000
AXPZ20 KNHC 180318
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI APR 18 2008

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 02N78W 07N105W 03N120W 03N140W. 
ISOLATED MODERATE CONVECTION FROM 02N-06N BETWEEN 86W-101W. 
SCATTERED MODERATE FROM 07N-12N BETWEEN 104W-108W. ISOLATED 
SHOWERS/TSTMS FROM 08N-10N BETWEEN 124W-135W.

...DISCUSSION...

W OF 115W...
MID/UPPER LEVEL CUT-OFF LOW REMAINS NEARLY STATIONARY NEAR 
25N136W AND WILL ULTIMATELY MOVE VERY LITTLE OVER THE NEXT 
SEVERAL DAYS UNTIL IT IS SHEARED OUT BY A STRENGTHENING 
SUBTROPICAL JET ON SUN. MODERATE SUBSIDENCE LIES WITHIN 420 NM 
OF THE UPPER LOW AND IS INDUCING A SUBSIDENCE INVERSION AND 
RESULTANT BROKEN STRATOCUMULUS FIELD N OF 14N W OF 126W. THE 
SUBTROPICAL JET SPLITS AS IT APPROACHES 140W FROM THE W...WITH 
ONE BRANCH DIVING SE AND CROSSING THE EQUATOR BETWEEN 130W-140W 
...AND THE OTHER BRANCH TURNING NE TOWARDS BAJA CALIFORNIA WITH 
JET CORE SPEEDS OF 60 KT. A BROAD UPPER DIFFLUENT REGION RESIDES 
DOWNSTREAM OF WHERE THE JET DIVERGES...AND A WEAK UPPER TROUGH 
LIES FROM 12N133W TO 02N120W...WHICH IS INDUCING ISOLATED 
SHOWERS/TSTMS ABOUT 300 NM N OF THE ITCZ BETWEEN 125W-130W. 
SOUTHWESTERLY FLOW WITHIN THE JET IS ADVECTING CIRRUS OUTFLOW 
FROM THIS ACTIVITY NE TOWARDS BAJA BUT THE ATMOSPHERE IS QUITE 
DRY IN THAT REGION WITH NEAR CLOUDLESS SKIES N OF 18N E OF 120W.

E OF 115W...
A VIGOROUS MID/UPPER LEVEL TROUGH IS SWINGING E INTO THE U.S. 
CENTRAL PLAINS WITH THE TAIL END OF THE AXIS BRUSHING THROUGH 
NORTHERN MEXICO. STRONG CONFLUENCE IS OCCURRING OVER NORTHERN 
MEXICO N OF 23N AS THE STRONG POLAR JET AROUND THE TROUGH 
COLLIDES WITH THE SOUTHWESTERLY SUBTROPICAL JET...PRODUCING 
MODERATE/STRONG SUBSIDENCE AND LIMITING SHOWER DEVELOPMENT OVER 
THE MEXICAN PLATEAU. A WEAK SHORTWAVE TROUGH ALSO EXTENDS 
FARTHER S ROUGHLY ALONG THE W/CENTRAL MEXICAN COAST WITH WEAKER 
SUBSIDENCE OCCURRING NEAR THE MOUTH OF THE GULF OF CALIFORNIA. 
FARTHER S...A ZONE OF DEEPER MOISTURE LIES BETWEEN 05N-15N W OF 
100W WITHIN WHICH THERE IS A CLUSTER OF DEEP CONVECTION UP TO 
480 NM N OF THE ITCZ AXIS BETWEEN 104W-110W. STRONGEST 
INDICATION IS THAT SLIGHTLY ENHANCED EASTERLY FLOW FROM THE GAP 
WIND EVENTS IS CONVERGING INTO SLIGHTLY WEAKER WINDS TO THE 
W...WITH THE REGION UNDER A WEAK AREA OF UPPER DIFFLUENCE. 
FARTHER E...A LARGE AREA OF MODERATE/STRONG SUBSIDENCE LIES E OF 
97W AND IS LIMITING THE AMOUNT OF DEEP CONVECTION. CONVECTIVE 
ACTIVITY MAY BEGIN TO FORM NEAR THE COLOMBIAN COAST BEGINNING ON 
FRI OR SAT AS DEEPER MOISTURE OVERSPREADS THE REGION FROM THE E.

$$
BERG