000
AXPZ20 KNHC 222205
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON JUN 22 2009

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 
2145 UTC.

...SPECIAL FEATURE...

TROPICAL STORM ANDRES WAS CENTERED NEAR 16.0N 102.0W OR ABOUT 
125 MILES S OF LAZARO CARDENAS AND ABOUT 230 MILES SSE OF 
MANZANILLO MEXICO AT 22/2100 UTC MOVING W 4 KT. ESTIMATED 
MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WINDS 50 
KT GUSTS 60 KT. SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCPEP/WTPZ32 KNHC AND THE FULL FORECAST ADVISORY 
UNDER AWIPS/WMO HEADERS MIATCMEP2 WTPZ22 KNHC FOR MORE DETAILS. 
SATELLITE VISIBLE IMAGERY FROM THROUGHOUT THE DAY HAS SHOWN 
THAT THE OVERALL CLOUD STRUCTURE AND ASSOCIATED CONVECTION 
CONTINUES TO BECOME BETTER ORGANIZED UNDER FAVORABLE UPPER LEVEL 
CONDITIONS. LATEST PASSIVE MICROWAVE IMAGERY AND VISIBLE 
SATELLITE IMAGERY INDICATE WHAT MAY BE AN EYE FEATURE FORMING 
WITHIN THE DENSE CIRRUS OVERCAST OVER THE CENTER. THIS IS 
SUGGESTING FURTHER STRENGTHENING...AND THE CYCLONE MAY BECOME A 
HURRICANE SOONER THAN THE OFFICIAL NHC GUIDANCE FORECAST SHOWS. 
A GROWING LARGE CLUSTER OF VERY DEEP CONVECTION IS OBSERVED OVER 
AND AROUND THE CENTER. THIS CONVECTION IS MARKED BY NUMEROUS 
STRONG CONVECTION WITHIN 100 NM OF THE CENTER IN THE SE 
QUADRANT. SCATTERED STRONG CONVECTION IS ELSEWHERE WITHIN 120 NM 
OF THE CENTER OVER THE S AND SW QUADRANTS AND WITHIN 60 NM OF 
THE CENTER IN THE N SEMICIRCLE. SCATTERED MODERATE TO STRONG 
CONVECTION IS OCCURRING FROM 14N-19N BETWEEN 104W-107W...AND E 
OF THE CYCLONE FROM 11N-16N BETWEEN 94W-98W.

COASTAL STORM SURGE FLOODING OF 1 TO 3 FEET ABOVE NORMAL TIDE
LEVELS...ALONG WITH LARGE AND DANGEROUS BATTERING WAVES...ARE
POSSIBLE AS ANDRES MOVES CLOSE TO THE WARNING AREA DESCRIBED IN
THE NHC PUBLIC ADVISORY. IN ADDITION...ANDRES IS EXPECTED TO
PRODUCE HEAVY RAINS ACROSS SECTIONS OF WEST CENTRAL MEXICO WITH
POSSIBLE LOCALIZED AMOUNTS OF 8 INCHES.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 6N78W 6N90W
14N97W...THEN RESUMES AT 13N103W 10N114W 11N120W 10N130W 7N140W. 
SCATTERED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE
AXIS BETWEEN 84W-86W. SCATTERED MODERATE CONVECTION EXISTS FROM
8N-12N BETWEEN 121W-127W...AND WITHIN 30 NM OF THE AXIS BETWEEN
129W-131W.

...DISCUSSION...

