000
AXPZ20 KNHC 111556
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU MAR 11 2010

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 
1500 UTC.

...ITCZ...
THE ITCZ AXIS IS ALONG 06N77W TO 05N110W TO 07N116W TO 01N140W. 
SCATTERED MODERATE CONVECTION IS FROM 02N TO 05N E OF 80W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION CAN BE FOUND 
WITHIN 120-140 NM S OF AXIS BETWEEN 85W AND 100W. SIMILAR 
CONVECTION IS NOTED FROM 02N TO 06N BETWEEN 110W AND 115W.

...DISCUSSION...
A FLAT BROAD UPPER LEVEL RIDGE DOMINATES THE AREA N OF 23N W OF 
120W PRODUCING MAINLY A ZONAL WLY FLOW OVER THE FORECAST AREA. E 
OF THIS RIDGE...AN UPPER LEVEL TROUGH AXIS EXTENDS FROM NEW 
MEXICO ACROSS THE NW PORTION OF MEXICO. A STRONG UPPER JET 
ROUNDS THE BASE OF THIS TROUGH. THE JET STREAM ENTERS THE AREA 
NEAR 22N140W AND EXTENDS MAINLY EWD TO SOUTHERN BAJA CALIFORNIA 
THEN TURNS ANTICYCLONICALLY OVER N MEXICO AND S TEXAS INTO THE 
GULF COAST STATES. A CORE OF SWLY WINDS IN EXCESS OF 150 KT IS 
NOTED E OF 110W. THIS JET CONTINUES TO ADVECT PLENTIFUL MID TO 
UPPER LEVEL MOISTURE FROM THE DEEP TROPICAL CENTRAL PACIFIC NE 
ACROSS SOUTHERN BAJA CALIFORNIA AND NORTH-CENTRAL MEXICO. BY 
FRI...A DEEP LAYER TROUGH WILL MOVE INTO NW WATERS. THE COLD 
FRONT ASSOCIATED WITH THIS NEW TROUGH IS EXPECTED TO BE WEAK.

A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 
09N111W EXTENDING A RIDGE E-NE OVER CENTRAL AMERICA INTO THE 
CARIBBEAN SEA. UPPER DIFFLUENCE ASSOCIATED WITH THIS FEATURE IS 
HELPING TO INDUCE CONVECTION ALONG THE ITCZ PARTICULARLY E OF 
100W. A SECOND RIDGE AXIS EXTENDS W OF THE ANTICYCLONE COVERING 
MOST OF THE SW PORTION OF THE FORECAST AREA. 

AT THE SURFACE...A 1027 MB HIGH PRES LOCATED NEAR 27N136W IS IN 
CONTROL OF THE WEATHER CONDITIONS ACROSS THE REGION MAINLY N OF 
15N W OF 110W. SOUTH OF THE SURFACE RIDGE AXIS LIES A BROAD AREA 
OF STRONG NE TRADE WINDS IN THE 20 TO 25 KT RANGE. THE 0540 UTC 
ASCAT PASS AND A FEW SHIP REPORTS CONFIRMED THE EXISTENCE OF THE 
TRADES COVERING ROUGHLY THE AREA FROM 06N TO 22N W OF 115W. 
ANOTHER AREA OF NW WINDS 20 KT IS ON THE EASTERN SIDE OF THE 
RIDGE JUST OFFSHORE THE W COAST OF BAJA CALIFORNIA AS A RESULT 
OF A TIGHT PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES OVER 
MEXICO. THE 0544 UTC ASCAT PASS VERIFIED THESE WIND SPEEDS. THE 
HIGH PRES WILL REMAIN NEARLY STATIONARY DURING THE NEXT 24-48 
HOURS OR SO. IN ADDITION...PRES GRADIENT ALONG THE MEXICAN 
PACIFIC COAST NEAR 20N BETWEEN LOWER PRES TO THE E AND THE RIDGE 
TO THE W IS RESULTING IN AREA OF NW TO N WINDS 20-25 KT FROM 16N 
TO 20 N E OF 110W...EXPECTED TO PERSIST FOR THE NEXT TWO DAYS. 
THIS WEATHER PATTERN WILL ALSO FAVOR AN INCREASE IN WINDS AND 
SEAS ACROSS THE GULF OF CALIFORNIA IN ABOUT 12 HOURS. EXPECT NW 
WINDS OF 20 KT AND SEAS RANGING FROM 5 TO 7 FT.

REGIONAL SEAS ARE BEING DOMINATED BY LONG PERIOD NW SWELL AND NE 
TRADE WIND WAVES W OF 110W. CROSS EQUATORIAL SW SWELL ARE NOTED 
OVER THE REMAINDER OF THE REGION PARTICULARLY W OF 100W. 
ADDITIONAL PULSES OF NW SWELL WILL PROPAGATE ACROSS THE AREA 
WITHIN THE NEXT 48 HOURS...RAISING SEAS TO AROUND 14 FT OVER THE 
FAR NW CORNER BY SAT MORNING.

GAP WINDS...
THE NEXT TEHUANTEPEC GAP WIND EVENT IS FORECAST TO BEGIN IN 
ABOUT 36 HOURS AS A COLD FRONT MOVES ACROSS THE GULF OF MEXICO. 
WINDS OF 20 TO 25 KT ARE EXPECTED.  


FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
GR