000
AXPZ20 KNHC 190334
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED JAN 19 2011

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 05N78W 
TO 05N100W TO 10N112W TO 1010 MB LOW NEAR 10N116W TO 08N130W TO 
08N140W. ISOLATED MODERATE CONVECTION IS NEAR 11N111W AND NEAR 
09N121W. NO SIGNIFICANT CONVECTION ELSEWHERE.

...DISCUSSION...

ALOFT...A SHORT-WAVE TROUGH MOVING EWD EXTENDS FROM 31N118W TO 
25N122W. ISOLATED TO SCATTERED SHOWERS ARE NOTED AHEAD OF THE 
TROUGH AXIS. A MID/UPPER LEVEL RIDGE EXISTS TO THE E OF THE 
TROUGH ACROSS THE GULF OF CALIFORNIA AND NORTHERN MEXICO. TO THE 
W OF THE TROUGH...THERE IS A RIDGE COVERING THE NW PORTION OF 
THE FORECAST AREA. AN UPPER LEVEL RIDGE...ANCHORED ON A HIGH 
OVER NORTHERN VENEZUELA IS HELPING TO INDUCE SOME CONVECTION 
NEAR A WEAK 1008 MB SURFACE LOW PRES LOCATED NEAR 05N78W. 

ELSEWHERE AT THE SURFACE...A 1030 MB HIGH PRESSURE IS CENTERED 
NEAR 37N134W AND EXTENDS A RIDGE SE OVER FORECAST WATERS TO NEAR 
20N110W. THE PRESSURE GRADIENT BETWEEN THE HIGH PRESSURE AND 
LOWER PRESSURE ASSOCIATED WITH THE ITCZ IS MAINTAINING 20 KT 
TRADE WINDS FROM 14N TO 20N W OF 135W. AN AREA OF NLY WINDS 20 
KT ARE ALSO NOTED ON THE EASTERN PERIPHERY OF THE RIDGE PER AN 
EARLIER ASCAT PASS. THESE WINDS ARE COVERING THE REGION N OF 27N 
BETWEEN 121W AND 132W. THE PRES GRADIENT WILL REMAIN TIGHT 
ENOUGH TO PRODUCE NLY OF 20 TO 25 KT OVER THE WATERS N OF 20N W 
OF 125W DURING THE NEXT COUPLE OF DAYS AS THE HIGH PRES MOVE 
SLOWLY WWD. 

LONG PERIOD NW SWELLS...WAVE PERIODS BETWEEN 16 TO 18 SECONDS... 
GENERATED FROM A LARGE AND INTENSE STORM CENTER WELL NW OF THE 
REGION PREVAIL OVER THE NW PART OF THE AREA WITH COMBINED SEAS 
TO 13 FT. THESE SWELLS WILL SPREAD SE THROUGH THE NEXT 48 HOURS 
WHILE SLIGHTLY SUBSIDING. A NEW BATCH OF NW SWELL SHOULD REACH 
THE FAR NW CORNER OF THE AREA IN ABOUT 48 HOURS. 

WINDS ARE EXPECTED TO INCREASE TO 20 KT ACROSS THE N PORTION OF 
THE GULF OF CALIFORNIA BY THU AS HIGH PRES SETTLES OVER THE 
GREAT BASIN.

$$
GR