Subject: Pacific-EN: Tropical Weather Discussion

From: SIU Weather Processor <[email-masked]>
Date: Thu, 20 Jan 2005 03:28:22 -0600

AXPZ20 KNHC 200928
TWDEP

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JAN 20 2005

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
0845 UTC.

..ITCZ...
INTERTROPICAL CONVERGENCE ZONE AXIS ALONG 5N79W 5N86W 2N95W
7N109W 6N127W 8N138W 7N140W. SCATTERED MODERATE CONVECTION
WITHIN 30 NM OF A LINE FROM 7N83W TO 2N95W. ISOLATED MODERATE
NEAR 1N100W 8N110W 6N113W 7N123W 5N131W AND 8N140W. SCATTERED
MODERATE ALONG A LINE FROM 8N133W TO 10N139W.

OTHER CONVECTION...MODERATE CONVECTION WITHIN 60 NM EITHER SIDE
OF A LINE FROM 19N111W TO 13N113W.

..DISCUSSION...
.W OF 110W...
A CUTOFF UPPER LOW WAS NEAR 26N117W JUST W OF THE LOWER BAJA
PENINSULA WAS NEARLY STATIONARY. THE LOW IS EMBEDDED IN AN UPPER
RIDGE THAT COVERS THE WESTERN US. A WEAK SURFACE TROUGH HAS
FORMED OFF THE NW COAST OF BAJA IN RESPONSE TO THE UPPER LOW. A
85 KT JET SEGMENT WAS LOCATED ON THE SE SIDE OF THE LOW
SPREADING MULTILAYERED CLOUDS OVER BAJA. AN AREA OF EMBEDDED
CONVECTION WAS LOCATED ALONG 19N111W TO 13N113W. A STRONG
SUBSIDENCE AREA WAS NOTED ON WATER VAPOR IMAGERY BETWEEN 120W
AND 135W FROM 10N TO 20N. SPEED CONVERGENCE APPEARED TO BE THE
MAIN INGREDIENT IN PRODUCING THE SUBSIDENCE.

THE LOWER PORTION OF AN UPPER TROUGH WAS BRUSHING THE NW CORNER
OF THE AREA ALONG 135W. THE TROUGH IS MOVING RAPIDLY NE WITH
MOSTLY HIGH CLOUDS ASSOCIATED WITH IT. A STRONG 160 KT ZONAL JET
WAS ALONG 35N W OF THE AREA NOSING IN BEHIND THE SHORTWAVE
TROUGH.

.E OF 110W...
AN OPEN RIDGE ALOFT APPEARS ALONG 100W FROM NEAR 5N TO NORTHERN
MEXICO. CONSIDERABLE MULTILAYERED CLOUDINESS IS SPREADING
THROUGH THE RIDGE FROM THE PACIFIC.

A PERSISTENT WEAK UPPER TROUGH WAS LOCATED FROM 10N90W TO
2N100W. THE TROUGH IS STATIONARY. THE TROUGH IS CAUGHT BETWEEN
THE OPEN RIDGE TO THE W AND ANOTHER RIDGE OVER S AMERICA. A
LARGE AREA OF SUBSIDENCE IS NOTED N OF 5N AND E OF 95W AND SPEED
CONVERGENCE APPEARS TO BE THE MAIN FACTOR. AN AREA OF SCATTERED
CONVECTION IS NOTED ALONG THE SE SIDE OF THE TROUGH WHERE THE
UPPER FLOW BECOMES DIVERGENT IN DIRECTION AND SPEED.

$$
RRG

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