000
AXPZ20 KNHC 130954
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE JUN 13 2006

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
 
...SPECIAL FEATURES...
LOW PRES 1008 MB AT 17N105W HAS SCATTERED DEEP CONVECTION 
PULSATING ON S QUADRANT.  SLIGHT DIFFLUENCE OVERHEAD HELPS KEEP 
CONVECTION ALIVE IN SPITE OF 20 KT SHEAR...WHICH MIGHT BE THE 
REASON FOR THE ON AND OFF CONVECTION PULSES.  LOW PRES MONITORED 
FOR SIGNS OF DEVELOPMENT. 

ANOTHER LOW PRES 1008 MB 7N127W HAS SCATTERED DEEP CONVECTION 
SURROUNDING IT POSSIBLE AIDED BY UPPER DIFFLUENCE PRODUCED BY 
APPROACHING UPPER LEVEL TROUGH MENTIONED ABOVE.  LOW PRES MOVING 
INTO DRIER AIRMASS WITH CHANCES OF DEVELOPMENT CURTAILED.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 83W MOVING W AT 10 KT. MINOR CONVECTION 
TRAILS WAVE AXIS BUT STRONG UPPER EASTERLY WIND SHEAR PRECLUDES 
DEVELOPMENT. 

TROPICAL WAVE ALONG 97W FROM 4N TO 13N MOVING W AT 12 KT.  NO 
SIGNIFICANT CONVECTION ASSOCIATED WITH WAVE AND STRONG E WINDS 
ALOFT OVER WAVE EXPECTED TO PRECLUDE ANY DEVELOPMENT. 
 
TROPICAL WAVE ALONG 109W MOVING W AT 10 KT.  NO SIGNIFICANT 
CONVECTION NOTED ASSOCIATED WITH WAVE POSSIBLY DUE TO ADVERSE 
UPPER LEVEL ENVIRON.  UPPER SHEAR EXPECTED TO DECREASE AND MOIST 
AIRMASS AHEAD MIGHT GIVE THIS WAVE LAST GASP BEFORE REACHING DRY 
AIR MASS AHEAD. 

TROPICAL WAVE ALONG 131W FROM 3N TO 12N MOVING W 10 KT CARRIES 
LITTLE SIGNIFICANT CONVECTION TO SPEAK OF.  THERE ARE NO SIGNS 
OF DEVELOPMENT. 

..ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS ALONG...9N83W 12N97W 8N110W 
5N140W.  SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 
180 NM OF AXIS FROM 115W TO 133W. 

...DISCUSSION...
SHARP LARGE AMPLITUDE UPPER LEVEL LONGWAVE TROUGH FROM 32N126W 
TO 15N140W BRINGS VERY DRY AIR MASS INTO NW PART OF E PAC.  JET 
STREAM 125 KT WRAPS AROUND TROUGH NEAR 32N AT THE EDGE OF WELL 
ANCHORED ANTICYCLONE CENTER OVER MEXICO AT 25N09W.  LARGE AREA 
OF CONFLUENCE BETWEEN RIDGE AND TROUGH MAINTAINS VERY DRY AIR 
MASS N OF 20N THROUGH ENTIRE EPAC WITH POSSIBLE EXCEPTION OF N 
OF 27N W OF 124W.  RIDGE EXPANDS ANTICYCLONIC FLOW DOWN TO 15N.

S OF 15N E OF 120W QUASI ZONAL E-NE UPPER LEVEL FLOW BRINGS 
ABUNDANT MOISTURE INTO ITCZ PATH BUT IS STRONG ENOUGH TO 
PRECLUDE WIDE AREAS OF DEEP CONVECTION WITH SHEAR.    


RATHER STABLE BUT UNUSUALLY AMPLIFIED MIDDLE 
TO UPPER LEVEL PATTERN CONTINUES OVER DISCUSSION AREA.  PATTERN 
COMPRISED OF SHARP TROUGH EXTENDING FROM JUST OFF CALIFORNIA 
COAST SWD TO 20N135W THEN CONTINUING TO BEYOND 16N140W AS 
CYCLONIC SHEAR AXIS.  ANOTHER TROUGH SWEEPING SEWD ON HEELS OF 
FIRST TROUGH AND EXTENDS FROM 32N126W TO 26N135W.  TROUGH TO 
MERGE WITH FIRST TROUGH WITHIN NEXT 24 HOURS.  FARTHER E...LARGE 
ANTICYCLONE CENTERED AT 26N107W WITH ASSOCIATED RIDGE EXTENDING 
SW TO 18N120W.  UPPER LEVEL FLOW BETWEEN AFOREMENTIONED TROUGH 
AND RIDGE CONFLUENT PRODUCING MODERATE TO STRONG SUBSIDENCE AND 
DRY/STABLE CONDITIONS ACROSS ENTIRE E PAC AND MEXICO N OF 15N.
S OF 15N...STRONG E FLOW ALOFT CONTINUES E OF 115W ASSOCIATED 
WITH RIDGE OVER MEXICO AND SECOND RIDGE OVER W ATLC AND 
CARIBBEAN.  SMALL AREA OF LIGHT E FLOW NEAR WEAK TROUGH WHICH 
EXTENDS SWD FROM AN UPPER LOW OVER BAY OF CAMPECHE OVER ISTHMUS 
OF TEHUANTEPEC TO 17N97W.  UPPER LEVEL FLOW OVER W PART OF ITCZ 
WEAKER AND FROM SE TO S.  AT THE SURFACE...DIFFUSE COLD FRONT 
ENTERS AREA ALONG 32N122W AND EXTENDS SWD TO 23N132W WHERE IT 
BECOMES DISSIPATING STATIONARY FRONT THROUGH 21N140W. 
   
$$
WALLY BARNES