000
AXPZ20 KNHC 202152
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED FEB 20 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 
2130 UTC.
 
...ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N77W 7N87W 4N104W 5N140W. ISOLATED 
MODERATE CONVECTION FROM 3N-8N BETWEEN 83W-86W. SCATTERED 
SHOWERS/TSTMS WITHIN 60 NM OF AXIS BETWEEN 112W-124W.

...DISCUSSION...

SUBTROPICS...
THE MID/UPPER LEVEL PATTERN ACROSS THE N PACIFIC WATERS AND 
NORTH AMERICA CONSISTS OF A GENERAL LARGE-SCALE RIDGE OVER THE 
WESTERN UNITED STATES AND A BROAD LONGWAVE TROUGH E OF THE ROCKY 
MOUNTAINS. BECAUSE OF THE PACIFIC RIDGE...A SPLIT FLOW REGIME IS 
IN PLACE BETWEEN HAWAII AND CALIFORNIA AND IS ACTING TO MAKE THE 
PATTERN SOMEWHAT STAGNANT. A SHORTWAVE TROUGH IS MOVING EWD 
WITHIN THE SUBTROPICAL PORTION OF THE SPLIT...EXTENDING FROM 
ARIZONA SW TO 20N128W AND ULTIMATELY PART OF A CUT-OFF LOW 
CENTERED OVER NEVADA. A DECAYING FRONTAL BOUNDARY ASSOCIATED 
WITH THE TROUGH IS DRAPED FROM SOUTHERN CALIFORNIA TO 28N123W TO 
30N130W BUT NOW IS ONLY ASSOCIATED WITH A BROKEN DECK OF LOW/MID 
LEVEL CLOUDS. ANOTHER FRONT IS LOCATED JUST NW OF THE REGION AND 
IS EXPECTED TO EASE SE OF 30N140W BY THU AFTERNOON. THERE IS 
ENOUGH MOISTURE AHEAD OF THE FRONT THAT SCATTERED SHOWERS/ 
ISOLATED TSTMS COULD DEVELOP PRIMARILY N OF 25N W OF 130W 
THROUGH THE DAY ON THU. HIGH PRES COVERS THE REMAINDER OF THE 
SUBTROPICAL WATERS WITH A 1024 MB HIGH CENTERED NEAR 24N127W.

OVER MEXICO...THE SUBTROPICAL JET EXTENDS ACROSS BAJA CALIFORNIA 
TOWARDS S/CENTRAL TEXAS WITH MAXIMUM WINDS OF 90 KT...AND A 
BROAD CANOPY OF CIRRUS LYING N OF 20N.

TROPICS...
A LARGE CUT-OFF MID/UPPER LOW IS LOCATED DEEP IN THE TROPICS 
NEAR 10N140W AND IS EXPECTED TO REMAIN DETACHED FROM THE 
MID-LATITUDE FLOW FOR SEVERAL DAYS. AN 80 KT JET STREAK LIES ON 
THE SE PERIPHERY OF THE LOW BUT THE FEATURE IS NOT CAUSING ANY 
NOTICEABLE WEATHER. THE ITCZ IS QUITE LINEAR W OF 110W WITH ONLY 
SCATTERED SHOWERS/TSTMS WITHIN 60 NM OF ITS AXIS. FARTHER E...AN 
ELONGATED MID-LEVEL RIDGE AXIS EXTENDS FROM THE NW CARIBBEAN TO 
NEAR 15N115W AND IS CAUSING MODERATE SUBSIDENCE ACROSS SOUTHERN 
MEXICO. OTHERWISE...A FAIRLY PRONOUNCED UPPER LEVEL EASTERLY JET 
EMANATING FROM COLOMBIA IS ADVECTING HIGH LEVEL MOISTURE 
WESTWARD TO NEAR 100W. THIS HAS DEEPENED THE MOISTURE 
AVAILABILITY AND PRODUCED WIDESPREAD CLOUDINESS E OF 92W WITH 
ISOLATED EMBEDDED CELLS OF MODERATE CONVECTION PRIMARILY ALONG 
THE ITCZ. SCATTERED TSTMS HAVE ALSO DEVELOPED OVER THE MOUNTAINS 
OF SW GUATEMALA AND THE ADJACENT WATERS FROM 10N-13N BETWEEN 
91W-94W.

$$
BERG