000
AXPZ20 KNHC 211602
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE SEP 21 2010

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 
1545 UTC.


...SPECIAL FEATURE...

TROPICAL STORM GEORGETTE CENTERED NEAR 22.5N 121.5W OR ABOUT
30 MILES...45 KM S OF CABO SAN LUCAS MEXICO AT 21/1500 UTC
MOVING NNW AT 8 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH 
GUSTS TO 45 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1001 MB. 
SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP2/WTPZ42 KNHC FOR MORE DETAILS. VERY DEEP CONVECTION 
ASSOCIATED WITH GEORGETTE HAS MARKEDLY INCREASED DURING THE 
EARLY MORNING HOURS PRODUCING A LARGE CANOPY...ABOUT 170 NM IN 
DIAMETER...OF COLD TOPS. LATEST NHC FORECAST TRACKS GEORGETTE 
NNW TO INLAND THE BAJA PENINSULA EARLY THIS EVENING NEAR 24.0N 
110.7W. IT IS THEN FORECAST TO WEAKEN TO A DEPRESSION OVERNIGHT 
INTO WED MORNING...AND TO A REMNANT LOW WED EVENING. TOTAL 
RAINFALL ACCUMULATIONS OF 4 TO 6 INCHES ARE EXPECTED OVER THE 
SOUTHERN BAJA PENINSULA AND THE MEXICAN STATES OF SINALOA AND 
WESTERN SONORA...WITH ISOLATED MAXIMUM AMOUNTS OF 10 INCHES 
POSSIBLE.  THESE RAINFALL AMOUNTS MAY PRODUCE LIFE-THREATENING 
FLASH FLOODS AND MUD SLIDES.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS WAS ANALYZED FROM JUST SW OF GEORGETTE
SW TO 17N118W TO A 1007 MB LOW NEAR 14N122W...TO 11N130W TO 
11N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 30 NM OF THE
TROUGH BETWEEN 128W-136W.

...DISCUSSION...

ALOFT...
AN ANTICYCLONIC CIRCULATION CENTERED NEAR 27N115W EXTENDS A 
RIDGE WSW TO JUST W OF THE REGION NEAR 21N142W. ANOTHER RIDGE
EXTENDS SE FROM THE ANTICYCLONE ACROSS MUCH OF CENTRAL AND SE
MEXICO. TO THE S OF THE ANTICYCLONE AND AND SW OF THIS RIDGE
ACTIVE CLUSTERS OF MOSTLY SCATTERED MODERATE/ISOLATED CONVECTION
WERE NOTED WITHIN 90 NM EITHER SIDE OF LINE FROM 12N98W TO 
11N108W. SCATTERED MODERATE TO STRONG CONVECTION WAS CONFINED 
FROM 10N TO 16N BETWEEN 95W AND 98W. SMALL CLUSTERS OF SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION WERE ELSEWHERE N OF 6N E OF 
95W. THESE AREAS OF CONVECTION WERE OCCURRING IN THE CONFLUENT 
SWLY FLOW ON THE S SIDE OF THE MONSOON TROUGH...WHICH WAS ACTING 
TO INDUCE DIVERGENT FLOW ALOFT.

SURFACE...
NOW THAT TROPICAL STORM GEORGETTE HAS FORMED ON THE EASTERN TIP 
OF WHAT WAS A LARGE CYCLONIC GYRE ON TIED TO THE MONSOON 
TROUGH...ASSOCIATED EXTENSIVE CLOUDINESS HAS CONSOLIDATED
THE TROPICAL CYCLONE WHILE THAT WAS ALSO EVIDENT W OF ABOUT
118W HAS DIMINISHED AS MOST...IF NOT ALL THE CONVECTION IN THE
TROPICS...IS OCCURRING S OF THE ABOVE MENTIONED RIDGE AND E OF
110W.

A 1019 MB HIGH CENTERED JUST W OF THE REGION NEAR 30N142W EXTENDS
A RIDGE SE TO 28N134W TO 25N121W. THE INTERACTION BETWEEN THIS
RIDGE AND LOWER PRESSURES OVER NW MEXICO IS RESULTING IN NW TO N
WINDS OF 20 KT WITH SEAS OF 8 FT N OF 23N AND BETWEEN 115W AND 
120W. AS THE GRADIENT TIGTHENS THROUGH THE NEXT 48 HOURS...THE 
WINDS WILL DIMINISH WITH SEAS SUBSIDING TO LESS THAN 8 FT. THE 
LOW NEAR 14N122W MENTIONED ABOVE UNDER THE ITCZ/MONSOON SECTION 
IS PRODUCING 20 TO 25 KT WITHIN 120 NM OF ITS CENTER...WHILE 
SEAS IN THE 8 TO 10 FT RANGE PRIMARILY DUE TO A SW SWELL ARE 
NOTED. THE LOW AND ASSOCIATED CONDITIONS ARE FORECAST BY GLOBAL 
MODELS TO GRADUALLY MOVE EASTWARD OVER THE NEXT 48 HOURS TO 
WITHIN 9N AND 14N AND BETWEEN 102W AND AND 120W. THE MODELS HINT 
AT ANOTHER LOW DEVELOPING ALONG THE MONSOON TROUGH OVER THE FAR 
WESTERN PORTION OF THE AREA ALSO WITHIN THE NEXT 48 
HOURS...HOWEVER CURRENTLY THERE ARE NO VISIBLE INDICATIONS OF 
THIS MATERIALIZING.

$$
AGUIRRE