[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 090551
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE AUG 09 2011

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ANALYZED FROM 11N26W TO 19N23W MOVING W AT
10-15 KT. SHORTWAVE INFRARED METEOSAT-9 SATELLITE IMAGERY
REVEALS A BROAD LOW TO MID-LEVEL CYCLONIC CIRCULATION IN THE
VICINITY OF 12N27W...WHICH IS PRIMARILY A MONSOON TROUGH GYRE
ENCOMPASSING THE AREA FROM 08N-17N BETWEEN 21W-42W. THE WAVE IS
EMBEDDED IN AN AREA OF ENHANCED DEEP-LAYERED TOTAL PRECIPITABLE
WATER VALUES LOCATED OFF THE COAST OF W AFRICA FROM 10N-21N E OF
28W. ISOLATED MODERATE CONVECTION IS FROM 11N-13N BETWEEN
26W-29W.

TROPICAL WAVE IS ANALYZED FROM 10N50W TO 18N49W MOVING W AT
10-15 KT. A 1012 MB LOW IS LOCATED ALONG THE WAVE AXIS NEAR
14N50W AND AN AREA OF HIGHER TOTAL PRECIPITABLE WATER VALUES IS
FROM 10N-18N BETWEEN 51W-60W. TPW IMAGERY ALSO INDICATES THE
MOISTURE AND SOME ENERGY ASSOCIATED WITH THIS WAVE IS STRETCHING
NORTHEASTWARD AS IT INTERACTS WITH A MIDDLE TO UPPER LEVEL
TROUGH ACROSS THE CENTRAL ATLC. NO SIGNIFICANT DEEP CONVECTION
IS ASSOCIATED WITH THE WAVE.

TROPICAL WAVE IS ANALYZED FROM 11N74W TO 20N71W MOVING W AT 15
KT. THE WAVE CONTINUES WESTWARD ON THE SOUTHWESTERN PERIPHERY OF
A 1018 MB WESTERN ATLC HIGH CENTERED NE OF THE WAVE NEAR 23N63W.
THE WAVE IS BECOMING MORE DIFFICULT TO TRACK THROUGH TIME AND NO
SIGNIFICANT DEEP CONVECTION IS OCCURRING IN THE VICINITY OF THE
WAVE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 17N16W
ALONG 09N39W TO 12N45W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 12N45W TO 14N50W TO 14N60W. WIDELY SCATTERED
MODERATE CONVECTION IS FROM 10N-16N BETWEEN 15W-20W...AND FROM
07N-09N BETWEEN 39W-44W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE NE
GULF AND EXTENDS AN UPPER LEVEL RIDGE AXIS SW TO OVER
EAST-CENTRAL MEXICO NEAR 19N98W. AT THE SURFACE...A SURFACE
RIDGE AXIS EXTENDS FROM THE W ATLC WATERS ALONG 25N AND IT
REMAINS ANCHORED BY A 1015 MB HIGH CENTERED IN THE SE GULF NEAR
15N85W. THE RIDGE IS PROVIDING MOSTLY FAIR CONDITIONS AND CLEAR
SKIES OVER A LARGE PORTION OF THE GULF N OF 21N W OF 85W. WITH
VERY WEAK SURFACE TROUGHING AND REMNANT DAYTIME SEABREEZE
DYNAMICS EXTENDING OVER THE FLORIDA PENINSULA...A FEW ISOLATED
SHOWERS ARE NOTED THIS EVENING E OF 85W. ANOTHER AREA OF
ISOLATED SHOWERS IS LOCATED OVER THE SW GULF S OF 21N E OF 93W
TO THE YUCATAN PENINSULA COAST. THE HIGH PRESSURE RIDGE IS
FORECAST TO REMAIN IN PLACE OVER THE GULF ALONG 25N THROUGH THE
REMAINDER OF THE WEEK.

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH BISECTS THE
CARIBBEAN SEA. THE UPPER LEVEL TROUGH AXIS EXTENDS FROM THE SW
NORTH ATLC NEAR 26N71W TO OVER HONDURAS NEAR 14N87W. MOST LIFT
ASSOCIATED WITH THIS UPPER LEVEL FEATURE IS IN THE FORM OF
ISOLATED SHOWERS AND TSTMS OCCURRING IN THE NW CARIBBEAN FROM
14N-20N BETWEEN 81W-86W...INCLUDING INTERIOR PORTIONS OF
NORTHERN NICARAGUA AND ALL OF HONDURAS. ELSEWHERE ACROSS THE
REMAINDER OF THE CARIBBEAN...LOW-LEVEL MOISTURE ASSOCIATED WITH
A WEAKENED SHEAR LINE EXTENDS EAST OF THE WINDWARD ISLANDS FROM
16N58W TO 13N63W AND IS GENERATING AN AREA OF WIDELY SCATTERED
SHOWERS FROM 13N-17N BETWEEN 60W-66W. OTHERWISE...EASTERLY
TRADES ACROSS CENTRAL PORTIONS OF THE CARIBBEAN ARE EXPECTED TO
REMAIN STRONG DUE TO A HIGH PRESSURE RIDGE ALONG 25N IN THE W
ATLC.

ATLANTIC OCEAN...
THE SW NORTH ATLC REMAINS FAIRLY TRANQUIL THIS EVENING AS A HIGH
PRESSURE RIDGE AXIS HOLDS ALONG 25N AND IS ANCHORED BY A 1018 MB
HIGH CENTERED NEAR 23N63W. RELATIVELY WEAK SURFACE TROUGHING
EXTENDS INLAND ACROSS THE FLORIDA PENINSULA WITH POSSIBLE
ISOLATED SHOWERS N OF 26N W OF 79W. FARTHER EAST...THE REMNANTS
OF EMILY CONTINUES AS A COMPLEX OF TSTMS THAT HAS MERGED WITH A
WARM FRONTAL BOUNDARY EXTENDING FROM BEYOND 35N58W TO 31N55W.
THIS AREA OF SCATTERED MODERATE CONVECTION IS FROM 31N-35N
BETWEEN 54W-59W. WATER VAPOR IMAGERY SHOWS A DEEP LAYER TROUGH
OVER THE CENTRAL NORTH ATLC AND AN ASSOCIATED UPPER LEVEL TROUGH
AXIS EXTENDING SOUTHWARD INTO THE DISCUSSION AREA ALONG 32N45W
TO 22N57W. THIS MIDDLE TO UPPER LEVEL TROUGH SUPPORTS A COLD
FRONT FROM 32N39W TO 30N44W THEN CONTINUES AS A STATIONARY FRONT
TO 27N52W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING
WITHIN 150 NM EITHER SIDE OF THE FRONT N OF 27N. A PRE-FRONTAL
SURFACE TROUGH ALSO EXTENDS SW FROM THE COLD FRONT ANALYZED FROM
30N41W TO 25N50W. ISOLATED SHOWERS ARE OCCURRING WITHIN 180 NM
SE OF THE SURFACE TROUGH. THE REMAINDER OF THE EASTERN ATLC IS
UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1029 MB
HIGH CENTERED NE OF THE AZORES NEAR 45N14W. THE SURFACE RIDGE
AXIS EXTENDS SW FROM THE HIGH TO 32N27W TO 20N46W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
HUFFMAN




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