000
AXPZ20 KNHC 270946
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT OCT 27 2007

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0845 UTC.

...ITCZ....
AXIS ALONG 9N82W 12N110W 11N120W 12N134W 11N140W. ISOLATED 
MODERATE CONVECTION NEAR 6N78W AND 9N84W. SCATTERED MODERATE 
FROM 10N102W TO 14N104W TO 18N110W. SCATTERED MODERATE NEAR 
10N125W AND WITHIN 45 NM OF A LINE FROM 12N134W TO 12N140W.

...DISCUSSION...

AN ELONGATED UPPER TROUGH HAS MOVED INTO THE REGION WITH TWO 
CENTERS OF ROTATION..ONE N OF THE AREA NEAR 35N126W AND THE 
OTHER NEAR 25N136W. BOTH SHOW UP ON WATER VAPOR IMAGERY. AN OLD 
MID LEVEL LOW CIRCULATION NEAR 25N125W LAST NIGHT IS LIFTING NE 
TO 28N122W WITH APPROACH OF THE UPPER TROUGH. MID LEVEL HIGH 
PRES OVER MEXICO REMAINS STATIONARY WHILE ANOTHER MID LEVEL 
RIDGE SHOWS UP W OF THE AREA NEAR 42N150W. ON THE SURFACE 
TONIGHT THE PACIFIC RIDGE REMAINS FAIRLY STRONG BUT MOST OF IT 
IS NW OF THE AREA UNDER THE RIDGE MENTIONED ABOVE. THE PORTION 
OVER OUR REGION IS PRODUCING STRONG NE WINDS TO 30 KT N OF 25N W 
OF 130W WITH SEAS TO 15 FT. WINDS ALONG THE BAJA COAST REMAIN 
LIGHT DUE TO A WEAK PRES GRADIENT. GAP WINDS THROUGH TEHUANTEPEC 
ARE 15 TO 20 KT ACCORDING TO QUIKSCAT AND SSMI AND IN FAIRLY 
GOOD AGREEMENT WITH THE GFS MODEL FOR 06Z. CROSS EQUATORIAL 
WINDS ARE MOSTLY 15 TO 20 KT WITH SLY SWELL TO 8 FT.

LATER DAY 1 ROTATION OF THE TWO UPPER CENTERS OF THE TROUGH 
BEGIN TO DUMBELL AROUND EACH OTHER WHILE MID LEVEL RIDGE CENTERS 
HOLD THEIR POSITIONS. ON THE SURFACE LATER DAY 1 THE PACIFIC 
RIDGE SHOWS SIGNS OF WEAKENING AND NE WINDS DECREASE SOME TO 20 
TO 25 KT N OF 25N W OF 132W. GFS MODEL HINTS AT SURFACE 
TROUGHING ALONG 122W N OF 20N WHERE THE UPPER TROUGH IS LOCATED. 
WINDS INCREASE THROUGH TEHUANTEPEC TO GALE FORCE AS HIGH PRES 
BUILDS OVER THE GULF OF MEXICO. LOOK FOR SEAS INCREASING TO 12 
FT. SOME INCREASE IN SLY WINDS S OF 5N E OF 100W AND S OF 5N W 
OF 120W.

FOR DAY 2 THE MID LEVEL CYCLONIC CENTER N OF THE AREA MOVES 
SLOWLY SW TO NEAR 32N130W WHILE THE OTHER CENTER DRIFTS SW TO 
22N138W AND WEAKENS. THE MID LEVEL RIDGE OVER MEXICO WEAKENS BUT 
REMAINS STATIONARY WHILE THE MID LEVEL RIDGE W OF THE AREA 
SLIDES S ALONG 150W. ON THE SURFACE DAY 2 A WEAK LOW CENTER WILL 
DEVELOP NEAR 31N131W IN CONJUNCTION WITH THE UPPER LOW CENTER. 
NE TRADES N OF 25N W OF 130W DECREASE TO 15 KT AS THE PACIFIC 
RIDGE MOVES W AND WEAKENS. WINDS ALONG THE BAJA COAST REMAIN 
LIGHT NLY WHILE GAP WINDS THROUGH TEHUANTEPEC CONTINUE TO BLOW 
AT GALE FORCE. CROSS EQUATORIAL SLY WINDS CHANGE LITTLE E OF 
100W BUT DECREASE W OF 100W..PROBABLY DUE TO WEAKENING OF 
CONVECTION ALONG THE ITCZ. 

$$
RRG