[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 070001
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED AUG 06 2008

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
2315 UTC.

...TROPICAL WAVES...
A HIGH AMPLITUDE TROPICAL WAVE IS LOCATED ALONG 38W SOUTH OF 21N
MOVING W AT 15 KT. SATELLITE IMAGERY REVEALS AN INVERTED-V
PATTERN...AND THE SSMI-DERIVED TPW PRODUCT FROM CIMSS SHOWS A
NORTH-SOUTH MOISTURE MAXIMUM ALONG THE WAVE AXIS. NO DEEP
CONVECTION IS ASSOCIATED WITH THIS FEATURE. MAINLY LOW/MID
CLOUDS AND ISOLATED SHOWERS ARE EITHER SIDE OF THE WAVE AXIS.

A TROPICAL WAVE IS ALONG 54W S OF 18N MOVING W NEAR 15 KT. THIS
IS A LOW AMPLITUDE WAVE WITH SCATTERED SHOWERS WHERE THE WAVE
MEETS THE ITCZ.

A HIGH AMPLITUDE TROPICAL WAVE EXTENDS FROM THE SE BAHAMAS
THROUGH HISPANIOLA TO THE COLOMBIA/VENEZUELA BORDER ALONG 73W
MOVING WEST AROUND 15 KT. THE WAVE SHOWS UP VERY WELL ON THE
MIMIC-TPW PRODUCT WHERE A GOOD SURGE OF MOISTURE IS NOTED. THIS
SYSTEM IS ENHANCING SOME CONVECTIVE ACTIVITY OVER DOMINICAN
REPUBLIC AND N COLOMBIA.

THE TROPICAL WAVE THAT WAS PREVIOUSLY ALONG 96W IS NOW MAINLY
OVER THE EASTERN PACIFIC. SEE TROPICAL WEATHER DISCUSSION FOR
THE EPAC...TWDEP.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 12N16W 11N25W 13N34W 9N45W 9N62W.
A LOW/MID CYCLONIC CIRCULATION IS SEEN EMBEDDED IN THE ITCZ NEAR
11N22W WITH A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION
WITHIN 100 NM SW QUADRANT. WILL WAIT FOR ADDITIONAL DATA BEFORE
PLACING A LOW ON THE SURFACE MAP. CLUSTERS OF MODERATE
CONVECTION ARE NEAR 9N29W...9N32W AND 9N41W.

...DISCUSSION...

GULF OF MEXICO...
THE BOOK OF EDOUARD IS NOT CLOSED YET. AS A TROPICAL DEPRESSION
CONTINUES TO WEAKEN ACROSS NORTH-CENTRAL TEXAS. STORM TOTAL
RAINFALL AMOUNTS ARE BETWEEN 4 AND 6.5 INCHES IN HARRIS COUNTY
TEXAS THROUGH 06/1800 UTC. ADDITIONAL RAINFALL ACCUMULATIONS OF
1 TO 2 INCHES WITH ISOLATED AMOUNTS TO 4 INCHES ARE EXPECTED
ACROSS NORTH-CENTRAL TEXAS. MEANWHILE...HIGH PRES IS BUILDING
OVER THE GULF REGION WITH A WEAK 1020 MB CENTER OVER SE
LOUISIANA. SCATTERED SHOWERS AND ISOLATED TSTMS AREA OVER THE SE
PORTION OF THE GULF AND THE YUCATAN PENINSULA. UPPER DIFFLUENT
BETWEEN AN UPPER-LEVEL HIGH OVER THE SE CONUS/W ATLANTIC AND AN
INVERTED TROUGH OVER THE CARIBBEAN SEA IS SUPPORTING THIS
CONVECTIVE ACTIVITY. AN UPPER-LEVEL LOW HAS ALSO DEVELOPED OVER
THE N GULF WATERS NEAR 29N88W AND IS HELPING TO INDUCE SCATTERED
SHOWERS AND TSTMS OVER THE SE U.S.. SOME SHOWER ACTIVITY IS
OBSERVER OVER THE SW GULF THANKS TO AN UPPER-LEVEL LOW SPINNING
INLAND OVER CENTRAL MEXICO. CONSIDERABLE UPPER LEVEL MOISTURE
COVERS THE ENTIRE GULF OF MEXICO. LOOKING AHEAD...A COLD FRONT
IS FORECAST TO APPROACH THE NRN GULF WATERS LATE SATURDAY.

