000
AXPZ20 KNHC 271000
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE OCT 27 2009

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 
0830 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 09N76W TO 
10N91W TO 13N102W TO 12N117W TO 06N134W TO 08N140W. SCATTERED 
MODERATE TO STRONG WITHIN 120 NM N AND 150 NM S OF THE AXIS 
BETWEEN 90W AND 100W. SCATTERED MODERATE ISOLATED STRONG WITHIN 
210 NM N OF AXIS BETWEEN 105W AND 110W. SCATTERED MODERATE 
WITHIN 90 NM EITHER SIDE OF AXIS W OF 115W. SCATTERED TO 
NUMEROUS STRONG N OF 14N BETWEEN 99W AND 103W. SCATTERED 
MODERATE WITHIN 90 NM OF COAST BETWEEN 88W AND 91W.

...DISCUSSION...

A LONGWAVE TROUGH EXTENDING FROM THE CENTRAL U.S. THROUGH EAST 
CENTRAL TEXAS CONTINUED SW TO ACROSS N CENTRAL MEXICO TO JUST S 
OF SOUTHERN BAJA CALIFORNIA NEAR 21N110W...TO NEAR 17N130W... 
WILL BE ENERGIZED DURING THE NEXT 24 HOURS BY SHORTWAVE ENERGY 
THAT WILL DIVE SE FROM THE PACIFIC NW AND NORTHERN CALIFORNIA 
AMPLIFYING THE TROUGH OVER THE S CENTRAL U.S. THE ASSOCIATED 
SECONDARY SURFACE COLD FRONT WAS N OF THE AREA...BUT WILL PUSH 
SWD AS A RESULT OF THE SHORTWAVE ENERGY REACHING THE WATERS JUST 
N OF 30N INCLUDING NORTHERN BAJA THIS MORNING WHERE IT WILL 
GRADUALLY BECOME DIFFUSE THROUGH WED. THE COMBINATION OF BROAD 
LOW PRES DEEPENING OVER THE SOUTHERN GREAT PLAINS AND HIGH PRES 
BUILDING SE OVER THE WATERS ALONG THE U.S. W COAST HAS BROUGHT 
AND INCREASE OF NW WINDS TO THE GULF OF CALIFORNIA WHERE NW 
WINDS TO 20 KT WERE SUGGESTED BY A PARTIAL ASCAT PASS OVERNIGHT. 
THE AREA OF LOW PRES WILL BEGIN TO LIFT NE WHILE HIGH PRES 
CENTERED N OF THE AREA INTENSIFIES AS IT BEGINS TO MOVE S. THIS 
WILL ALLOW FOR THESE WINDS TO SHIFT TO THE S TO SW IN DIRECTION 
IN ABOUT 24 HOURS ...THEN BACK TO NW IN 48 HOURS. THESE WINDS 
ARE EXPECTED TO MAX OUT UP TO 30 KT ACROSS THE NORTHERN PART OF 
THE GULF IN OR CLOSE TO 48 HOURS.

TO THE SE OF THE LONGWAVE TROUGH...A JET STREAM BRANCH EXTENDED 
FROM 13N115W TO 18N108W NE ACROSS MEXICO AT 24N100W...THEN 
CONTINUED N TO NE ACROSS THE GULF COAST STATES.  MAXIMUM WINDS 
OF 80-110 KT AS NOTED IN SATELLITE DERIVED WINDS WERE NEAR THE 
JET CORE. THE JET WAS ADVECTING UPPER LEVEL MOISTURE IN THE FORM 
OF BROKEN CIRRUS CLOUDS ALONG AND WITHIN 220 NM S OF IT ENE TO 
ACROSS CENTRAL MEXICO. DIVERGENT FLOW ALOFT TO THE SE OF THE 
LONGWAVE TROUGH IN COMBINATION WITH LOW LEVEL CONVERGENCE ALONG 
THE ITCZ HAS INITIATED CLUSTERS OF TSTMS TO FLARE UP ALONG AND 
NEAR THE ITCZ E OF 110W. THIS CONVECTION WILL REMAIN ACTIVE 
THROUGH AT LEAST THE NEXT 48 HOURS. THE LATEST RUNS OF THE 
GLOBAL MODELS WITH THE BOTH THE GFS AND EUROPEAN MEAN ENSEMBLES 
AGAIN SUGGESTED THAT A LOW TO MID LEVEL CYCLONIC GYRE IN THE 
AREA BETWEEN 95W AND 105W MAY COMBINE TO FORM A MORE DEFINITIVE 
LOW THAT TRACKS IN A NE FASHION LATER ON THE WEEK. A FEW WEAK 
AND TRANSIENT LOWS CONTINUE TO BE SUGGESTED BY SATELLITE IMAGERY 
AND SCATTEROMETER PASSES ACROSS THIS AREA...BUT AS OF YET NONE 
HAS BECOME DOMINANT. 

A MID/UPPER LEVEL ANTICYCLONE MOVING NE IS MEXICO AND INTO THE 
YUCATAN WITH A RIDGE SW TO 10N99W TO 5N107W. SW FLOW TO THE NW 
OF THE ANTICYCLONE WAS ADDING ADDITIONAL MOMENTUM TO FLOW 
ASSOCIATED WITH THAT ASSOCIATED WITH THE JET STREAM. THE RIDGE 
WAS SUPPLYING ADDITIONAL LIFT FOR CONVECTION ALONG AND NEAR THE 
ITCZ E OF 110W AS MENTIONED ABOVE.

TO THE W OF THE LONGWAVE TROUGH...HIGH PRES WAS IN CONTROL 
THROUGH ALL LEVELS OF THE ATMOSPHERE WITH A MID/UPPER LEVEL 
RIDGE AXIS ALONG 139W EXTENDING TO AN ANTICYLONE NEAR 12N138W. 
AT THE SURFACE...A NEARLY STATIONARY 1029 MB HIGH CENTER WAS 
ANALYZED N OF THE AREA NEAR 34N138W WITH A RIDGE SE TO 24N126W. 
HIGH PRES GENERALLY COVERS THE AREA N OF 20N AND W OF 120W. THE 
PRES DIFFERENCE BETWEEN THE RIDGE AND LOW PRES OVER THE WESTERN 
U.S. IS ALLOWING FOR N-NE WINDS OF 20-25 KT N OF 22N AND W OF 
127W WITH SEAS 8-11 FT. NE TRADE WINDS OF 20 KT WERE NOTED ON 
THE S SIDE OF THE RIDGE AXIS FROM 09N-22N W OF 125W...AND FROM 
9N-18N BETWEEN 118W AND 130W. THE RIDGE IS FORECAST TO 
STRENGTHEN THROUGH THE NEXT 48 HOURS WITH PARENT HIGH TO THE N. 
LONG PERIOD NW-N SWELLS PRODUCING SEAS OF 11-19 FT ARE EXPECTED 
TO BEGIN TO FILTER INTO THE FAR NE PORTION OF THE AREA BEGINNING 
EARLY TUE EVENING WITH SEAS MAXING OUT WED MORNING INTO THE 
AFTERNOON BEFORE SUBSIDING TO 14 FT LATE WED NIGHT OVER THE FAR 
NE PORTION. NW-N WINDS IN THIS AREA ARE FORECAST TO INCREASE TO 
20-30 KT IN 24 HOURS WITH GALE CONDITIONS N OF 30N...AND 
POSSIBLE SINKING VERY CLOSE TO 30N...THEN LESSEN TO 20-25 KT 
WITHIN  48 HOURS...WHILE SWELLS THEN SLOWLY SUBSIDE.

$$
STRIPLING