000
AXPZ20 KNHC 051010
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON OCT 05 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 
0930 UTC.

...SPECIAL FEATURES...

NONE. 

...ITCZ...

THE ITCZ AXIS WAS ANALYZED ALONG 09N83W TO 08N93W TO 13N110W TO 
07N122W TO 13N134W TO 10N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WAS WITHIN 180 NM S OF THE AXIS E OF 93W. 

...DISCUSSION...

MID TO UPPER LEVEL TROUGHING PERSISTS THIS MORNING ACROSS W AND 
NW PORTIONS OF THE AREA...EXTENDING FROM AN UPPER LOW OVER THE 
PACIFIC NW OF THE U.S. SOUTHWESTWARD TO A MIDDLE/UPPER LEVEL LOW 
NEAR 28N132W...THAT IS BECOMING INCREASINGLY ELONGATED AND 
APPEARS TO HAVE BEGUN TO LIFT OUT TOWARD THE ENE. A SHARP 
MIDDLE/UPPER LEVEL TROUGH AXIS EXTENDS S FROM THIS VORTEX 
THROUGH 20N138W TO AN ELONGATED EQUATORIAL VORTEX ALONG 134W. 
THE MIDDLE/UPPER LEVEL LOW IS FORECAST TO CONTINUE TO STRETCH 
AND BECOME ELONGATED AS SOME ENERGY LIFTS OR SHEARS OUT TO THE 
ENE...AND A S/W DIVING INTO THE BACKSIDE OF THE LARGE LOW OVER 
THE PACIFIC NW REINFORCED THIS TROUGH OVER THE NEXT 48 HOURS. 
THIS WILL MAINTAIN A SWLY JET FROM NEAR 24N130W INTO FAR NRN 
BAJA CALIFORNIA AND SRN ARIZONA OF 70-85 KT THAT IS FORECAST TO 
INCREASE BY 24 HOURS TO 80-100 KT. WATER VAPOR IMAGERY SHOWS 
STRONG SUBSIDENCE N AND NW OF THE JET AXIS...WHILE ALONG AND 
JUST TO THE S OF THE JET...MID TO UPPER LEVEL TROPICAL MOISTURE 
IS STREAMING THE SW U.S.

TO THE SE OF THIS TROUGH ALSO PERSIST A BLOCKING RIDGE WITH 
UPPER HIGH CENTERED OVER THE SW GULF OF MEXICO NEAR 
21N96W...WITH RIDGE EXTENDING WSW TO THE TROUGH ALONG 134W. E 
AND SE OF THIS RIDGE A TUTT AXIS EXTENDS FROM THE WINDWARD 
PASSAGE SW TO A TUTT LOW STRADDLING CENTRAL AMERICA FROM THE FAR 
SW CARIBBEAN TO 08N84W IN THE EPAC. A TROPICAL WAVE MOVING INTO 
THE WRN CARIBBEAN UNDERNEATH THIS TUTT LOW AND THE S AMERICA 
MONSOONAL CIRCULATION ARE COMBINING WITH THIS LOW ALOFT TO 
PRODUCE WIDESPREAD ACTIVE WEATHER ACROSS THE EPAC E OF 92W. THE 
TUTT LOW WILL CONTINUE TO SHIFT SW NEXT 24 HOURS AND MAINTAIN 
ACTIVE WEATHER ACROSS CENTRAL AMERICA AND THE EPAC E OF 102W. 

LEFT OVER FROM THE REMNANTS OF OLAF IS A LOW TO MID LEVEL TROUGH 
EXTENDING FROM MAINLAND MEXICO NEAR 24N108W...SW TO 14N121W THEN 
W TO A WEAKENING SURFACE LOW NOW NEAR 14N137W. CONVERGENCE ALONG 
THIS TROUGH HS RESULTED IN BROKEN TO OVERCAST LOW AND MID LEVEL 
CLOUDS AND ISOLATED MODERATE CONVECTION W OF 113W. THE SURFACE 
LOW HAS BEEN ACTIVE CONVECTIVELY OF RECENT BUT HAS MOVED INTO 
STRONG CONVERGENCE ASSOCIATED WITH THE EQUATORIAL TROUGH ALONG 
134W...AND HAS WEAKENED TO A LOW CLOUD SWIRL. SHEARED MOISTURE 
TO ITS E AND ALONG THE LOW LEVEL TROUGH CONTINUE TO PRODUCE 
SCATTERED MODERATE CONVECTION BETWEEN 132W AND 136W UNDER GOOD 
DIVERGENCE ALOFT. TO THE SE OF THIS LOW WAS CENTERED A LOW TO 
MID LEVEL ANTICYCLONE NEAR 10N125W. THIS CIRCULATION WAS HELPING 
TO MAINTAIN THE CONVERGENCE IN THE TROUGH TO THE N...AND ALSO 
ACROSS AN ELONGATED LOW LEVEL LEVEL TROUGH TO THE SE AND WITHIN 
THE ITCZ BETWEEN 106W AND 117W. A WEAK 1010 MB LOW NEAR 10N111W 
WAS EMBEDDED IN THE ELONGATED CYCLONIC CIRCULATION...WHERE 
ISOLATED TO SCATTERED MODERATE CONVECTION WAS FLARING. THIS LOW 
AND AREA OF MOISTURE CONVERGENCE WILL SHIFT SLOWLY WSW OVER THE 
NEXT FEW DAYS.

OTHERWISE AT THE SURFACE...A 1032 MB HIGH WAS OVER THE NE 
PACIFIC NEAR 43N146W...WITH RIDGE AXIS EXTENDING SE TO THE ABOVE 
MENTIONED LOW TO MID LEVEL TROUGH EXTENDING OFF THE BAJA 
PENINSULA. FRESH TO STRONG NNW FLOW WAS OFFSHORE AND ALONG THE 
COAST OF CALIFORNIA...WITH 20 KT FLOW EXTENDING TO WITHIN 180 NM 
OFF THE W COAST OF BAJA PER AN OVERNIGHT QUIKSCAT PASS. 



$$
STRIPLING