[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 151804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT WED JUN 15 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
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...

EAST ATLANTIC TROPICAL WAVE REPOSITIONED ALONG 20W AT 15/0600 UTC
STAYS NEAR 20W/21W AT 15/1200 UTC BASED ON VISIBLE SATELLITE
IMAGERY. IT IS SOUTH OF 17N MOVING WEST ABOUT 10 KT. THE WAVE IS
CHARACTERIZED BY WELL-DEFINED MID-LEVEL VORTICITY RESULTING FROM
HORIZONTAL SHEAR ACROSS A STRONG AFRICAN EASTERLY JET WHICH LIES
ROUGHLY ALONG 10N. THE WAVE IS POSITIONED FOLLOWING THE CYCLONIC
ROTATION IN THE CLOUDS AROUND THE AXIS AS SEEN ON VISIBLE
IMAGERY. POSSIBLE SHOWERS FROM 10N TO 13N BETWEEN 20W AND 24W.
ITCZ PRECIPITATION FROM 5N TO 10N BETWEEN 20W AND 30W. THE GFS
LATCHES ON TO THIS FEATURE... EVENTUALLY AMPLIFYING THE WAVE AS
IT APPROACHES THE CAPE VERDE ISLANDS LATER TODAY.

CENTRAL ATLANTIC TROPICAL WAVE ALONG 44W/45W SOUTH OF 15N MOVING
WEST 10 TO 15 KT. FAINT CYCLONIC TURNING IN THE VISIBLE IMAGERY.
NO ASSOCIATED DEEP SHOWERS AND THUNDERSTORMS.

EASTERN CARIBBEAN SEA TROPICAL WAVE ALONG 19N63W 14N64W 8N65W
MOVING WEST 10 TO 15 KT. ANY CYCLONIC TURNING IN THE LOW CLOUDS
IN VISIBLE IMAGERY IS NOT EASY TO FIND. ISOLATED MODERATE SHOWERS
FROM 9N TO 14N BETWEEN 56W AND 64W...SOME ARE NEAR THE ITCZ.

CENTRAL CARIBBEAN SEA TROPICAL WAVE ALONG 77W SOUTH OF JAMAICA
AT 17N MOVING WEST 10 KT. THE WAVE IS MOVING INTO AN AREA WHICH
HAS HAD THE PRESENCE OF EITHER A SURFACE LOW PRESSURE CENTER AND
TROUGHS AND/OR MIDDLE TO UPPER LEVEL TROUGHS FOR AT LEAST THE
LAST FEW DAYS. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS WERE
PRESENT YESTERDAY WERE WITHIN 250 NM SOUTH OF HAITI AND IN
EASTERN JAMAICA. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS
CONTINUE TODAY WITHIN ABOUT 150 NM SOUTH OF THE SOUTHWESTERN
PENINSULA OF HAITI BETWEEN 71W AND 74W. IT IS EASILY POSSIBLE
THAT FLOODING AND MUDSLIDES IN HAITI MAY ACCOMPANY AND FOLLOW
THE HEAVY RAINS WHICH MAY CONTINUE FOR THE REST OF TODAY AND
TONIGHT. STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN ABOUT
180 NM SOUTH OF THE WESTERN TIP OF JAMAICA BETWEEN 77W AND 79W.
STRONG SHOWERS AND THUNDERSTORMS ALSO ARE AT THE COAST OF
EASTERN CUBA FROM 19N TO 20N BETWEEN 75W AND 76W.

SOUTHWESTERN GULF OF MEXICO TROPICAL WAVE ALONG 96W/97W SOUTH
OF 25N MOVING WEST 10 KT. THE WAVE IS EMBEDDED WITHIN STRONG
CYCLONIC SURFACE WIND FLOW FEEDING FROM THE NORTHERN COAST OF
THE YUCATAN PENINSULA TO THE ISTHMUS OF TEHUANTEPEC. BROKEN TO
OVERCAST MULTILAYERED CLOUDS AND SCATTERED MODERATE TO ISOLATED
STRONG SHOWERS AND THUNDERSTORMS FROM THE SHORE TO 24N BETWEEN
92W AND 99W. STRONG SHOWERS AND THUNDERSTORMS ALONG THE WESTERN
FRINGES OF THE GULF OF TEHUANTEPEC IN SOME CELLS FROM 14N TO 16N
BETWEEN 95W AND 96W.

