000
AXPZ20 KNHC 230307
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON AUG 23 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

...SPECIAL FEATURES...

AT 23/0300 UTC...TROPICAL STORM FRANK IS CENTERED NEAR 14.0N 
96.8W MOVING WEST OR 275 DEGREES AT 6 KT. A TURN TOWARD THE 
WEST-NORTHWEST IS EXPECTED OVER THE NEXT COUPLE OF DAYS. ON THE 
FORECAST TRACK...FRANK WILL BE MOVING PARALLEL TO THE COAST OF 
SOUTHERN MEXICO THROUGH TUESDAY. ESTIMATED MINIMUM CENTRAL 
PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WINDS ARE 50 KT WITH 
GUSTS TO 60 KT. SOME STRENGTHENING IS FORECAST DURING THE NEXT 
48 HOURS AND FRANK IS EXPECTED TO BECOME A HURRICANE BY LATE 
TODAY. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. NUMEROUS 
MODERATE AND SCATTERED STRONG CONVECTION IS NOTED WITHIN 150 NM 
IN THE W SEMICIRCLE. SCATTERED MODERATE CONVECTION IS NOTED 
WITHIN 90 NM IN THE E SEMICIRCLE.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 11N86W TO 
12N89W THEN FROM 11N100W TO 10N110W TO 12N124W THEN FROM 12N125W 
TO 10N135W TO 10N140W. SCATTERED MODERATE CONVECTION IS WITHIN 
90 NM S OF THE AXIS BETWEEN 100W AND 103W AND ALSO WITHIN 60 NM 
EITHER SIDE OF THE AXIS BETWEEN 121W AND 124W.

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER N CENTRAL NEW MEXICO 
WITH AN UPPER RIDGE EXTENDING TO ACROSS NW OLD MEXICO TO 30N129W 
TO 20N140W. AN INVERTED UPPER TROUGH EXTENDS FROM 17N127W TO 
28N120W. VERY DRY AIR ALOFT UNDER MODERATE TO STRONG SUBSIDENCE 
COVERS THE AREA N OF 16N AND W OF 130W AS INDICATED BY WATER 
VAPOR SATELLITE IMAGERY. NE TO E FLOW PREVAILS OVER THE MAJORITY 
OF THE REMAINDER OF THE TROPICS WITH THE EXCEPTION OF THE REGION 
SURROUNDING T.S. FRANK WHICH IS UNDER AN UPPER RIDGE EXTENDING 
FROM AN UPPER ANTICYCLONE LOCATED IN THE NW GULF OF MEXICO TO 
THE GULF OF TEHUANTEPEC. 

AT THE SURFACE...A RIDGE DOMINATES THE AREA ROUGHLY N OF 20N
AND W OF 120W PRODUCING LIGHT TO MODERATE WINDS. A 1009 MB AREA 
OF LOW PRES...THE REMNANT OF T.D. EIGHT-E...IS CENTERED NEAR 
22N115W. A LOW LEVEL CLOUD SWIRL IS ALL THAT REMAINS. 

A 1010 MB LOW IS POSITIONED NEAR 13N125W. AN EARLIER 1818 UTC 
ASCAT SCATTEROMETER PASS INDICATED 20 KT WINDS WITHIN 90 NM IN 
THE N AND WITHIN 180 NM IN THE S AND SW QUADRANTS OF THE LOW 
CENTER WITH COMBINED SEAS OF 8-10 FT IN S SWELL. SCATTERED 
MODERATE CONVECTION IS OCCURRING WITHIN 60 NM OF THE LOW CENTER 
IN THE E AND N QUADRANTS. THIS LOW IS EXPECTED TO CONTINUE TO 
DRIFT TO THE NE-E DEGENERATING INTO AN OPEN TROUGH BY ABOUT 12 
HOURS. A WEAKER 1010 MB LOW IS LOCATED TO THE W-NW NEAR 14N131W. 
NO SIGNIFICANT CONVECTION IS NOTED WITH THIS LOW WHICH IS 
EXPECTED TO DISSIPATE WITHIN THE NEXT 24 HOURS.

CROSS EQUATORIAL S AND SW SWELL WITH PEAK WAVE PERIODS OF 18-20 
SECONDS CONTINUES TO AFFECT THE SOUTHEAST WATERS FROM SE OF 
18N103W TO 16N130W TO 08N140W WITH COMBINED SEAS OF 8-11 FT. 
THIS SOUTHERLY SWELL WILL CONTINUE TO PROPAGATE AND EXPAND TO 
THE N-NE THROUGH THE NEXT 48 HOURS WHILE NORTHERLY SWELL OF 8-9 
FT MOVES S OF 30N OVER THE N CENTRAL WATERS BEGINNING AROUND 18 
HOURS AND CONTINUING THROUGH AT LEAST 48 HOURS.

$$
LEWITSKY