Tropical Weather Discussion
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000
AXNT20 KNHC 021111
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT THU JUL 02 2015

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.

...SPECIAL FEATURES...

GALE-FORCE WINDS ARE FORECAST AT 24 HOURS...BASED ON THE
FORECAST FOR 02/0600 UTC...IN THE COASTAL WATERS OF COLOMBIA...
FROM 11.5N TO 14.5N BETWEEN 72W AND 77W. THE SEA HEIGHTS ARE
FORECAST TO RANGE FROM 11 FEET TO 17 FEET. PLEASE READ THE HIGH
SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE
FORECAST...MIAOFFNT3/FZNT23 KNHC...FOR MORE DETAILS.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 32W/33W FROM 13N
SOUTHWARD...MOVING WESTWARD 10 TO 15 KNOTS. CONVECTIVE
PRECIPITATION...ISOLATED MODERATE TO LOCALLY STRONG WITHIN 60 NM
TO 90 NM ON EITHER SIDE OF 6N28W 8N36W 10N43W...IN THE ITCZ. THE
WAVE IS APPARENT IN A LONG-TERM OF SATELLITE IMAGERY.

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 47W/48W FROM 11N
SOUTHWARD...MOVING WESTWARD 10 TO 15 KNOTS. NO SIGNIFICANT DEEP
CONVECTIVE PRECIPITATION IS APPARENT.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 77W/78W FROM 19N
SOUTHWARD...PASSING ACROSS JAMAICA...MOVING WESTWARD 20 KNOTS.
UPPER LEVEL SOUTHWESTERLY WIND FLOW IS MOVING ACROSS THE AREA OF
THE WAVE FROM 15N SOUTHWARD. MIDDLE LEVEL TO UPPER LEVEL
EASTERLY WIND FLOW IS MOVING ACROSS THE AREA OF THE WAVE FROM
13N TO 16N. 600 MB TO 800 MB LEVEL EASTERLY WIND FLOW COVERS THE
AREA THAT IS FROM 17N SOUTHWARD BETWEEN 78W AND CENTRAL AMERICA.
THE WAVE IS MOVING TOWARD THE AREA OF AN ALREADY-EXISTING UPPER
LEVEL TROUGH WHOSE CYCLONIC WIND FLOW COVERS THE NORTHWESTERN
CORNER OF THE CARIBBEAN SEA. CONVECTIVE PRECIPITATION...ISOLATED
MODERATE TO LOCALLY STRONG IN THE WATERS THAT ARE BETWEEN HAITI
AND JAMAICA.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 86W/87W FROM 18N
SOUTHWARD...MOVING WESTWARD 20 KNOTS. THE WAVE IS CUTTING
THROUGH HONDURAS AND NICARAGUA...INTO THE EASTERN PACIFIC OCEAN.
NO SIGNIFICANT DEEP CONVECTIVE PRECIPITATION IS APPARENT.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH COASTAL SECTIONS OF GUINEA-
BISSAU NEAR 12N16W TO 9N20W. THE ITCZ CONTINUES FROM 9N20W TO
8N25W 8N34W AND 8N44W. CONVECTIVE PRECIPITATION...WIDELY
SCATTERED TO SCATTERED MODERATE AND ISOLATED STRONG FROM 6N TO
11N BETWEEN AFRICA AND 20W. ISOLATED MODERATE TO LOCALLY STRONG
WITHIN 60 NM TO 90 NM ON EITHER SIDE OF 6N28W 8N36W 10N43W.

...DISCUSSION...

FROM THE GULF OF MEXICO INTO THE NORTHWESTERN CORNER OF THE
CARIBBEAN SEA...

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN
MEXICO NEAR 21N103W. UPPER LEVEL ANTICYCLONIC WIND FLOW CURVES
AWAY FROM MEXICO INTO THE WESTERN SECTIONS OF THE GULF OF
MEXICO. THAT NORTHWESTERLY WIND FLOW CROSSES THE SOUTHWESTERN
CORNER OF THE GULF OF MEXICO AND THE YUCATAN PENINSULA...INTO
THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA...TOWARD AN EASTERN
AND SOUTHEASTERN GULF OF MEXICO TROUGH. THE TROUGH STARTS IN THE
GULF OF MEXICO...AND THEN IT CROSSES NORTHWESTERN CUBA...AND IT
REACHES ITS BASE NEAR 13N81W IN THE SOUTHWESTERN CORNER OF THE
CARIBBEAN SEA. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM
28N NORTHWARD BETWEEN 86W AND 90W.

A DIURNAL SURFACE TROUGH IS ALONG 92W/93W FROM 18N IN THE
NORTHERN PART OF THE ISTHMUS OF TEHUANTEPEC TO 23N. CONVECTIVE
PRECIPITATION...ISOLATED MODERATE IN THE COASTAL WATERS OF
MEXICO FROM 23N SOUTHWARD BETWEEN 94W AND 98W.

