000
AXPZ20 KNHC 272201
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI NOV 27 2009

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 
2115 UTC.

...ITCZ...

AXIS ANALYZED ALONG 07N78W TO 06.5N96W TO 06N99W TO 09N119W TO 
08N123W TO 08N140W. SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 120 NM S OF THE AXIS BETWEEN 85W AND 
88W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 60 NM EITHER 
SIDE OF THE AXIS BETWEEN 88W TO 95W AND WITHIN 120 NM N OF THE 
AXIS BETWEEN 130W AND 140W. NUMEROUS MODERATE AND SCATTERED 
STRONG CONVECTION WAS NOTED WITHIN 210 NM S OF THE AXIS AND 120 
NM N OF THE AXIS BETWEEN 114W AND 130W.

...DISCUSSION...
UPPER LEVEL TROUGH EXTENDS FROM 35N114W TO 29N138W WITH DEEP SW 
MOIST FLOW MOVING UP ALONG THE TROUGH AXIS FROM JUST S OF THE 
HAWAIIAN ISLANDS UP INTO CALIFORNIA. N OF THIS TROUGH A LARGE 
UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 39N130W WITH DRY AND 
STABLE AIR BUILDING IN BEHIND THE TROUGH. AT THE SURFACE A 1037 
MB HIGH PRES IS CENTERED NEAR 38N138W WITH A RIDGE AXIS 
EXTENDING FROM THE HIGH TO NEAR 22.5N118.5W. A TIGHT PRES 
GRADIENT IS IN PLACE BETWEEN THE HIGH AND ITCZ W OF 122W AND A 
1900 UTC ASCAT PASS AND A 1500 UTC WINDSAT PASS BOTH INDICATED
20 TO 25 KT TRADE WINDS ACROSS THAT AREA. MEANWHILE LARGE LONG 
PERIOD NW SWELL UP TO 16 FT CONTINUES TO PROPAGATE THROUGH THE 
DISCUSSION AREA W OF 115W. THESE CONDITIONS WILL CONTINUE FOR 
THE NEXT FEW DAYS. A SECOND LONG WAVE AND DEEP LAYER TROUGH 
EXTENDS FROM S TEXAS TO NEAR 15N118W WITH DRY AND STABLE AIR 
ALOFT NW OF THE TROUGH SUPPRESSING ANY CONVECTION. 

ELSEWHERE...A 1008 MB LOW IS CENTERED NEAR 06N97W WITH A TROUGH 
FLANKING THE LOW FROM 02N98W TO 11N95W. THIS FEATURE IS 
PRODUCING SCATTERED MODERATE CONVECTION AND WINDS OF 20 TO 25 
KT...AND WILL CONTINUE TO MOVE TO THE W AROUND 10 KT DURING THE 
NEXT 48 HOURS. ANOTHER TROUGH IS LOCATED FROM 12N122W TO 19N116W 
WITH 20 TO 25 KT NE WINDS REALIZED NW OF THE TROUGH. THIS 
FEATURE WILL DRIFT TO THE N-NE DURING THE NEXT 48 HOURS. LATEST 
GFS GUIDANCE EVOLVES THE TROUGH INTO A CLOSED AREA OF LOW PRES BY
48 HOURS HOWEVER THE ECMWF KEEPS IT AS A MUCH WEAKER SYSTEM/ 
TROUGH. WILL FOLLOW A BLEND OF THESE TWO DIFFERING SOLUTIONS FOR 
NOW.  

...GAP WINDS...
STRONG HIGH PRES OF 1026 MB HAS BECOME ESTABLISHED ACROSS THE 
GULF OF MEXICO IN WAKE OF A SURFACE COLD FRONT WHICH HAS NOW 
MOVED INTO THE NW CARIBBEAN. COLD AIR CONTINUES TO BE CHANNELED 
FROM THE SOUTHERN GULF OF MEXICO ACROSS THE ISTHMUS OF 
TEHAUNTEPEC AND OVER THE GULF OF TEHUANTEPEC AND DOWNSTREAM 
WATERS. STORM FORCE WINDS WILL DIMINISH TO GALE FORCE IN THE 
NEXT 6 HOURS...AND WILL FURTHER DIMINISH TO LESS THAN 20 KT IN 
LESS THAN 48 HOURS WITH THE THERMAL GRADIENT DIMINISHING AS THE 
AIRMASS BECOMES MODIFIED.

EASTERLY TRADES IN THE W CARIBBEAN WILL CONTINUE TO FUNNEL WINDS 
THROUGH GULF OF PAPAGAYO AND DOWNSTREAM WATERS TO NEAR 91W 
THROUGH SUN TO MAINTAIN A FRESH TO STRONG BREEZE. 

$$
LEWITSKY