[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201803
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE AUG 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 23N25W 16N28W...TO A
1012 MB LOW PRESSURE CENTER THAT IS NEAR 13N29W...TO 8N31W...
MOVING WESTWARD 10 TO 15 KNOTS. THE CYCLONIC CIRCULATION THAT IS
AROUND THE WAVE COVERS THE ATLANTIC OCEAN FROM 8N TO 22N BETWEEN
AFRICA AND 32W. THE MONSOON TROUGH IS BROKEN UP BY THE CYCLONIC
WIND FLOW THAT IS MOVING AROUND THE TROPICAL WAVE. CONVECTIVE
PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG FROM 13N
TO 18N TO THE EAST OF 24W...AND FROM 12N TO 13N BETWEEN 26W AND
27W.

AN ATLANTIC OCEAN-TO-CARIBBEAN SEA TROPICAL WAVE IS ALONG
71W/72W TO THE SOUTH OF 24N...MOVING WESTWARD 10 TO 15 KNOTS.
THE WAVE PASSES OVER THE BORDER OF HAITI AND THE DOMINICAN
REPUBLIC. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO
ISOLATED STRONG FROM 20N TO 25N BETWEEN 69W AND 73W IN THE
ATLANTIC OCEAN. WIDELY SCATTERED MODERATE TO ISOLATED STRONG
FROM 15N TO 16N BETWEEN 70W AND 73W IN THE CARIBBEAN SEA.
ISOLATED MODERATE IS IN THE WINDWARD PASSAGE.

A GULF OF MEXICO TROPICAL WAVE IS ALONG 26N88W...TO 21N89W AT
THE COAST OF THE YUCATAN PENINSULA...TO THE BORDER OF MEXICO
WITH NORTHERN GUATEMALA. THE FORWARD SPEED OF THE WAVE HAS
SLOWED DOWN TO 10 KNOTS OR LESS DURING THE LAST 24 HOURS OR SO.
CONVECTIVE PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED
STRONG FROM 22N TO 24N BETWEEN 87W AND 93W.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH IS BROKEN UP BY THE CYCLONIC WIND FLOW THAT
IS MOVING AROUND THE 23N25W 16N28W 13N29W 8N31W TROPICAL WAVE.
THE MONSOON TROUGH EXTENDS FROM THE 1012 MB LOW PRESSURE CENTER
THAT IS NEAR 13N29W...TO 10N32W 8N40W. THE ITCZ CONTINUES FROM
8N40W TO 7N49W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE TO
LOCALLY STRONG FROM 5N TO 9N BETWEEN 30W AND 37W.

...DISCUSSION...

THE GULF OF MEXICO...

MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS MEXICO AND
TEXAS FROM 18N TO 31N BETWEEN 95W AND 108W. THE CYCLONIC
CIRCULATION CENTER IS IN MEXICO NEAR 24N102W...SURROUNDED BY
COMPARATIVELY DRIER AIR IN SUBSIDENCE IN WATER VAPOR IMAGERY.
CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO SCATTERED
MODERATE TO ISOLATED STRONG IN THE COASTAL WATERS AND COASTAL
PLAINS TO THE WEST OF 19N94W 23N95W 30N94W.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 26N82W IN THE COASTAL SECTIONS OF SOUTHWESTERN FLORIDA.
CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG
WITHIN A 30 NM RADIUS OF 25N82W. ISOLATED MODERATE WITHIN A 30
NM RADIUS OF 24N85W.

A SURFACE TROUGH EXTENDS FROM THE WESTERN PART OF THE FLORIDA
PANHANDLE TO 28N89W. CONVECTIVE PRECIPITATION...SCATTERED
MODERATE TO ISOLATED STRONG IN THE WATERS AND COASTAL PLAINS
TO THE NORTH OF 27N BETWEEN 85W AND 90W.

MULTILAYERED CLOUD CEILINGS AND RAINFALL COVER THE COASTAL
PLAINS OF THE U.S.A. FROM TEXAS INTO SOUTHWESTERN LOUISIANA...
AND FROM SOUTHEASTERN MISSISSIPPI INTO FLORIDA TO THE WEST OF
85W.

