000
AXPZ20 KNHC 020405
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT MAY 02 2009

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...

ITCZ AXIS IS CENTERED ALONG 8N86W 6N96W 3N105W 4N115W 2N121W
4N140W. SCATTERED MODERATE CONVECTION EXISTS FROM 4N-8N BETWEEN
86W-89W.

...DISCUSSION...

HIGHLY AMPLIFIED FEATURES AREA ACROSS THE DISCUSSION AREA. THE 
FIRST BEING BROAD MID AND UPPER RIDGING STRETCHING FROM FROM 
NW MEXICO TO THE CENTRAL PORTION OF THE AREA WITH A MEAN AXIS
GENERALLY ALONG 32N107W SW TO ACROSS SRN BAJA TO 20N115W TO
A WELL ANCHORED ANTICYCLONE NEAR 10N120W. A WEAK LOW TO MID 
LEVEL INVERTED TROUGH EXTENDS FROM 8N134W TO 2N131W. UPPER LEVEL 
DIFFLUENCE BETWEEN THE TROUGH AND THE ANTICYCLONE MAY ALLOW
FOR CONVECTION TO INCREASE ALONG OR NEAR THE ITCZ BETWEEN 
132W-135W. THE TROUGH IS EXPECTED TO LOSE ITS IDENTITY OVER THE 
NEXT 24 HRS AS THE DEEP LAYER TROUGH DESCRIBED BELOW TAKES 
PRECEDENCE.

A NEARLY STATIONARY SHARPENING MID/UPPER LEVEL TROUGH IS OVER 
THE FAR ERN PORTION OF THE AREA EXTENDING FROM SE MEXICO SW TO 
10N103W TO 1N108W. A SMALL UPPER LEVEL CYCLONIC CIRCULATION 
MOVING W IS EMBEDDED IN THE TROUGH ALONG THE COAST OF MEXICO 
NEAR 17N97W. BROKEN MID AND UPPER LEVEL CLOUDS ARE BEING 
CHANNELED NEWD ACROSS CENTRAL AMERICA DRIVEN BY A JET STREAM 
FOUND TO THE E OF THE TROUGH ALONG 7N105W TO 11N98W NE TO ACROSS 
SE MEXICO AND WRN GUATEMALA. SCATTERED SHOWERS AND TSTMS ARE 
ALONG THE TROUGH AXIS AND JUST N OF THE ITCZ FROM 6N-9N BETWEEN 
90W-97W. SIMILAR ACTIVITY IS INCREASING OVER SE MEXICO E OF 98W 
TO OVER GUATEMALA AND NW HONDURAS FURTHER ENHANCED BY LATE 
DAYTIME HEATING. THIS CONVECTIVE ACTIVITY IS FORECAST TO 
CONTINUE THROUGH AT LEAST THE NEXT COUPLE OF DAYS AS THE LOW AND 
TROUGH REMAIN ABOUT STATIONARY.

MEANWHILE...THE RIDGE WILL GET NUDGED E OF THE AREA THROUGH SAT 
BY A RATHER SHARP DEEP LAYER TROUGH PRESENTLY ALONG 32N125W TO 
25N127W TO 18N134W TO 12.5N140W. A VERY WELL PRONOUNCED NRN 
STREAM JET STREAM BRANCH WITH MAXIMUM WINDS OF 70-120 KT SHARPLY 
DIVES SEWD BRUSHING THE FAR NRN BOUNDARY OF THE AREA. THE TROUGH 
WILL QUICKLY LIFT NE AND SHEAR OUT OVER THE FAR NE PART OF THE 
AREA AND ACROSS NRN BAJA CALIFORNIA AND SRN CALIFORNIA ON SAT. 
AT THE PRESENT TIME...DEEP LAYER MOISTURE CONSISTING OF BROKEN 
MULTILAYERED CLOUDS WITH SCATTERED SHOWERS AND ISOLATED TSTMS IS 
ADVECTING NEWD ACROSS THE CENTRAL AND NE PORTIONS OF THE AREA 
WITHIN 160 NM E OF THE TROUGH.

BROAD/MID UPPER LEVEL RIDGING IS LOCATED TO THE E OF THE TROUGH
WITH A MEAN AXIS STRETCHING NW TO SE ALONG THE WRN CARIBBEAN 
SEA.

AT THE SURFACE...HIGH PRES OF 1022 MB IS NEAR 26N126W WITH A 
RIDGE SE TO 14N104W. AS THE TROUGH W OF THE AREA ADVANCES EWD 
THROUGH THE NEXT 48 HRS...THE RIDGE WILL ALSO SLIDE E WHILE LOW 
PRES DEEPENS OVER THE PLAINS INTO NRN MEXICO. THIS WILL ALLOW 
FOR THE PRES GRADIENT TO INCREASE OVER THE NE PART OF THE AREA 
INCREASING NW WINDS ALONG THE BAJA CALIFORNIA COAST TO THE RANGE 
OF 20-25 KT IN ABOUT 24 HRS...WITH SEAS TO 9 FT MAYBE A 
SHORT-LIVED
10 FT SEA HEIGHT COULD BE POSSIBLE.

A WEAKENING FRONTAL TROUGH IS ANALYZED FROM 30N131W TO 26N140W
AND IS FAINTLY SEEN ON THE LAST FEW VISIBLE IMAGES. N OF 29N
WITHIN 240 NM E OF TROUGH SW WINDS TO 20 KT ARE TAKING PLACE.
THE TROUGH IS FORECAST TO DISSIPATE INTO SAT MORNING ALLOWING 
FOR A WEAKER GRADIENT TO ITS E TO SUPPORT WEAKER SW WINDS TO 20 
KT. HOWEVER...A STRONGER COLD FRONT VISIBLE TO THE NW OF THE 
AREA IN A FASTER WLY FLOW NRN STREAM WILL QUICKLY ADVANCE EWD 
DURING THE NEXT 48 HRS WHILE PASSING JUST TO THE N OR BRUSH 30N.
STRONG SW WINDS WILL EXIST N OF THE AREA AHEAD THE 
FRONT...HOWEVER
IN ITS WAKE A LARGE NW SWELL TRAIN CONSISTING OF SEA HEIGHTS IN 
THE 8-11 FT RANGE WITH WAVE PERIODS OF 11-13 SECONDS WILL BEGIN 
TO INVADE THE FAR NW WATERS SAT NIGHT THROUGH SUN PER LATEST 
WAVE MODEL GUIDANCE.

A WEAK TROUGH MOVING W 10-15 KT EXTENDS FROM 2N139W TO 9N138W.
ISOLATED WEAK CONVECTION IS W OF THE TROUGH FROM 4N-7N MAINLY 
TIED TO THE ITCZ...WITH SLIGHTLY MORE CONVECTION JUST W OF THE 
AREA.

$$
AGUIRRE