[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 230547
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI AUG 23 2013

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 EXTENDS FROM 06N51W TO 16N50W MOVING W AT 15 KT.
THE WAVE REMAINS LOW-AMPLITUDE AND EMBEDDED WITHIN THE MONSOON
TROUGH. CONVECTION REMAINS LIMITED WITH ONLY A FEW ISOLATED
SHOWERS OCCURRING FROM 06N-13N BETWEEN 48W-53W.

TROPICAL WAVE EXTENDS FROM 11N82W TO 22N84W MOVING W AT 5-10 KT.
THE WAVE REMAINS WITHIN BROAD LOW-LEVEL...SURFACE TO 700
MB...TROUGHING LOCATED ACROSS THE WESTERN CARIBBEAN SEA WITH
TOTAL PRECIPITABLE WATER IMAGERY INDICATING MAXIMUM VALUES
GENERALLY BETWEEN 78W-86W. SCATTERED MODERATE AND ISOLATED
STRONG CONVECTION IS FROM 10N-24N BETWEEN 78W-85W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 15N17W TO
10N51W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM
10N51W TO 08N59W. SCATTERED MODERATE CONVECTION IS FROM 12N-17N
BETWEEN 15W-19W...AND FROM 09N-12N BETWEEN 19W-24W. A SURFACE
TROUGH IS ANALYZED NORTH OF THE MONSOON TROUGH AXIS FROM 15N35W
TO 19N36W AND IS LIKELY ANOTHER IMPULSE OF ENERGY OR TROPICAL
WAVE THAT MOVED OFF OF AFRICA EARLIER IN THE WEEK. LOW-LEVEL
CYCLONIC MOTION IS NOTED IN THE CLOUD FIELD SURROUNDING THE
SURFACE TROUGH WITH ISOLATED MODERATE CONVECTION OCCURRING IN
THE VICINITY OF 17N35W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL DIFFLUENT FLOW IS NOTED ON WATER VAPOR IMAGERY
OCCURRING OVER THE WESTERN GULF BETWEEN AN UPPER LEVEL LOW
CENTERED OVER NORTHERN MEXICO NEAR 28N105W AND AN UPPER LEVEL
RIDGE EXTENDING FROM OVER CENTRAL MEXICO TO THE WESTERN GULF
NEAR 25N95W. MIDDLE TO UPPER LEVEL DIFFLUENCE IS GENERATING
ISOLATED SHOWERS AND TSTMS OVER THE WESTERN GULF THIS EVENING
WEST OF 95W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED OVER
THE YUCATAN CHANNEL NEAR 22N86W. THIS UPPER LEVEL FEATURE ALONG
WITH A MID-LEVEL VORTICITY MAXIMUM OVER THE NE GULF NEAR 27N87W
IS GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS N OF
23N BETWEEN 82W-88W. MOST OF THIS CONVECTIVE ACTIVITY IS FOCUSED
IMMEDIATELY OFFSHORE OF THE FLORIDA PENINSULA FROM 25N-29N
BETWEEN 82W-85W...AND IN THE VICINITY OF A SURFACE TROUGH
ANALYZED FROM 27N-30N ALONG 87W. LOOKING AHEAD...GENERALLY E-SE
WINDS ARE EXPECTED TO PREVAIL THROUGH THE UPCOMING WEEKEND AS A
SURFACE RIDGE CONTINUES TO BE ANCHORED OVER THE SE CONUS AND SW
NORTH ATLC.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED OVER THE YUCATAN CHANNEL NEAR
22N86W AND ALONG WITH A TROPICAL WAVE ALONG 83W CONTINUES TO
GENERATE SCATTERED SHOWERS AND TSTMS ACROSS THE WESTERN
CARIBBEAN BETWEEN 76W-87W. THE STRONGEST CONVECTION AT THIS TIME
IS LOCATED OFFSHORE OF NICARAGUA AND EASTERN HONDURAS IN THE
VICINITY OF 14N82W. THE WAVE IS EXPECTED TO CONTINUE A SLOW
WESTWARD MOVEMENT OVER THE NEXT 24 TO 48 HOURS BRINGING
INCREASED PRECIPITATION CHANCES TO CENTRAL AMERICA AND THE NW
CARIBBEAN WATERS OVER THE WEEKEND. TO THE SOUTH...THE MONSOON
TROUGH IS ALONG 10N/11N EXTENDING FROM NORTHERN COLOMBIA
WESTWARD INTO THE EAST PACIFIC REGION. ISOLATED SHOWERS AND
TSTMS ARE OCCURRING WITHIN 150 NM EITHER SIDE OF THE
AXIS...INCLUDING PORTIONS OF PANANA...COSTA RICA...AND NICARAGUA
THIS EVENING. FINALLY...E-SE TRADES CONTINUE ACROSS THE EASTERN
CARIBBEAN WITH AN UPPER LEVEL LOW CENTERED OVER PUERTO RICO NEAR
18N67W. ISOLATED SHOWERS ARE OCCURRING FROM 14N-20N BETWEEN 61W-
70W.

HISPANIOLA...
EARLIER EVENING CONVECTION HAS DIMINISHED WITH ONLY A FEW
ISOLATED SHOWERS POSSIBLE THROUGH THE OVERNIGHT HOURS. AN UPPER
LEVEL LOW IS CENTERED OVER PUERTO RICO NEAR 18N67W AND
HISPANIOLA LIES ON THE WESTERN AND RELATIVELY DRIER SIDE OF THIS
UPPER LEVEL FEATURE AS NOTED ON WATER VAPOR IMAGERY. THE UPPER
LEVEL LOW IS EXPECTED TO DRIFT WESTWARD OVER THE NEXT 24 TO 48
HOURS AND PROVIDE A MORE FAVORABLE ATMOSPHERE FOR AFTERNOON AND
EVENING CONVECTION. THESE ADDED MIDDLE TO UPPER LEVEL DYNAMICS
ALONG WITH PEAK DAYTIME HEATING AND INSTABILITY WILL INITIATE
AFTERNOON SHOWERS AND TSTMS. ANY ACTIVITY THAT FORMS WILL LIKELY
LAST INTO THE EVENING HOURS AND DIMINISH THEREAFTER.

ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE AXIS EXTENDS OVER THE FLORIDA PENINSULA
EASTWARD TO 24N70W PROVIDING MUCH OF THE SW NORTH ATLC WITH
NORTHWESTERLY FLOW ALOFT. WITH AN MID-LEVEL SHORTWAVE TROUGH
PROGRESSING OFF THE MID-ATLC COAST...MOISTURE AND CLOUDINESS IS
NOTED N OF 28N W OF 70W. WITHIN THE AREA...ISOLATED SHOWERS ARE
POSSIBLE...HOWEVER A SURFACE RIDGE REMAINS THE DOMINATE SURFACE
FEATURE ANCHORED BY A 1019 MB HIGH CENTERED NEAR 31N75W. FARTHER
EAST...A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM 32N54W
SW TO 26N63W. THIS TROUGHING SUPPORTS A WEAK COLD FRONT ANALYZED
FROM 32N55W TO 28N60W. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED
FROM 31N52W TO 26N62W WITH ISOLATED SHOWERS OCCURRING WITHIN 240
NM SOUTHEAST OF THE COLD FRONT. OTHERWISE...THE REMAINDER OF THE
CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE
RIDGE ANCHORED BY A 1025 MB HIGH CENTERED S-SW OF THE AZORES
NEAR 34N31W.

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

$$
HUFFMAN

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