000
AXPZ20 KNHC 281603
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI AUG 28 2009

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 
1530 UTC.

...SPECIAL FEATURES...

.BROAD LOW PRES NEAR 11N118W IS ANALYZED AT 1009 MB MOVING WNW 
NEAR 10 KT. BANDS OF TSTMS CONTINUE TO DEVELOP ACROSS MUCH OF 
THE WRN SEMICIRCLE OF THE LOW. WIDELY SCATTERED MODERATE 
CONVECTION IS FROM 08N TO 15N BETWEEN 188W AND 123W. SEAS 
SURFACE TEMPERATURES ARE MODESTLY WARM IN THE PATH OF THIS 
SYSTEM...AND IT COULD DEVELOP INTO A TROPICAL CYCLONE WITHIN THE 
NEXT 48 HOURS.   

.LOW PRES NEAR 14N99W IS ANALYZED AT 1008 MB MOVING W NEAR 
10 KT. A LOW TO MID LEVEL CYCLONIC CIRCULATION HAS BEEN EVIDENT 
WITH THIS WAVE FOR THE PAST SEVERAL DAYS...SINCE MOVING ACROSS 
THE SW CARIBBEAN. BANDS OF TSTMS CONTINUE TO FLARE ACROSS MUCH 
OF THE NE QUADRANT. AN UPPER LEVEL HIGH OVER S MEXICO TO THE NE 
IS PRODUCING DIFFLUENT FLOW ALOFT ACROSS THE SYSTEM...FAVORABLE 
FOR CONTINUED TSTM DEVELOPMENT. 20 TO 25 KT WINDS PERSIST ACROSS 
THE NRN SEMICIRCLE BASED ON PARTIAL SCATTEROMETER PASSES AND 
MODEL DATA. SEA SURFACE TEMPERATURES ARE VERY WARM IN THE PATH 
OF THIS SYSTEM...AND IT  COULD DEVELOP INTO A TROPICAL CYCLONE 
IN THE NEXT 48 HOURS. CLOSE PROXIMITY TO LAND MAY BRING HEAVY 
RAINS AND MUDSLIDES TO PORTIONS OF COASTAL MEXICO.   

...TROPICAL WAVES...

A TROPICAL WAVE IS N OF 06N ALONG 83W MOVING W AT 15 KT. THIS 
WAVE WAS JUST A SMALL PORTION OF THE WAVE THAT HAS DEVELOPED 
INTO TROPICAL STORM DANNY IN THE ATLANTIC...AND IS BERING 
TRACKED BY CONTINUITY. ABUNDANT TROPICAL MOISTURE... LIKELY 
ASSOCIATED WITH THE S AMERICAN MONSOON CIRCULATION...IS W FROM 
COLOMBIA DURING THE PAST 24 HOURS AND IS ASSUMED TO BE 
ASSOCIATED WITH THIS WAVE. THIS WAVE WILL CONTINUE TO MOVE W AND 
ENHANCE LOW LEVEL CONVERGENCE ACROSS COSTA RICA AND NICARAGUA 
TODAY.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 09N78W 07N90W 
10N100W 11N118W 08N125W 11N140W. SCATTERED MODERATE TO ISOLATED 
STRONG CONVECTION IS ALONG THE COAST OF PANAMA FROM 06N TO 08N 
BETWEEN 79W AND 81W. SIMILAR CONVECTION IS FROM 04N TO 08N 
BETWEEN 83W AND 99W. 

...DISCUSSION...

A QUASI-STATIONARY FRONT IS OVER THE NW CORNER OF THE DISCUSSION 
AREA ALONG 32N136W 30N140W 27N150W. SCATTERED SHOWERS ARE WITHIN 
90 NM OF THE FRONT. A 1012 MB LOW...THE REMNANTS OF IGNACIO IS 
CENTERED NEAR 29N128W. THE LOW IS QUASI-STATIONARY AND IS 
WEAKENING. A WEAK 1015 MB HIGH IS FURTHER SE NEAR  
23N123W. LASTLY A SURFACE TROUGH IS IN THE TROPICS ALONG 19N131W 
13N135W. SCATTERED MODERATE CONVECTION IS FROM 17N TO 19N 
BETWEEN 131W AND 133W. 

IN THE UPPER LEVELS...AN UPPER ANTICYCLONE IS CENTERED NEAR 
22N131W. A RIDGE EXTENDS SW TO BEYOND 16N140W. A SECOND 
ANTICYCLONE IS CENTERED OVER THE YUCATAN PENINSULA NEAR 18N91W. 
A RIDGE AXIS EXTENDS SW TO 10N110W. A SMALL CYCLONE IS IN 
BETWEEN THE TWO SYSTEMS...OFF THE S COAST OF BAJA CALIFORNIA 
NEAR 19N114W. NE UPPER LEVEL FLOW IS FURTHER S OVER THE TROPICS 
FROM THE EQUATOR TO 10N. SIGNIFICANT UPPER MOISTURE IS OVER THE 
TROPICS FROM 02N TO 16N BETWEEN 80W AND 140W...AND OVER MOST OF 
CENTRAL AMERICA E 110W. 

$$
FORMOSA