Subject: Pacific-EN: Tropical Weather Discussion

From: SIU Weather Processor <[email-masked]>
Date: Fri, 18 Feb 2005 04:13:08 -0600

AXPZ20 KNHC 181012
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI FEB 18 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

..ITCZ...
ITCZ AXIS ALONG 5N77W 6N90W 4N100W 4N115W 4N125W 4N132W 5N140W.
NO SIGNIFICANT CONVECTION IS NOTED.

DISCUSSION...
BROAD MID/UPPER LEVEL TROUGH IS THE DOMINATE WEATHER FEATURE 
COVERING THE AREA N OF 15N W OF 120W WITH MEAN AXIS ROUGHLY 
EXTENDING FROM 32N126W ALONG 22N127W SSW TO 15N135W. THIS TROUGH 
IS ASSOCIATED WITH A PERSISTENT NEARLY STATIONARY LOW PRESSURE
..BOTH AT THE SURFACE AND ALOFT...LOCATED N OF THE AREA NEAR 
32N131W MOVING SE 15 KT. A COUPLE OF SURFACE TROUGHS ASSOCIATED 
WITH THE UPPER LEVEL LOW ARE NOTED ON 0600 UTC SURFACE ANALYSES. 
THE FIRST TROUGH EXTENDING FROM 30N123W ALONG 24N122W TO 18N124W 
WILL DISSIPATE IN ABOUT 24 HOURS WHILE A SECOND TROUGH EXTENDING 
FROM 30N129W ALONG 26N130W TO 22N133W WILL CONTINUE TO SWEEP 
EASTWARD ACROSS THE AREA MOVING INLAND AND DISSIPATING IN 48 
HOURS. UPPER LEVEL DISTURBANCES CONTINUE TO ROTATE AROUND THE 
UPPER TROUGH N OF 26N CREATING ENOUGH INSTABILITY TO PRODUCE 
WIDELY SHOWERS WITHIN 180 NM W OF SECOND TROUGH. SUBTROPICAL JET 
STREAM EXTENDS NE FROM 18N126W ALONG 22N119W TO ACROSS BAJA 
CALIFORNIA NEAR 28N114W AND CONTINUES NE TO ACROSS THE SW UNITED 
STATES. SATELLITE DERIVED WINDS AGAIN INDICATE MAXIMUM WINDS IN 
THE 95-105 KT RANGE WITHIN THE JET STREAM CORE. THESE WINDS ARE 
CONTINUING TO ADVECT PLENTIFUL TROPICAL MOISTURE NE ACROSS 
NORTHERN MEXICO AND ACROSS THE SW UNITED STATES. AREAS OF 
SCATTERED MODERATE CONVECTION MOVING RAPIDLY N TO ALONG AND 
INLAND EXTREME SOUTHERN CALIFORNIA AND NE MEXICO ARE SEEN N OF 
28N E OF THE FIRST TROUGH. WIDELY SCATTERED SHOWERS AND POSSIBLE 
ISOLATED THUNDERSTORMS ARE WITHIN 180 NM EITHER SIDE OF THE JET 
STREAM N OF 17N. POSSIBLE ISOLATED SHOWERS AND THUNDERSTORMS ARE 
ELSEWHERE WITHIN 150 NM EITHER SIDE OF THE JET STREAM AXIS. 
MODERATE TO STRONG SUBSIDENCE IS INDICATED ELSEWHERE ON 
SATELLITE WATER VAPOR IMAGERY S OF 26N
W OF 120W. NEXT COLD FRONT WELL W OF THE REGION EXPECTED TO MOVE 
INTO THE NW CORNER IN ABOUT 30 HOURS.

MID/UPPER LEVEL RIDGING DOMINATES THE REMAINDER OF THE AREA 
EXCEPT FOR A BROAD EMBEDDED UPPER LEVEL CYCLONIC CIRCULATION SEEN
ON WATER VAPOR IMAGERY NEAR 10N96W MOVING N 15 KT. RATHER DRY 
CONDITIONS AND VERY LIMITED SHOWER ACTIVITY....EXCEPT FOR WIDELY 
ISOLATED SHOWERS AND WEAK ISOLATED SMALL THUNDERSTORMS ALONG THE 
ITCZ BETWEEN 90W-95W AND 105W-127W. ISOLATED SHOWERS AND 
THUNDERSTORMS ALSO NOTED ALONG THE ITCZ AXIS W OF 135W. AN AREA 
OF MID/UPPER LEVEL MOISTURE WITHIN ABOUT 500 NM SE OF JET 
STREAM. ELSEWHERE SCATTERED TO LOCALLY BROKEN LOW CLOUDS WITH 
POSSIBLE ISOLATED LIGHT SHOWERS ARE S OF 14N E OF 110W...
OTHERWISE MOSTLY CLEAR SKIES UNDER STRONG SUBSIDENCE AND 
RESULTANT DRY SINKING AIR ARE PRESENT E OF 120W. LITTLE OVERALL 
CHANGE EXPECTED IN THIS PATTERN FOR THE NEXT 72-96 HOURS.

$$
AGUIRRE

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