[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191754
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN AUG 19 2012

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...SPECIAL FEATURES...

HURRICANE GORDON IS CENTERED NEAR 35.8N 28.7W AT 19/1800 OR
ABOUT 190 NM SW OF SAO MIGUEL ISLAND IN THE AZORES MOVING ENE
AT 18 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 976 MB. MAXIMUM
SUSTAINED WIND SPEED IS 80 KT WITH GUSTS TO 100 KT. SCATTERED
MODERATE CONVECTION IS FROM 35N-38N BETWEEN 25W-31W. SEE LATEST
NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT3/WTNT33 AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO
HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS.

TROPICAL WAVE EXTENDS FROM 14N36W TO 20N34W MOVING W AT 20 KT. A
1011 MB LOW IS ANALYZED AT THE SOUTHERN EXTENT OF THE WAVE AXIS
NEAR 14N36W AND CONTINUES TO PROVIDE FOCUS FOR SCATTERED
MODERATE CONVECTION FROM 14N-18N BETWEEN 36W-39W TO THE NW OF
THE LOW AND FROM 11N-13N BETWEEN 36W-41W TO THE SOUTH OF THE
LOW. ENVIRONMENTAL CONDITIONS REMAIN FAVORABLE FOR A TROPICAL
CYCLONE TO FORM DURING THE NEXT DAY OR TWO.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 11N47W TO 18N46W MOVING W AT 15-20
KT. EMBEDDED LARGELY WITHIN THE MONSOON TROUGH GYRE...A 1013 MB
LOW IS CENTERED NEAR 11N47W AND CONTINUES TO PRODUCE SCATTERED
MODERATE CONVECTION FROM 09N-15N BETWEEN 47W-51W.

TROPICAL WAVE EXTENDS FROM 14N76W TO 22N78W MOVING W AT 15-20
KT. LOW-LEVEL MOISTURE ASSOCIATED WITH THE WAVE HAS BROADENED
OVER A LARGER AREA THE PAST FEW DAYS AS THE WAVE HAS TRACKED
ACROSS THE EASTERN AND CENTRAL CARIBBEAN SEA. TOTAL PRECIPITABLE
WATER IMAGERY INDICATES THE SAME WHERE DEEP LAYER MOISTURE IS
NOTED BETWEEN 70W-83W. ISOLATED MODERATE CONVECTION IS FROM
17N-19N BETWEEN 75W-78W...AND FROM 11N-15N BETWEEN 80W-85W.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO
12N21W TO 16N30W TO 14N36W TO 11N41W TO 11N47W TO 08N54W. THE
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N54W TO
07N58W. SCATTERED MODERATE CONVECTION IS FROM 08N-10N BETWEEN
15W-19W...FROM 10N-15N BETWEEN 18W-23W...FROM 03N-09N BETWEEN
32W-39W...FROM 06N-11N BETWEEN 43W-47W...AND FROM 08N-11N
BETWEEN 57W-63W.

...DISCUSSION...

GULF OF MEXICO...
THE BASE OF A BROAD UPPER LEVEL TROUGH IS LOCATED ACROSS THE
CENTRAL AND EASTERN CONUS AND CONTINUES TO SUPPORT SEVERAL MID-
LEVEL SHORTWAVE TROUGHS ROTATING THROUGH AND OVER THE NORTHERN
GULF N OF 26N. AT THE SURFACE...A WEAK SURFACE TROUGH AXIS
EXTENDS FROM EASTERN SOUTH CAROLINA TO 31N86W TO 30N94W ALONG
MUCH OF THE GULF COAST GENERATING SCATTERED SHOWERS AND TSTMS
WITHIN 90 NM EITHER SIDE OF A LINE FROM NORTHERN FLORIDA NEAR
30N82W TO THE NW GULF NEAR 28N96W. A WEAKER SURFACE PRESSURE
FIELD THEN EXTENDS SOUTHWARD OVER MUCH OF THE WESTERN GULF WITH
AMPLE RETURN FLOW...MOISTURE...AND INSTABILITY FOCUSED ALONG
MAXIMUM LOW-LEVEL CONVERGENCE FROM 20N96W TO 24N98W. SATELLITE
IMAGERY INDICATES SCATTERED SHOWERS AND STRONG ISOLATED TSTMS
OCCURRING FROM 21N-24N BETWEEN 95W-98W...AND ISOLATED SHOWERS
AND TSTMS ELSEWHERE FROM 19N-27N BETWEEN 91W-98W. OTHERWISE...
THE REMAINDER OF THE GULF S OF 28N E OF 90W...INCLUDING THE
FLORIDA PENINSULA IS UNDER THE INFLUENCE OF A RIDGE AXIS ALOFT
AND AT THE SURFACE EXTENDING FROM THE SW NORTH ATLC ALONG 25N.

