[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 291741
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT AUG 29 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...

THE TROPICAL WAVE PREVIOUSLY ALONG ALONG 16N37W 11N39W 6N41W NOW
HAS A LOW PROBABILITY OF DEVELOPING INTO A TROPICAL CYCLONE IN
THE NEXT 48 HOURS. THEREFORE IT WILL BE MOVED TO THE TROPICAL
WAVE SECTION BELOW.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 22W/23W S OF 17N MOVING W NEAR 10 KT. A
MID LEVEL CYCLONIC ROTATION IS OBSERVED ALONG THE WAVE NEAR 15N.
WAVE IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE BUT ONLY
PRODUCING ISOLATED MODERATE CONVECTION WITHIN 90/120 NM EITHER
SIDE OF THE WAVE FROM 13N-16N.

TROPICAL WAVE EXTENDS FROM 16N38W SW TO 8N43W WITH A 1011 MB LOW
ALONG THE WAVE NEAR 11N. THIS SYSTEM IS MOVING W NEAR 15 KT.
THIS WAVE/LOW IS WITHIN A VERY BROAD AREA OF CYCLONIC ROTATION
AND IS UNDER UPPER LEVEL EASTERLY SHEAR. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION IS FROM 8N-12N BETWEEN 41W-44W. SMALL
CLUSTERS OF SIMILAR CONVECTION ARE FROM 6N-15N BETWEEN 41W-49W.

TROPICAL WAVE IS ALONG 59W/60W S OF 16N MOVING W NEAR 15 KT.
WAVE IS EMBEDDED WITHIN AN AREA OF DRY STABLE AIR. THEREFORE THE
WAVE POSITION IS BASED ON EXTRAPOLATION AS THE SATELLITE
SIGNATURE IS IMPOSSIBLE TO DETECTED DUE TO THE DRY AIR WITH NO
ASSOCIATED SHOWERS/CONVECTION.

TROPICAL WAVE IS ALONG 90W WHICH IS INLAND OVER GUATEMALA AND IN
THE E PACIFIC REGION. SEE MIATWDEP FOR MORE DETAILS.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 15N15W 14N18W 15N28W 13N37W
8N51W 11N62W THEN ACROSS THE N PORTION OF SOUTH AMERICA INTO THE
E PACIFIC REGION. SCATTERED MODERATE/ISOLATED STRONG IS WITHIN
45 NM LINE FROM 12N26W TO 14N27W. SMALL CLUSTERS OF SIMILAR
CONVECTION ARE WITHIN 60 NM ALONG THE COAST OF W AFRICA FROM
6N-16N.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE ANCHORED IN THE E PACIFIC REGION AND
ASSOCIATED WITHIN HURRICANE JIMENA COVERS MUCH OF THE GULF WITH
THE EXCEPTION OF THE NE GULF WHERE A SHORTWAVE UPPER TROUGH IS
MOVING ACROSS THE FLORIDA PANHANDLE. THE UPPER RIDGE IS DRAWING
UPPER LEVEL MOISTURE ACROSS THE GULF AND COUPLED WITH DIFFLUENCE
ALOFT IS GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS W OF 90W AND OVER THE SE GULF S OF 27N E OF 90W.
THE NEXT FRONTAL BOUNDARY IS EXPECTED TO MOVE INTO THE NW GULF
EARLY MON.

CARIBBEAN SEA...
AN UPPER LEVEL LOW COVERS THE CARIBBEAN W OF 78W TO THE YUCATAN
PENINSULA AND CENTERED NEAR 16N82W. AN UPPER HIGH OVER THE SW
ATLC COVERS THE E CARIBBEAN DRAWING UPPER LEVEL MOISTURE OVER
THE CENTRAL CARIBBEAN BUT DUE TO THE DRY AIR OVER THE AREA THERE
IS NO SIGNIFICANT WEATHER. HOWEVER THE DIFFLUENCE ALOFT COUPLED
WITH THE LOW LEVEL CONVERGENCE OVER THE SW CARIBBEAN IS
GENERATING SCATTERED MODERATE/STRONG CONVECTION S OF 12N W OF
79W TO INLAND OVER W PANAMA TO SE NICARAGUA. MODERATE/STRONG
EASTERLY TRADE WINDS ARE ACROSS THE CARIBBEAN BASIN USHERING IN
ISOLATED LOW LEVEL FAST MOVING SHOWERS MAINLY N OF 16N E OF 72W
TO OVER THE LEEWARD ISLANDS TO PUERTO RICO AND FROM 12N-14N E OF
66W TO THE WINDWARD ISLANDS. OTHERWISE THE REMAINDER OF THE
CARIBBEAN REMAINS RATHER TRANQUIL TODAY.

ATLANTIC OCEAN...
THE REMNANTS OF DANNY IS A 1004 MB LOW OFF THE COAST OF NORTH
CAROLINA EXTENDING A SURFACE TROUGH INTO THE REGION THROUGH
32N73W TO THE N BAHAMA ISLANDS NEAR 26N78W GENERATING
SCATTERED/NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS WITHIN
150 NM E OF THE SURFACE TROUGH N OF 27N AND WITHIN 120 NM W OF
THE SURFACE TROUGH S OF 30N. CLUSTERS OF SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS ARE FROM 24N-29N W OF 73W TO OVER THE
FLORIDA PENINSULA. AN UPPER RIDGE IS ANCHORED IN THE SW ATLC
NEAR 24N71W EXTENDING THE RIDGE NW THROUGH 32N74W AND S TO COVER
THE E CARIBBEAN. AN UPPER LOW IS OVER THE CENTRAL ATLC NEAR
29N47W AND WITH DIFFLUENCE ALOFT TO THE SW IS GENERATING
SCATTERED SHOWERS FROM 23N-28N BETWEEN 55W-64W. THE REMAINDER OF
THE CENTRAL AND E ATLC ARE DOMINATED BY BENIGN UPPER LEVEL
FEATURES AND A SURFACE RIDGE ANCHORED BY A 1031 MB HIGH NE OF
THE AZORES AND A WEAKER 1025 MB HIGH E OF BERMUDA NEAR 33N49W.
A BROAD AREA OF DEEP LAYERED MOISTURE COVERS THE TROPICAL ATLC
FROM 10N-18N E OF 45W AND ENCOMPASSES BOTH OF THOSE TROPICAL
WAVES.

$$
WALLACE



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