...ITCZ...

ITCZ 12N15W 9N20W...8N22W 7N33W 8N43W...8N46W 9N50W 12N56W
14N60W. SCATTERED STRONG SHOWERS AND THUNDERSTORMS FROM 7N
TO 9N BETWEEN 15W AND 17W. WIDELY SCATTERED MODERATE TO
ISOLATED STRONG SHOWERS AND THUNDERSTORMS FROM 3N TO 10N
BETWEEN 20W AND 42W. SHOWERS POSSIBLE IN BROKEN LOW TO
MIDDLE LEVEL CLOUDS WITHIN 90 TO 150 NM ON EITHER SIDE
OF 5N42W 7N50W 11N57W.

...DISCUSSION...

THE GULF OF MEXICO...
A FAIRLY BENIGN WEATHER PATTERN IS ESTABLISHED OVER THE GULF OF
MEXICO WITH A SFC RIDGE EXTENDING FROM JUST EAST OF FLORIDA AND
NORTH OF THE NORTHERN BAHAMAS TO THE TX COAST. A TROPICAL WAVE
IS MOVING THROUGH THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO.
SHOWERS AND THUNDERSTORMS ARE IN THIS CORNER OF THE AREA. THE
UPPER LEVELS ARE DOMINATED BY A LARGE CUT-OFF LOW IS JUST SOUTH
OF CUBA NEAR 21N81W...DRAGGING DRY AIR OVER THE EASTERN GULF AND
FLORIDA FROM THE NORTH. ANOTHER STRIP OF DRY AIR IS FLOWING FROM
NORTHEASTERN MEXICO TO THE NW GULF AND N GULF COAST AHEAD OF AN
AMPLIFYING TROF OVER THE SRN PLAINS. THE TROF WILL MOVE E AND
CONTINUE STRENGTHENING OVER THE NEXT 5 DAYS AS A CUT-OFF LOW
DEVELOPS OVER THE SRN APPALACHIANS...AND THIS WILL BEGIN TO DRAW
TROPICAL MOISTURE NWD OVER THE E GULF AND FLORIDA BY THE WEEKEND
EFFECTIVELY INCREASING THE CHANCE FOR TSTMS. UPPER LEVEL
ANTICYCLONIC WIND FLOW COVERS THE SOUTHWESTERN CORNER OF THE
AREA FROM THE SOUTHERN PART OF MEXICO TO PANAMA.

