000
AXPZ20 KNHC 280318
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON APR 28 2008

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 
0300 UTC.

...ITCZ...
ITCZ AXIS ALONG 03N78W TO 05N90W TO 06N120W TO 04N128W TO 
02N140W. SCATTERED MODERATE AND EMBEDDED ISOLATED STRONG 
CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 
102W-107W. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 120 NM 
EITHER SIDE OF AXIS BETWEEN 88W-98W. ISOLATED MODERATE 
CONVECTION IS WITHIN 150 NM N OF AXIS BETWEEN 108W-128W.

...DISCUSSION...

W OF 100W...
AN AMPLIFIED MID-UPPER PATTERN REMAINS OVER THE REGION WITH A 
SPRAWLING RIDGE BEING THE MAIN FEATURE ROUGHLY ALONG 123W. 
DIFFLUENCE ALOFT TO THE W OF THE RIDGE AXIS...ASSOCIATED WITH A 
SERIES OF SHORTWAVES N AND W OF THE REGION...IS PRODUCING 
ABUNDANT CLOUDINESS AND SCATTERED SHOWERS S OF 16N W OF 126W AND 
SCATTERED TO BROKEN MID-HIGH LEVEL CLOUDS FROM 20N-25N W OF 
135W. THIS BLOCKING RIDGE IS PREVENTING A FRONT ALONG 
THE NW CORNER OF THE DISCUSSION ZONE...30N140W...TO MAKE MUCH 
FURTHER PROGRESS INTO THE REGION. UPPER CONFLUENCE TO THE E OF 
THE RIDGE AXIS...GREATLY ENHANCED BY A LARGE SCALE TROUGH 
EXTENDING SSW FROM CENTRAL CANADA TO THE SOUTHERN TIP OF 
BAJA...IS PRODUCING A VERY DRY ATMOSPHERE FROM 17N-29N E OF 
126W. A SUBTROPICAL JET ORIGINATES JUST SE OF THE TROUGH BASE 
AND IS GENERATING AND TRANSPORTING A PLUME OF HIGH LEVEL 
MOISTURE WITHIN 300 NM SE OF A LINE FROM 16N110W TO INLAND OVER 
MAINLAND MEXICO NEAR 25N100W. THIS TROUGH AND ASSOCIATED JET IS 
PRODUCING SIGNIFICANT TSTM ACTIVITY OVER PORTIONS OF MEXICO AND 
THE GULF OF MEXICO.

IN THE LOWER LEVELS...BESIDES FOR THE AFOREMENTIONED WEAKENING 
STATIONARY FRONT...A 1029 MB SUBTROPICAL HIGH IS IN CONTROL 
PRODUCING AN AREA OF N WINDS NEAR 20 KT N OF 27N BETWEEN 
121W-127W AND  SIMILAR MAGNITUDE NE TRADES OVER THE SW PORTION 
OF THE ZONE. N TO NE WINDS NEAR 20 KT WILL EXPAND AND COVER MUCH 
OF THE REGION BY TUE AS HIGH PRES SHIFTS E AND STRENGTHENS.

E OF 100W...
LIGHT SLY FLOW ALOFT LIES OVER MUCH OF THIS TROPICAL PORTION ON 
THE W SIDE OF UPPER RIDGING EXTENDING FROM COLOMBIA TO THE 
YUCATAN CHANNEL. THIS FLOW IS DRAWING ITCZ-MOISTURE NWD TOWARD 
THE COAST OF CENTRAL AMERICA...THOUGH MOST OF DEEP MOISTURE IS 
FARTHER W OVER MEXICO TRIGGERED BY THE SUBTROPICAL JET DISCUSSED 
ABOVE.     

GAP WINDS...
A LATE SEASON STRONG COLD FRONT THAT JUST ENTERED THE GULF OF 
MEXICO IS EXPECTED TO SURGE SWD INTO THE BAY OF CAMPECHE 
SPREADING COOLER AIR INTO THE GULF OF TEHUANTEPEC BY MON 
NIGHT. NWP MODELS ARE IN GOOD AGREEMENT IN DEPICTING A GALE 
EVENT BEGINNING IN THE VICINITY OF TUE 0600 UTC. HOWEVER... 
GUIDANCE AND CLIMATOLOGY SUGGESTS THAT THE EVENT SHOULD BE 
FAIRLY SHORT LIVED. 

$$
CANGIALOSI