000
AXPZ20 KNHC 042208
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU JUN 04 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...TROPICAL WAVE...
TROPICAL WAVE ALONG 85W N OF 05N THROUGH CENTRAL 
NICARAGUA...MOVING W AT 10 KT. THE WAVE IS EMBEDDED IN A BROAD 
AREA OF SW TO W FLOW...AND THERE IS NO CLEAR SIGNATURE OF THE 
WAVE. THE POSITION IS BASED ON CONTINUITY. CLUSTERS OF 
CONVECTION ARE TO THE EAST AND WEST OF THE WAVE...ALONG THE 
ITCZ...AND ARE ENHANCED BY DIVERGENT FLOW ALOFT.

...ITCZ...
AXIS FROM 07N78W TO 08N95W TO 06N105W TO 10N115W TO 06N140W. 
SCATTERED MODERATE CONVECTION WITHIN 90 NM EITHER SIDE OF AXIS E 
OF 84W. SCATTERED MODERATE CONVECTION WITHIN 120 NM EITHER SIDE 
OF AXIS BETWEEN 89W TO 92W. SCATTERED MODERATE CONVECTION WITHIN 
120 NM N OF AXIS BETWEEN 125W TO 127W.

...DISCUSSION...
W OF 110W...DEEP LAYER TROUGH N OF THE AREA IS MOVING EAST 
TOWARD THE CALIFORNIA COAST. THIS LEAVES A SURFACE RIDGE IN 
PLACE FROM A 1025 MB SURFACE HIGH NEAR 35N141W...SE TO THE 
SOUTHERN TIP OF BAJA. THE UPPER TROUGH EXTENDS FROM 37N125W TO 
27N128W TO 23N140W. DIVERGENCE ALOFT SE OF THE UPPER TROUGH 
CONTINUES TO AID A PAIR OF SURFACE TROUGHS. ONE OF THESE IS 
ALONG 127W. A 1011 MB LOW PRES AREA NEAR 14N114W ALONG THE OTHER 
TROUGH. CONVECTION IS FAIRLY MODEST HOWEVER DUE TO DRY SUBSIDENT 
NW FLOW ALOFT...AND WEAK LOW LEVEL CONVERGENCE. A QUIKSCAT PASS 
SHOWED A SMALL AREA OF 20 KT NE TRADES S OF THE SURFACE RIDGE 
AND W OF THE SURFACE TROUGH NEAR 127W. 20 KT WINDS ARE ALSO 
LIKELY ON THE NORTH SIDE OF THE 1011 MB LOW NEAR 14N114W. 
SPORADIC 20 KT NW FLOW IS ALSO POSSIBLE ALONG THE CENTRAL BAJA 
COAST WHERE THE RIDGE IS NOSING IN...ALTHOUGH PAST SCATTEROMETER 
AND SHIP OBSERVATIONS HAVE SHOWN MUCH EVIDENCE OF THIS. STRONG 
WESTERLY MID LEVEL IS POISED TO ENHANCE MORNING DRAINAGE OVER 
THE FAR NORTHERN GULF OF CALIFORNIA.

E OF 110W...A BROAD UPPER ANTICYCLONES IS CENTERED NEAR 15N105W. 
NW FLOW ON THE EAST SIDE OF THIS FEATURE IS BRINGING DRY AIR 
ACROSS SOUTHERN MEXICO OVER THE WATERS N OF 10N. THIS FLOW 
DIVERGES DOWNSTREAM AIDING CONVECTION ALONG THE ITCZ. GAP WIND 
FLOW IS STARTING TO DIMINISH THROUGH THE GULF OF PAPAGAYO...BUT 
IS  PICKING UP THROUGH THE GULF OF TEHUANTEPEC AS EVIDENCED BY 
20 KT FLOW ON A 16Z ASCAT PASS. THIS IS RELATED TO TROUGHING 
OVER THE SOUTHERN GULF OF MEXICO...AND WILL DIMINISH THROUGH 
TONIGHT. LITTLE CHANGE EXPECTED OTHERWISE.

$$
CHRISTENSEN