000
AXPZ20 KNHC 060951
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE APR 06 2010

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...ITCZ...

AXIS IS CENTERED ALONG 4N78W 4N90W 2N103W 2N114W 2N124W 4N140W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION WAS WITHIN 120 NM  
N OF THE AXIS BETWEEN 134W-138W.

...DISCUSSION...

A BROAD UPPER TROUGH COVERS THE AREA N OF 26N E OF 130W TO INLAND
THE WESTERN UNITED STATES. STRONG NW FLOW ORIGINATING FROM WELL 
N OF THE AREA DIVES SE INTO THE BACK SIDE OF THE TROUGH...AND 
ROUNDS THE BASE OF THE TROUGH N OF 27N BETWEEN 120W AND 130W. 
TWO JET STREAM BRANCHES...POLAR JET FROM THE NW AND A SUBTROPICAL
JET STREAM BRANCH FROM THE CENTRAL PACIFIC TROPICS MERGE OVER 
THE NE PORTION OF THE DISCUSSION AREA GENERALLY SE OF THE TROUGH 
AXIS.

THE TROUGH IS FORECAST TO SLIDE EWD OVER THE W-CENTRAL CONUS 
OVER THE NEXT FEW DAYS AS MID/UPPER LEVEL RIDGING OVER THE NW
PORTION OF THE AREA N OF 25N SHIFTS E AND DAMPENS OUT THROUGH
WED. MAJORITY OF WAVEWATCH MODEL GUIDANCE INDICATES THAT A 
RATHER LARGE NW SWELL TRAIN WILL PROPAGATE INTO THE NE PART OF 
THE AREA BEGINNING TODAY GENERATING COMBINED SEAS OF UP TO 15 FT 
NEAR 30N E OF 130W BY THIS AFTERNOON AND INTO TONIGHT. SWELLS 
WILL THEN BEGIN TO SLOWLY SUBSIDE THROUGH WED.

THE PRES GRADIENT BETWEEN HIGH PRES BUILDING E ACROSS WATERS N OF
20N AND LOWER PRES OVER THE SW U.S. WILL CONTINUE TO RESULT IN NW
WINDS OF 20-25 KT N OF 23N E OF 117W TO ALONG THE BAJA CALIFORNIA
COAST THROUGH LATE TONIGHT WITH SEAS IN THE RANGE OF 9-13 FT.
THESE WINDS THEN DIMINISH TO LESS THAN 20 KT IN 48 HRS AS THE 
PARENT HIGH CENTER N OF THE AREA BREAKS DOWN. NW WINDS OF 
20-25 KT WILL INCREASE THROUGH THE GULF OF CALIFORNIA N OF
26N BEGINNING THIS AFTERNOON...AND TO N OF 24N BY 48 HRS.

TO THE SE OF THE TROUGH...THE UPPER FLOW PATTERN IS GENERALLY 
CONTROLLED BY AN ANTICYCLONIC CIRCULATION NEAR 7N109W WITH A 
RIDGE WNW TO 9N127W AND ANOTHER RIDGE E TO ACROSS THE NW PORTION 
OF S AMERICA. MODERATE SWLY FLOW BETWEEN THE ANTICYCLONE/RIDGE
WITH THE ADDITIONAL SUPPORT OF A JET STREAM BRANCH THAT EXTENDS
FROM THE DEEP CENTRAL TROPICAL PACIFIC NE THROUGH 9N140W TO 
13N129W TO 17N120W AND TO ACROSS NORTHERN MEXICO IS BRINGING 
PATCHES OF MOSTLY UPPER LEVEL TROPICAL MOISTURE IN THE FORM OF 
SCATTERED CIRRUS CLOUDS ACROSS THE REGION...AND TO INLAND NW 
MEXICO. AN UPPER LEVEL IMPULSE RIDING ALONG THE JET STREAM IS 
NOTED ON WATER VAPOR IMAGERY NEAR 10N138W. A WEAK MID LEVEL 
TROUGH IS EMBEDDED IN THE SWLY FLOW...AND EXTENDS FROM 21N109W 
SE TO 14N105W. AT THE SURFACE...A TROUGH IS ANALYZED TO THE SW OF
THE MID LEVEL TROUGH ALONG A PSN FROM 5N117W TO 13N112W. SINCE
THE TROUGH IS ALSO UNDER THE ABOVE RIDGE...CONVECTION IN THE
FORM OF SCATTERED SMALL CLUSTERS OF TSTMS IS ACTIVE ALONG AND
WITHIN 30-60 NM E OF THE TROUGH. 

WITH A SERIES OF STRONG FRONTAL SYSTEMS N OF THE AREA 
APPROACHING THE UNITED STATES W COAST THROUGH THE NEXT 48 
HRS...HIGH PRES WILL BE SHUNTED S INTO THE AREA AS AREAS OF 
STRONGER HIGH PRES N OF THE AREA MIGRATE EWD BEHIND THESE 
SYSTEMS. THIS PATTERN WILL ALLOW FOR THE CURRENT AREA OF TRADES 
CONSISTING OF NE-E 20 KT WINDS FROM 8N-24N W OF 124W TO EXPAND
E TO NEAR 118W BY 24 HRS THEN DECREASE TO W OF ABOUT 124W IN 
48 HRS. EXPECT CROSS-EQUATORIAL NWLY SWELLS IN THE RANGE 9-11 FT
TO CONTINUE TO IMPACT THE WATERS W OF A LINE FROM THE SOUTHERN
TIP OF BAJA CALIFORNIA TO 10N100W TO THE EQUATOR AT 92W THROUGH
48 HRS.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
AGUIRRE