000
AXPZ20 KNHC 090917
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU AUG 09 2007

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0845 UTC.

...SPECIAL FEATURE...

TROPICAL STORM FLOSSIE CENTERED NEAR 13.2N 129.6W AT 09/0900Z 
MOVING WEST AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 
MB. MAXIMUM SUSTAINED WINDS ARE 45 KT WITH GUSTS TO 55 KT. SEE 
LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS 
MIATCMEP4/WTPZ24 KNHC FOR MORE DETAILS. FLOSSIE IS GETTING 
BETTER ORGANIZED BY THE HOUR. SHE HAS A VERY STRONG BAND ON THE 
W SIDE AND NUMEROUS SQUALLS WITHIN 125 NM OF THE CENTER. HER 
OUTFLOW IS SYMMETRICAL AND SHE IS FORECAST TO BECOME A CATEGORY 
ONE HURRICANE BY 10/1800Z.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 111W IN THE EASTERN PACIFIC MOVING W 10 
TO 15 KT. THIS WAVE TRANSVERSED MEXICO FROM THE CARIBBEAN AND 
STILL IS PRODUCING SCATTERED STRONG CONVECTION OVER WRN MEXICO. 
THERE IS NO CLOSED SURFACE LOW THUS NO INTENSIFICATION IS 
EXPECTED. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N83W 11N89W 10N94W 15N107W 10N113W 
15N127W 8N140W. SCATTERED MODERATE FROM 7N78W TO 8N84W AND FROM 
8N92W TO 11N101W. SCATTERED MODERATE WITHIN 90 NM EITHER SIDE OF 
A LINE FROM 16N105W TO 12N110W TO 9N117W.  

OTHER MODERATE TO STRONG CONVECTION NEAR THE COAST FROM 11N88W 
TO 15N94W TO 15N97W AND FROM 19N106W TO 20N109W TO 21N106W TO 
25N109W.

...DISCUSSION...

MID LEVELS DOMINATED BY TWO LARGE FEATURES..A TROUGH ORIENTED 
NE/SW OVER THE NW CORNER OF THE AREA AND A RIDGE OVER THE SRN 
CONUS AND NRN MEXICO. WATER VAPOR IMAGERY SHOWS THE RIDGE 
EXTENDS W TO 128W. THE TROUGH HAS EMBEDDED LOW CENTERS..ONE NEAR 
THE CA COAST AND THE OTHER NEAR 28N137W. BOTH MOVING NE 15 KT. 
IMAGERY ALSO SHOWS STRONG UPPER WINDS SWEEPING SW S OF 20N 
BETWEEN 100W AND 120W. ON THE SURFACE TONIGHT THE MAIN FEATURE 
IS T.S. FLOSSIE NEAR 13N128W MOVING W 12 KT. FLOSSIE REMAINS 
EMBEDDED IN THE ITCZ. THE STORM HAS TWO GOOD BANDS AND FAIRLY 
GOOD OUTFLOW ALOFT. OTHERWISE THE PACIFIC RIDGE REMAINS FAIRLY 
WEAK EXTENDING OVER THE REGION TO 17N115W. WINDS ALONG THE BAJA 
COAST ARE NWLY AT 15 TO 20 KT ACCORDING TO SSMI. QUIKSCAT HAS 
LIMITED COVERAGE TONIGHT SHOWING ONLY THE SRN PORTION WITH 10 TO 
15 KT. GAP WINDS ARE LIGHT WHILE CROSS EQUATORIAL SLY WINDS TO 
20 KT ARE EVIDENT S OF 10N E OF 120W TO 90W. SLY SWELL 8 TO 10 
FT IS CROSSING THE EQUATOR BETWEEN 105W AND 115W. 

LATER DAY 1 BOTH MAIN FEATURES AT MID LEVELS HOLD THEIR 
POSITIONS WHILE WEAK SHORTWAVE TROUGH MIGRATE AROUND THEM. 
TROPICAL EASTERLIES ARE CONFINED TO S OF 22N WHERE TROPICAL 
WAVES ARE MOVING WWD. ON THE SURFACE LATER DAY 1 LITTLE CHANGE 
TO THE PACIFIC RIDGE AND WINDS ALONG THE BAJA COAST WILL REMAIN 
10 TO 15 KT. GAP WINDS ALSO WILL BE LIGHT. CROSS EQUATORIAL SLY 
WINDS TO 20 KT MAINLY S OF 10N BETWEEN 110W TO 135W AND SWLY TO 
20 KT S OF 5N FROM 90W TO 110W.

FOR DAY 2 THE MID LEVE RIDGE SLIDES WWD AND SHOULD BE CENTERED 
OVER W TX. IT WILL CONTINUE TO RIDGE SW TO 15N125W. THE MID 
LEVEL TROUGH OVER THE NW CORNER OF THE AREA APPEARS TO BE 
WEAKENING WITH ONLY A WEAK TROUGH AXIS EXTENDING SW TO 25N144W. 
ON THE SURFACE DAY 2 SOME SLIGHT STRENGTHENING OF THE PACIFIC 
RIDGE AS SOME COLD AIR DROPS SE IN THE MID LEVEL TROUGH. THIS 
STRENGTHENS NE TRADES W OF 125W TO 20 KT. T.S. FLOSSIE CONTINUES 
WWD ALONG 14N AND ALSO HELPS TIGHTEN THE GRADIENT AGAINST THE 
RIDGE. OTHERWISE WINDS ALONG THE BAJA COAST REMAIN LIGHT AS DO 
GAP WINDS. CROSS EQUATORIAL SLY WINDS REMAIN ABOUT THE SAME. SLY 
SWELL WILL MIGRATE NWD TO 12N WITH LONG PERIOD SELY SWELL TO 10 
FT MAINLY W OF 105W.

$$
RRG