000
AXPZ20 KNHC 172125
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU APR 17 2008

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.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 01N79W 06N103W 03N130W 03N140W. 
SCATTERED MODERATE CONVECTION FROM 01N-04N BETWEEN 87W-91W. 
SCATTERED MODERATE FROM 05N-12N BETWEEN 100W-110W. SCATTERED 
SHOWERS/TSTMS FROM 09N-12N BETWEEN 125W-130W.

...DISCUSSION...

W OF 115W...
MID/UPPER LEVEL CUT-OFF LOW REMAINS NEARLY STATIONARY NEAR 
25N137W 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 125W. 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 10N130W TO 01N117W...WHICH IS INDUCING SCATTERED 
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 ACROSS THE FRONT 
RANGE OF THE ROCKIES OVER THE UNITED STATES 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 E OF 100W WITHIN WHICH A SIGNIFICANT CLUSTER OF DEEP 
CONVECTION HAS DEVELOPED UP TO 480 NM N OF THE ITCZ AXIS BETWEEN 
102W-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