000
AXPZ20 KNHC 201535
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON DEC 20 2010

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

.ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N77W TO 
LOW PRES AT 07N87W TO 05N90W TO 13N117W TO LOW PRES AT 09N119W 
TO 06N140W. NO SIGNIFICANT CONVECTION.

.DISCUSSION...

WEAK HIGH PRES RIDGE CENTERED NEAR 1015 MB HIGH AT 25N116W. WEAK 
SURFACE LOW PRES NEAR 07N87W IS MOVING SLOWLY W WITH LITTLE OR NO
DEEP CONVECTION. LOW PRES NEAR 09N119W WITH TROUGH NE TO 16N115W 
HAS STUBBORN CONVECTION FLARING OCCASIONALLY NEAR THE CENTER AND 
ALONG THE TROUGH AXIS. TRADE WIND CONVERGENCE ALSO TRIGGERING AN 
AREA OF WEAK CONVECTION NEAR 15N138W. 

A SLOW MOVING COLD FRONT IS OVER NW PORTION OF AREA FROM 32N119W 
TO 24N140W. SCATTEROMETER DATA FROM 0600 UTC SHOWS 15-20 KT WINDS
ON EITHER SIDE OF FRONTAL BOUNDARY. STRONG 120-140 KT JET STREAM 
CORE ALONG 31N NEAR 140W LIFTS POLEWARD NEAR CALIFORNIA...AND AN 
UPPER LEVEL TROUGH IS ANALYZED FROM 27N119W TO 08N135W. MOST OF 
THE UPPER LEVEL THERMAL SUPPORT LIES WELL N OF 30N. AS A RESULT 
EXPECT THIS FRONT AND THE NEXT FRONT...WHICH WILL DEVELOP FROM A 
SHORT WAVE TROUGH TUE...TO LOSE MOST OF ITS STRENGTH S OF 27-28N.
BUT LARGE NW SWELL GENERATED BY HIGH WINDS N OF THE FRONT WILL 
SWEEP SOUTHWARD INTO THE TROPICS THE NEXT SEVERAL DAYS. WW3 MODEL
GUIDANCE SHOWS SEAS TO 14-15 FT BEHIND THE FRONT TODAY FOLLOWED 
BY ANOTHER SURGE OF 15-16 FT SWELL TUE NIGHT. GFS MODEL GUIDANCE 
INDICATES WINDS 20 KT OR GREATER WILL BE CONFINED PRIMARILY WITH 
FRONTAL BOUNDARIES N OF 27-28N THE NEXT SEVERAL DAYS EXCEPT FOR A
FEW AREAS OF GAP WINDS. TRADE WINDS S OF 25N AND ALONG THE ITCZ 
BOUNDARY WILL BE 15 KT OR LESS EXCEPT FOR AN AREA OF ENHANCED SE 
CROSS-EQUATORIAL FLOW WITH WINDS TO 20 KT WED S OF 10N W OF 125W.


.GAP WINDS...

SOUTHERLY RETURN FLOW IS WELL ESTABLISHED OVER THE GULF OF 
MEXICO. NO LONGER EXPECT WINDS TO EXCEED 20 KT IN THE GULF OF 
TEHUANTEPEC THROUGH TUE NIGHT...ALTHOUGH DRAINAGE FLOW MAY PEAK 
AT 15-20 KT AROUND SUNRISE TUE MORNING. WINDS INCREASE TO 20-25 
KT WED MORNING...AND AROUND 25 KT THU MORNING. DEPENDING ON THE 
STRENGTH OF THE PERSISTENT LOW PRESSURE NEAR 07N87W...EXPECT NE 
WINDS TO CONTINUE PULSE AT 15 TO 20 KT IN THE GULF OF PAPAGAYO 
POSSIBLY BECOMING A LITTLE STRONGER ON TUE. AS THE COLD FRONT 
APPROACHES NORTHERN BAJA CALIFORNIA PENINSULA WED...S WINDS WILL 
INCREASE TO 20-25 KT OVER THE GULF CALIFORNIA N OF 30N WED.
        
$$
MUNDELL