[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 142352
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON SEP 14 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...

TROPICAL WAVE IS ALONG 65W S OF 15N MOVING W NEAR 10 KT. THIS
WAVE IS LOW-AMPLITUDE AND IS MOSTLY INLAND OVER CENTRAL
VENEZUELA. HOWEVER...THE LOW-LEVEL CLOUD FIELD ACROSS THE SE
CARIBBEAN EXHIBITS CYCLONIC TURNING ALONG THE WAVE AXIS S OF
14N. THE WAVE CONTINUES MOVING BENEATH A VERY DRY AND STABLE
ATMOSPHERE ALOFT OVER THE CARIBBEAN SEA WATERS...THEREFORE NO
SIGNIFICANT CONVECTION OR SHOWERS ACCOMPANY THE WAVE N OF 11N.
SCATTERED MODERATE CONVECTION IS S OF 11N BETWEEN
62W-68W...REMAINING MOSTLY OVER INLAND VENEZUELA.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N13W 10N22W AND DISCONTINUOUS
TO 11N30W THEN CONTINUOUS ALONG 9N42W 9N61W. WIDELY SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS ALONG THE W AFRICA COAST
FROM 8N-18N BETWEEN 13W-20W. ELSEWHERE...SCATTERED SHOWERS AND
ISOLATED MODERATE CONVECTION ARE WITHIN 200 NM EITHER SIDE OF A
LINE FROM 6N22W TO 8N44W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL TROUGH IS LOCATED ACROSS THE CENTRAL AND SRN
PLAINS OF THE CONUS AND CONTINUES TO SUPPORT A 1008 MB LOW
CENTERED OVER ERN TEXAS NEAR 32N94W. ELSEWHERE OVER THE GULF IN
THE UPPER LEVELS...MOSTLY WESTERLY NEAR ZONAL FLOW IS PRESENT. A
SERIES OF FAST MOVING FRONTAL WAVES ARE ROTATING AROUND THE
MIDDLE TO UPPER LEVEL LOW WITH A DISSIPATING COLD FRONT
EXTENDING INTO THE GULF NEAR VERMILION BAY LOUISIANA TO 25N94W
THEN AS A DISSIPATING STATIONARY FRONT TO 22N97W. SCATTERED
SHOWERS AND A FEW ISOLATED TSTMS ARE WITHIN 60 NM OF THE FRONT
ACROSS THE WRN GULF. FARTHER TO THE E OVER THE N/CENTRAL
GULF...A SURFACE TROUGH IS ANALYZED FROM PENSACOLA FLORIDA TO
25N90W. THIS SURFACE BOUNDARY ALONG WITH A LARGE AREA OF UPPER
LEVEL DIFFLUENCE E OF 90W...ARE GENERATING SCATTERED SHOWERS AND
TSTMS N OF 27N BETWEEN 83W-87W...INCLUDING PORTIONS OF THE
FLORIDA PANHANDLE AND WITHIN 60 NM EITHER SIDE OF THE SURFACE
TROUGH. A DISSIPATING STATIONARY FRONT IS ALONG THE WRN FLORIDA
PANHANDLE FROM POMPANO BEACH TO TAMPA BAY AND OVER THE FLORIDA
PANHANDLE. THIS BOUNDARY IS SUPPORTING A FEW SCATTERED SHOWERS
AND ISOLATED TSTMS MAINLY INLAND OVER THE WRN FLORIDA PENINSULA
THIS EVENING.

CARIBBEAN SEA...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED IN THE
YUCATAN CHANNEL AND EXTENDS UPPER LEVEL RIDGING ACROSS CARIBBEAN
W OF 68W. THIS ANTICYCLONIC FLOW SUPPORTS A 1016 MB HIGH LOCATED
S OF WRN CUBA NEAR 21N81W. MOSTLY FAIR SKIES ARE LOCATED ACROSS
THE NW CARIBBEAN...HOWEVER UPPER LEVEL DIFFLUENCE AND DAYTIME
INSTABILITY ARE SUPPORTING SCATTERED SHOWERS AND TSTMS ACROSS
CUBA AND THE NEARBY COASTAL WATERS WITHIN 60 NM. AN UPPER LEVEL
LOW IS CENTERED OVER THE VIRGIN ISLANDS AND COVERS THE ERN
CARIBBEAN E OF 68W. MOIST SWLY UPPER LEVEL DIFFLUENT FLOW IS
SUPPORTING SCATTERED SHOWERS E OF 63W...INCLUDING MOST OF THE
LESSER ANTILLES. ELSEWHERE ACROSS THE SW CARIBBEAN...SCATTERED
SHOWERS ARE OCCURRING S OF 10N BETWEEN COLOMBIA AND COSTA RICA
DUE TO THE CLOSE PROXIMITY OF THE ITCZ AXIS.

ATLANTIC OCEAN...
A COLD FRONT EXTENDS FROM THE CENTRAL ATLC THROUGH 32N67W TO A
1011 MB LOW IN THE W ATLC NEAR 28N74W CONTINUING SW TO NEAR
POMPANO BEACH FLORIDA. THIS FRONTAL SYSTEM AND LOW IS SUPPORTED
ALOFT BY UPPER LEVEL TROUGHING PRESENT OVER MUCH OF THE WRN ATLC
N OF 30N. THE UPPER LEVEL ANTICYCLONIC CIRCULATION ANCHORED OVER
THE YUCATAN CHANNEL EXTENDS UPPER LEVEL RIDGING OVER THE W ATLC
W OF 66W NARROWING ALONG 27N64W TO 29N59W. LOW-LEVEL CONVERGENCE
ALONG AND E OF THE FRONTAL BOUNDARY COUPLED WITH DIFFLUENCE
ALOFT ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN
300 NM SE OF THE FRONTAL BOUNDARY. AN UPPER LOW IS CENTERED OVER
THE VIRGIN ISLANDS NEAR 18N64W COVERING THE ERN CARIBBEAN. MOIST
SWLY UPPER LEVEL DIFFLUENT FLOW IS GENERATING A LARGE AREA OF
SCATTERED SHOWERS AND ISOLATED TSTMS E OF THE UPPER TROUGH FROM
10N-20N BETWEEN 55W-61W. FARTHER TO THE EAST...THE REMNANTS OF
FRED...A 1012 MB LOW...IS CENTERED NEAR 19N40W WITH SCATTERED
MODERATE/ISOLATED STRONG CONVECTION LOCATED NW OF THE LOW FROM
18N-22N BETWEEN 41W-43W. FARTHER TO THE SE NEAR THE CAPE VERDE
ISLANDS...A DISCONTINUOUS AREA OF THE ITCZ CONTAINS A 1012 MB
LOW CENTERED NEAR 14N25W AND IS GENERATING SCATTERED MODERATE
CONVECTION FROM 14N-16N BETWEEN 25W-30W. THIS ACTIVITY IS BEING
ENHANCED BY UPPER LEVEL DIFFLUENCE ON AN UPPER LEVEL
ANTICYCLONIC CIRCULATION CENTERED NEAR 20N17W THAT COVERS THE
ERN ATLC FROM 10N-32N E OF 38W. ELSEWHERE ACROSS THE ATLC
BASIN...SURFACE RIDGING DOMINATES N OF 25N E OF 50W.

$$
HUFFMAN



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