CARIBBEAN SEA...
AN UPPER LEVEL INVERTED TROUGH IS ACROSS THE FAR WESTERN
CARIBBEAN WITH AXIS ALONG 87W...HOWEVER WATER VAPOR IMAGERY
INDICATES THAT CONDITIONS REMAIN FAIRLY DRY ALOFT AND THIS IS
RESULTING IN MOSTLY FAIR SKIES NW OF A LINE FROM 16N85W TO
EASTERN CUBA NEAR 20N76W. A TROPICAL WAVE ALONG 78W HOWEVER IS
EXPECTED TO TRACK WESTWARD OVER THE NEXT FEW DAYS AND INCREASE
CLOUDINESS AND MOISTURE. WIDELY SCATTERED SHOWERS AND ISOLATED
TSTMS ARE OCCURRING OVER A LARGE AREA FROM 11N-19N BETWEEN
70W-85W ACROSS A LARGE PORTION OF THE CENTRAL CARIBBEAN. THIS
AREA OF CONVECTION LIES ON THE WESTERN PERIPHERY OF AN UPPER
LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE EASTERN
CARIBBEAN NEAR 14N70W. FARTHER EAST...WATER VAPOR IMAGERY
INDICATES A DRY AIRMASS ALOFT THAT CONTINUES TO ADVECT FROM THE
WESTERN TROPICAL ATLC OVER THE LESSER ANTILLES AND PORTIONS OF
THE EASTERN CARIBBEAN E OF 64W KEEPING CLEAR SKIES AND FAIR
CONDITIONS N OF 13N E OF 67W THIS AFTERNOON. A FEW ISOLATED
SHOWERS AND TSTMS ARE OCCURRING S OF 13N E OF 65W IN CLOSE
PROXIMITY TO THE ITCZ WHICH LOCATES ALONG 08N.

ATLANTIC OCEAN...
WATER VAPOR IMAGERY INDICATES A BROAD LONGWAVE UPPER LEVEL
TROUGH ACROSS THE EASTERN CONUS THAT CONTINUES TO GENERATE
WIDELY SCATTERED SHOWERS AND TSTMS ACROSS THE SW NORTH ATLC N OF
30N BETWEEN 60W-77W. SOME OF THIS ACTIVITY STRETCHES TO THE
SOUTHWEST AND IS OCCURRING WITHIN 60 NM EITHER SIDE OF A LINE
FROM 30N75W TO 26N80W NEAR THE FLORIDA PENINSULA COAST. FARTHER
EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 25N57W THAT EXTENDS A
TROUGH AXIS W-SW TO 23N66W WITHOUT ANY SIGNIFICANT IMPACTS.
OTHERWISE...BROAD SURFACE RIDGING DOMINATES THE REMAINDER OF THE
CENTRAL AND EASTERN ATLC...GUARDED BY A 1020 MB HIGH CENTERED
NEAR 26N32W...AND A 1023 MB HIGH CENTERED NEAR 27N59W. THE FAIR
WEATHER PRODUCED BY THESE SURFACE FEATURES IS FURTHER ENHANCED
ALOFT BY THE SAHARAN AIR LAYER AND ASSOCIATED DUST ACROSS MOST
OF THE DISCUSSION AREA E OF 65W AS NOTED ON GOES-R PROVING
GROUND IMAGERY. THE HIGHEST CONCENTRATION OF SAHARAN DUST IS
FOUND OVER THE FAR EASTERN ATLC N OF 16N E OF 40W.

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

$$
HUFFMAN



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