THE CARIBBEAN SEA...
A DISORGANIZED 1010 MB SURFACE LOW PRESSURE CENTER IS NEAR
19N81W...ONE TROUGH RUNS FROM THE LOW CENTER TO THE EASTERN END
OF HAITI NEAR 20N76W...AND ANOTHER TROUGH GOES FROM THE LOW
CENTER TO 17N84W. A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION
CENTER IS NEAR 21N81W ABOUT 110 NM SOUTH OF CUBA. THE MID/UPPER
LOW OVER W CUBA...AND THE RESULTANT WESTERLY SHEAR ARE KEEPING
ALL ASSOCIATED PRECIPITATION FROM CUBA TO HAITI AND JAMAICA
AND ADJACENT WATERS. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS
WERE PRESENT YESTERDAY WERE WITHIN 250 NM SOUTH OF HAITI AND
IN EASTERN JAMAICA. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS
CONTINUE TODAY WITHIN ABOUT 150 NM SOUTH OF THE SOUTHWESTERN
PENINSULA OF HAITI BETWEEN 71W AND 74W. IT IS EASILY POSSIBLE
THAT FLOODING AND MUDSLIDES IN HAITI MAY ACCOMPANY AND FOLLOW
THE HEAVY RAINS WHICH MAY CONTINUE FOR THE REST OF TODAY AND
TONIGHT. STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN ABOUT
180 NM SOUTH OF THE WESTERN TIP OF JAMAICA BETWEEN 77W AND 79W.
STRONG SHOWERS AND THUNDERSTORMS ALSO ARE AT THE COAST OF
EASTERN CUBA FROM 19N TO 20N BETWEEN 75W AND 76W. THE UPPER LOW
IS KEEPING MOST OF THE NW CARIBBEAN UNDER AN AREA OF MIDDLE TO
UPPER LEVEL DRY AIR WITH LIMITED CLOUD COVER. SCATTERED MODERATE
TO ISOLATED STRONG SHOWERS AND THUNDERSTORMS ARE BEING ENHANCED
SOMEWHAT BY UPPER LEVEL DIFFLUENT FLOW BECAUSE OF THE LOCATION
OF THE TROUGH AND UPPER LEVEL ANTICYCLONIC WIND FLOW IN THE
SOUTHWESTERN CORNER OF THE AREA. AN UPPER RIDGE EXTENDS EAST OF
THE SFC LOW FROM THE ABC ISLANDS NE ACROSS GUADELOUPE...WHICH IS
FUNNELING MOST OF THE MOISTURE N OF THE NRN LEEWARD ISLANDS. THE
FAVORED AREA OF CONVECTION WILL SHIFT TO THE W CARIBBEAN LATER
IN THE WEEK AS A DEEP TROF DEVELOPS OVER THE GULF OF MEXICO AND
DRIER AIR MOVES OVER THE EASTERN CARIBBEAN SEA FROM THE ATLC.

THE ATLANTIC OCEAN...
AN ACTIVE SUBTROPICAL JET EMERGES OUT OF THE CNTRL CARIBBEAN NE
OF ERN CUBA AND EXTENDS TO 26N75W 25N60W BEYOND 30N40W WITH A
LARGE AREA OF MID/UPPER LEVEL CLOUDINESS EXTENDING ACROSS A GOOD
CHUNK OF THE SUBTROPICAL ATLC W OF 30W. A 1012 MB SFC LOW IS
EMBEDDED WITHIN THIS WESTERLY FLOW NEAR 26N50W WITH ONE TROUGH
TRAILING WSW TO 24N60W AND 24N65W...AND ANOTHER ONE GOING FROM
THE LOW CENTER TO 27N47W AND 24N45W. A LARGE AREA OF UPPER
DIFFLUENCE LIES WITHIN THE RIGHT REAR QUADRANT OF A JET STREAK
ALONG 26N50W 29N33W (PRODUCED WHERE THE SUBTROPICAL AND POLAR
JETS ARE MERGING)...SCATTERED STRONG SHOWERS AND THUNDERSTORMS
ARE FOUND FROM 22N TO 23N BETWEEN 54W AND 57W...FROM 20N TO 22N
BETWEEN 46W AND 51W...AND FROM 22N TO 24N BETWEEN 40W AND 42W.
FARTHER EAST...A NEARLY STATIONARY UPPER TROF EXTENDS FROM THE
COAST OF MOROCCO ACROSS THE CANARY ISLANDS TO 23N25W...THEN SOUTH
OF THE CAPE VERDE ISLANDS NEAR 13N25W. SUBSIDENCE IN THE TROF IS
PRODUCING A STRONG TRADE INVERSION AND SUBTROPICAL RIDGE...
KEEPING THE E ATLC RATHER DRY AND ALMOST CLOUD-FREE. THIS SET UP
IS ALSO KEEPING A RATHER THICK DUST PLUME AND HAZY SKIES ACROSS
THE ATLC SOUTH OF 22N. AN UPPER RIDGE ORIENTED ALONG 15N IS
SUPPORTING DEEP EASTERLY FLOW OVER THE ITCZ BUT AT THE MOMENT
THE AIR MASS IS TOO DRY TO SUPPORT MUCH PRECIPITATION. THE
PRECIPITATION IS INCREASING IN COVERAGE SE OF THE E ATLC UPPER
TROF AS THE TRPCL WAVE NEAR 20W MOVES INTO AN AREA OF UPPER
DIFFLUENCE.

$$
MT

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