THE CARIBBEAN SEA...

AN ATLANTIC OCEAN-TO-CARIBBEAN SEA TROPICAL WAVE IS ALONG
71W/72W TO THE SOUTH OF 24N...MOVING WESTWARD 10 TO 15 KNOTS.
THE WAVE PASSES OVER THE BORDER OF HAITI AND THE DOMINICAN
REPUBLIC. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO
ISOLATED STRONG FROM 20N TO 25N BETWEEN 69W AND 73W IN THE
ATLANTIC OCEAN. WIDELY SCATTERED MODERATE TO ISOLATED STRONG
FROM 15N TO 16N BETWEEN 70W AND 73W IN THE CARIBBEAN SEA.
ISOLATED MODERATE IS IN THE WINDWARD PASSAGE.

A SURFACE TROUGH EXTENDS FROM THE WESTERN COASTAL WATERS OF
PUERTO RICO TO CURACAO. CONVECTIVE PRECIPITATION...NUMEROUS
STRONG FROM 15N TO 18N BETWEEN 65W AND 70W. ISOLATED MODERATE
FROM 18N TO 21N BETWEEN 61W AND 71W TO THE NORTH OF THE GREATER
ANTILLES.

OTHER CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO SCATTERED
MODERATE FROM 12N TO 15N BETWEEN 75W AND 80W. THE 24-HOUR
RAINFALL TOTALS IN INCHES AS OF 20/1200 UTC...ACCORDING TO THE
PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLE...
MIATPTPAN...ARE 0.34 IN ST. THOMAS.

MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS THE
CARIBBEAN SEA AND CENTRAL AMERICA FROM 14N TO THE FLORIDA
STRAITS BETWEEN 80W AND 92W IN SOUTHEASTERN MEXICO. A CYCLONIC
CIRCULATION CENTER IS NEAR 19N85W. CONVECTIVE PRECIPITATION...
SCATTERED MODERATE TO ISOLATED STRONG FROM BELIZE INTO THE
SOUTHEASTERN AND EASTERN SECTIONS OF THE YUCATAN PENINSULA.
RAINSHOWERS ARE POSSIBLE IN THE CARIBBEAN SEA TO THE NORTH OF
15N TO THE WEST OF 80W.

MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS
THE CARIBBEAN SEA TO THE EAST OF THE CYCLONIC WIND FLOW...
ALONG A 13N EAST-TO-WEST ORIENTED RIDGE.

THE MONSOON TROUGH IS ALONG 8N/9N BETWEEN 73W IN COLOMBIA...
BEYOND 84W IN COSTA RICA...INTO THE EASTERN PACIFIC OCEAN.
CONVECTIVE PRECIPITATION...NUMEROUS STRONG WITHIN 30 NM ON
EITHER SIDE OF 10N BETWEEN 79W AND 81W. SCATTERED MODERATE TO
ISOLATED STRONG ELSEWHERE TO THE SOUTH OF 12N TO THE WEST OF
75W.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...AND THE
OFFSHORE FORECAST...MIAOFFNT3...FOR MORE DETAILS ABOUT THE 12-
HOUR FORECAST OF EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS LOWER
THAN 8 FEET TO THE NORTH OF 16N BETWEEN 70W AND 74W. EXPECT ALSO
NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS LOWER
THAN 8 FEET TO THE SOUTH OF 14N BETWEEN 67W AND 71W.

HISPANIOLA...

AN ATLANTIC OCEAN-TO-CARIBBEAN SEA TROPICAL WAVE IS ALONG
71W/72W TO THE SOUTH OF 24N...MOVING WESTWARD 10 TO 15 KNOTS.
THE WAVE PASSES OVER THE BORDER OF HAITI AND THE DOMINICAN
REPUBLIC. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO
ISOLATED STRONG FROM 20N TO 25N BETWEEN 69W AND 73W IN THE
ATLANTIC OCEAN. WIDELY SCATTERED MODERATE TO ISOLATED STRONG
FROM 15N TO 16N BETWEEN 70W AND 73W IN THE CARIBBEAN SEA.
ISOLATED MODERATE IS IN THE WINDWARD PASSAGE.

