000
AXPZ20 KNHC 162130
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN MAY 16 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 79W FROM 02N TO 10N MOVING W AROUND 10 
KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS NOTED 
WITHIN 180 NM W OF THE WAVE AXIS FROM 05N TO 09N. THE WAVE 
COINCIDES WITH A MAXIMUM IN TOTAL PRECIPITABLE WATER IMAGERY AND 
POTENTIAL VORTICITY DIAGNOSTICS.

A WEAK TROPICAL WAVE IS ALONG 99W 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 09N84W TO 10N97W TO 10N101W TO 09N111W TO 08N124W 
TO 08N140W. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM EITHER 
SIDE OF THE AXIS BETWEEN 123W AND 128W...AND W OF 138W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM 32N121W TO 23N130W TO 
20N140W. MID TO UPPER LEVEL MOISTURE IS NOTED N OF 24N W OF THE 
TROUGH AXIS. AN UPPER RIDGE EXTENDS INTO THE FAR NW PORTION OF 
THE AREA FROM 27N140W TO 26N132W WITH MID TO UPPER LEVEL 
MOISTURE NOTED N OF THE RIDGE AXIS. VERY DRY AIR IS IN PLACE N 
OF 21N AND E OF THE TROUGH AXIS ACROSS BAJA CALIFORNIA AND NW 
OLD MEXICO. 

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 
11N140W. A JETSTREAM AXIS ENTERS THE AREA NEAR 17N140W AND 
CONTINUES TO THE NE-E TO 21N120W TO 22N106W AND INTO CENTRAL 
MEXICO. A JETCORE WITH MAXIMUM WINDS OF 75-95 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 122W.

A LARGE UPPER LEVEL CYCLONE IS CENTERED OVER BRAZIL SE OF THE 
EQUATOR WITH AN UPPER TROUGH EXTENDING FROM THE CYCLONE TO NEAR 
00N95W. CONVERGENT FLOW BETWEEN THIS CYCLONE AND THE ABOVE 
MENTIONED RIDGE OVER THE FAR E PORTION OF THE AREA IS ENHANCING 
CONVECTION ALONG THE ITCZ E OF 93W.

AT THE SURFACE...A WEAKENING RIDGE AXIS EXTENDS FROM 26N140W TO 
22N119W TO 15N105W. NE TRADES OF 20 KT EXIST SW OF THE RIDGE 
AXIS FROM 09N TO 18N W OF 124W. 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