGH GUATEMALA
TO 5N104W. A 95-100 KT JETSTREAM IS E OF THE TROUGH FROM 9N91W 
ACROSS EL SALVADOR AND HONDURAS INTO THE NW CARIBBEAN. MODERATE 
TO STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER
LEVELS OF THE ATMOSPHERE HAS SUPPRESSED ITCZ CONVECTION.

A WEAK SURFACE TROUGH EXTENDS FROM NORTHERN BAJA CALIFORNIA NEAR
32N117W TO 26N123W. OTHERWISE HIGH PRES RIDGE IS N OF 18N W OF 
110W. A 1012 MB LOW IS CENTERED NEAR 13N124W. A FEW SHOWERS ARE
NEAR THE LOW PRES CENTER.

N TO NE WINDS OF 20 TO 30 KT ARE OCCURRING THROUGH THE GULF OF 
TEHUANTEPEC AND ARE EXPECTED DECREASE LATER TODAY.

THE COMBINATION OF STRONG TRADE WINDS IN THE CARIBBEAN AND LOCAL 
DRAINAGE EFFECTS WILL ALLOW FOR NE TO E 20 KT WINDS THROUGH THE 
GULF OF PAPAGAYO...THESE CONDITIONS ARE EXPECTED TO DECREASE 
LATER TODAY.

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