000
AXPZ20 KNHC 231544
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI JAN 23 2009

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

BASED ON 0900 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
AXIS ALONG 04N77W TO 05N87W TO 03N97W TO 06N112W TO 05N140W.  
ISOLATED TO SCATTERED MODERATE CONVECTION WAS OCCURRING WITHIN 
90 NM S OF AXIS AND 45 NM N OF AXIS E OF 97W. ISOLATED TO 
SCATTERED MODERATE CONVECTION WAS OCCURRING WITHIN 90 NM OF AXIS 
BETWEEN 112W AND 126W AND BETWEEN 131W AND 140W. SCATTERED 
MODERATE WITH ISOLATED DEEP CONVECTION WAS OCCURRING FROM 08N TO 
18N BETWEEN 105W AND 114W.

...DISCUSSION...
MID TO UPPER LEVEL TROUGH CONTINUES ACROSS THE AREA...EXTENDING 
FROM W TEXAS SSW THROUGH 24N107W THEN CONTINUES SW AS A SHARP 
TUTT LIKE FEATURE TO 07N121W. SLY FLOW TO THE E OF THIS TROUGH 
HAS CONTINUED TO ADVECT MOISTURE FROM THE TROPICS NWD FOR THE 
PAST WEEK OR SO...WITH ACTIVE CONVECTION PERSISTING TO THE E OF 
TROUGH S OF 18N...AND GRADUALLY WEAKENING. CONVECTIVE DEBRIS AND 
HIGH LEVEL CLOUDS AND MOISTURE WAS ALSO BEING TRANSPORTED NE AND 
INTO W COASTAL MEXICO AND FROM BAJA CALIFORNIA ACROSS MUCH OF 
NRN MEXICO. A DOWNSTREAM UPPER RIDGE CENTERED OVER VENEZUELA IS 
FORCING MOISTURE OVER THE RIDGE AND N OF 20N. UPSTREAM OF THIS 
TROUGH...AN APPROACHING LONG WAVE TROUGH WAS SUPPORTING A COLD 
FRONT ACROSS NW PORTIONS OF THE AREA...FROM 30N130W TO 
21N140W...WITH SEAS BUILDING 14 TO 20 FT IN NW SWELL BEHIND THE 
FRONT. THE TROUGH AND FRONTAL SYSTEM ARE FORECAST TO MOVE SLOWLY 
SE DURING THE NEXT 48 HOURS...WITH SEAS GRADUALLY SUBSIDING 10 
TO 12 FT BEHIND THE FRONT. THIS SWELL WILL PROPAGATE SEWD 
THROUGH 48 HOURS AND MAINTAIN SEAS AT 8 FT AND HIGHER W OF 110W. 

HIGH PRESSURE CENTERED OVER FLORIDA IS PRODUCING FRESH TRADES IN 
THE W AND SW CARIBBEAN...WHICH ARE SPILLING OVER CENTRAL AMERICA 
...AND RESULTING IN COOL DRY GAP WINDS ALONG THE PACIFIC 
COASTLINES OF CENTRAL AMERICA FROM THE GULF OF FONSECA TO THE 
GULF OF PANAMA. THESE COOL NELY WINDS HAVE BEEN IN THE 20 TO 25 
KT RANGE AND WILL LIKELY LINGER AT AROUND 20 KT THROUGH 48 
HOURS. WINDS THROUGH THE GULF OF TEHUANTEPEC CONTINUE TO 
GRADUALLY DIMINISH...AND ARE EXPECTED TO DROP BELOW 20 KT BY 
THIS EVENING...BEFORE INCREASING AGAIN OVER 20 KT BY 48 HOURS. 

THE LINGERING TUTT LIKE TROUGH MENTIONED ABOVE EXTENDING DOWN 
INTO THE TROPICS HAS AIDED IN PRODUCING SEVERAL LOW LEVEL 
CYCLONIC CURLS AND WEAK LOWS DURING THE PAST SEVERAL DAYS...WITH 
A WEAK SURFACE TROUGH RECENTLY ANALYZED ALONG 115/116W. THIS 
PERTURBATION IS FORECAST TO MOVE MORE NW AFTER 24 HOURS AS THE 
LONG WAVE TROUGH APPROACHES...AND WILL ACT TO STRETCH AND WEAKEN 
THIS SURFACE TROUGH.  

AN OLD AND LINGERING 1012 MB SURFACE LOW CONTINUES TO DRIFT NE 
TOWARD THE CALIFORNIA-BAJA BORDER...WITH A NEARLY DIFFUSE FRONT 
HAVING MOVED INTO THE N HALF OF THE BAJA IN THE PAST 6 HOURS. AS 
THIS FRONTAL SYSTEM CROSSES THE GULF OF CALIFORNIA AND NUDGES UP 
AGAINST THE SIERRA MADRE OCCIDENTALES IN THE NEXT 24 HOURS...NW 
TO N FLOW OF 20 KT WILL SPILL OUT OF THE SRN HALF OF THE GULF OF 
CALIFORNIA AND INTO THE OFFSHORE WATERS TO 18N...WITH SEAS 
LIKELY TO BUILD TO 8 FT THERE BY 48 HOURS.

$$
STRIPLING