[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 032329
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON AUG 03 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...TROPICAL WAVES...

THE TROPICAL WAVE THAT WAS ADDED TO THE 1200 UTC ANALYSIS
REMAINS ALONG 19W/20W BASED ON VISIBLE SATELLITE IMAGERY MOVING
W 10-15 KT. WAVE WAS RELOCATED SLIGHTLY EASTWARD BASED ON
LOW/MID LEVEL CYCLONIC ROTATION. THE MOISTURE MAXIMUM ON THE
TOTAL PRECIPITABLE WATER IS VERY BROAD COVERING THE AREA FROM
26W TO THE COAST OF AFRICA. HOWEVER...THE SHOWER ACTIVITY HAS
DIMINISHED OVER THE PAST FEW HOURS.

TROPICAL WAVE EXTENDS FROM 23N48W 16N43W TO 9N41W MOVING W NEAR
15 KT. THE FRESH TO STRONG MID-LATITUDE WINDS ARE PUSHING THE
NORTH PORTION OF THE WAVE WEST FASTER THAN THE SOUTHERN PORTION
WHICH IS EMBEDDED WITHIN THE ITCZ. THE SOUTHERN PORTION OF THE
WAVE ALIGNS WITH THE MOISTURE MAXIMUM ON THE TOTAL PRECIPITABLE
WATER WITH NO ASSOCIATED SHOWERS/CONVECTION.

TROPICAL WAVE OVER THE E CARIBBEAN REMAINS ALONG 62W/63W S OF
17N BASED ON MOISTURE MAXIMUM ON THE TOTAL PRECIPITABLE WATER
IMAGERY DRIFTING WESTWARD. THE MOISTURE MAXIMUM ON THE TOTAL
PRECIPITABLE WATER ACTUALLY SHOWS THE WAVE AXIS TO BE JUST E OF
THE LESSER ANTILLES. ISOLATED SHOWERS ARE FROM 9N-13N BETWEEN
57W-60W.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 14N15W 9N29W 11N42W 9N50W
12N61W. BROAD AREA OF MID LEVEL CYCLONIC ROTATION IS EMBEDDED
WITHIN THE ITCZ NEAR 9N29W WHERE A SURFACE TROUGH WILL BE
ANALYZED AT 04/0000 UTC. SCATTERED TO NUMEROUS STRONG CONVECTION
IS WITHIN A 60 NM RADIUS OF 9N31W. SCATTERED MODERATE TO
ISOLATED STRONG CONVECTION COVERS THE REMAINDER OF THE AREA FROM
6N-11N BETWEEN 27W-33W. CLUSTERS OF ISOLATED MODERATE CONVECTION
DOT THE AREA WITHIN 200 NM EITHER SIDE OF THE ENTIRE ITCZ.

...DISCUSSION...

GULF OF MEXICO...
THE SURFACE RIDGE CONTINUES TO DOMINATE THE GULF WITH THE AXIS
EXTENDING FROM THE W ATLC ALONG 29N TO A 1019 MB HIGH NEAR
28N92W. AN UPPER HIGH REMAINS ANCHORED OVER NE MEXICO/S TEXAS
EXTENDING AN UPPER RIDGE E ACROSS THE GULF TO NEAR TAMPA
FLORIDA. DUE TO THE INTERACTION OF THIS UPPER RIDGE AND THE
UPPER TROUGH EXTENDING FROM AN UPPER LOW IN THE GULF OF
TEHUANTEPEC TO OVER THE YUCATAN PENINSULA...A BAND OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS THE GULF WITHIN 75 NM
OF LINE FROM ACROSS THE FLORIDA PENINSULA NEAR TAMPA TO 25N92W.
SIMILAR ACTIVITY IS INLAND OVER THE YUCATAN PENINSULA AND IN THE
BAY OF CAMPECHE S OF 21N E OF 93W.

CARIBBEAN SEA...
ALTHOUGH THERE IS A TROPICAL WAVE IN THE E CARIBBEAN IT IS NOT
PRODUCING ANY SIGNIFICANT WEATHER. A BROAD UPPER RIDGE DOMINATES
MUCH OF THE CARIBBEAN EXTENDING FROM COLOMBIA TO CENTRAL CUBA
AND COUPLED WITH THE UPPER TROUGH OVER THE YUCATAN PENINSULA IS
PROVIDING UPPER DIFFLUENCE TO GENERATE AN ISOLATED/SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS MAINLY W OF 83W INCLUDING W
CUBA...THE YUCATAN CHANNEL... AND THE YUCATAN PENINSULA. THIS
SAME UPPER RIDGE IS GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 120 NM ALONG THE COAST OF CENTRAL AMERICA S
OF 15N W OF 81W. OTHERWISE...THE REMAINDER OF THE CARIBBEAN
REMAINS RATHER TRANQUIL AGAIN THIS EVENING.

ATLANTIC OCEAN...
SCATTERED/NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS REMAIN
OFF THE E COAST OF THE SE US NW OF A LINE FROM NEAR MELBOURNE
FLORIDA TO BEYOND 32N73W IN RESPONSE TO AN UPPER TROUGH INLAND
OVER THE US AND AN UPPER RIDGE THAT EXTENDS FROM THE W CARIBBEAN
ACROSS CENTRAL CUBA TO BEYOND 32N73W. AN UPPER LOW IS CENTERED
NEAR 28N63W BUT IS NOT GENERATING ANY SIGNIFICANT WEATHER. A
SURFACE TROUGH...PREVIOUSLY A PORTION OF A TROPICAL WAVE...
EXTENDS FROM 24N67W ACROSS E DOMINICAN REPUBLIC TO 17N69W
GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS
FROM 23N ACROSS THE TURKS AND CAICOS TO OVER HISPANIOLA E OF THE
TROUGH AXIS TO 72W. THE ENTIRE ATLC BASIN IS DOMINATED BY A
SURFACE RIDGE ANCHORED N OF THE REGION AND EXTENDS W OVER THE
GULF OF MEXICO. OTHERWISE THE REMAINDER OF THE ATLC IS TRANQUIL
THIS EVENING WITH AN AREA OF SAHARAN DUST CLEARLY SEEN ON
INFRARED SATELLITE IMAGERY E OF 60W FROM THE ITCZ TO 31N
ALTHOUGH IT IS BEGINNING TO CLEAR N OF 26N E OF 25W.

$$
WALLACE



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