[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 080515
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT AUG 08 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
0445 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS ALONG 9N19W  ACROSS THE CAPE VERDE ISLANDS
TO 19N27W MOVING W NEAR 15 KT. WAVE REMAINS EMBEDDED WITH A
MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER IMAGERY.
THERE IS NO ASSOCIATED DEEP CONVECTION IN THE VICINITY OF THE
WAVE AXIS BUT ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM EITHER
SIDE OF THE WAVE AXIS.

TROPICAL WAVE IS ALONG 39W S OF 16N MOVING W NEAR 15 KT. WAVE
HAS LOST MOST OF IDENTITY AS IT MOVES THROUGH AN AREA OF DRY
STABLE AIR. THERE IS NO ASSOCIATED SHOWERS/CONVECTION ASSOCIATED
WITH THE WAVE.

TROPICAL WAVE IS ALONG 56W S OF 15N MOVING W NEAR 15 KT. WAVE
HAS MOVED INTO AN AREA BENEATH AN UPPER RIDGE THUS MASKING THE
WAVE SIGNATURE AT NIGHT. SCATTERED SHOWERS ARE FROM 10N-12N
BETWEEN 54W-58W.

TROPICAL WAVE IS ALONG 73W/74W S OF 19N MOVING W NEAR 15 KT.
WAVE REMAINS EMBEDDED WITH A MOISTURE MAXIMUM OBSERVED IN TOTAL
PRECIPITABLE WATER IMAGERY. HOWEVER...WITH THE DRY STABLE AIR
COVERING MOST OF THE CARIBBEAN...ONLY A SMALL AREA OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 17N-20N BETWEEN 72W-75W.

TROPICAL WAVE IS ALONG 92W S OF 21N MOVING W NEAR 20 KT. WAVE
REMAINS WITHIN A BROAD AREA OF DEEP LAYER MOISTURE AS NOTED ON
TOTAL PRECIPITABLE WATER IMAGERY THAT COVERS THE GULF OF MEXICO
AND INTO THE E PACIFIC REGION. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE OVER THE E BAY OF CAMPECHE S OF 22N TO OVER
MEXICO E OF 93W TO INLAND OVER THE YUCATAN PENINSULA.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 13N15W 9N30W 13N45W 10N63W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS INLAND OVER W
AFRICA MOVING INTO THE ATLC WATERS WITHIN 90 NM ALONG THE COAST
FROM 9N-14N. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ
EXTENDING FROM 15N46W TO 8N51W WITH CLUSTERS OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION WITHIN 200 NM W OF THE
TROUGH AXIS. SCATTERED CLUSTERS OF SCATTERED MODERATE CONVECTION
ARE WITHIN 150 NM OF 10N BETWEEN 28W-48W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL TROUGH EXTENDS ACROSS THE GULF OF MEXICO FROM THE W
FLORIDA PANHANDLE THROUGH 25N90W TO AN UPPER LEVEL LOW CENTERED
OVER E/CENTRAL MEXICO NEAR 21N100W. A SURFACE TROUGH EXTENDS
BELOW THIS UPPER TROUGH FROM JACKSONVILLE FLORIDA ALONG 28N85W
TO 24N89W WITH CLUSTERS OF SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS SE OF THE SURFACE TROUGH TO OVER THE SE GULF. ONLY
ISOLATED SHOWERS REMAIN OVER THE FLORIDA PENINSULA. A BROAD
UPPER RIDGE COVERS THE SE GULF COAST STATES ANCHORED WELL INLAND
OVER NW ARKANSAS. THIS IS PRODUCING UPPER LEVEL DIFFLUENCE TO
GENERATE ISOLATED SHOWERS/THUNDERSTORMS THAT DOT THE REMAINDER
OF THE GULF.

CARIBBEAN SEA...
AN UPPER LEVEL DIFFLUENT PATTERN IS OVER THE NW CARIBBEAN AND
CENTRAL AMERICA DUE TO THE UPPER LEVEL LOW CENTERED OVER
E/CENTRAL MEXICO AND AN UPPER RIDGE CENTERED OVER NICARAGUA.
THIS IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM
12N-16N BETWEEN 80W-86W INCLUDING PORTIONS OF HONDURAS AND
NICARAGUA. DRY STABLE AIR DOMINATES MUCH OF THE REMAINDER OF THE
CARIBBEAN...LIMITING SHOWER ACTIVITY. FRESH TO STRONG TRADE
WINDS CONTINUE ACROSS MUCH OF THE E AND CENTRAL CARIBBEAN.

ATLANTIC OCEAN...
AN UPPER RIDGE IS OVER THE W ATLC ANCHORED OVER THE N BAHAMA
ISLANDS WITH A NARROW UPPER TROUGH TO THE E EXTENDING FROM NEAR
BERMUDA TO THE WINDWARD PASSAGE. THIS COMBINATION IS PROVIDING
UPPER LEVEL DIFFLUENCE TO GENERATE SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 75 NM OF LINE FROM 25N71W TO 31N68W. A
SURFACE TROUGH IS BENEATH THE UPPER RIDGE EXTENDING FROM 29N73W
TO OVER THE BAHAMAS NEAR 25N77W BUT IS NOT GENERATING ANY
SIGNIFICANT WEATHER. A LARGE UPPER LOW IS IN THE CENTRAL ATLC
NEAR 26N45W WITH A SURFACE TROUGH EXTENDING 30N48W TO 25N45W.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ALONG THE N
PERIPHERY OF THE UPPER LOW WITHIN 75 NM OF LINE FROM 32N43W
30N48W TO 27N51W AND ISOLATED SHOWERS/THUNDERSTORMS ARE WITHIN
120 NM NE OF THE SURFACE TROUGH. THE REMAINDER OF THE ATLC
REMAINS TRANQUIL TONIGHT WITH A BROAD AREA OF SAHARAN DUST
COVERING THE AREA E OF 40W AND FROM 60W-70W.

$$
WALLACE



This weather bulletin was brought to you by:
www.nashvilleweather.net