000
AXPZ20 KNHC 270927
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE JUL 27 2010

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 
0900 UTC.

...ITCZ...

AXIS IS ALONG 10N85W TO 12N89W TO 11N92W TO 09N104W TO 10N120W 
TO 11N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 180 NM S OF THE AXIS BETWEEN 85W AND 92W...AND WITHIN 120 
NM EITHER SIDE OF THE AXIS BETWEEN 95W AND 99W. SCATTERED 
MODERATE CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN 105W 
AND 108W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 75 
NM EITHER SIDE OF THE AXIS BETWEEN 121W AND 128W.

...DISCUSSION...

AN UPPER LEVEL TROUGH EXTENDS FROM WELL N OF THE DISCUSSION AREA 
JUST W OF VANCOUVER ISLAND BRITISH COLOMBIA INTO THE AREA NEAR 
32N127W TO 25N129W...WITH AN UPPER LEVEL RIDGE NOSING INTO THE 
AREA FROM THE W FROM 22N140W TO A COL NEAR 23N131W. AN UPPER 
ANTICYCLONE IS POSITIONED OVER THE NORTHERN GULF OF CALIFORNIA 
NEAR 31N114W WITH A RIDGE EXTENDING SW TO NEAR 22N129W JUST E OF 
THE ABOVE MENTIONED COL. VERY DRY AND STABLE AIR UNDER MODERATE 
TO STRONG SUBSIDENCE IS NOTED N OF 22N E OF 132W...AND S OF 25N 
W OF 132 WITH MID LEVEL MOISTURE BEING ADVECTED INTO THE NW 
PORTION OF THE AREA. 

A WEAK CYCLONIC VORTEX IS CENTERED NEAR 10N120W WITH AN INVERTED 
TROUGH EXTENDING NW TO THE COL. OTHERWISE MAINLY ZONAL/EASTERLY 
FLOW ALOFT DOMINATES THE REMAINDER OF THE BASIN S OF 20N. THIS 
FLOW IS ADVECTING PLENTIFUL CONVECTIVE DEBRIS FROM CENTRAL 
AMERICA AND ALONG THE ITCZ E OF 130W.

AT THE SURFACE...A WEAK TROUGH...THE REMNANTS OF A TROPICAL
WAVE...EXTENDS FROM 14N92W TO 10N89W. ANOTHER TROUGH EXTENDING 
FROM NE TO SW APPEARS TO BE DEVELOPING JUST N OF THE ITCZ 
BETWEEN 96W AND 103W. GFS MODEL GUIDANCE HAS DECREASED THE 
CHANCES OF A STRONG LOW PRES SYSTEM DEVELOPING ALONG THIS TROUGH 
DURING THE NEXT FEW DAYS ALTHOUGH THE LATEST ECMWF STILL FAVORS 
A STRONGER AREA OF LOW PRES FORMING OVER THE CENTRAL E PACIFIC.

BROAD 1028 MB HIGH PRES IS CENTERED WELL NW-N OF THE AREA WITH A 
RIDGE AXIS EXTENDING SE-S TO NEAR 21N123W. FRESH NW BREEZE 
CONTINUES TO FUNNEL UP ALONG THE W COAST OF THE BAJA PENINSULA 
FROM 24N TO 28N. IN ADDITION A WEAK LOW PRES TROUGH OVER FAR NW 
MEXICO HAS TIGHTENED THE PRES GRADIENT OVER THE NORTHERN GULF OF 
CALIFORNIA PROMPTING FRESH SE BREEZE N OF 28N THAT IS EXPECTED 
TO DIMINISH TO LESS THAN 20 KT BY 24 HOURS.

FRESH TO STRONG WINDS OVER THE SUBTROPICAL SE PACIFIC CONTINUE 
TO GENERATE LONG PERIOD SOUTHERLY SWELL WITH SEAS UP TO 9 FT 
ENCROACHING INTO THE E PACIFIC WATERS S OF 10N. THESE SEAS ARE 
EXPECTED TO PERSIST DURING THE NEXT 48 HOURS OVER THE SAME 
GENERAL AREA.

$$
LEWITSKY