000
AXPZ20 KNHC 171613
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED NOV 17 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 
1430 UTC.

...ITCZ...
AXIS ANALYZED ALONG 08N83W TO 06N90W TO 13N111W TO 08N136W TO 
08N140W. SCATTERED TO LOCALLY NUMEROUS MODERATE TO STRONG 
CONVECTION WAS NOTED WITHIN 120 NM N AND 180 NM S OF AXIS FROM 
109W TO 115W. 

...DISCUSSION...
THE OMEGA BLOCKING PATTERN ACROSS THE DISCUSSION AREA IS 
BREAKING DOWN THIS MORNING AS A LARGE UPPER CYCLONE OVER THE FAR 
NE PACIFIC IS DIGGING S INTO THE STRONG UPPER RIDGE THAT HAS 
DOMINATED THE PAST SEVERAL DAYS. THIS LEAVING A COMPLEX MID TO 
UPPER PATTERN ACROSS THE AREA...BUT STILL WITH MEAN RIDGING FROM 
10N TO 30N CENTERED ALONG ABOUT 130W. SEE CIMSS SATELLITE 
DERIVED WINDS FOR SPECIFICS. UPPER RIDGING ACROSS THE CENTRAL 
CARIBBEAN CONTINUES TO COMBINE WITH AN EQUATORIAL UPPER TROUGH 
ALONG ABOUT 120W TO PRODUCE SWLY FLOW ALOFT S OF 20N AND E OF 
118W. SCATTERED STRONG CONVECTION MENTIONED ABOVE IS ASSOCIATED 
WITH A WEAK LOW PRESSURE CENTER ALONG THE ITCZ NEAR 13N111W... 
WITH THE DEEP CONVECTION CONTINUING TO ACT TO PRODUCE DIVERGENT 
FLOW ALOFT...AND A RESULTANT SUBTLE TROUGH ABOUT 360 NM 
DOWNSTREAM.   

STRONG 1042 MB SURFACE HIGH OF 24 HOURS AGO HAS WEAKENED TO A 
1026 MB HIGH NOW CENTERED NEAR 37N141W WITH WEAK RIDGING TO NEAR 
28N123W. THIS QUICKLY WEAKENING HIGH HAS ALSO RESULTED IN A 
RAPID DIMINISHING OF THE TRADEWINDS TO THE S AND SE OF THE 
HIGH...WITH NE TO E TRADES TO 20 KT CONFINED TO N OF 28N AND W 
OF 127W THIS MORNING...WITH SEAS THERE 10-11 FT IN MIXED SWELL. 
REMNANT NELY TRADE WIND SWELL AND LONG PERIOD SWELL MOVING 
THROUGH THE REGIONAL WATERS WAS YIELDING SEAS OF 8-10 FT ACROSS 
THE REMAINDER OF THE NW HALF OF THE AREA. 

LLVL MONSOONAL FLOW PREVAILED ACROSS THE REMAINDER OF THE AREA E 
OF 115W...WITH GENERALLY LIGHT TO MODERATE W TO NW WINDS TO THE 
N OF THE ITCZ...AND MODERATE SW TO W WINDS S OF THE ITCZ. EARLY 
MORNING SATELLITE IMAGERY SUGGESTED A BRIEF PULSE OF NLY WINDS 
BLOWING THROUGH THE GULF OF TEHUANTEPEC...TO AROUND 20 KT. THIS 
FLOW WILL DECREASE AND BECOME VARIABLE DURING THE 
AFTERNOON...BUT IS EXPECTED TO BLAST FROM THE N AGAIN LATE 
TONIGHT AND REACH GALE FORCE BY AROUND SUNRISE THURSDAY AS A NEW 
COLD FRONT PUSHES S ACROSS THE GULF OF MEXICO. WINDS ACROSS THE 
TEHUANTEPEC AREA WILL INCREASE FURTHER TO AT OR ABOVE STORM 
FORCE BY AROUND SUNSET THURSDAY EVENING AND CONTINUE THROUGH 
MUCH OF FRIDAY.

THE LOW PRES CENTER NEAR 13N111W HAS BEEN DRIFTING NW ALONG THE 
ITCZ FOR THE PAST FEW DAYS AND HAS ATTAINED A CONSIDERABLE 
AMOUNT OF DEEP CONVECTION THIS MORNING. THIS LOW IS BEING 
MONITORED FOR POTENTIAL IMPROVED ORGANIZATION...AND IS LIKELY TO 
DRIFT SW OVER THE NEXT FEW DAYS...AND MAINTAIN WINDS TO AROUND 
20 KT AND SEAS AT OR JUST BELOW 8 FT.

$$
STRIPLING