[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 121040
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT AUG 12 2006

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND THE 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS JUST OFF THE W COAST OF AFRICA ALONG 17W/18W S
OF 21N MOVING W 15 KT. WAVE HAS A WELL DEFINED MID LEVEL
ROTATION NEAR 18N WITH THE TYPICAL LOW LEVEL INVERTED V
CURVATURE FURTHER S. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
ARE FROM 11N-16N BETWEEN THE COAST OF AFRICA AND 20W.

TROPICAL WAVE IS ALONG 50W/51W S OF 20N MOVING W 10-15 KT. WAVE
CONTINUES TO HAVE A WELL DEFINED LOW LEVEL INVERTED V-SHAPE
CURVATURE HOWEVER LACKS DEEP CONVECTION DUE A VERY DRY
ENVIRONMENT. MID/UPPER LEVEL HIGH HAS DEVELOPED JUST TO THE W OF
THE WAVE AXIS AND THE UPPER RIDGE EXTENDING ACROSS THE ATLC
GENERATING CONVECTION TO THE W OF THE WAVE AXIS.

TROPICAL WAVE IN THE CARIBBEAN IS ALONG 74W/75W S OF 21N MOVING
W 15 KT. WAVE IS MOVING BENEATH AN UPPER LOW/TROUGH WHICH IS
PARTIALLY MASKING THE SIGNATURE CURVATURE AND DIMINISHING ANY
ASSOCIATED CONVECTION.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 11N19W 7N31W 9N41W 7N46W 11N59W
10N63W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 225
NM N OF THE AXIS FROM 37W-44W AND FROM 10N-15N BETWEEN 52W-60W.
ISOLATED THUNDERSTORMS DOT THE REMAINING ITCZ AREA.

...DISCUSSION...
GULF OF MEXICO...
THE UPPER LEVEL LOW COVERING THE W GULF CENTERED CONTINUES TO
MOVE FURTHER INLAND ALONG THE TEXAS/MEXICO BORDER NEAR 26N98W
COVERING THE GULF W OF 90W. THE UPPER HIGH OFF THE COAST OF NE
FLORIDA AND THE UPPER RIDGE EXTENDING ACROSS THE W ATLC ARE
GIVING THE REMAINDER OF THE GULF S TO SE UPPER FLOW WITH DRY
UPPER AIR. AT THE SURFACE...A RIDGE EXTENDS FROM THE W ATLC
ACROSS S FLORIDA WITH A 1015 MB HIGH IN THE E GULF NEAR 25N84W.
SOME UPPER MOISTURE BEING ADVECTED ACROSS S MEXICO INTO THE SW
GULF BUT IS NOT ENOUGH TO SUPPORT ANY SIGNIFICANT SHOWER
ACTIVITY. THUS...THE GULF IS RELATIVE QUIET AGAIN THIS MORNING.

CARIBBEAN SEA...
THE UPPER RIDGE OVER THE W ATLC EXTENDS S OVER CUBA AND THE
YUCATAN CHANNEL GIVING ENOUGH DIFFLUENCE TO MAINTAIN ISOLATED
SHOWERS/THUNDERSTORMS FROM 17N21N BETWEEN 79W-82W. AN UPPER
TROUGH IN THE W ATLC EXTENDS INTO THE CARIBBEAN ACROSS
HISPANIOLA TO AN UPPER LOW IN THE CENTRAL CARIBBEAN NEAR 16N76W.
THE TROPICAL WAVE IS MOVING BENEATH THIS UPPER LOW/TROUGH. THE E
CARIBBEAN REMAINS UNDER THE INFLUENCE OF AN UPPER RIDGE THAT
COVERS THE TROPICAL ATLC AND IS ADVECTING IN MORE DRY AIR OVER
THE LESSER ANTILLES. MODERATE/STRONG TRADEWINDS ARE ACROSS THE
CARIBBEAN S OF 17N.

ATLANTIC OCEAN...
AND UPPER HIGH IS OFF THE NE COAST OF FLORIDA NEAR 28N77W
EXTENDING AN UPPER RIDGE ACROSS THE W ATLC TO THE CENTRAL ATLC
NEAR 29N60W BRINGING WITH IT CLUSTERS OF SCATTERED MODERATE/
ISOLATED STRONG CONVECTION N OF 30N FROM 68W-79W AND SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS N OF 30N FROM 55W-68W. AN UPPER
TROUGH EXTENDS FROM N OF THE REGION INTO THE W/CENTRAL ATLC NEAR
32N49W SW ALONG 25N56W TO AN UPPER LOW NEAR N OF HISPANIOLA NEAR
21N69W CONTINUING ACROSS HISPANIOLA INTO THE CENTRAL CARIBBEAN
AND YET ANOTHER UPPER LOW. A NARROWING DEEP LAYERED TROUGH IS N
OF THE E/CENTRAL ATLC N OF 25N FROM 34W-43W WITH A 1015 MB
SURFACE LOW N OF THE REGION AND A WEAK SURFACE TROUGH EXTENDING
THROUGH 32N32W SW TO 29N36W. AN UPPER RIDGE EXTENDS ACROSS THE
TROPICAL ATLC FROM AFRICA INTO THE E CARIBBEAN AND COVERING THE
E ATLC E OF 34W. HOWEVER...DUE TO THE ABUNDANCE OF DRY AIR...ANY
SHOWER ACTIVITY IS SEVERELY LIMITED. THE REMAINDER OF THE
SURFACE ATLC IS DOMINATED BY A SURFACE RIDGE WITH A SERIES OF
HIGHS EXTENDING ACROSS THE ATLC INTO THE GULF OF MEXICO THROUGH
A 1020 MB HIGH IN THE E ATLC NEAR 26N33W AND A 1018 MB HIGH IN
THE CENTRAL ATLC NEAR 22N59W. THIS IS GIVING THE ENTIRE AREA
LITTLE IN THE WAY OF CLOUDS MUCH LESS SHOWER ACTIVITY.

$$
WALLACE



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