A SURFACE TROUGH EXTENDS FROM THE WESTERN COASTAL WATERS OF
PUERTO RICO TO CURACAO. CONVECTIVE PRECIPITATION...NUMEROUS
STRONG FROM 15N TO 18N BETWEEN 65W AND 70W. ISOLATED MODERATE
FROM 18N TO 21N BETWEEN 61W AND 71W TO THE NORTH OF THE GREATER
ANTILLES.

THE 700 MB GFS FORECAST SHOWS THAT BROAD CYCLONIC WIND FLOW WILL
COVER THE AREA...DUE TO THREE DIFFERENT WEAK INVERTED TROUGHS
THAT WILL MOVE ACROSS THE AREA DURING THE NEXT 48 HOURS. THE 500
MB GFS MODEL SHOWS THAT HISPANIOLA WILL BE IN AN AREA OF
PREDOMINANTLY CYCLONIC WIND FLOW BECAUSE OF ONE INVERTED TROUGH
FOR MUCH OF THE TIME PERIOD...FOLLOWED BY A SECOND ONE AT THE
END OF THE 48-HOUR TIME PERIOD. THE 250 MB GFS FORECAST SHOWS
THAT ANTICYCLONIC WIND FLOW WILL COVER THE AREA WITH AN EAST-TO-
WEST ORIENTED RIDGE FOR ABOUT THE FIRST 30 HOURS. CYCLONIC WIND
WITH AN EAST-TO-WEST ORIENTED TROUGH WILL COVER THE AREA FOR THE
REST OF THE TIME PERIOD.

THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 26N55W. CYCLONIC WIND FLOW IS WITHIN 120 NM TO 180 NM ON
EITHER SIDE OF THE LINE THAT RUNS FROM 33N47W...TO THE
CENTER...TO 23N60W TO 22N68W. A SHEAR AXIS/TROUGH CONTINUES FROM
22N68W TO 26N77W...TO A CYCLONIC CIRCULATION CENTER THAT IS NEAR
26N82W IN THE COASTAL SECTIONS OF SOUTHWESTERN FLORIDA.
CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE TO THE NORTH
OF 21N BETWEEN 45W AND 60W...AND ELSEWHERE TO THE NORTH OF 25N
TO THE WEST OF 60W.

A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 32N12W
CYCLONIC CIRCULATION CENTER TO THE CANARY ISLANDS...TO A 23N17W
CYCLONIC CIRCULATION CENTER TO 20N20W. RAINSHOWERS ARE POSSIBLE
TO THE NORTH OF 21N TO THE EAST OF 31W.

A 1012 MB LOW PRESSURE CENTER IS NEAR 13N56W. IT HAS BEEN MOVING
WESTWARD 10 TO 15 KNOTS. CONVECTIVE PRECIPITATION...ISOLATED TO
WIDELY SCATTERED MODERATE AND ISOLATED STRONG FROM 12N TO 16N
BETWEEN 54W AND 60W.

A SURFACE TROUGH IS ALONG 47W/48W FROM 15N TO 21N. THE TROUGH IS
THE REMNANT OF ERIN. NO SIGNIFICANT DEEP CONVECTIVE
PRECIPITATION ACCOMPANIES THE TROUGH.

A SURFACE RIDGE EXTENDS FROM A 1022 MB HIGH PRESSURE CENTER THAT
IS NEAR 34N34W...TO 29N46W 29N60W...TO A 1021 MB HIGH PRESSURE
CENTER THAT IS NEAR 33N71W. SURFACE ANTICYCLONIC WIND FLOW
COVERS THE ATLANTIC OCEAN TO THE NORTH OF 25N TO THE EAST OF 80W.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2...FOR MORE
DETAILS ABOUT THE 12-HOUR FORECAST OF EAST WINDS 20 TO 25 KNOTS
AND SEA HEIGHTS LOWER THAN 8 FEET TO THE SOUTH OF 22N BETWEEN
70W AND 74W INCLUDING THE APPROACH TO THE WINDWARD PASSAGE.

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

$$
MT


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