[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290004
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN JUN 28 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 2315 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE EXTENDS ALONG 14N40W 9N43W 3N45W MOVING W NEAR
12 KT. LOCATED NEAR THE LEADING EDGE OF AN ELONGATED MAXIMUM IN
DEEP LAYER MOISTURE BASED ON THE TPW PRODUCT FROM CIMSS...THIS
TROPICAL WAVE ON SATELLITE IMAGERY EXHIBITS AN INVERTED-V
LOW-LEVEL CLOUD PATTERN THAT IS FOLLOWED BY A LARGE AREA OF
AFRICAN DUST WITHIN A DRY SAHARAN AIR LAYER E OF 37W.

A TROPICAL WAVE IS ALONG 78W S OF 20N MOVING W NEAR 15 KT. THIS
WAVE REMAINS ILL-DEFINED ON SATELLITE IMAGERY AND PRESENT
POSITION IS BASED ON CONTINUITY. ALSO OF NOTE...A 1100 UTC QSCAT
PASS CAPTURED WINDS UP TO 20 KT ACROSS THE ERN CARIBBEAN E OF
77W INDICATING THE WAVE IS POSSIBLY W OF THESE STRONGER E-SE
TRADES. THE PRESENCE OF DRY LOW/MID-LEVEL SAHARAN AIR IS ALSO
OBSERVED OVER PORTIONS OF THE CENTRAL AND ERN CARIBBEAN THAT IS
INHIBITING ANY DEEP CONVECTION NEAR THE WAVE. HOWEVER...
SCATTERED MODERATE TO STRONG CONVECTION IS S OF 11N IN THE SW
CARIBBEAN AS A PORTION OF THE E PACIFIC ITCZ AXIS EXTENDS ALONG
10N TO 80W.

THE TROPICAL WAVE PREVIOUSLY ACROSS SRN MEXICO AND GUATEMALA
ALONG 90W HAS BEEN POSITIONED FARTHER TO THE W ALONG 96W IN THE
E PACIFIC REGION BASED ON SATELLITE IMAGERY. A NRN PORTION OF
THE WAVE HAS FRACTURED...ANALYZED AS A SURFACE TROUGH...ACROSS
THE S/CENTRAL GULF OF MEXICO...SEE GULF OF MEXICO DISCUSSION
BELOW FOR MORE DETAILS.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N13W 7N18W 6N42W 6N46W 7N59W.
SCATTERED MODERATE CONVECTION IS FROM 5N-12N BETWEEN 14W-22W AND
MAY BE ASSOCIATED WITH THE NEXT TROPICAL WAVE EMERGING OFF THE W
AFRICA COAST.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
IN NORTHEASTERN MEXICO...ABOUT 100 NM TO THE SOUTHWEST OF
REYNOSA MEXICO/MCALLEN TEXAS. SCATTERED MODERATE SHOWERS TO
ISOLATED STRONG THUNDERSTORMS COVER MEXICO FROM THE ISTHMUS
OF TEHUANTEPEC NORTHWARD. A SURFACE TROUGH IS ALONG THE LINE
FROM 26N85W TO A 1011 MB LOW PRESSURE CENTER NEAR 22N90W TO
20N92W IN THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO.
STRONG SHOWERS AND THUNDERSTORMS COVER THE SOUTHERN AND
WESTERN SECTIONS OF THE YUCATAN PENINSULA. UPPER LEVEL
DIFFLUENT WIND FLOW IS ON TOP OF THIS AREA. ISOLATED MODERATE
SHOWERS COVER THE GULF OF MEXICO TO THE SOUTH OF 25N BETWEEN
83W AND 90W. STRONG SHOWERS AND THUNDERSTORMS ARE MOVING
INTO NORTHERN FLORIDA FROM GEORGIA IN AN AREA OF UPPER LEVEL
DIFFLUENT WIND FLOW.

THE CARIBBEAN SEA TO THE NORTH OF 16N TO THE WEST OF 65W...
AND THE ATLANTIC OCEAN TO THE WEST OF 60W...
BROAD MIDDLE LEVEL TO UPPER LEVEL CYCLONIC FLOW COVERS THE
CARIBBEAN SEA AND THE ATLANTIC OCEAN FROM 18N TO 27N BETWEEN
70W AND 80W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND ISOLATED
MODERATE SHOWERS FROM 17N TO 28N BETWEEN 65W AND 80W. THE
SOUTHERNMOST POINT OF A DEEP LAYER TROUGH THAT IS TO THE NORTH
OF THE AREA REACHES 28N65W. SCATTERED MODERATE SHOWERS TO
ISOLATED STRONG THUNDERSTORMS COVER THE AREA FROM 28N TO 31N
BETWEEN 62W AND 70W.

THE REST OF THE CARIBBEAN SEA...
BROAD SURFACE LOW PRESSURE COVERS CENTRAL AMERICA. STRONG
SHOWERS AND THUNDERSTORMS HAVE DEVELOPED IN SOUTHERN
GUATEMALA...EL SALVADOR...SOUTHERN HONDURAS...SOUTHWESTERN
NICARAGUA...AND FROM COSTA RICA INTO PANAMA IN THE BROAD LOW
PRESSURE COMBINED WITH SOME UPPER LEVEL DIFFLUENT FLOW IN THE
COMPARATIVELY MORE MOUNTAINOUS AREAS OF THOSE COUNTRIES.
AN UPPER LEVEL TROUGH REACHES THE SOUTHERN SECTIONS OF THE
CARIBBEAN SEA. STRONG SHOWERS AND THUNDERSTORMS ARE NORTHEASTERN
COLOMBIA AND NORTHWESTERN VENEZUELA...AND FROM PANAMA TO 12N
BETWEEN 78W AND 80W...AT THE BASE OF THIS TROUGH...AND IN
AN AREA OF UPPER LEVEL DIFFLUENT WIND FLOW. THE SOUTHERNMOST
EXTENT OF A MIDDLE LEVEL TO UPPER LEVEL TROUGH THAT ORIGINATES
IN THE ATLANTIC OCEAN NEAR 27N51W REACHES 15N65W IN THE EAST
CENTRAL CARIBBEAN SEA.

THE REST OF THE ATLANTIC OCEAN...
A MIDDLE LEVEL TO UPPER LEVEL TROUGH EXTENDS FROM A 27N51W
CYCLONIC CIRCULATION CENTER TO 21N52W TO 17N58W...INTO THE EAST
CENTRAL CARIBBEAN SEA NEAR 15N65W. ISOLATED MODERATE SHOWERS
COVER THE AREA FROM 26N TO 30N BETWEEN 47W AND 52W.

$$
MT





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