000
AXPZ20 KNHC 220916
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JUL 22 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 DEPRESSION SEVEN-E CENTERED NEAR 12.8N 106.0W...OR 
ABOUT 410 NM SSW OF MANZANILLO MEXICO...AT 0900 UTC MOVING WNW 
11 KT. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 35 
KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. SEE LATEST 
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 
KNHC FOR MORE DETAILS. STRONG NE WINDS ALOFT OVER THE DEPRESSION 
HAS BEEN DETREMENTAL IN ALLOWING THE SYSTEM TO INTENSIFY.

...ITCZ...

ITCZ AXIS ALONG 9N80W 8N85W 13N96W 14N113W 9N127W 9N140W. 
SCATTERED MODERATE CONVECTION WITHIN 60 NM OF A LINE FROM 6N78W 
TO 6N88W TO 11N95W TO 8N104W AND FROM 13N118W TO 8N131W TO 
7N140W. 

SCATTERED MODERATE TO STRONG CONVECTION WITHIN 100 NM OF THE 
COAST OF CENTRAL AMERICA FROM 8N79W TO 8N85W TO 12N88W TO 14N93W.

...DISCUSSION...

AN UPPER TROUGH ALONG 140W N OF THE REGION ONCE AGAIN IS WORKING 
IT'S WAY SWD WHERE A WEAKNESS IN THE PRES FIELD LIES BETWEEN 
130W AND 140W. LATEST WATER VAPOR IMAGERY SHOWS A JET DIGGING SE 
INTO THE BASE OF THE TROUGH. OTHERWISE AT MID LEVELS A RIDGE 
CONTINUES OVER THE SW CONUS WITH A WEAKER ONE ALONG 30N W OF 
140W. THE OLD INVERTED TROUGH AT MID LEVELS REMAINS STUCK IN THE 
SW CONUS RIDGE. THE TROUGH EXTENDS FROM OVER NW MEXICO SW TO 
NEAR 15N130W. MID LEVEL TRPL EASTERLIES LIE S OF 20N WITH 
INVERTED TROUGHS ALONG 107W AND 129W. ON THE SURFACE TONIGHT 
T.D. SEVEN E HAS FORMED NEAR 13N105W AND IS MOVING W 10 KT. 
WATER VAPOR SHOWS GOOD ANTI-CYCLONIC FLOW OVER THE SYSTEM WHICH 
IS NEEDED FOR FURTHER DEVELOPMENT. THE PACIFIC RIDGE REMAINS 
WEAK EXTENDING SE TO 20N110W WITH NE TRADES TO 20 KT BETWEEN 15N 
AND 24N W OF 125W. WINDS ALONG THE BAJA COAST ARE NWLY AND LIGHT 
AS CONFIRMED BY SSMI AND QUIKSCAT DATA. GAP WINDS ARE ALSO 
LIGHT. CROSS EQUATORIAL SLY WINDS TO 20 KT ARE BLOWING S OF 10N 
BETWEEN 95W AND 105W AND W OF 115W. 

LATER DAY 1 THE UPPER TROUGH SLOWLY WORKS IT'S WAY TO 30N W OF 
130W WITH SHORTWAVES BRUSHING BY THE REGION. LITTLE CHANGE 
ELSEWHERE AT MID LEVELS. ON THE SURFACE LATER DAY 1 WATCH FOR 
T.D. SEVEN E TO BECOME A TRPL STORM AS IT MOVES SLOWLY W. LITTLE 
CHANGE ELSEWHERE WITH THE PRES PATTERN REMAINING WEAK. 

FOR DAY 2 SLOWLY FALLING MID LEVEL HEIGHTS ALONG 140W N OF 28N 
AS SHORTWAVES DIVE INTO THE BASE OF THE LARGE UPPER TROUGH. THE 
GFS MODEL HINTS AT THE UPPER TROUGH HAVING SOME INFLUENCE ON THE 
INVERTED TROUGH THAT HAS BEEN STUCK IN THE SW CONUS RIDGE THE 
PAST FEW DAYS. THE INVERTED TROUGH WEAKENS AS IT MOVES NWD..BUT 
ANOTHER INVERTED TROUGH MAY BE FORMING ALONG 108W READY TO TAKE 
IT'S PLACE TO THE NW. ON THE SURFACE DAY 2 A 1021 MB HIGH WILL 
ANCHOR THE PACIFIC RIDGE NEAR 29N135W. LITTLE CHANGE TO WINDS 
ABOUT THE RIDGE. BAJA WINDS REMAIN LIGHT NWLY. T.D. SEVEN 
FORECAST TO BECOME A TRPL STORM AS IT MOVES SLOWLY WNW. GAP 
WINDS REMAIN LIGHT AND CROSS EQUATORIAL SLY WINDS SHOULD BE 
STRONGEST BETWEEN 100W AND 105W WITH MOVEMENT OF THE TRPL STORM 
TO THE N. 

$$
RRG