000
AXPZ20 KNHC 170305
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON MAY 17 2010

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.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 81W FROM 03N TO 10N MOVING W AROUND 10 
KT. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 120 NM W OF 
THE WAVE AXIS FROM 07N TO 09N. THE WAVE COINCIDES WITH A MAXIMUM 
IN TOTAL PRECIPITABLE WATER IMAGERY AND POTENTIAL VORTICITY 
DIAGNOSTICS.

A WEAK TROPICAL WAVE IS ALONG 100W FROM 05N TO 12N MOVING W 
AROUND 10 KT. SCATTERED SHOWERS ARE NOTED ON EITHER SIDE OF THE 
WAVE AXIS. THE WAVE COINCIDES WITH A MAXIMUM IN TOTAL 
PRECIPITABLE WATER IMAGERY.

...ITCZ...

AXIS IS ALONG 10N83W TO 10N99W TO 10N102W TO 09N111W TO 09N115W 
TO 08N140W. NO SIGNIFICANT CONVECTION WAS NOTED.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM 32N120W TO 21N130W TO 
20N140W. MID TO UPPER LEVEL MOISTURE IS NOTED N OF 22N W OF THE 
TROUGH AXIS. VERY DRY AIR IS NOTED WITHIN 300 NM E OF THE TROUGH 
AXIS. AN UPPER RIDGE EXTENDS INTO THE FAR NW PORTION OF THE AREA 
FROM 25N140W TO 25N132W WITH MID TO UPPER LEVEL MOISTURE NOTED N 
OF THE RIDGE AXIS.

AN UPPER ANTICYCLONE IS CENTERED NEAR 08N105W WITH A RIDGE AXIS 
EXTENDING TO THE E ALONG 09-10N ACROSS CENTRAL AMERICA AND INTO 
THE NW CARIBBEAN SEA. A RIDGE AXIS ALSO EXTENDS TO THE W TO NEAR 
10N140W. A JETSTREAM AXIS ENTERS THE AREA NEAR 16N140W AND 
CONTINUES TO THE NE-E TO 20N121W TO 22N106W AND INTO CENTRAL 
MEXICO. A JETCORE WITH MAXIMUM WINDS OF 80-100 KT WINDS IS 
ADVECTING MID TO UPPER LEVEL MOISTURE FROM THE DEEP TROPICS S OF 
THE STATE OF HAWAII TO THE NE-E AROUND THE NORTHERN PERIPHERY OF 
THE ANTICYCLONE AND RIDGE. SPORADIC CONVECTION IS BEING ENHANCED 
ALONG THE ITCZ S OF THE RIDGE AXIS MAINLY W OF 123W.

A LARGE UPPER LEVEL CYCLONE IS CENTERED OVER BRAZIL SE OF THE 
EQUATOR WITH AN UPPER TROUGH EXTENDING FROM THE CYCLONE TO NEAR 
00N99W. CONVERGENT FLOW BETWEEN THIS CYCLONE AND THE ABOVE 
MENTIONED RIDGE OVER THE FAR E PORTION OF THE AREA IS ENHANCING 
CONVECTION SLIGHTLY ALONG THE ITCZ E OF 94W.

AT THE SURFACE...A WEAKENING RIDGE AXIS EXTENDS FROM 27N140W TO 
21N119W TO 14N110W. NE TRADES OF 20 KT EXIST SW OF THE RIDGE 
AXIS FROM 09N TO 16N W OF 128W. NE SWELL GENERATED BY THE TRADES 
IS MIXING WITH CROSS EQUATORIAL SW SWELL WITH COMBINED SEAS 
BETWEEN 8-10 FT. THE AREAL EXTENT OF THE TRADES WILL SHRINK 
DURING THE NEXT 24-48 HOURS AS THE RIDGE CONTINUES TO WEAKEN.

A COLD FRONT IS APPROACHING THE FAR NW PORTION OF THE DISCUSSION 
AREA. THIS FRONT WILL SKIRT ACROSS THE NORTHERN WATERS N OF 29N 
DURING THE NEXT 48 HOURS EVENTUALLY DISSIPATING BY LATE TUE AS 
IT NEARS BAJA CALIFORNIA. A TIGHT PRES GRADIENT NEAR THE FRONTAL 
REMNANTS WILL PRODUCE NW WINDS AT 20 KT ALONG THE W BAJA 
CALIFORNIA COAST BY 48 HOURS AND BEYOND.

$$
LEWITSKY