000
AXPZ20 KNHC 220928
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON FEB 22 2010

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 
0900 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 06N77W TO 03N100W TO 06N112W TO 
02N125W TO 06N140W. SCATTERED MODERATE TO STRONG CONVECTION IS  
FROM 01N TO 05N BETWEEN 88W AND 98W. SIMILAR CONVECTION IS NOTED 
FROM 03N TO 06N BETWEEN 110W AND 117W. 

...DISCUSSION...

ALOFT...SHEARED UPPER-LEVEL TROUGH EXTENDS FROM THE WESTERN U.S. 
SW TO 23N130W TO W OF THE AREA AT 20N140W. A SUBTROPICAL JET 
STREAM ROUNDS THE BASE OF THIS TROUGH AND CONTINUES E-NE TO THE 
COAST OF BAJA CALIFORNIA WITH CORE JET SPEEDS OF 125-150 KT. IN 
ADDITION TO MAINTAINING MAINLY A ZONAL FLOW PATTERN ACROSS MOST 
OF THE AREA...THIS JET ALSO CONTINUES TO ADVECT PLENTIFUL MID TO 
UPPER LEVEL MOISTURE FROM THE DEEP CENTRAL TROPICAL PACIFIC NE 
TO E ACROSS CENTRAL AND SOUTHERN MEXICO AND INTO THE GULF OF 
MEXICO. THE UPPER TROUGH WILL CONTINUE TO SHEAR OUT AS IS MOVES 
EWD DURING THE NEXT 24 TO 48 HRS. 

ELSEWHERE A NEARLY STATIONARY ELONGATED UPPER LEVEL ANTICYCLONE 
IS NOTED NEAR 9N101W. ASSOCIATED BROAD MID TO UPPER LEVEL 
ANTICYCLONIC FLOW COVERS THE AREA SOUTH OF THE ABOVE MENTIONED 
JET STREAM AND W OF ABOUT 97W. A MID TO UPPER LEVEL TROUGH 
EXTENDS FROM THE WESTERN CARIBBEAN SEA SW TO ACROSS HONDURAS AND 
EL SALVADOR TO NEAR 9N94W. ANOTHER RIDGE COVERS THE REMAINDER OF 
THE EPAC BETWEEN THE TROUGH AXIS AND THE COAST OF SOUTH AMERICA. 
A DIFFLUENT PATTERN ALOFT BETWEEN THESE TWO UPPER LEVEL FEATURES 
IS ENHANCING ITCZ CONVECTION BETWEEN 88W-98W. 

AT THE SURFACE...A 1026 MB HIGH IS ANALYZED NEAR 26N132W WITH A 
RIDGE ESE TO NEAR 18N110W. THE HIGH IS FORECAST TO SLOWLY MOVE E 
OVER THE NEXT 48 HRS MAINTAINING CONTROL OF THE WIND REGIME 
ACROSS THE MAJORITY OF THE FORECAST REGION. THE PRES DIFFERENCE 
BETWEEN THE HIGH AND LOWER PRES ASSOCIATED WITH THE ITCZ 
CONTINUES TO ALLOW FOR A LARGE AREA OF NE TO E 20 TO 25 KT TRADE 
WINDS FROM 6N TO 18N W OF 115W. WITH THE HIGH CENTER FORECAST TO 
SHIFT EASTWARD OVER THE NEXT 48 HRS...EXPECT THE TRADES TO 
EXPAND SOME EASTWARD TO NEAR 112W IN 24 HOURS. ALSO EXPECT NW TO 
N WINDS TO INCREASE ALONG AND ACROSS THE BAJA CALIFORNIA 
INCLUDING THE GULF OF CALIFORNIA IN APPROXIMATELY 24 HOURS AS 
PRES GRADIENT TIGHTENS BETWEEN THE HIGH AND LOWER PRES OVER 
NORTHERN MEXICO. IN ADDITION...THE GRADIENT WILL ALSO TIGHTEN 
WITHIN 90 NM OF THE MEXICAN COAST FROM 16N TO 20N IN 6 HOURS...  
INCREASING FROM 16N TO 23N WITHIN 120 NM OF THE MEXICAN IN 24 
HOURS WHERE NW WINDS OF 20-25 KT CAN BE EXPECTED.

LARGE AND LONG PERIOD SWELL FROM THE NW CONTINUES TO AFFECT MOST 
OF THE AREA W OF 110W...RAISING SEAS TO AROUND 13 FT OVER THE NW 
PORTION. ANOTHER SET OF NW SWELL SHOULD REACH THE FAR NW PORTION 
LATE TUE WITH SIGNIFICANT WAVE HEIGHTS AS HIGH OF 17 FT.  

GAP WINDS...

GULF OF PAPAGAYO NE TO E WINDS OF 20 KT ARE FORECAST TO DIMINISH 
TO LESS THAN 20 KT IN 12 HRS.

LOOKING AHEAD...NWP MODELS ARE CONSISTENTLY FORECASTING THE NEXT 
GULF OF TEHUANTEPEC EVENT TO BEGIN BY LATE WED WITH WINDS LIKELY 
REACHING GALE FORCE. THE LATEST RUN OF THE NAM MODEL FORECAST 
NEAR STORM FORCE WINDS BY THU BETWEEN 06 AND 12 UTC. 

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

$$
GR/JA