[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 100532
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI APR 10 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N8W 2N14W CROSSING THE EQUATOR NEAR
18W AND EXTENDING TO 3S27W 4S35W INTO NE BRAZIL NEAR 4S39W.
SCATTERED MODERATE CONVECTION IS FROM 1N-3N BETWEEN 1W-2W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM
OF AXIS BETWEEN 10W-20W.

...DISCUSSION...

THE GULF OF MEXICO...
SFC HIGH PRES HAS MOVED E OF THE AREA INTO THE W ATLC. THIS HAS
ALLOWED SLY RETURN FLOW TO DEVELOP ACROSS THE ENTIRE GULF
ADVECTING A MILDER AND MORE MOIST AIRMASS THAN WHAT WAS IN PLACE
EARLIER THIS WEEK. LATEST SFC OBS AND QSCAT DATA SHOW THE
STRONGEST FLOW...20-25 KT...OVER THE W WATERS IN RESPONSE TO LOW
PRES OVER THE PLAINS AND ASSOCIATED TROUGHING EXTENDING S INTO
MEXICO. THE FRONTAL BOUNDARY WILL ENTER THE FAR N WATERS TODAY
AND SAT BUT IS NOT EXPECTED TO MAKE MUCH PROGRESS SOUTHWARD. IN
THE MID AND UPPER LEVELS...STRONG WLY FLOW IS ADVECTING MOISTURE
ACROSS THE AREA BUT IT APPEARS TO BE MAINLY IN THE FORM OF
MID-HIGH LEVEL CLOUDS.

THE CARIBBEAN SEA...
A WEAK INVERTED SFC TROUGH CONTINUES WESTWARD AT 10-15 KT
CENTERED ALONG 68W N OF 13N. LOW-MID LEVEL CLOUDINESS AND
EMBEDDED SHOWERS AND LOW TOPPED TSTMS ARE WITHIN 300 NM E OF THE
TROUGH AXIS. GUADELOUPE REPORTED 1.22 INCHES OF RAIN MAINLY TIED
TO THIS TROUGH. PATCHY CLOUDS AND EMBEDDED ISOLATED SHOWERS ARE
OCCURRING OVER THE ISLAND OF HISPANIOLA ASSOCIATED WITH REMNANT
TROUGHING AND LOCAL UPSLOPE CONDITIONS. ALL OF THE AREAS
OUTLINED ARE SHALLOW IN NATURE CAPPED BY DRY AIR IN THE MID AND
UPPER LEVELS. E TO SE WINDS NEAR 20 KT ARE BLOWING OVER THE NW
CARIBBEAN DUE TO THE ENHANCED PRES GRADIENT BETWEEN TROUGHING
OVER S MEXICO AND HIGH PRES OVER THE W ATLC. SIMILAR MAGNITUDE
NE TO E WINDS ARE OCCURRING IN THE USUAL ZONE NEAR THE COAST OF
COLOMBIA.

THE ATLANTIC OCEAN...
A LARGE SCALE MID-UPPER TROUGH OVER THE W ATLC IS FLATTENING
PROVIDING LIMITED SUPPORT FOR A QUASI-STATIONARY FRONT
EXTENDING FROM 32N57W TO 25N65W TO W HAITI. ONLY BROKEN
CLOUDINESS AND ISOLATED SHOWERS ACCOMPANY THE FRONT. THIS
BOUNDARY IS EXPECTED TO DISSIPATE OVER THE NEXT DAY OR SO AS IT
CONTINUES TO LOSE UPPER SUPPORT. A WEAK SFC RIDGE IS BUILDING E
OVER THE W ATLC BEHIND THE FRONT CENTERED NEAR 27N71W. WINDS ARE
GENERALLY LIGHT ACROSS THE W ATLC BESIDES FOR SW 20-25 KT WINDS
NEAR THE N BORER BETWEEN BERMUDA AND 73W ENHANCED BY LOW PRES N
OF THE AREA. FARTHER E...AN UPPER LOW CENTERED NEAR 24N34W IS
PRODUCING MULTILAYER CLOUDINESS AND EMBEDDED ISOLATED SHOWERS
FROM 21N-26N BETWEEN 28W-36W. A SW TO W UPPER JET WITH CORE
WINDS NEAR 100 KT ORIGINATES JUST E OF THE BASE OF THE UPPER
TROUGH FROM 9N35W TO 17N25W TO 25N15 GENERATING AND ADVECTING
MID-HIGH LEVEL CLOUDINESS WITHIN 300 NM SE OF THE JET AXIS.

$$
CANGIALOSI



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