[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161038
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON JUN 16 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...TROPICAL WAVES...

THE TROPICAL WAVE THAT WAS PREVIOUSLY ALONG 26W/27W IS
REPOSITIONING ON THE 0600 UTC MAP ALONG 24W/25W S OF 12N BASED
ON SFC OBSERVATIONS...SATELLITE IMAGERY AND LOW LEVEL SATELLITE
DERIVED WINDS. THE MIMIC-TPW PRODUCT ALSO CONFIRMS THE POSITION
OF THE WAVE AXIS. EARLY MORNING VIS SATELLITE IMAGERY SHOWS A
DISTINCT LOW/MID LEVEL CYCLONIC CIRCULATION AHEAD OF THE WAVE
AXIS NEAR 7N28W...BUT IT APPEARS EMBEDDED IN THE ITCZ. ISOLATED
MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE WAVE AXIS
FROM 6N-10N.

A TROPICAL WAVE IS ALONG 43W S OF 15N MOVING W NEAR 15 KT. LOW
LEVEL SATELLITE DERIVED WINDS AND THE TPW PRODUCT FROM CIMSS
SUPPORT THE POSITION OF THE WAVE. AN INVERTED-V CLOUD PATTERN IS
OBSERVED ON SATELLITE IMAGERY BUT NO DEEP CONVECTION IS NOTED.
THE SAHARAN AIR LAYER FROM CIMMS REVEALS AN EXTENSIVE AREA OF
AFRICAN DUST TRAILING THIS TROPICAL WAVE.

A TROPICAL WAVE EXTENDS FROM CENTRAL CUBA AND THE CAYMAN ISLANDS
SWD TO THE SW CARIBBEAN. IT AXIS LIES ALONG 81W. THE TOTAL
PRECIPITABLE WATER...TPW...SHOWS A NORTH-SOUTH MOISTURE MAXIMUM
ASSOCIATED WITH THIS WAVE. SCATTERED SHOWERS AND ISOLATED TSTMS
ARE WITHIN 150 NM EAST OF THE WAVE AXIS MORE CONCENTRATED JUST
SOUTH OF JAMAICA.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N12W 7N22W 4N34W 6N43W 4N53W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 130 NM
NORTH OF THE ITCZ AXIS BETWEEN 28W-36W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER-LEVEL TROUGH EXTENDS FROM OVER THE SE CONUS TO THE SW
PORTION OF THE GULF. A BROAD UPPER RIDGE REMAINS ANCHORED OVER
NORTH/CENTRAL MEXICO COVERING THE NW CORNER OF THE GULF WITH
MODERATE TO STRONG SUBSIDENCE. SW TO W UPPER LEVEL WINDS ARE
NOTED OVER THE BAY OF CAMPECHE AND THE YUCATAN PENINSULA AHEAD
OF THE ABOVE MENTIONED UPPER TROUGH WHICH IS HELPING TO SUPPORT
SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE NE GULF REGION.
AT THE SURFACE...A WEAK RIDGE...WITH A 1013 MB HIGH NEAR 27N91W
IS IN CONTROL OF THE WEATHER PATTERN ACROSS THE GULF GIVING THE
AREA MAINLY LIGHT WINDS. THE EXCEPTION IS THE FAR WESTERN GULF
WHERE SE TO S WINDS OF 10-15 KT ARE BLOWING. AN ASCAT PASS FROM
AROUND 0400 UTC CONFIRMS THESE WINDS. THE RIDGE IS EXPECTED TO
PERSIST TO AT LEAST MIDWEEK.

CARIBBEAN...
A RIDGE/TROUGH/RIDGE PATTERN COVERS THE BASIN. AN UPPER-LEVEL
HIGH ANCHORED OVER THE SW CARIBBEAN NEAR THE ISLAND OF SAN
ANDRES DOMINATES THE WESTERN CARIBBEAN AND CENTRAL AMERICA.
UPPER DIFFLUENCE ASSOCIATED WITH THIS SYSTEM IS PROVIDING
SUPPORT FOR SOME SHOWER/TSTM ACTIVITY OVER PARTS OF CENTRAL
AMERICA. A SHORT-WAVE TROUGH IS ALONG 68W. A BROAD UPPER RIDGE
FROM THE TROPICAL ATLC ENVELOPS THE E CARIBBEAN...INCLUDING ALSO
PUERTO RICO AND THE US/UK VIRGIN ISLANDS. THIS FEATURE IS
PRODUCING STRONG SUBSIDENCE AND DRY AIR. A TROPICAL WAVE IS
MOVING WWD ACROSS THE WESTERN CARIBBEAN. MOISTURE FROM THIS WAVE
WILL AFFECT CENTRAL CUBA AND THE CAYMAN ISLANDS TODAY...AND
CENTRAL AMERICA LATER. MODERATE TO FRESH TRADE WINDS ARE BLOWING
ACROSS THE CARIBBEAN SEA.

ATLANTIC...
THE MID/UPPER LEVEL LOW THAT WAS ENHANCING CONVECTION OVER
FLORIDA AND THE BAHAMAS DURING THE PREVIOUS DAYS HAS WEAKENED.
INSTEAD...AN UPPER LEVEL TROUGH EXTENDS FROM THE LOW NEAR 30N72W
TO THE STRAITS OF FLORIDA. UPPER DIFFLUENCE TO THE E OF THE
UPPER TROUGH IS SUPPORTING AN AREA OF SCATTERED SHOWERS AND
TSTMS FROM 22N-27N BETWEEN 68W-74W. SIMILAR CONVECTION IS OVER
THE CENTRAL BAHAMAS. A SFC TROUGH IS ANALYZED IN THIS ZONE AND
RUNS FROM 26N70W TO 18N75W. A DEEP LAYERED TROUGH IS OVER THE
CENTRAL ATLC WITH THE BASE OF THE TROUGH REACHING 27N. THE
ATTENDANT COLD FRONT HAS DISSIPATED AND NOW A SFC TROUGH EXTENDS
FROM 31N44W TO 26N60W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE
WITHIN 100 NM AHEAD OF THE N OF 25N. BROAD UPPER E/W RIDGE
DOMINATES THE TROPICS S OF 22N FROM AFRICA TO OVER THE E
CARIBBEAN. THE REMAINDER OF THE ATLC IS DOMINATED BY BENIGN
UPPER-LEVEL FEATURES AND A BROAD SURFACE RIDGE EXTENDING SW FROM
A 1025 MB HIGH LOCATED 30N30W. THIS SYSTEM IS FORECAST TO REMAIN
NEARLY STATIONARY DURING THE NEXT 24 HOURS. PRES GRADIENT
BETWEEN THIS HIGH AND LOWER PRES OVER AFRICA WILL CONTINUE TO
PRODUCE MODERATE TO FRESH NLY WINDS MAINLY N OF 18N AND E OF
25W.

$$
GR







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