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS AN INVERTED TROUGH EXTENDING OVER E
CUBA AND JAMAICA TO THE SW CARIBBEAN. UPPER NLY WINDS ON THE
WEST SIDE OF THE TROUGH ARE ENHANCING CONVECTION OVER PARTS OF
CUBA AND THE CAYMAN ISLANDS. THESE WINDS ARE ALSO TRANSPORTING
A FAIR AMOUNT OF UPPER-LEVEL MOISTURE ACROSS THE NW CARIBBEAN
INTO N CENTRAL AMERICA. AN UPPER-LEVEL HIGH IS BUILDING OVER THE
E CARIBBEAN PRODUCING MODERATE TO STRONG SUBSIDENCE/DRY AIR
BETWEEN PUERTO RICO AND THE LEEWARD ISLANDS. HAZY CONDITIONS DUE
TO AFRICAN DUST SHOULD CONTINUE OVER THOSE ISLANDS TONIGHT
THROUGH MOST OF THURSDAY. THE SAHARAN AIR LAYER FROM CIMSS AND
LATEST VIS IMAGERY FOR THE DAY CONFIRM THE PRESENCE OF AFRICAN
DUST OVER THE NE CARIBBEAN AND THE TROPICAL N ATLC. A TROPICAL
WAVE IS OVER THE CENTRAL CARIBBEAN. SEE ABOVE. MODERATE TO
ISOLATED STRONG CONVECTION HAS DEVELOPED OVER N COLOMBIA LIKELY
ASSOCIATED WITH THE COLOMBIAN LOW THAT IS CENTERED NEAR 9N75W
WITH 1006 MB. TRADE WINDS OF 20 TO 25 KT ARE FOUND OVER THE
SOUTH-CENTRAL CARIBBEAN.

ATLANTIC OCEAN...
A SMALL AREA OF SHOWERS AND THUNDERSTORMS PREVIOUSLY ASSOCIATED
WITH A HIGH AMPLITUDE TROPICAL WAVE IS MOVING WWD ACROSS THE
CENTRAL BAHAMAS. CONDITIONS ARE NOT FAVORABLE FOR SIGNIFICANT
DEVELOPMENT OF THIS SYSTEM...BUT IT COULD PRODUCE PERIODS OF
SHOWERS OVER PORTIONS OF THE BAHAMAS AND SOUTHERN FLORIDA DURING
THE NEXT DAY OR TWO. A SFC TROUGH IS ANALYZED IN THAT AREA AND
RUNS FROM 27N70W TO 23N76W. ELSEWHERE...THREE WEAK HIGH PRES
CENTERS DOMINATES THE FORECAST REGION WITH THE MAIN ONE LOCATED
NEAR 29N52W WITH 1022 MB. THE RIDGE AXIS EXTENDS WWD TO CENTRAL
FLORIDA. ALOFT...A RIDGE IS OVER THE W ATLANTIC N OF 25N W OF
65W. AN UPPER-LEVEL LOW REMAINS OVER THE SE BAHAMAS WITH A
TROUGH EXTENDING ACROSS E CUBA AND JAMAICA INTO THE SW
CARIBBEAN. ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 18N54W. YET
ANOTHER UPPER LEVEL LOW IS CENTERED NEAR 23N41W. AN UPPER-LEVEL
TROUGH ENTERS THE AREA THROUGH THE CANARY ISLANDS THEN CONTINUES
MAINLY WWD TO THE UPPER LOW LOCATED NEAR 23N41W. SOUTH OT THIS
UPPER TROUGH THERE IS AN UPPER-LEVEL HIGH NEAR 19N31W. THIS HIGH
IS ASSISTING THE DEVELOPMENT OF SCATTERED DEEP CONVECTION ALONG
THE ITCZ AXIS.

$$
GR










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