000
AXPZ20 KNHC 121005
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI MAR 12 2010

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 
0945 UTC.

...ITCZ...

AXIS IS CENTERED ALONG 6N78W 4N90W TO 4N102W TO 4N114W 4N125W
4N140W. SCATTERED MODERATE TO STRONG CONVECTION WAS WITHIN
60 NM N OF THE AXIS BETWEEN 91W-95W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION WAS NOTED FROM 2N-6N BETWEEN 108W-112W. 
SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM N OF THE AXIS  
BETWEEN 84W-88W.

...DISCUSSION...

A DEEP LAYER TROUGH IS QUICKLY MOVE E ACROSS THE ACROSS THE 
NW PORTION OF THE AREA WHILE AMPLIFYING. THE ASSOCIATED COLD
FRONT HAS JUST CROSSED INTO THE NW CORNER OF THE AREA. TO THE 
E OF THE TROUGH...A LARGE MID/UPPER RIDGE WAS AMPLIFYING 
N OF 25N AND E OF 129W WITH MEAN N TO S RIDGE AXIS ACROSS
THE WRN U.S. A JET STREAM BRANCH WITH JET CORE WINDS IN THE 
RANGE OF 70-120 KT ENTERED THE REGION ROUNDING THE BASE OF
THE TROUGH AT 20N140W...AND EXTENDED ENE TO 21N125W TO 23N115W
AND TO ACROSS EXTREME SRN BAJA CALIFORNIA TO CENTRAL MEXICO
AND THE WELL E OF THE AREA ACROSS THE GULF OF MEXICO. A 450 NM 
WIDE SWATH OF MODERATE SUBSIDENCE INDICATIVE OF DRY...STABLE AIR
IS TO THE SE OF THE TROUGH TO NEAR 130W...AND N OF JET E OF 
130W. THE TROUGH IS FORECAST TO MOVE INLAND THE U.S. W COAST
IN ABOUT 36 HRS...WHILE THE COLD FRONT WEAKENS. RIDGING BOTH
AT THE SURFACE AND ALOFT THEN BUILDS E ACROSS THE NORTHERN AND
CENTRAL PORTIONS OF THE AREA THROUGH THE NEXT 48 HRS AND 
INTERACTS WITH THE WEAKENING FRONT AND LOW PRES OVER THE SW U.S. 
AND NRN MEXICO INCREASING THE PRES GRADIENT TO INCREASE OVER THE 
FAR ERN PORTION RESULTING IN NW TO N WINDS OF 20 KT N OF ABOUT 
21N AND E OF 124W. LARGE NW SWELLS N OF THE AREA ARE FORECAST TO 
PROPAGATE SE ACROSS THE N CENTRAL AND NE WATERS DURING THE 
WEEKEND BUILDING SEA HEIGHTS UP TO 13 OR 14 FT.
 
TO THE S OF THE JET STREAM...BROAD UPPER LEVEL ANTICYCLONIC
CIRCULATION WITH A MEAN ANTICYCLONE CENTER NEAR 7N105W COVERS
THE AREA TO THE E OF 131W WITH A MEAN W TO E RIDGE ALONG 8N.
W OF 131W A WEAK MID/UPPER LEVEL TROUGH EXTENDS FROM 13N139W SE
TO 6N135W. UPPER DIFFLUENT FLOW PATTERN TO THE SW OF THE 
ANTICYCLONE IS HELPING TO SUSTAIN ITCZ CONVECTION BETWEEN 
115W-120W. THE ANTICYCLONE IS EXPECTED TO CHANGE LITTLE OVER THE 
NEXT 24 HRS...THEN BEGIN TO SHIFT E IN 36-48 HRS.

A SURFACE 1025 MB HIGH WAS ANALYZED NEAR 27N136W WITH A RIDGE
SE TO NEAR 19N111W. HIGH PRES COVER THE AREA N OF 13N AND W OF 
110W. THIS HIGH CENTER IS FORECAST TO DISSIPATE WITHIN THE NEXT
24 HRS AS ANOTHER HIGH N OF THE AREA MOVES ESE. EXPECT GRADIENT
THROUGH THE GULF OF CALIFORNIA TO INCREASE AS NW WINDS OF 20-25 
KT S OF 28N SHORTLY...WITH LITTLE CHANGE IN 24 HRS THEN TO N OF 
29N IN 48 HRS WITH WINDS POSSIBLY INCREASING TO 30 KT THEREAFTER.

S OF THE SURFACE RIDGE AXIS LIES A BROAD AREA OF STRONG NE TRADE 
WINDS FROM 6N-22N W OF 119W. A 0512 UTC ASCAT PASS PRETTY MUCH 
CONFIRMED THIS AREA OF TRADES. AS HIGH PRES OVER NW WATERS
WEAKENS SOME AHEAD OF THE APPROACHING COLD FRONT...THE 
AREA OF TRADE SHOULD DIMINISH SOME ON THE E SIDE THROUGH THE 
NEXT 24 HRS...WITH LITTLE CHANGE IN 48 HRS.

GAP WINDS...
THE NEXT TEHUANTEPEC GAP WIND EVENT IS FORECAST TO BEGIN EARLY 
THIS EVENING WITH N-NE WINDS OF 20 KT...THEN INCREASE TO POSSIBLY
30 KT IN 24 HRS AND TO LESS THAN 20 KT IN 42 HRS.

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

$$
AGUIRRE