000
AXPZ20 KNHC 160953
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN DEC 16 2007

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 
0915 UTC.
 
...ITCZ...

INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 6N78W 7N95W
9N105W 8N116W 10N130W 10N140W. SCATTERED MODERATE CONVECTION IS
WITHIN 60 NM N OF THE AXIS W OF 138W...AND WITHIN 120 NM S OF 
THE AXIS BETWEEN 134W-137W.

...DISCUSSION...

MID/UPPER LEVEL TROUGH/SHEAR AXIS EXTENDS FROM SW TEXAS/NORTHERN 
MEXICO SW INTO THE REGION THROUGH NE MEXICO AND ACROSS SOUTHERN
BAJA CALIFORNIA SW TO 24N1115W. SHORTWAVE RIDGE EXTENDS FROM 
24N115W NW TO 32N121W. ANOTHER MID/UPPER LEVEL TROUGH...
RESEMBLING MORE LIKE A SHEAR AXIS...EXTENDS INTO THE REGION 
THROUGH 32N131W AND DROPS S TO A MID/UPPER LEVEL CYCLONIC 
CIRCULATION NEAR 25N135W. THE TROUGH AXIS THEN CONTINUES WSW 
FROM THE CYCLONIC CIRCULATION TO NEAR 22N140W. ANTICYCLONIC 
UPPER LEVEL FLOW WAS MOVING SWD INTO THE AREA N OF THE TROUGH 
AXIS. SATELLITE DERIVED WINDS FROM GOES-11 SHOWED A 90-120 KT 
SUBTROPICAL JTST S OF THE TROUGH ENTERING THE REGION THROUGH 
22N140W AND CONTINUING ENE THROUGH 21N130W 23N120W AND NE ACROSS 
THE SOUTHERN TIP OF BAJA CALIFORNIA AND INTO NW MEXICO. THE 
SUBTROPICAL JET CONTINUES TO ADVECT ABUNDANT TROPICAL MOISTURE 
ACROSS NORTHERN MEXICO AND INTO A STRONG FRONTAL SYSTEM 
CURRENTLY PROGRESSING RAPIDLY EASTWARD OVER THE SE UNITED STATES 
AND WESTERN GULF OF MEXICO.

THE FLOW AT THE UPPER LEVELS WAS MAINLY ANTICYCLONIC OVER THE 
DEEP TROPICS S OF THE JTST W OF 115W...AND ALSO E OF ABOUT 102W.
A NARROW MID/UPPER TROUGH EXTENDS FROM E MEXICO SSW THROUGH 
17N101W AND TO NEAR 12N105W...AND SEPARATES BOTH AREAS OF 
ANTICYCLONIC FLOW. MODERATE SUBSIDENCE DOMINATES JUST ABOUT THE
ENTIRE E PORTION OF THE REGION E OF LINE FROM 20N105W 8N113.5W
...AND S OF THE JTST AS WELL. CONVECTION REMAINS RATHER LIMITED 
OVER THIS AREA WITH ONLY CONVECTION SEEN IS THAT ASSOCIATED WITH 
THE ITCZ AS DESCRIBED ABOVE.

AT THE SURFACE...A 1027 MB HIGH CENTER NEAR 32N133W IS MOVING SE
...WITH A RIDGE EXTENDING SE THROUGH 27N126W 23N118W TO 18N110W.
HIGH PRES COVERS THE REGION N OF 13N W OF 110W. RESULTANT 
GRADIENT SUPPORTS NE-E TRADES IN THE RANGE OF 20-25 KT FROM 
10N-24N W OF 132W...BUT SHOULD WEAKEN SLIGHTLY OVER THE NEXT 48 
HRS AS THE RIDGE BREAKS DOWN SOME DUE TO THE TRAILING SOUTHERN 
SEGMENTS OF WEAKENING COLD FRONTS PASSING ACROSS THE FAR 
NORTHERN WATERS. BROKEN TO OVERCAST STRATOCUMULUS CLOUDS MOVING 
WSW WITH POSSIBLE ISOLATED SHOWERS ARE PRESENT N OF 12N W OF 
121W.

GAP WINDS...
PRESENTLY...WIND AND SEA CONDITIONS ARE QUIET IN THE GAP WIND 
AREAS WITH THE EXCEPTION OF 20 KT WINDS IN THE GULF OF 
CALIFORNIA. AS STRONG HIGH PRES CONTINUES TO BUILD SWD IN THE 
GREAT BASIN AND E OF THE SIERRA MADRE IN MEXICO BEHIND A STRONG 
COLD FRONT CURRENTLY MOVING ACROSS THE WRN GULF OF MEXICO. THIS 
SAME SYNOPTIC SETUP WILL BRING GALE FORCE WINDS OF 25-35 KT IN 
THE GULF OF TEHUANTEPEC STARTING IN ABOUT 12 HOURS. THESE WINDS 
ARE THEN FORECAST TO INCREASE UP TO 45 KT IN 24 HOURS PER GFS 
AND NAM MODEL WIND GUIDANCE. SEAS THERE WILL BUILD TO 10-16 FT. 
THESE CONDITIONS WILL THEN DIMINISH BEGINNING MON AFTERNOON AND 
THROUGH LATE TUE. GULF OF CALIFORNIA WINDS ARE EXPECTED TO 
DIMINISH TO LESS THAN 20 KT BY THIS AFTERNOON. EXPECT GULF OF 
PAPAGAYO WINDS TO INCREASE TO 20 KT BEGINNING IN 24 HOURS AND 
CONTINUING THROUGH MID-WEEK.

$$
AGUIRRE