000
AXPZ20 KNHC 150959
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON MAR 15 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 
0930 UTC.

...ITCZ...

AXIS WAS CENTERED ALONG 3N78W 4N90W 4N100W 3N121W 5N140W. 
SCATTERED MODERATE/ISOLATED STRONG CONVECTION WAS WITHIN
180 NM S OF THE AXIS BETWEEN 91W-94W...AND 60 NM S OF THE 
AXIS BETWEEN 132W-134W.

...DISCUSSION...

A STRONG UPPER LEVEL LOW OVER CONUS NEAR THE FOUR CORNERS 
REGION EXTENDED A TROUGH SW ACROSS NW MEXICO TO 24N115W TO
A DEVELOPING UPPER LOW NEAR 18N122W...THEN CONTINUED S TO NEAR
4N. THE RELATED SURFACE FEATURE WAS ANALYZED AS A COLD FRONT
OVER NW MEXICO THE LOW IS FORECAST TO MOVE NE TOWARDS FAR SRN
BAJA CALIFORNIA THROUGH TONIGHT THEN BE REPLACED BY MID/UPPER
LEVEL RIDGING THAT TRANSLATES EWD BEHIND THE TROUGH ON TUE. TO
THE SE OF THE UPPER LEVEL TROUGH...BROAD SCALE RIDGING COVERED 
THE AREA WITH THE ASSOCIATED MID/UPPER LEVEL ANTICYCLONE NEAR 
8N102W. A RIDGE EXTENDED FROM THE ANTICYCLONE NE TO ACROSS 
HONDURAS AND NICARAGUA...AND TO THE WRN CARIBBEAN SEA. ANOTHER 
RIDGE EXTENDED SW FROM THE ANTICYCLONE TO 4N115W. SLIGHT UPPER
LEVEL DIFFLUENT FLOW SW OF THE RIDGE MAY HELP SET-OFF ITCZ
CONVECTION BETWEEN 104W-110W TODAY.

A SUBTROPICAL JET STREAM BRANCH WITH CORE WINDS IN THE RANGE 
OF 80-120 KT DOVE SE INTO THE AREA THROUGH 14N140W REACHING TO 
11N125W...THEN TURNED NE ROUNDING THE BASE OF THE TROUGH TO 
21N116W AND NE AROUND THE NRN PERIPHERY OF THE RIDGE TO OVER NRN 
MEXICO TO WELL E OF THE AREA.

UPPER LEVEL CONFLUENT FLOW RESIDES WEST OF THE TROUGH BRINGING
RY AIR AND STABLE CONDITIONS TO THE NW OF THE TROUGH. THE TROUGH 
IS FORECAST TO BE PUSHED E OF THE AREA BY THE UPPER LEVEL LOW
ON TUE WHILE MOST OF THE UPPER LEVEL ENERGY OVER THE PACIFIC 
WATERS N OF 15N BECOMES ABSORBED INTO MEAN WESTERLY FLOW BY 
EARLY WEDNESDAY.

NW WINDS OF 20-25 KT THROUGH THE GULF OF CALIFORNIA FROM 23N-28N
DUE TO A TIGHT PRES GRADIENT CREATED FROM THE INTERACTION 
BETWEEN HIGH OVER THE NE PORTION AND LOW PRES OVER THE SW U.S. 
WILL CHANGE LITTLE THROUGH THE NEXT 24 HRS. A PARTIAL 0420 UTC
ASCAT SHOWED SOME OF THESE WINDS. THESE WINDS ARE FORECAST TO 
INCLUDE JUST ABOUT THE ENTIRE GULF BY 48 HRS. W OF THE BAJA 
PENINSULA NW-N 20 KT WINDS ARE FORECAST TO DIMINISH IN 12 HRS AS 
THE SURFACE HIGH DRIFTS E AND WEAKENS IN ADVANCE OF THE NEXT 
COLD FRONT CURRENTLY WITHIN 160 NM NW OF THE AREA.

THE COLD FRONT IS FORECAST TO MOVE TO A LINE FROM 30N135W TO 
25N140W BY EARLY THIS EVENING...THEN WEAKEN FROM 30N132W TO 
24N140W IN 24 HRS. THE FRONT IS FORECAST TO DISSIPATE INLAND
IN 48 HRS AS STRONG HIGH PRES RIDGING BEGINS TO BUILD SE ACROSS
THE NW WATERS. LATEST SURFACE ANALYSIS SHOWED A 1028 MB HIGH 
NEAR 32N130W. THE HIGH WILL MOVE WELL NE OF THE AREA WITH 
THE FAST APPROACH OF THE COLD FRONT.

THE 0600 UT WAVEWATCH GUIDANCE AGAIN SUGGESTED THAT THE FRONT
WILL MARK THE LEADING EDGE OF YET ANOTHER SURGE OF LONG PERIOD 
NW SWELLS. THE GUIDANCE SHOWED SEAS UP TO 17 FT BEHIND THE FRONT 
BEGINNING IN ABOUT 30 HRS AND SUBSIDING THEREAFTER. WINDS BEHIND
THE FRONT ARE FORECAST TO BE NW-N 20 KT THIS EVENING...THEN
BECOME N-NE 20 KT LATE TONIGHT. AFTER THE FRONT DISSIPATES...
THE WINDS CONTINUE AT N-NE 20 KT AS THEY THEN JOIN UP WITH THE 
TRADES TO THE S COVERING THE WRN PORTION OF THE AREA.

A LARGE AREA OF MODERATE NE TRADES WAS OBSERVED OVER THE AREA
FROM 6N-21N W OF 125W AS WAS REVEALED BY A 0600 UTC ASCAT PASS.
THIS AREA OF TRADES WILL CHANGE LITTLE CHANGE THROUGH TONIGHT
...THEN EXPAND NWD TO N OF 7N AND W OF 129W TUE INTO TUE NIGHT 
DUE TO THE ABOVE MENTIONED RIDGE. SEAS OF AT LEAST 8 FT WITH 
MAXIMUM VALUES UP TO 12 FT CONTINUED TO AFFECT THE AREA 
ELSEWHERE W OF 100W. BY 48 HRS...THE LARGEST SEAS SHOULD BE 
CONFINED TO THE NW PORTION WHERE THE LATEST WAVEWATCH GUIDANCE 
SHOWED UP TO 16 FT IN NW SWELL. ELSEWHERE OUTSIDE OF THE TRADE 
WIND REGION SEAS SHOULD BE IN THE RANGE OF 8-11 FT PRIMARILY DUR
TO A NW SWELL WITH THE HIGHEST OF THESE SEAS OVER THE N CENTRAL 
PORTION.

GAP WINDS...
NEXT GULF OF TEHUANTEPEC WIND EVENT SHOULD BEGIN LATE TUE NIGHT 
AS HIGH PRES RIDGING BUILDS S ALONG THE SIERRA MADRE ORIENTAL 
MOUNTAINS OF ERN MEXICO TIGHTENING THE PRES GRADIENT JUST ENOUGH 
TO USHER IN N-NE WINDS 20-30 KT INTO THE GULF. MODEL GUIDANCE 
HINTS AT THESE WINDS POSSIBLY REACHING GALE FORCE GOING INTO WED 
MORNING.

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

$$
AGUIRRE