080
AXPZ20 KNHC 090912
TWDEP
TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON NOV 09 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
0730 UTC.
..TROPICAL LOWS
1009 MB LOW PRES IS EMBEDDED IN THE ITCZ NEAR 08N102W. THE
CONVECTION PREVIOUSLY ASSOCIATED WITH THIS SYSTEM HAS BEEN
SHEARED TO THE SOUTH BY A 20 KT NORTHERLY UPPER JET. THERE IS NO
SIGNIFICANT CONVECTION CURRENTLY NOTED NEAR THE LOW.
1008 MB LOW PRES IS EMBEDDED IN THE ITCZ NEAR 11N112W. SCATTERED
MODERATE WITH ISOLATED STRONG CONVECTION CAN BE FOUND WITHIN 210
NM OF THE LOW CENTER EXCEPT TO 300 NM IN THE NW QUADRANT. THIS
SURFACE LOW CURRENTLY LIES UNDER A REGION OF WEAK...DIFFLUENT
UPPER LEVEL FLOW. THE SOUTHWESTERLY JET ON THE EASTERN SIDE OF
THE UPPER TROUGH TO THE WEST OF THIS LOW IS EXPECTED TO SHEAR
THE SYSTEM BY LATE TUE AND INHIBIT ANY FURTHER DEVELOPMENT.
1008 MB LOW PRES IS EMBEDDED IN THE ITCZ NEAR 10N122W. SCATTERED
MODERATE WITH ISOLATED STRONG CONVECTION LIES WITHIN 240 NM E
AND SW QUADRANTS OF THE LOW. THIS PERSISTENT SURFACE LOW IS
UNDER INCREASING SOUTHWESTERLY SHEAR ASSOCIATED WITH THE JET ON
THE LEADING EDGE OF THE UPPER TROUGH CENTERED FROM 20N125W TO
10N140W. THIS TROUGH IS EXPECTED TO SLOWLY SHIFT NW OVER THE
NEXT TWO DAYS...PRIMARILY PASSING N OF THE LOW. BRIEF
ENHANCEMENT OF THE CONVECTION ASSOCIATED WITH THE LOW IS
POSSIBLE AS THE UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE REAR
RIGHT QUADRANT OF THE JET APPROACHES IT OVERNIGHT TONIGHT. THE
LOW WILL THEN MOVE UNDER INCREASING NORTHERLY UPPER FLOW THAT
SHOULD DISSIPATE THE SYSTEM.
..ITCZ
THE ITCZ AXIS EXTENDS FROM 07N77W TO 08N85W TO 08N105W TO
11N115W TO 08N140W. OUTSIDE OF THE TROPICAL LOWS EMBEDDED IN THE
ITCZ MENTIONED ABOVE...SCATTERED MODERATE CONVECTION CAN BE
FOUND WITHIN 90 NM S OF AXIS BETWEEN 126W AND 130W...IN THE
VICINITY OF THE REAR RIGHT QUADRANT OF THE AFOREMENTIONED UPPER
JET.
..DISCUSSION
A HIGH PRES RIDGE STEMMING FROM A 1022 MB HIGH NEAR 33N133W WITH
A RIDGE EXTENDING SE TO NEAR 17N110W DOMINATES NORTH WATERS AT
THE SURFACE. THIS HIGH PRES SYSTEM IS PART OF A LARGER NORTH
PACIFIC RIDGE THAT IS CURRENTLY BEING COMPROMISED BY A COLD
FRONT JUST NORTH OF THE FORECAST AREA. WHILE THIS FRONT IS
EXPECTED TO DISSIPATE AS IT REACHES FORECAST WATERS TUE...LONG
PERIOD NW SWELL FROM THE SYSTEM HAS ALREADY PUSHED WELL INTO
WATERS N OF 06N W OF 110W WITH THE HIGHEST SIGNIFICANT WAVE
HEIGHTS...15 TO 17 FT...FOUND N OF THE RIDGE AXIS. THIS SWELL
WILL CONTINUE TO SPREAD S THROUGH THE FORECAST AREA W OF 100W
OVER THE NEXT FEW DAYS...WITH MAXIMUM WAVE HEIGHTS OVER N WATERS
SUBSIDING TO THE 10 TO 14 FT RANGE BY EVENING. THE SE
PROGRESSION OF THE COLD FRONT N OF FORECAST WATERS WILL FORCE
THE HIGH CENTER SE INTO N WATERS TODAY. EASTERLY TRADE WINDS
WILL PERSIST THROUGH THE FORECAST PERIOD ON THE S SIDE OF THE
RIDGE AXIS. QUIKSCAT PASSES FROM 0156 AND 0338 UTC SHOW A BROAD
AREA OF NE WINDS IN THE 15 TO 25 KT RANGE W OF 110W AND S OF THE
RIDGE.
GAP WINDS...
THE 0016 UTC QUIKSCAT PASS SHOWED LIGHT AND VARIABLE WINDS IN
THE GULF OF TEHUANTEPEC. HOWEVER...NORTH WINDS ARE EXPECTED TO
ONCE AGAIN FUNNEL THROUGH THE ISTHMUS OF TEHUANTEPEC THIS
AFTERNOON AS A COLD FRONT PASSES SOUTH THROUGH THE WESTERN GULF
OF MEXICO ON THE WESTERN SIDE OF HURRICANE IDA. WINDS IN THE
GULF OF TEHUANTEPEC ARE EXPECTED TO INCREASE TO GALE FORCE BY
SUNRISE TOMORROW AND PERSIST THROUGH THE FORECAST PERIOD. IT
SHOULD BE NOTED THAT THERE IS CONSIDERABLE UNCERTAINTY IN THE
TIMING AND STRENGTH OF THE GAP WINDS IN THE GULF OF TEHUANTEPEC
DUE TO THE UNCERTAINTY IN THE TRACK AND INTENSITY OF IDA. FOR
NOW...WINDS ARE FORECAST TO REACH 40 KT BY THE END OF THE
FORECAST PERIOD WED MORNING.
SCHAUER
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page