000
AXPZ20 KNHC 151528
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU NOV 15 2007

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N77W 9N83W 7N105W 10N130W 9N140W. 
WIDELY SCATTERED MODERATE CONVECTION N OF 6N BETWEEN 80W-87W. 
SCATTERED MODERATE WITHIN 75 NM OF AXIS BETWEEN 109W-116W. 
SCATTERED MODERATE WITHIN 150 NM OF AXIS W OF 128W. 

...DISCUSSION...

E OF 110W...
A BROAD UPPER LEVEL RIDGE SPANS ACROSS THE ENTIRE LENGTH OF THE 
MEXICAN/CENTRAL AMERICAN LAND MASS INTO NW SOUTH AMERICA AND A 
MID-LEVEL HIGH IS CENTERED OVER THE BAY OF CAMPECHE NEAR 22N94W. 
SOME SCATTERED DEEP CONVECTION IS OCCURRING NEAR PANAMA AND 
CENTRAL AMERICA DUE TO THE PROXIMITY OF THE ITCZ...BUT OTHERWISE 
CONVECTION IS SUPPRESSED ACROSS MOST OF THE REGION DUE TO 
MODERATE/STRONG SUBSIDENCE BENEATH THE RIDGE. STRATOCUMULUS IS 
QUITE WIDESPREAD S OF THE ITCZ AXIS DUE TO INSTABILITY 
ASSOCIATED WITH COOL OCEAN WATERS...WHEREAS DRIER AIR AND WARMER 
WATERS TO THE N HAVE KEPT MOST OF THE CLOUDS AT BAY. SOME OF THE 
DRY IS AIR DERIVED FROM THE GAP FLOW THROUGH THE GULF OF 
TEHUANTEPEC AND GULF OF PAPAGAYO. WINDS OVER THE GULF OF 
TEHUANTEPEC ARE CURRENTLY NEAR 30 KT AND ARE EXPECTED TO REACH 
GALE FORCE BY 1800 UTC...LIKELY REACHING 45 KT WITHIN THE NEXT 
12-18 HRS OR SO. THE GALE CONDITIONS ARE THEN EXPECTED TO END 
WITHIN 48 HRS...BY SAT MORNING.

W OF 110W...
A MID/UPPER LEVEL CUT-OFF LOW REMAINS LOCATED OVER THE BAJA 
PENINSULA NEAR 28N116W AND IS BEING BLOCKED BY UPPER RIDGING 
OVER THE U.S. INTERMOUNTAIN WEST. A BROAD AND DISORGANIZED AREA 
OF SURFACE LOW PRES HAS LIFTED N FROM NRN BAJA CALIFORNIA TO SRN 
CALIFORNIA BUT IS NOT ASSOCIATED WITH ANY SIGNIFICANT WEATHER. 
AN UPPER LEVEL SHORTWAVE TROUGH IS CURRENTLY APPROACHING THE W 
COAST OF THE UNITED STATES AND WILL KICK THE WRN RIDGE OUT OF 
THE AREA...ULTIMATELY LIFTING THE CUT-OFF LOW OUT OF THE AREA. 
THE TAIL END OF THE SHORTWAVE DRAGS INTO THE AREA FROM 30N134W 
TO 21N140W BUT IT APPEARS TO BE BECOMING STATIONARY AND READY TO 
CUT-OFF...WITH THE RESULTANT UPPER LOW EVENTUALLY RETROGRADING W 
TO HAWAII. A LARGE AREA OF MODERATE/STRONG SUBSIDENCE LIES N OF 
19N DUE TO UPPER LEVEL CONVERGENCE INTO THE AFOREMENTIONED 
CUT-OFF LOW. S OF 19N...WESTERLY FLOW ALOFT IS ADVECTING LARGE 
AMOUNTS OF MOISTURE INTO THE AREA WITH SCATTERED CONVECTION 
LOCATED NEAR THE ITCZ W OF 130W...SPECIFICALLY NEAR A SURFACE 
TROUGH LOCATED ALONG 139W/140W.
 
$$
BERG