A WEAK MID/UPPER LEVEL TROUGH EXTENDS FROM 29N1119W SE TO A COL
REGION NEAR 16N116W. A STRONGER DEEP LAYER TROUGH ENTERS THE 
REGION THROUGH 32N131W AND EXTENDS TO SW OF THE AREA AT 25N140W. 
BROAD ANTICYCLONIC FLOW IS PRESENT S OF THIS TROUGH...AND W OF 
THE WEAK TROUGH WITH THE ASSOCIATED MID/UPPER LEVEL ANTICYCLONE 
CENTERED NEAR 16N125W. A RIDGE EXTENDS W FROM THE ANTICYCLONE TO 
SW OF THE AREA AT 13N140W. RATHER STABLE CONDITIONS UNDER 
MODERATE TO STRONG SUBSIDENCE ARE OBSERVED OVER MUCH OF THE AREA 
N OF 16N. SATELLITE IMAGERY SHOWS A BLANKET O BROKE TO 
OVERCAST STRATOCUMULUS MOVING SSW N OF 20N W OF 115W. THE 
ANTICYCLONE NEAR 12N125W IS DRAWING ITCZ MOISTURE BETWEEN 
125W-135W ALONG WITH THAT ASSOCIATED WITH A WEAK LOW NEAR 
11N127W NWD TO NEAR 15N BEFORE IT EVAPORATES IN THE DRIER AIR. 
THE LOW IS MOVING SLOWLY NE...AND IS ACCOMPANIED BY SCATTERED 
STRONG CONVECTION WITHIN 60 NM WNW OF ITS CENTER.

THE LOW HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING 
THE NEXT 48 HOURS AS IT REMAINS RATHER ELONGATED AND 
DISORGANIZED. ELSEWHERE AT THE SURFACE...A RIDGE ENTERS THE AREA 
THROUGH 32N136W AND CONTINUES SE 26N126W TO NEAR 21N118W. HIGH 
PRES COVERS THE AREA N OF 18N W OF 120W. A TIGHT PRES GRADIENT 
BETWEEN THE SOUTHERN PERIPHERY OF THE RIDGE AND LOWER PRES 
WITH THE ITCZ MAINTAINS NE WINDS OF 20 KT FROM 16N-24N W OF 
127W. THESE WINDS ARE FORECAST TO CONTINUE WITH LITTLE CHANGE 
DURING THE 24 HOURS...THEN DIMINISH TO LESS THAN 20 KT IN 48 
HOURS. LIKEWISE...A TIGHT PRES GRADIENT BETWEEN THE RIDGE AND 
LOW PRES OVER THE SW U.S. IS RESULTING IN NW-N WINDS OF 20 KT N 
OF 26N E OF 125W AS WAS NOTED IN SCATTEROMETER DATA FROM THIS
MORNING...AND FURTHER SUPPORTED BY SEVERAL SHIP OBSERVATIONS FROM
THROUGHOUT THE DAY. THESE WINDS ARE EXPECTED TO BE WITHIN THE 
AREA BETWEEN 120W-130W N OF 28N IN 48 HOURS...OR COULD POSSIBLY 
EXTEND FURTHER E CLOSE TO THE COAST AS HIGH PRES NW OF THE AREA
SHIFTS SOUTHWARD.

OVER THE EASTERN PORTION OF THE AREA...A MID/UPPER LEVEL RIDGE 
EXTENDS SW FROM ACROSS NORTHERN MEXICO SW TO THE COL REGION
REGION IN BETWEEN THE TWO TROUGHS DESCRIBED ABOVE. THE UPPER 
FLOW IS VERY DIFFLUENT S OF 19N PARTLY DUE TO AN UPPER CYCLONE 
MOVING W OVER EASTERN MEXICO NEAR 24N98W. THIS IS GREATLY 
SUPPORTING CONVECTION ASSOCIATED WITH TROPICAL STORM ANDRES. 
STRONG NE UPPER LEVEL WINDS EVIDENT S OF 10N ARE TRANSPORTING 
UPPER LEVEL ITCZ MOSITURE ALONG WITH THAT FROM TROPICAL 
DEPRESSION TWO-E SWD. OTHER UPPER LEVEL MOSITURE FROM THE 
SCATTERED TO MODERATE STRONG ITCZ CONVECTION E OF 84W...ENHANCED 
BY THE TAIL END OF A WEAK SHORTWAVE TROUGH OVER THE FAR SW 
CARIBBEAN SEA...IS BEING CHANNELED SWD BY THESE WINDS. AS 
CONVECTION WITH TROPICAL STORM ANDRES CONTINUES TO INCREASE
...THE RESULTANT UPPER LEVEL MOISTURE WILL SLOWLY SPREAD 
WESTWARD OVER THE AREA FROM 10N-21N W TO NEAR 117W OVER THE
NEXT 24-36 HOURS.

$$
AGUIRRE