[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 130548
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN SEP 13 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0345 UTC.

...TROPICAL WAVES...

THE TROPICAL WAVE THAT WAS ALONG 22W HAS NOT PROGRESSED WESTWARD
OVER THE PAST 24 HOURS. HOWEVER THE 1012 MB LOW REMAINS NEAR
12N22W AND IS MENTIONED IN THE MIATWOAT AS HAVING A LOW
PROBABILITY OF FORMING A TROPICAL SYSTEM. THEREFORE THE TROPICAL
WAVE PORTION WILL BE DROPPED ON THE 0600 UTC ANALYSIS. SCATTERED
STRONG CONVECTION IS FROM 12N-14N BETWEEN 21W-24W.

TROPICAL WAVE IS ALONG 89W S OF 19N MOVING W NEAR 15 KT. WAVE IS
INLAND OVER THE YUCATAN PENINSULA AND INTO THE E PACIFIC REGION.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 15N15W 12N28W 9N40W 12N52W
10N62W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE
OVER THE CAPE VERDE ISLANDS FROM 15N-19N BETWEEN 22W-26W.
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE
WITHIN 75 NM OF ITCZ FROM 34W-40W.

...DISCUSSION...

GULF OF MEXICO...
A NEAR STATIONARY BOUNDARY EXTENDS ACROSS THE N GULF FROM A 1011
MB LOW OFF THE NE COAST OF FLORIDA THROUGH APALACHICOLA FLORIDA
THEN JUST S OF NEW ORLEANS LOUISIANA SW TO A 1004 MB LOW NEAR
27N96W WITH A SURFACE TROUGH EXTENDING S TO 23N96W. A SURFACE
TROUGH IS FROM 24N86W ACROSS S FLORIDA NEAR NAPLES TO PALM
BEACH. A STRONG UPPER LOW IS INLAND OVER E TEXAS WITH THE UPPER
TROUGH EXTENDING S TO 20N COVERING THE GULF W OF 91W WHILE AN
UPPER RIDGE EXTENDS FROM THE NE YUCATAN PENINSULA TO ACROSS S
FLORIDA INTO THE W ATLC. THIS SCENARIO COUPLED WITH THE
ABUNDANCE OF DEEP LAYER MOISTURE IS GENERATING SCATTERED/HEAVY
SHOWERS WITH SCATTERED/NUMEROUS THUNDERSTORMS ACROSS THE SE GULF
WITHIN 120 NM S OF THE SURFACE TROUGH E OF 86W TO OVER S
FLORIDA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE NE
GULF N OF THE SURFACE TROUGH E OF 86W TO INLAND OVER FLORIDA.
ISOLATED SHOWERS/THUNDERSTORMS DOT THE NW GULF N OF 26N W OF
90W.

CARIBBEAN SEA...
THE UPPER RIDGE OVER THE GULF OF MEXICO COVERS THE W CARIBBEAN N
OF 13N W OF 74W WHILE AN UPPER TROUGH COVERS THE NE CARIBBEAN
EXTENDING FROM AN UPPER LOW N OF THE VIRGIN ISLANDS. EVEN THOUGH
THERE IS DIFFLUENCE ALOFT...THE SURFACE REMAINS DRY OVER THE W
CARIBBEAN LEAVING ISOLATED SHOWERS/THUNDERSTORMS INLAND AND
ALONG THE IMMEDIATE COASTAL WATERS OF CUBA AND HAITI. THE ITCZ
EXTENDS FROM COLOMBIA ACROSS PANAMA INTO THE E PACIFIC REGION
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N TO
INLAND OVER COLOMBIA AND PANAMA FROM 74W-82W. AN UPPER RIDGE
EXTENDING ACROSS VENEZUELA FROM THE W TROPICAL ATLC IS GIVING
THE SE CARIBBEAN DENSE CIRRUS CLOUDS BUT NO SHOWER ACTIVITY.
OTHERWISE THE REMAINDER OF THE CARIBBEAN IS REMARKABLY CLEAR
AGAIN TONIGHT.

ATLANTIC OCEAN...
A 1011 MB LOW IS JUST OFF THE NE FLORIDA COAST NEAR 31N80W WITH
A STATIONARY BOUNDARY EXTENDING W INTO THE GULF OF MEXICO. THE
UPPER RIDGE FROM THE GULF OF MEXICO EXTENDS OVER THE W ATLC W OF
70W PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS N OF 27N W OF 75W. AN UPPER LOW
IS N OF VIRGIN ISLANDS NEAR 21N65W WITH THE UPPER TROUGH DIPPING
S OVER THE NE CARIBBEAN. A BROAD UPPER TROUGH COVERS THE CENTRAL
ATLC N OF 15N BETWEEN 35W-54W WITH THE ASSOCIATED FRONTAL
BOUNDARY ENTERING THE REGION NEAR 32N37W EXTENDING SW ALONG
29N42W W 30N48W SW TO 28N52W THEN NW TO BEYOND 32N58W. SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM EITHER SIDE OF
THE ENTIRE FRONTAL BOUNDARY. A REMNANT SURFACE TROUGH REMAINS IN
THE TROPICAL ATLC EXTENDING FROM 18N52W TO 11N54W WITH NO
SIGNIFICANT WEATHER. A BROAD UPPER RIDGE COVERS THE E ATLC FROM
THE TROPICS TO 30N ANCHORED NEAR 19N21W AND PROVIDING THE SLY
SHEAR OVER A 1006 MB LOW...THE REMNANTS OF FRED...CENTERED NEAR
17N34W AND ENHANCING THE CONVECTION OVER THE CAPE VERDE
ISLANDS.

$$
WALLACE





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