000
AXPZ20 KNHC 012121
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU NOV 01 2007

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 9N77W 5N100W 13N127W 10N140W. 
SCATTERED SHOWERS N OF 6N E OF 88W. SCATTERED MODERATE 
CONVECTION WITHIN 120 NM OF AXIS W OF 122W.

...DISCUSSION...

E OF 110W...
WESTERLY MID-LATITUDE FLOW HAS SHIFTED FARTHER S OVER THE PAST 
FEW DAYS COURTESY OF A SHORTWAVE TROUGH NOW LOCATED OVER THE ERN 
GULF OF MEXICO. THE SRNMOST EXTENT OF THE UPPER LEVEL WESTERLIES 
IS AROUND 20N WITH A RIDGE AXIS SPANNING ACROSS SRN MEXICO ALONG 
18N. THE FLOW IS QUITE ZONAL AT THE MOMENT...SO THE LACK OF AN 
UPPER TROUGH/DIVERGENCE IS KEEPING THE AREA UNDER THE INFLUENCE 
OF MODERATE/STRONG SUBSIDENCE BETWEEN 90W-110W. E OF 90W...THE 
ITCZ HAS BEEN PULLED N ACROSS COSTA RICA AND PANAMA DUE TO BROAD 
CYCLONIC FLOW OVER THE SW CARIBBEAN...AND WEAK UPPER DIVERGENCE 
IS HELPING TO PRODUCE SCATTERED SHOWERS N OF 6N E OF 88W.

VISIBLE IMAGERY CONTINUES TO SHOW A CLEAR SWATH EMANATING SSW OF 
THE GULF OF TEHUANTEPEC WHERE MAXIMUM WINDS ARE NEAR 30 KT. HIGH 
PRES IS EXPECTED TO BUILD OVER THE GULF OF MEXICO BY SAT...AND 
GALES COULD ONCE AGAIN BECOME ESTABLISHED OVER TEHUANTEPEC BY 
SAT NIGHT.

W OF 110W...
THE MID/UPPER RIDGE OVER MEXICO EXTENDS WWD ROUGHLY ALONG 17N AS 
FAR W AS ABOUT 120W. TO THE N OF THE RIDGE...THE WESTERLY FLOW 
IS BECOMING ESTABLISHED WITH A CUT-OFF MID-LEVEL LOW LOCATED 
JUST W OF BAJA CALIFORNIA NEAR 25N115W GRADUALLY BECOMING 
ABSORBED. LARGE-SCALE SUBSIDENCE LIES E OF 120W...AND THIS IS 
PRODUCING MOSTLY CLEAR SKIES N OF THE ITCZ...WITH THE EXCEPTION 
OF A BROKEN STRATOCUMULUS DECK LOCATED N OF 24N. W OF 120W...THE 
ATMOSPHERE CONTAINS A LITTLE MORE MOISTURE DUE TO UPPER LEVEL 
SOUTHERLIES EXTENDING N OF 15N. THESE ARE LOCATED ON THE ERN 
PERIPHERY OF A LARGE CUT-OFF LOW CENTERED NE OF THE HAWAIIAN 
ISLANDS. S OF 15N...THE UPPER LEVEL FLOW TURNS TO THE SE TOWARDS 
THE EQUATOR...AND THE RESULTING DIVERGENCE IS ENHANCING 
SHOWER/TSTM ACTIVITY ALONG THE ITCZ W OF 120W. SOME OF THIS 
ACTIVITY IS ALSO LOCATED NEAR A SURFACE TROUGH ALONG 130W S OF 
16N...MOVING W NEAR 15 KT.

$$
BERG