000
AXPZ20 KNHC 301540
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN JAN 30 2011

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 IS ALONG 05N77W TO 
03N100W TO 08N120W TO 07N140W. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS WITHIN 150 NM N OF AXIS FROM 116W TO 122W. 
A DIFFLUENT PATTERN ALOFT IS HELPING TO INDUCE THIS CONVECTIVE 
ACTIVITY.

...DISCUSSION...
ALOFT...A TROUGH/RIDGE PATTERN DOMINATES THE FORECAST AREA W OF 
110W. A DEEP LAYER TROUGH IS OVER THE W PORTION EXTENDING FROM 
27N132W TO 11N138W. SW WINDS AHEAD OF THE TROUGH AXIS ARE 
TRANSPORTING ABUNDANT MID/UPPER LEVEL MOISTURE COVERING THE 
MAJORITY OF THE AREA N OF 5N W OF 120W. A 70-90 KT JET STREAM 
BRANCH IS OVER THE NE PORTION CROSSING CENTRAL BAJA CALIFORNIA 
INTO NORTHERN MEXICO. 

IN THE DEEP TROPICS...AN UPPER LEVEL CYCLONIC CIRCULATION IS 
CENTERED NEAR 7N98W. A FEW SHOWERS ARE NOTED NEAR THIS FEATURE. 
UPPER DIFFLUENCE IS SUPPORTING SOME SHOWER ACTIVITY NEAR THE 
COAST OF COLOMBIA. SW TO W WINDS OF 70 TO 85 KT ARE SEEN S OF 5N 
W OF 113W.  

AT THE SURFACE...A 1026 MB HIGH PRES CENTERED NEAR 31N133W 
EXTENDS A RIDGE SE OVER FORECAST WATERS TO NEAR 18N107W. THE
ANTICYCLONIC FLOW AROUND THE SOUTHERN PERIPHERY OF THE RIDGE IS 
PRODUCING AN AREA OF 20-25 KT TRADES FROM 13N TO 23N W OF 125W. 
THE PRESSURE GRADIENT BETWEEN THIS FEATURE AND LOW PRESSURE OVER 
MEXICO WILL SUPPORT 20 KT NW WINDS WITHIN 120 NM OF THE COAST OF 
BAJA CALIFORNIA N OF 25N BY MON AFTERNOON. THE HIGH PRES WILL 
MOVE NE OVER THE NEXT 24 HOURS WHILE SLIGHTLY STRENGTHENING. A 
TROUGH IS WITHIN THE ITCZ AND EXTENDS FROM 11N122W TO 5N124W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED IS OF 
TROUGH AXIS AND N OF THE ITCZ AS DESCRIBED ABOVE. A COLD FRONT 
WILL BE NEAR 30N140W TUE MORNING.  

REGIONAL SEAS WILL CONTINUE TO BE DOMINATED BY NW SWELLS. A NEW  
BATCH OF LONG PERIOD NW SWELL IS SPREADING SE ACROSS THE NW 
PORTION OF THE AREA RAISING SEAS 8 TO 12 FT. THE HIGHEST SEAS 
CAN BE FOUND OVER THE NW PORTION OF THE AREA TODAY...THEN N OF 
25N BETWEEN 121W AND 126W BY MON MORNING. ANOTHER SET OF NW 
SWELL WILL REACH THE FAR NW CORNER BY TUE WITH SIGNIFICANT WAVE 
HEIGHTS AS HIGH AS 15 FT LATER IN THE DAY.    

GAP WINDS...
NE WINDS OF 20 TO 25 KT...AND SEAS OF 8 FT PREVAIL OVER THE GULF 
PAPAGAYO AS FRESH TRADE WINDS FLOW IN THE SW CARIBBEAN FUNNELS 
THROUGH THE GAP. THE 1226 ASCAT 25 KM COASTAL WINDS VERIFIED 
THESE WIND SPEEDS...AND ALSO SHOWED NE WINDS OF 20 TO 25 KT 
THROUGH LAKE NICARAGUA. THESE WINDS WILL CONTINUE TO PULSE OVER 
THE NEXT COUPLE OF DAYS DURING THE OVERNIGHT AND EARLY 
MORNING HOURS WITH THE ASSISTANCE OF THE NOCTURNAL DRAINAGE 
FLOW.  

THE 1104 UTC WINDSAT PASS SHOWED NW WINDS OF 20 TO 25 KT THROUGH 
THE GULF OF PANAMA TO 5N. THESE WINDS ARE EXPECTED TO DIMINISH 
BELOW 20 KT IN ABOUT 24 HOURS.

$$
GR