000
AXPZ20 KNHC 222143
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED SEP 22 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2130 UTC.

...SPECIAL FEATURE...

TROPICAL DEPRESSION GEORGETTE WAS CENTERED JUST ALONG THE COAST
OF MAINLAND MEXICO NEAR 28.0N 111.1W AT 22/2100 UTC MOVING N OR
355 DEG AT 14 KT. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS 
TO 40 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1002 MB. LATEST
SATELLITE IMAGERY SHOWS THAT MOST OF THE ASSOCIATED SHOWER AND TSTM 
ACTIVITY HAS JUST ABOUT ALL MOVED INLAND OVER THE STATE OF SONORA
MEXICO. GEORGETTE IS FORECAST TO CONTINUE MOVING INLAND TONIGHT
WEAKENING TO A REMNANT LOW LATE TONIGHT INTO THU MORNING. THE 
POTENTIAL FOR HEAVY RAINFALL AMOUNTS OVER THE WESTERN PORTIONS OF 
THE STATE OF SONORA MAY LEAD TO LIFE-THREATENING FLASH FLOODS AND 
MUD SLIDES. REMNANT MOISTURE FROM GEORGETTE WILL THEN SPREAD INTO 
PORTIONS OF THE SOUTHWESTERN U.S. OVER THE NEXT COUPLE OF DAYS. SEE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP2/WTPZ22 KNHC AND WTPZ32 KNHC FOR MORE DETAILS.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 13N89W TO 13N101W TO 14N110W TO A 
1010 MB LOW NEAR 12N116W TO 10N126W TO 09N140W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION EXISTS FROM 9N TO 13N BETWEEN
95W AND 102W...AND S OF THE ITCZ WITHIN 45 NM OF LINE FROM 9N102W TO 
9N110W. SIMILAR CONVECTION IS WITHIN 30 NM OF LINE FROM 9N123W TO
9N127W.

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS OVER FAR NE MEXICO WITH A RIDGE SW TO 
23N120W AND WNW TO 25N137W. TO THE N OF THE RIDGE...A MID/UPPER 
LEVEL TROUGH MOVING E 20 KT IS PRESENT N OF 25N E OF 126W. TO THE S 
OF THE RIDGE...UPPER LEVEL NE TO E MODERATE FLOW IS PRESENT WITH A 
DIFFLUENT FLOW PATTERN SUSTAINING CONVECTION E OF ABOUT 109W. 
ELSEWHERE S OF THE ITCZ...CONVECTION IS INDUCING UPPER LEVEL 
DIVERGENCE IN THE NE TO E FLOW ALOFT BETWEEN 121W AND 128W. AN UPPER 
LEVEL DIFFLUENT FLOW PATTERN IS SUPPORTING AN AREA OF DISTURBED 
WEATHER CONSISTING OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION 
S OF THE GULF OF TEHUANTEPEC AS DESCRIBED ABOVE UNDER ITCZ. LOW PRES 
OF 1010 MB IS LOCATED WITHIN THIS AREA NEAR 14N97W. WINDS OF 20 KT 
ARE WITHIN 90 NM S SEMICIRCLE OF THE LOW. THIS SYSTEM IS SLOWLY 
MOVING WNW.

AT THE SURFACE TO LOW LEVELS BROAD HIGH PRESSURE DOMINATES THE 
SUBTROPICS N OF 19N W OF 120W...WITH A SURFACE HIGH OF 1021 MB W OF 
THE AREA NEAR 28N142W WITH ITS ASSOCIATED RIDGE EXTENDING ESE TO 
NEAR 25N122W. THE INTERACTION BETWEEN THE RIDGE AND BROAD LOW PRES E 
OF 122W WHERE TROPICAL DEPRESSION GEORGETTE IS LOCATED CONTINUES TO 
SUPPORT NW TO N 20 KT WINDS N OF 24N E OF 120W TO THE BAJA PENINSULA 
COAST. AS GEORGETTE CONTINUES TO MOVE INLAND AND WEAKEN...THE 
GRADIENT WILL RELAX WITH WINDS DIMINISHING TO LESS THAN 20 KT AND 
SEAS SUBSIDING TO LESS THAN 8 FT IN ABOUT 30 HOURS. A 1010 MB LOW IS
NEAR 12N116W WITH WINDS OF 20-25 KT WITHIN 180 NM IN THE SE 
SEMICIRCLE...AND 20 KT WITHIN 60 NM IN THE NW SEMICIRCLE. SEAS OF 8 
TO 11 FT ARE IN THE SW SEMICIRCLE. GLOBAL MODELS CONTINUE TO SPIN UP 
WEAK LOWS ALONG THE ITCZ OVER THE NEXT 48 HOURS WITH GENERAL MOTION 
TO THE E. THIS SEEMS PLAUSIBLE GIVEN THAT ALREADY OVER THE PAST FEW 
DAYS SIMILAR WEAK LOWS HAVE BEEN OBSERVED ACROSS THIS SAME AREA. 
ABUNDANT TROPICAL MOISTURE CONVERGING ON THE S SIDE OF THE ITCZ E OF 
ABOUT 130W IS EXPECTED TO REMAIN THROUGH AT LEAST THE NEXT 48 HOURS 
WHILE SW TO W WINDS OF 20 KT ARE OCCURRING FROM 8N TO 13N BETWEEN 
100W AND 125W. THIS AREA IS FORECAST TO EXPAND FROM 7N TO 13N BETWEEN
90W AND 130W IN 48 HOURS.

$$
AGUIRRE