000
AXPZ20 KNHC 070323
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED OCT 07 2009

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 
0315 UTC.

...TROPICAL WAVE... 

A TROPICAL WAVE WAS ANALYZED ALONG 91W N OF 08N ESTIMATED TO BE
MOVING ABOUT 15 KT. THE WAVE IS WITHIN A BROAD AREA OF DEEP 
LAYER MOISTURE NOTED IN TOTAL PRECIPITABLE WATER IMAGERY. THIS 
FEATURE IS ACTING IN COMBINATION WITH MORNING DRAINAGE FLOW TO 
ENHANCE AREAS OF SHOWERS AND TSTMS ALONG THE COASTS OF GUATEMALA 
AND MEXICO. E TO SE WINDS TO 20 KT ARE OCCURRING WITHIN 180 NM E 
OF THE WAVE. PRESENTLY...OUTSIDE OF CONVECTION NEAR THE ITCZ 
WITH THE WAVE...SCATTERED MODERATE CONVECTION IS JUST S OF THE 
MEXICAN COAST WITHIN 30 NM OF 15N94W.

...ITCZ...

THE ITCZ AXIS WAS CENTERED ALONG 9N78W TO 11N90W TO 9N100W TO
11N111W TO 7N130W TO 9N140W. SCATTERED MODERATE CONVECTION
IS WITHIN 120 NM S OF THE AXIS BETWEEN 92W-102W.

...DISCUSSION...

A BROAD ANTICYCLONIC CIRCULATION LOCATED OVER ERN MEXICO NEAR
24N99W EXTENDS A RIDGE SW TO 18N114W TO NEAR 14N124W. THIS RIDGE
WILL SHIFT E AND WEAKEN...AHEAD OF A MID TO UPPER LEVEL TROUGH
THAT STRETCHES FROM A MID/UPPER LEVEL UPPER LEVEL N OF THE AREA 
OFF THE SRN CALIFORNIA COAST SW TO 32N123W TO 27N125W...THEN S TO
A COL REGION NEAR 14N124W. A SWLY JET STREAM BRANCH BETWEEN THE
RIDGE AND TROUGH AS SEEN IN WATER VAPOR IMAGERY WITH CORE WINDS
OF UP TO 110 KT WILL CONTINUE TO ADVECT UPPER LEVEL THIN SWATHS
OF MOISTURE TO ACROSS MUCH OF BAJA CALIFORNIA...NRN MEXICO AND
THE SW U.S.

A SURFACE RIDGE ENTERS THE REGION THROUGH 32N135W AND EXTENDS
SE TO NEAR 21N123W. SHIP AND SCATTEROMETER DATA FROM EARLIER
TODAY INDICATED GENERALLY 15 KT NW FLOW ALONG THE BAJA 
COAST...ON THE EASTERN PERIPHERY OF THE RIDGE...WITH SOME 
EVIDENCE THAT WINDS ARE STARTING TO INCREASE TO 20 KT AS THE 
RIDGE BUILDS IN FROM THE W.

OVER THE SRN PORTION...A 1010 MB LOW IS NOTED ALONG THE MAIN 
ITCZ NEAR 111W. THE LOW IS FORECAST TO SLOWLY MOVE WNW OVER THE 
NEXT COUPLE OF DAYS...AND ALTHOUGH WILL NOT DEVELOP 
SIGNIFICANTLY IT MAY ENHANCE TRADE WIND FLOW AS IT INTERACTS 
WITH THE RIDGE TO THE N. GLOBAL MODELS SHOW A SCATTERING OF 
SIMILAR WEAK LOWS ALONG AND NEAR THE ITCZ. HOWEVER...WILL 
FOCUS ON THIS LOW FOR THE HIGH SEAS FORECAST AS IT WAS ANALYZED
ON THE 0000 UTC SURFACE MAP...AND WAS CLEARLY VISIBLE IN LAST
VISIBLE IMAGERY.

LONG PERIOD SWELL WITH SEAS TO 8 FT COVERS THE AREA MAINLY N OF 
12N W OF 118W...BUT WAVE MODEL SUGGESTS THAT THESE SEAS WILL 
DECAY BY THE NEXT 24 HOURS.

OVER THE FAR ERN PORTION E OF THE SURFACE RIDGE...NW WINDS TO 20 
KT ARE PRESENT N OF 26N E OF 120W TO THE BAJA CALIFORNIA COAST.
THIS AREA OF WINDS IS FORECAST TO DIMINISH FROM 19N TO 22N 
BETWEEN 109W AND 112W IN 24 HOURS...AND TO WITHIN 60 NM OF BAJA 
CALIFORNIA N OF ABOUT 25N IN 48 HOURS WITH SEAS LESS THAN 8 FT.

$$
AGUIRRE