[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 090513
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN AUG 09 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 IS ALONG 18W S OF 18N MOVING W NEAR 10 KT. LATEST
INFRARED SATELLITE IMAGERY INDICATES THE WELL DEFINED LOW/MID
LEVEL CYCLONIC CIRCULATION CENTER IS MOVING E OF THE WAVE AXIS
WHICH IS EMBEDDED WITHIN THE MOISTURE MAXIMUM OBSERVED IN TOTAL
PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS ASSOCIATED WITH THE LOW/MID LEVEL CIRCULATION
COVERING THE AREA FROM 11N-16N BETWEEN 19W-22W.

TROPICAL WAVE IS ALONG 34W/35W S OF 19N MOVING W 10-15 KT. WAVE
REMAINS EMBEDDED WITH A MOISTURE MAXIMUM OBSERVED IN TOTAL
PRECIPITABLE WATER IMAGERY. THERE IS NO DEEP CONVECTION
ASSOCIATED WITH THE WAVE BUT ISOLATED SHOWERS ARE WITHIN 120 NM
EITHER SIDE OF THE WAVE AXIS FROM 6N-9N.

TROPICAL WAVE IS ALONG 45W S OF 16N MOVING W NEAR 15 KT. WAVE
REMAINS IN AN AREA OF RATHER DRY STABLE AIR. HOWEVER...SCATTERED
MODERATE CONVECTION IS WITHIN 75 NM OF THE ITCZ AXIS JUST TO THE
E OF THE WAVE TO 42W.

TROPICAL WAVE IS ALONG 61W/62W S OF 18N MOVING WNW NEAR 15 KT.
WAVE REMAINS IN AN AREA BENEATH AN UPPER RIDGE THUS MASKING THE
WAVE SIGNATURE AND ANY SHOWERS/CONVECTION IS MORE ASSOCIATED
WITH THE UPPER LEVEL FEATURE THAN THE WAVE ITSELF.

TROPICAL WAVE IS ALONG 82W S OF 21N MOVING W NEAR 20 KT. WAVE IS
NOW ALONG THE TRAILING EDGE OF A MOISTURE MAXIMUM OBSERVED IN
TOTAL PRECIPITABLE WATER IMAGERY AND IS EMBEDDED IN RATHER DRY
STABLE AIR WITH NO ASSOCIATED DEEP CONVECTION.

THE TROPICAL WAVE THAT WAS ALONG 96W IS NO LONGER IN THE ATLC
BASIN.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 12N20W 10N39W 13N51W 11N61W. A
SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ EXTENDING FROM 17N52W
TO 9N54W WITH CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG
CONVECTION W OF THE TROUGH AXIS WITHIN 60/75 NM OF LINE FROM
16N52W TO 13N59W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS N OF THE ITCZ WITHIN 45 NM OF 15N BETWEEN 28W-32W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER RIDGE ANCHORED OVER SOUTH CAROLINA IS DIGGING S OVER
THE FAR W ATLC AND THE FLORIDA PENINSULA PUSHING ANY SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS INTO THE E GULF OF MEXICO WITHIN
120 NM ALONG THE COAST OF THE FLORIDA PENINSULA JUST N OF THE
FLORIDA KEYS WITH ISOLATED SHOWERS N OF 26N E OF 87W. AN UPPER
LEVEL TROUGH ANCHORED OVER CENTRAL MEXICO COVERS THE REMAINDER
OF THE GULF. A SURFACE TROUGH IS OVER THE E BAY OF CAMPECHE/W
YUCATAN PENINSULA FROM 22N89W TO 18N92W GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60 NM OF THE TROUGH AXIS.
OTHERWISE THE REMAINDER OF THE GULF IS TRANQUIL TONIGHT.

CARIBBEAN SEA...
AN UPPER RIDGE OVER THE W ATLC/E GULF OF MEXICO COVERS THE NW
CARIBBEAN WITH AN UPPER TROUGH OVER THE CENTRAL CARIBBEAN AND A
SECOND UPPER RIDGE OVER THE E CARIBBEAN. THE UPPER LEVEL
DIFFLUENCE OVER THE W CARIBBEAN IS GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS W OF 85W TO INLAND OVER CENTRAL AMERICA
AND THE YUCATAN PENINSULA. THE ITCZ EXTENDS ACROSS THE SW
CARIBBEAN FROM COLOMBIA TO COSTA RICA GENERATING SCATTERED
SHOWERS/THUNDERSTORMS FROM 11N TO THE COAST OF PANAMA BETWEEN
77W-81W. FRESH TO STRONG TRADE WINDS CONTINUE ACROSS MOST OF THE
CARIBBEAN USHERING IN FAST MOVING ISOLATED SHOWERS MAINLY ACROSS
THE E CARIBBEAN E OF 70W WHILE THE REMAINDER OF THE AREA IS
DOMINATED BY DRY STABLE AIR LIMITING SHOWER ACTIVITY.

ATLANTIC OCEAN...
AN UPPER RIDGE ANCHORED OVER SOUTH CAROLINA COVERS THE W ATLC
WITH A NARROW UPPER TROUGH TO THE E EXTENDING THROUGH 32N57W
ACROSS THE WINDWARD PASSAGE AND OVER THE CENTRAL CARIBBEAN. THIS
COMBINATION IS PROVIDING UPPER LEVEL DIFFLUENCE TO GENERATE
CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120
NM OF LINE FROM THE STRAITS OF FLORIDA NEAR 24N81W ACROSS THE
BAHAMAS ALONG 27N72W TO BEYOND 32N64W. A SURFACE TROUGH IS
BENEATH THE UPPER RIDGE EXTENDING FROM 31N71W TO OVER THE N MOST
BAHAMA ISLANDS NEAR 26N78W BUT IS NOT GENERATING ANY SIGNIFICANT
WEATHER. THE LARGE UPPER LOW OVER THE CENTRAL ATLC IS MOVING N
AND CENTERED NEAR 32N47W WITH ANY SHOWER/THUNDERSTORM ACTIVITY N
OF THE REGION AND A WEAKENING SURFACE TROUGH TO THE SW OF THE
UPPER LOW EXTENDING FROM 31N52W TO 24N54W. THE REMAINDER OF THE
ATLC REMAINS TRANQUIL AGAIN TONIGHT WITH A BROAD AREA OF SAHARAN
DUST COVERING THE AREA E OF 50W AND FROM 65W-75W.

$$
WALLACE





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