Subject: Pacific-EN: Tropical Weather Discussion

From: SIU Weather Processor <[email-masked]>
Date: Sat, 12 Feb 2005 09:57:57 -0600

AXPZ20 KNHC 121557
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT FEB 12 2005

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

..ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS 1N80W 7N98W 8N126W 7N140W. 
WIDELY SCATTERED MODERATE WITHIN 150 NM N OF AXIS BETWEEN 83W 
AND 93W AND BETWEEN 111W AND 122W AND W OF 130W.

DISCUSSION...
A SHORTWAVE MID TO UPPER RIDGE DOMINATES AREA N OF THE ITCZ W OF 
125W WITH AN EMBEDDED 180 NM DIAMETER CYCLONE AT 
14N133W...SHIFTING E WITH TIME. AN UPPER ANTICYCLONE IS CENTERED 
NEAR 8N95W WITH A RIDGE EXTENDING N ACROSS EASTERN OLD MEXICO 
EVENTUALLY CRESTING OVER THE CENTRAL CONUS. BETWEEN THESE TWO 
RIDGES...A SHORTWAVE TROUGH HAS MEAN AXIS FROM 32N119W TO A 
SMALL CYCLONE ALONG THE TROUGH BASE AT 10N115W. AN UPPER CYCLONE 
IS NOTED NEAR 6N102W.

A WESTERLY UPPER WIND MAXIMA IS NOTED ALONG 12N CONTINUING E 
ACROSS THE WESTERN RIDGE TO NEAR 10N115W...WHERE THE UPPER FLOW 
SPLITS. ONE BRANCH TURNS CYCLONICALLY NE ALONG THE EAST EDGE OF 
THE UPPER TROUGH BECOMING DIFFLUENT AGAIN OVER NORTHERN OLD 
MEXICO. THE OTHER BRANCH OF THE WESTERLY JET CONTINUES SE INTO 
THE UPPER CYCLONE AT 6N102W.

THE STRONG UPPER DIFFLUENCE NEAR THE UPPER FLOW SPILT IS 
ENHANCING ITCZ CONVECTION BETWEEN 111W AND 122W. UPPER 
DIFFLUENCE E OF THE UPPER ANTICYCLONE IS RESPONSIBLE FOR THE 
ITCZ CONVECTION BETWEEN 83W AND 93W.
   
STRONG UPPER DRY AIR/SUBSIDENCE IS OBSERVED N OF THE ITCZ W OF 
110W AND S OF 23N E OF 110W.

WINDS HAVE BECOME EASTERLY IN THE SOUTHERN GULF OF MEXICO SO 
EXPECT THE GALE FORCE GAP WINDS TO WIND DOWN THIS MORNING IN THE 
GULF OF TEHUANTEPEC. I KEPT GALE WARNING TILL 18Z TO COVER ANY 
RESIDUAL DRAINAGE. BRISK N TO NE WINDS WILL CONTINUE OVER THE SW 
CARIBBEAN MAINTAINING 20 TO 25 KT WINDS THROUGH THE CENTRAL 
AMERICAN GAPS E OF 94W THROUGH 48 HOURS.   

$$
NELSON

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
To unsubscribe from WX-TROPL send e-mail to [email-masked] with
"unsub wx-tropl" in the body of your message. For help with WX-TROPL
write to [email-masked] or see http://wxlist.5280tech.com. For more
information on tropical weather products, see the NHC Homepage
at http://www.nhc.noaa.gov.