[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 170543
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE JUN 17 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
0515 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 33W S OF 11N MOVING W NEAR 15-20 KT. WELL
DEFINED MID LEVEL CYCLONIC CIRCULATION REMAINS ALONG THE WAVE
NEAR 7N. LOW LEVEL SATELLITE DERIVED WINDS AND 850 MB VORTICITY
ALSO CONFIRM THE POSITION OF THE WAVE AXIS. SCATTERED MODERATE
CONVECTION IS WITHIN 100 NM W OF THE WAVE AXIS FROM 8N-11N.
MOISTURE FROM THIS TROPICAL WAVE IS FORECAST BY THE COMPUTER
MODELS TO REACH THE LESSER ANTILLES ON THU.

TROPICAL WAVE IS ALONG 49W S OF 15N MOVING W NEAR 20 KT. THE
WAVE SHOWS SOME INVERTED-V CLOUD PATTERN AND THERE IS STILL NO
ASSOCIATED DEEP CONVECTION. THE SAHARAN AIR LAYER FROM CIMSS
INDICATES THAT THE WAVE REMAINS AT THE LEADING EDGE OF A
EXTENSIVE AREA OF AFRICAN DUST.

TROPICAL WAVE IS OVER CENTRAL AMERICA ALONG 84W/85W S OF 21N
MOVING W AT 10-15 KT. THE WAVE IS EMBEDDED IN AN AREA OF DEEP
LAYERED MOISTURE AS DEPICTED ON THE TPW PRODUCT. THIS FEATURE IS
ONLY GENERATING ISOLATED SHOWERS AND TSTMS OVER HONDURAS AND
NICARAGUA.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N12W 9N25W 7N31W 5N40W 6N58W.
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE
FROM 6N-8N BETWEEN 50W-56W. SIMILAR CONVECTION IS NEAR 7N13W...
AND NEAR 6N20W.

...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 UPPER LEVEL WINDS AHEAD OF THE
TROUGH ARE HELPING TO INDUCE SCATTERED SHOWERS AND TSTMS OVER
THE YUCATAN PENINSULA AND WESTERN CUBA. AT THE SURFACE...A WEAK
RIDGE...WITH A 1014 MB HIGH NEAR 27N91W IS IN CONTROL OF THE
WEATHER PATTERN ACROSS THE GULF GIVING THE AREA MAINLY LIGHT
WINDS. THE EXCEPTION IS THE WESTERN GULF WHERE SE TO S WINDS OF
10-15 KT ARE BLOWING. THE RIDGE IS EXPECTED TO PERSIST DURING
THE NEXT SEVERAL DAYS WITH A WEAK COLD FRONT CLIPPING THE NE
PORTION OF THE GULF LATE. MOSTLY FAIR WEATHER IS NOTED OVER THE
GULF UNDER THE INFLUENCE OF THE RIDGE.

CARIBBEAN...
A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED ON A HIGH
OVER NICARAGUA. SWLY WINDS BETWEEN THIS HIGH AND THE UPPER
TROUGH THAT LIES OVER THE GULF ARE TRANSPORTING ABUNDANT UPPER
LEVEL MOISTURE FROM THE EPAC THROUGH CENTRAL AMERICA INTO THE MW
CARIBBEAN AND CUBA. THESE WINDS ARE SUPPORTING THE DEVELOPMENT
OF SOME CONVECTIVE ACTIVITY OVER CUBA AND THE BAHAMAS. LIGHTNING
DATA REVEALS SCATTERED TSTMS OVER PARTS OF WEST AND CENTRAL
CUBA...THE CAYMAN ISLANDS AND THE BAHAMAS. A TROPICAL WAVE IS
MOVING WWD OVER CENTRAL AMERICA. SEE TROPICAL WAVE SECTION FOR
DETAILS. BROAD UPPER RIDGE FROM THE TROPICAL ATLC COVERS THE E
CARIBBEAN WITH STRONG SUBSIDENCE AND DRY AIR. MODERATE TO FRESH
TRADE WINDS OF 20-30 KT ARE BLOWING ACROSS THE CENTRAL CARIBBEAN
DUE TO TIGHT PRES GRADIENT BETWEEN THE ATLC RIDGE AND THE
COLOMBIAN LOW.

ATLANTIC...
NEARLY ZONAL FLOW DOMINATES THE W AND CENTRAL ATLC ADVECTING
ABUNDANT UPPER LEVEL MOISTURE. AS A RESULTS...SOME CLOUDINESS
WITH POSSIBLE SHOWERS ARE OBSERVED IN THIS AREA. A DEEP LAYERED
TROUGH IS N OF THE REGION SUPPORTING A SFC TROUGH...REMNANTS OF
A FRONTAL BOUNDARY...THAT RUNS FROM 32N39W TO 29N44W. A SMALL
AREA OF MODERATE CONVECTION IS NEAR THE SOUTHERN END OF THE
TROUGH. AN UPPER-LEVEL LOW IS OVER THE E ATLC NEAR 28N22W. A
TROUGH EXTENDS FROM THIS LOW INTO THE TROPICS NEAR 14N30W. BROAD
UPPER E/W RIDGE DOMINATES THE TROPICS S OF 20N AND WEST OF 35W
TO OVER THE E CARIBBEAN. A BROAD BUT WEAK SURFACE RIDGE
DOMINATES THE ATLC ANCHORED BY A 1025 MB HIGH IN THE E ATLC NEAR
30N34W. THIS SYSTEM WILL REMAIN NEARLY STATIONARY DURING THE
NEXT 24 HOURS.

$$
GR/CW





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