[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221045
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU AUG 22 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 10N45W TO 18N42W MOVING W AT 15 KT.
THE WAVE REMAINS EMBEDDED WITHIN THE MONSOON TROUGH AT THE
SURFACE AND WITHIN A LOWER AMPLITUDE 700 MB TROUGH BETWEEN 40W-
50W. TO THE EAST OF THIS AREA...GLOBAL MODEL GUIDANCE INDICATES
ANOTHER HIGHER AMPLITUDE IMPULSE OF 700 MB TROUGHING IS LOCATED
BETWEEN 30W-40W. AT THIS TIME ANY SIGNIFICANT CONVECTION REMAINS
CONFINED SOUTH OF THE MONSOON TROUGH AXIS.

TROPICAL WAVE EXTENDS FROM 12N81W TO 22N80W MOVING W AT 10-15
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 73W-83W. WIDELY SCATTERED MODERATE CONVECTION
IS FROM 13N-22N BETWEEN 76W-83W.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 12N17W TO 16N27W TO 10N45W TO
07N51W. ISOLATED MODERATE CONVECTION IS FROM 08N-14N BETWEEN 15W-
28W...FROM 08N-11N BETWEEN 36W-40W...AND FROM 06N-10N BETWEEN
46W-54W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL DIFFLUENT FLOW IS NOTED ON WATER VAPOR IMAGERY
OCCURRING BETWEEN AN UPPER LEVEL LOW CENTERED OVER NORTHERN
MEXICO NEAR 27N103W AND AN UPPER LEVEL ANTICYCLONE CENTERED OVER
THE EAST PACIFIC REGION NEAR 16N100W. MIDDLE TO UPPER LEVEL
DIFFLUENCE IS GENERATING ISOLATED SHOWERS OVER THE WESTERN GULF
THIS MORNING WEST OF A LINE FROM 29N95W TO 19N93W. FARTHER
EAST...AN UPPER LEVEL LOW IS CENTERED OVER WESTERN CUBA NEAR
22N82W. THIS UPPER LEVEL FEATURE ALONG WITH A MID-LEVEL
VORTICITY MAXIMUM OVER THE NE GULF NEAR 26N87W IS GENERATING
SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS N OF 23N E OF
91W...INCLUDING PORTIONS OF THE FLORIDA PENINSULA AND FLORIDA
STRAITS. MOST OF THIS CONVECTIVE ACTIVITY IS FOCUSED IMMEDIATELY
OFFSHORE OF THE FLORIDA PENINSULA FROM 23N-29N BETWEEN 81W-86W.
LOOKING AHEAD...GENERALLY E-SE WINDS ARE EXPECTED TO PREVAIL
THROUGH THE UPCOMING WEEKEND AND REMAIN 20 KT OR LESS AS A
SURFACE RIDGE CONTINUES TO BE ANCHORED OVER THE SW NORTH ATLC
WITH A RIDGE AXIS EXTENDING WESTWARD ALONG 30N.

CARIBBEAN SEA...
AN UPPER LEVEL LOW IS CENTERED OVER WESTERN CUBA NEAR 22N82W AND
ALONG WITH A TROPICAL WAVE ALONG 81W CONTINUES TO GENERATE
SCATTERED SHOWERS AND TSTMS IN THE ADJACENT OFFSHORE WATERS OF
CUBA...THE CAYMAN ISLANDS...AND JAMAICA. THIS CONVECTION
STRETCHES SOUTHWARD IN THE VICINITY OF THE TROPICAL WAVE AXIS
FROM 13N-21N BETWEEN 76W-83W. THE WAVE IS EXPECTED TO CONTINUE A
WESTWARD MOVEMENT OVER THE NEXT 24 TO 48 HOURS BRINGING
INCREASED PRECIPITATION CHANCES TO CENTRAL AMERICA AND THE NW
CARIBBEAN WATERS. TO THE SOUTH...THE MONSOON TROUGH IS ALONG
09N/10N EXTENDING FROM NORTHERN COLOMBIA WESTWARD INTO THE EAST
PACIFIC REGION. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN
120 NM EITHER SIDE OF THE AXIS...INCLUDING PORTIONS OF PANANA
AND COSTA RICA THIS MORNING. FINALLY...E-SE TRADES CONTINUE
ACROSS THE EASTERN CARIBBEAN WITH ABUNDANT LOW-LEVEL MOISTURE AS
NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS ARE OCCURRING E OF 71W AND ARE
PRIMARILY FOCUSED IN THE VICINITY OF 16N66W.

HISPANIOLA...
EARLIER OVERNIGHT CONVECTION HAS DIMINISHED WITH ONLY A FEW
ISOLATED SHOWERS POSSIBLE THIS MORNING. NORTH-NORTHWESTERLY FLOW
ALOFT REMAINS OVER THE ISLAND BETWEEN AN UPPER LEVEL TROUGH TO
THE NE OVER THE ATLC...AND UPPER LEVEL RIDGING TO THE WEST.
PARTIAL DRYING ALOFT IS EXPECTED OVER THE NEXT 12 TO 24 HOURS...
HOWEVER LOW-LEVEL MOISTURE WILL CONTINUE TO ADVECT WESTWARD
WITHIN THE E-SE TRADES ACROSS THE EASTERN AND CENTRAL CARIBBEAN.
THE LOW-LEVEL MOISTURE 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 LOW IS CENTERED OVER WESTERN CUBA NEAR 22N82W
THAT CONTINUES TO PRODUCE ENHANCEMENT FOR WIDELY SCATTERED
SHOWERS AND ISOLATED TSTMS OCCURRING W OF 75W ACROSS PORTIONS OF
THE SW NORTH ATLC. THIS ACTIVITY REMAINS ON THE SOUTHWESTERN
PERIPHERY OF A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH CENTERED
OFF THE CAROLINA COAST NEAR 32N74W. THE SURFACE HIGH IS LARGELY
SUPPORTED BY A MIDDLE TO UPPER LEVEL ANTICYCLONE CENTERED NEAR
29N71W. FARTHER EAST...AN UPPER LEVEL TROUGH AXIS EXTENDS FROM
32N53W SW TO A BASE NEAR 17N67W. MOISTURE ASSOCIATED WITH A
STATIONARY FRONT ANALYZED FROM 32N55W TO 29N60W TO 29N65W
CONTINUES TO PRODUCE WIDELY SCATTERED SHOWERS WITHIN 90 NM
EITHER SIDE OF THE BOUNDARY. OTHERWISE...THE REMAINDER OF THE
CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE
RIDGE ANCHORED BY A 1022 MB HIGH CENTERED SOUTH OF THE AZORES
NEAR 34N27W. THE RIDGE AXIS EXTENDS SOUTHWEST FROM THE HIGH TO
NEAR 29N48W.

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

$$
HUFFMAN


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