[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 190556
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI AUG 19 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA... GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN
COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0415 UTC.

...TROPICAL WAVES...

E ATLC TROPICAL WAVE IS ALONG 29W S OF 22N MOVING W 10-15 KT.
BROAD ROTATION ACCOMPANIES THIS WAVE WITH LOWER PRESSURES
SUGGESTING THE PRESENCE OF A LOW LEVEL CIRCULATION CENTERED
ALONG THE WAVE NEAR 12N. THE WAVE COULD BEGIN MOVING FASTER NOW
THAT IT IS FARTHER AWAY FROM THE ENHANCING W WINDS OFF THE COAST
OF AFRICA. ASSOCIATED DEEP CONVECTION IS S OF THE ITCZ.

W ATLC WAVE ALONG 57W S OF 17N MOVING W 10-15 KT. WAVE
INVERTED-V SIGNATURE REMAINS STRONG BUT AS THIS WAVE IS AT THE
LEADING EDGE OF DRY AIR AND AFRICAN DUST THERE IS NO ASSOCIATED
DEEP CONVECTION. ISOLATED SHOWERS ARE ALONG THE ITCZ AXIS WITHIN
90/120 NM FROM 53W-60W.

W CARIBBEAN WAVE IS ALONG 83W/84W S OF 21N MOVING W 10-15 KT.
THE BROAD MID LEVEL ROTATION REMAINS NEAR 13N82W AS THE WAVE
CONTINUES WESTWARD. WAVE IS BENEATH AN UPPER LOW THAT HAS BEEN
MOVING W ACROSS THE CARIBBEAN THIS WEEK. ANY DEEP CONVECTION IS
TIED TO THE UPPER LOW RATHER THAN AS RESULT OF THE TROPICAL
WAVE.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 16N16W 8N38W 11N54W. SCATTERED
MODERATE STRONG CONVECTION IS MOVING OFF THE COAST OF
AFRICA...PRECEDING THE NEXT TROPICAL WAVE...WITHIN 60 NM FROM
13N-19N. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG
CONVECTION ARE FROM 5N-10N BETWEEN 26W-44W WITH SCATTERED
CLUSTERS FROM 8N-13N E OF 26W TO JUST INLAND OVER AFRICA.

...DISCUSSION...

GULF OF MEXICO...
MID/UPPER LOW IS ALONG THE COAST OF TEXAS NEAR 28N97W WITH AN
UPPER TROUGH EXTENDING S INTO THE BAY OF CAMPECHE. LARGE
MID/UPPER HIGH IS CENTERED OVER GEORGIA WITH ANTICYCLONIC FLOW
COVERING THE REMAINDER OF THE GULF. THIS IS LEAVING MOST OF THE
GULF WITH CLEAR SKIES. LATE EVENING THUNDERSTORMS HAVE MOVED OFF
THE FLORIDA PENINSULA NEAR FORT MYERS AND THE YUCATAN PENINSULA
INTO THE E BAY OF CAMPECHE. ONLY ISOLATED SHOWERS DOT THE NE
GULF. AT THE SURFACE...A 1016 MB HIGH IS IN THE NE GULF NEAR
28N85W. THE UPPER HIGH WILL DOMINATE THE GULF OVER THE NEXT FEW
DAYS AS THE UPPER LOW MOVES ACROSS TEXAS GIVING THE GULF
RELATIVE DRY WEATHER FOR THE WEEKEND EXCEPT IN THE SW WHERE WET
WEATHER ASSOCIATED WITH THE TROPICAL MOVING IN FROM THE W
CARIBBEAN.

CARIBBEAN SEA...
W CARIBBEAN IS DOMINATED BY AN UPPER LOW CENTERED IN THE GULF OF
HONDURAS NEAR 17N87W WHILE THE E IS DOMINATED BY AN UPPER RIDGE
EXTENDING FROM A HIGH ALONG THE COAST OF VENEZUELA NEAR 13N70W
WITH A RIDGE EXTENDING N OVER HISPANIOLA. WITH THE HIGH OVER THE
W ATLC...IS GIVING THE N CARIBBEAN DIFFLUENT FLOW AND GENERATING
SCATTERED SHOWERS AND STRONG THUNDERSTORMS FROM HAITI TO OVER
CUBA AND JAMAICA. DIFFLUENT FLOW BETWEEN THE UPPER SYSTEMS OF
THE CARIBBEAN IS ALSO GENERATING SIMILAR ACTIVITY FROM 11N-17N
BETWEEN 79W-84W. THIS IS LEAVING ISOLATED SHOWERS OVER THE FAR
NW CARIBBEAN. AT THE SURFACE...A TROUGH EXTENDS FROM THE
W/CENTRAL ATLC TO OVER THE VIRGIN ISLANDS AND PUERTO
RICO...REMNANTS OF A SURFACE LOW/TROPICAL DEPRESSION TEN...THAT
IS GENERATING A SIGNIFICANT AMOUNT OF SHOWERS AND THUNDERSTORMS
FROM THE N LEEWARD ISLANDS TO JUST BEYOND PUERTO RICO. THIS
FEATURE WILL CONTINUE MOVING WNW AND BE OVER THE BAHAMAS BY THE
WEEKEND.

ATLANTIC OCEAN...
THE W ATLC IS CHARACTERIZED BY THE TYPICAL RIDGE/TROUGH/RIDGE
SCENARIO WITH AN UPPER HIGH IS CENTERED OVER GEORGIA AND BROAD
ANTICYCLONIC FLOW COVERING THE AREA W OF 70W...A CUT-OFF IS THE
THE CENTERED TO THE E NEAR 25N64W WITH AN UPPER TROUGH EXTENDING
SSW TO JUST N OF PUERTO RICO...AND A SECOND HIGH CENTERED NEAR
28N54W. THIS IS GIVING THE AREA SURROUNDING THE UPPER LOW
UNSETTLED WEATHER WITH SCATTERED SHOWERS TO STRONG THUNDERSTORMS
S OF 27N BETWEEN 59W-70W. A SURFACE TROUGH EXTENDS JUST W OF THE
UPPER TROUGH FROM 27N66W SW TO THE TURKS AND CAICOS AND A SECOND
SURFACE TROUGH EXTENDS FROM 22N61W TO OVER THE VIRGIN ISLANDS
AND PUERTO RICO...REMNANTS OF A SURFACE LOW/TROPICAL DEPRESSION
TEN. THIS AREA FROM 18N-23N BETWEEN 61W-66W INCLUDING THE VIRGIN
ISLANDS AND PUERTO RICO ARE WHERE THE STRONGEST THUNDERSTORMS
ARE OCCURRING. A BROAD MID/UPPER LOW IN THE CENTRAL ATLC IS
CENTERED NEAR 27N43W WITH A TROUGH EXTENDING S TO 18N49W.
ALTHOUGH UPPER LEVEL MOISTURE IS BEING ADVECTED S OVER THE
AREA...THE LOWER LEVELS REMAIN DRY...THUS SHOWERS/CONVECTION
CANNOT BE MAINTAINED. THE E ATLC AND DEEP TROPICS ARE DOMINATED
BY AN UPPER RIDGE THAT EXTENDS FROM OFF THE COAST OF AFRICA FROM
OVER THE N PORTION OF MAURITANIA NEAR 20N16 ALONG 17N30W NEAR
15N50W. THIS IS LEAVING THE E ATLC UNDER STRONG SUBSIDENCE AND
DRY AIR AND KEEPING CONVECTION S OF THE ITCZ AXIS.

$$
WALLACE


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