A SURFACE RIDGE PASSES ACROSS THE NORTHWESTERN BAHAMAS...ACROSS
LAKE OKEECHOBEE IN FLORIDA...TO THE TEXAS COAST NEAR 28N.
SURFACE ANTICYCLONIC WIND FLOW COVERS THE GULF OF MEXICO
EVERYWHERE...EXCEPT NEAR THE DIURNAL SURFACE TROUGH.

THE REST OF THE CARIBBEAN SEA...

A SURFACE TROUGH STRETCHES ACROSS THE NORTHWESTERN PART OF CUBA.
THIS TROUGH IS PART OF THE ENERGY THAT WAS ASSOCIATED WITH THE
CURRENT 86W/87W TROPICAL WAVE AS THE WAVE HAS CONTINUED TO MOVE
WESTWARD. MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW FROM A
TROUGH ALSO SPANS CUBA. CONVECTIVE PRECIPITATION...ISOLATED
MODERATE FROM 10N NORTHWARD BETWEEN 80W AND 88W.

BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW SPANS THE
CARIBBEAN SEA...EXCEPT FOR THE RIDGE AND ANTICYCLONIC WIND FLOW
THAT ARE IN THE SOUTHEASTERN CORNER OF THE AREA/ALSO IN THE
ATLANTIC OCEAN...FROM 10N TO 20N BETWEEN 54W AND 80W

TWO TROPICAL WAVES ARE MOVING THROUGH THE AREA. PLEASE REFER TO
THE TROPICAL WAVES SECTION FOR DETAILS.

...HISPANIOLA...

MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW SURROUNDS
HISPANIOLA...THANKS TO THE ATLANTIC OCEAN-TO-HISPANIOLA TROUGH
THAT PASSES THROUGH A 24N70W CYCLONIC CIRCULATION CENTER. THE
600 MB TO 800 MB WIND FLOW IS FROM THE SOUTHEAST ACROSS
HISPANIOLA. RAINSHOWERS ARE BETWEEN HAITI AND JAMAICA AND
CUBA...AND BETWEEN THE BAHAMAS AND CUBA. EARLIER PRECIPITATION
THAT WAS OCCURRING IN HISPANIOLA APPEARS TO HAVE WEAKENED AND
DISSIPATED FOR THE MOMENT.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT SOUTHWESTERLY WIND
FLOW WILL MOVE ACROSS HISPANIOLA FOR THE NEXT 48 HOURS. THIS
FORECAST IS BASED ON THE IDEA THAT THE CURRENT TROUGH WILL
REMAIN TO THE WEST AND NORTHWEST JUST ENOUGH IN ORDER TO PUSH
THE SOUTHWESTERLY WIND FLOW ACROSS THE AREA. THE GFS MODEL
FORECAST FOR 500 MB SHOWS THAT MORE THAN ONE INVERTED TROUGH
WILL MOVE ACROSS HISPANIOLA DURING THE NEXT 48 HOUR PERIOD.
THE GFS MODEL FORECAST FOR 700 MB SHOWS THAT SOUTHEASTERLY-TO-
EASTERLY WIND FLOW WILL CROSS HISPANIOLA FOR THE NEXT 48 HOURS...
WITH AN ATLANTIC OCEAN-TO-GREATER ANTILLES NORTHEAST-TO-SOUTHWEST
ORIENTED RIDGE.

THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N67W...TO
A 24N70W CYCLONIC CIRCULATION CENTER...ACROSS HISPANIOLA...TO
15N75W IN THE CARIBBEAN SEA. CYCLONIC WIND FLOW COVERS THE
CARIBBEAN SEA AND THE ATLANTIC OCEAN FROM 15N NORTHWARD BETWEEN
60W AND 77W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE
RAINSHOWERS ARE IN THE AREAS OF THE CYCLONIC WIND FLOW.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 26N42W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE IS
FROM 25N TO 29N BETWEEN 45W AND 53W. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE ELSEWHERE FROM
24N TO 31N BETWEEN 30W AND 60W. THE CLOUDS AND PRECIPITATION ARE
IN THE AREA OF A FRONTAL BOUNDARY THAT WEAKENED AND DISSIPATED
DURING THE LAST 24 HOURS OR SO.

A SURFACE RIDGE EXTENDS FROM A 1023 MB HIGH PRESSURE CENTER THAT
IS NEAR 33N20W...TO 31N28W...TO A 1027 MB HIGH PRESSURE CENTER
THAT IS NEAR 33N49W...THROUGH 30N66W...TO 30N66W...ACROSS THE
NORTHWESTERN BAHAMAS TO LAKE OKEECHOBEE IN FLORIDA.

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

$$
MT



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