000
AXPZ20 KNHC 070326
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED NOV 07 2007

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 7N77W 10N90W 6N103W 10N120W 9N140W. 
SCATTERED MODERATE CONVECTION WITHIN 75 NM OF AXIS BETWEEN 
83W-97W. SCATTERED MODERATE WITHIN 90 NM OF AXIS BETWEEN 
115W-128W. SCATTERED SHOWERS/TSTMS WITHIN 60 NM OF AXIS W OF 
136W.

...DISCUSSION...

E OF 120W...
A STRONG MID/UPPER LEVEL HIGH REMAINS ANCHORED ACROSS S/CENTRAL 
MEXICO WITH THE ASSOCIATED RIDGE AXIS HAVING BECOME ROTATED IN A 
SE-NW FASHION SINCE THIS TIME YESTERDAY. THE AXIS NOW STRETCHES 
FROM BELIZE/GUATEMALA NW ACROSS MEXICO AND THROUGH THE GULF OF 
CALIFORNIA TO CALIFORNIA AND NEVADA. DEEP-LAYERED EASTERLY FLOW 
REMAINS ENTRENCHED S OF THE RIDGE AXIS...BUT SOME OF THE FLOW 
HAS TURNED SOUTHEASTERLY W OF 95W DUE TO THE NEW ORIENTATION OF 
THE RIDGE. THUS...UPPER LEVEL MOISTURE IS NOW BEING ADVECTED NW 
PARALLEL TO THE MEXICAN COAST THEN TURNS NE ACROSS THE BAJA 
PENINSULA AND FAR NW MEXICO. THE ITCZ IS PERTURBED NWD E OF 100W 
AND IS SOMEWHAT CONVECTIVELY ACTIVE DUE TO STRONG LOW-LEVEL 
CONVERGENCE WHERE THE SOUTHERLIES ARE INTERACTING WITH THE FLOW 
OUT OF THE GULF OF TEHUANTEPEC. SCATTERED SHOWERS/TSTMS ARE ALSO 
OCCURRING ACROSS PANAMA...COSTA RICA...AND SRN NICARAGUA DUE TO 
THE ITCZ AND MOISTURE MOVING IN FROM THE SW CARIBBEAN.

A 0050 UTC QUIKSCAT PASS INDICATED THAT MAXIMUM WINDS WITHIN THE 
GULF OF TEHUANTEPEC HAVE INCREASED TO 35-40 KT IN A SMALL AREA 
WITHIN ABOUT 120 NM OF THE COAST...MATCHING WELL WITH THE 
MIXED-LAYER WINDS GIVEN IN GFS FORECAST SOUNDINGS. THESE WINDS 
HAVE THE POTENTIAL TO INCREASE TO 45 KT WITHIN THE NEXT 24 
HRS...AND THEN DIMINISH BETWEEN 24-48 HRS SUCH THAT THE WARNING 
WILL LIKELY EXPIRE BY THU EVENING.

W OF 120W...
A MID/UPPER LEVEL CUT-OFF LOW REMAINS POSITIONED JUST W OF SAN 
FRANCISCO CALIFORNIA AND THE ASSOCIATED TROUGH AXIS EXTENDS S 
INTO THE AREA FROM 30N126W TO 15N124W. THE TROUGH IS CURRENTLY 
BEING REINFORCED BY A SHORTWAVE DROPPING INTO ITS BASE FROM 
28N132W TO 25N144W WITH A 75 KT JET STREAK. A BROKEN 
STRATOCUMULUS FIELD CONTINUES TO BE DRIVEN SEWD INTO THE REGION 
N OF 20N BETWEEN 115W-134W. FARTHER S...THE AFOREMENTIONED 
TROUGH CONNECTS TO A SHEARED UPPER LOW NEAR 9N115W. DIVERGENCE 
ON THE NW SIDE OF THE LOW IS ENHANCING CONVECTION ALONG THE ITCZ 
BETWEEN 115W-126W.

$$
BERG