[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 200549
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI JUN 20 2008

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.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 22W S OF 12N MOVING W 10-15 KT. THE
WAVE SHOWS UP VERY WELL ON THE TPW PRODUCT AND THE HOVMOLLER
DIAGRAM. LOW LEVEL SATELLITE DERIVED WINDS ALSO SUPPORTS THE
POSITION OF THE WAVE AXIS WHICH EXHIBITS SOME CYCLONIC TURNING
NEAR 7N. CONVECTION HAS INCREASED SINCE YESTERDAY AFTERNOON AND
NOW SATELLITE IMAGERY REVEALS CLUSTERS OF MODERATE TO ISOLATED
STRONG CONVECTION MAINLY AHEAD OF THE WAVE AXIS FROM 3N-11N
BETWEEN 21W-26W.

A TROPICAL WAVE IS ALONG 59W/60W S OF 19N MOVING W NEAR 20 KT.
A BROAD AREA OF CYCLONIC TURNING IS ASSOCIATED WITH THE WAVE.
SFC OBSERVATIONS FROM THE LESSER ANTILLES INDICATES THAT THE
WAVE ALREADY CROSSED BARBADOS WHICH IS REPORTING SE WINDS 20 KT
AND MAINLY LIGHT SHOWERS. PRESSURES ARE FALLING 2 MB AHEAD OF
THE WAVE AXIS. THE WAVE IS GENERATING SCATTERED SHOWERS AND
TSTMS OVER THOSE ISLANDS BUT MAINLY BETWEEN GUADELOUPE AND
DOMINICA. THE MIMIC-TPW PRODUCT SHOWS THE WAVE VERY WELL WHERE A
GOOD SURGE OF MOISTURE IS NOTED. MOISTURE ASSOCIATED WITH THIS
WAVE IS EXPECTED TO REACH THE UK/US VIRGIN ISLANDS THIS MORNING
AND PUERTO RICO THROUGHOUT THE DAY...BRINGING AN INCREASE IN
SHOWER ACTIVITY AND GUSTY WINDS.

...ITCZ...

THE ITCZ IS PRETTY ACTIVE TONIGHT. ITS AXIS IS CENTERED ALONG
10N14W 6N20W 5N30W 2N40W INTO NRN BRAZIL NEAR 2N51W. CLUSTERS OF
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM THE
EQUATOR TO 5N BETWEEN 26W-51W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH IS OVER THE WESTERN HALF OF THE GULF EXTENDING
FROM A CLOSED LOW NEAR 25N93W TO THE BAY OF CAMPECHE. AN UPPER
LEVEL RIDGE...ANCHORED ON A HIGH OVER CENTRAL AMERICA IS
BUILDING OVER THE EASTERN HALF OF THE GULF REGION. A SWATH OF
UPPER LEVEL MOISTURE IS BETWEEN THESE UPPER LEVEL FEATURES OVER
THE YUCATAN PENINSULA AND THE SE GULF. AT THE SURFACE...A
STATIONARY FRONT REMAINS OVER THE N GULF STATES WHILE A WEAK
RIDGE DOMINATES THE REMAINDER OF THE AREA WITH MOSTLY FAIR
WEATHER AND LIGHT WINDS. DIFFLUENCE ALOFT ON THE SE SIDE OF THE
UPPER TROUGH IS AIDING IN SCATTERED SHOWERS AND TSTMS ACROSS THE
THE EASTERN PORTION OF THE BAY OF CAMPECHE...THE YUCATAN
PENINSULA AND THE SE GULF.

CARIBBEAN...
A RIDGE/TROUGH PATTERN IS OBSERVED OVER THE CARIBBEAN SEA. THE
RIDGE COVERS THE WEST AND CENTRAL CARIBBEAN WHILE AN UPPER-LEVEL
TROUGH FROM THE CENTRAL ATLC HAS ITS BASE OVER THE FAR SE
CARIBBEAN AND THE WINDWARD ISLANDS. THE TROPICAL WAVE OVER THE
LESSER ANTILLES IS INTERACTING WITH THIS UPPER-LEVEL TROUGH. AS
A RESULTS...CONVECTION HAS SLIGHTLY INCREASED NEAR THE NORTHERN
END OF THE WAVE AXIS. UPPER DIFFLUENCE BETWEEN AN UPPER-LEVEL
TROUGH OVER THE EASTERN SEABOARD AND THE RIDGE OVER THE
CARIBBEAN IS HELPING TO INDUCE SOME SHOWER ACTIVITY OVER WESTERN
CUBA AND THE STRAITS OF FLORIDA. SOME SHOWER ACTIVITY IS ALSO
NOTED OVER N CENTRAL AMERICA. THE ATLC RIDGE WILL BUILD SW OVER
THE AREA AND STRENGTHEN THROUGH MON PRODUCING MODERATE TO FRESH
TRADE WINDS ACROSS THE BASIN WITH THE STRONGEST WINDS UP TO 30
KT OVER THE SOUTH-CENTRAL CARIBBEAN.

ATLANTIC...
A BROAD UPPER TROUGH IS OVER THE EASTERN U.S. WHILE AN UPPER
RIDGE EXTENDS FROM THE CARIBBEAN ALL THE WAY NE TO BEYOND
31N58W. UPPER DIFFLUENT BETWEEN THESE TWO UPPER LEVEL FEATURES
IS ASSISTING IN THE DEVELOPMENT OF SCATTERED SHOWERS AND TSTMS
OVER THE STRAITS OF FLORIDA AND JUST E OF THE CENTRAL BAHAMAS
FROM 24N-28N BETWEEN 70W-75W. A 1013 MB LOW IS LOCATED OFFSHORE
OF THE CAROLINAS NEAR 34N7OW WITH ASSOCIATED FRONTAL BOUNDARY
CLIPPING THE W ATLC W OF 74W TO S GEORGIA. AN UPPER LEVEL TROUGH
EXTENDS OVER THE E-CENTRAL ATLC WITH THE BASE REACHING THE FAR
SE CARIBBEAN AND THE WINDWARD ISLANDS. AN UPPER-LEVEL RIDGE
DOMINATES MOST OF THE TROPICS AND IS ENHANCING CONVECTION ALONG
THE ITCZ AXIS TONIGHT. HIGH PRES IS IN CONTROL OF THE FORECAST
AREA EXTENDING A RIDGE WWD TO EASTERN CUBA. THIS SYSTEM IS
FORECAST BY THE COMPUTER MODELS TO STRENGTHEN THROUGH MON
PRODUCING A BELT OF MODERATE TO FRESH ELY WINDS AROUND ITS
SOUTHERN PERIPHERY FROM THE AFRICAN COAST TO THE CENTRAL
CARIBBEAN.

$$
GR/CW



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