[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 210532
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST WED NOV 21 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
SECTIONS OF SOUTH AMERICA...AND THE 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
0445 UTC.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 82W S OF 19N MOVING W 10-15 KT. WAVE
CONTINUES TO WEAKEN AS IT MOVES OVER THE W CARIBBEAN. ANY
ACTIVITY IS ASSOCIATED WITH UPPER LEVEL DIFFLUENT PATTERN.

TROPICAL WAVE IS ALONG 95W S OF 21N MOVING W 10 KT. WAVE IS
MOSTLY IN THE E PACIFIC REGION WITH ONLY SOME ISOLATED LOW LEVEL
SHOWERS OVER THE W BAY OF CAMPECHE.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N9W 4N22W 7N38W 3N53W. SMALL
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE
WITHIN 45 NM ALONG THE ITCZ AXIS FROM 9W-24W. A BROAD AREA OF
SCATTERED MODERATE CONVECTION IS N OF THE ITCZ FROM 7N-13N
BETWEEN 26W AND A SURFACE TROUGH LOCATED FROM 13N39W TO 5N41W
AND IS PRODUCED BY UPPER LEVEL DIFFLUENCE.

DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL LOW IS CENTERED OVER NW MEXICO COVERING MOST OF
MEXICO INTO TEXAS. BROAD UPPER RIDGE COVERS THE GULF EXTENDING
FROM THE CARIBBEAN OVER THE NE YUCATAN PENINSULA GAINING
AMPLITUDE TO OVER THE E US ALONG THE MISSISSIPPI VALLEY. A
SURFACE RIDGE REMAINS OVER THE GULF ANCHORED BY A 1022 MB HIGH
OVER GEORGIA AND A 1024 MB HIGH INT HE W ATLC. PATCHES OF LOW
LEVEL CLOUDS WITH WIDELY ISOLATED SHOWERS DOTS THE SE GULF AND
THE N GULF N OF 28N FROM ALABAMA TO CENTRAL LOUISIANA. THE NEXT
COLD FRONT IS STILL EXPECTED TO ENTER THE GULF ON THU BRINGING
SHOWER ACTIVITY AND GUSTY WINDS BEHIND THE FRONT AS IT
TRANSVERSES THE GULF.

CARIBBEAN SEA...
THE BROAD UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS FROM THE
CARIBBEAN ANCHORED OVER SOUTH AMERICA EXTENDING A MEAN RIDGE
AXIS FROM COLOMBIA ACROSS THE NE YUCATAN PENINSULA COVERING THE
ENTIRE CARIBBEAN. THE UPPER DIFFLUENCE CONTINUES TO GENERATE
NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS OVER THE W CARIBBEAN S
OF 17N BETWEEN 80W-88W INCLUDING CENTRAL AMERICA. THE ITCZ AXIS
EXTENDS ACROSS SOUTH AMERICA AND PANAMA INTO THE E PACIFIC
REGION ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF
10N E OF 80W TO INLAND OVER PANAMA AND COLOMBIA. A FAST MOVING
COLD FRONT EXTENDS FROM THE CENTRAL ATLC JUST N OF PUERTO RICO
ALONG THE N COAST OF HISPANIOLA TO E CUBA GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS N OF 15N TO OVER THE GREATER
ANTILLES AND THE VIRGIN/LEEWARD ISLANDS E OF 78W WHILE THE
CENTRAL CARIBBEAN IS UNDER MOSTLY HIGH CLOUDS. THE FAR E
CARIBBEAN REMAINS RATHER CLEAR AGAIN TONIGHT.

ATLANTIC OCEAN...
AN UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC ACROSS THE W ATLC
N OF 20N W OF 50W OVER THE FLORIDA PENINSULA WITH THE ASSOCIATED
FAST MOVING COLD FRONT EXTENDING THROUGH 32N53W ALONG 27N54W N
OF PUERTO RICO NEAR 20N67W TO E CUBA MOVING E AT 20 TO 25 KT. A
JET STREAM WITH WINDS ESTIMATED TO BE 80 TO 120 KT EXTENDING
FROM THE TURKS AND CAICOS TO 25N58W COMBINING WITH A NORTHERN
JET EXTENDING THROUGH 32N65W CONTINUING TO 31N48W. NARROW UPPER
RIDGE AXIS EXTENDS FROM THE TROPICS NEAR 20N43W N TO BEYOND
32N47W PROVIDING UPPER LEVEL DIFFLUENCE AND COUPLED WITH THE
FAST MOVING COLD FRONT ARE GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS WITHIN 180 NM E OF THE FRONT N OF 23N AND FROM
23N-28N BETWEEN 42W-48W. SIMILAR ACTIVITY IS BETWEEN THE COLD
FRONT AND A SECONDARY BOUNDARY TO THE W THAT EXTENDS THROUGH
32N58W TO 28N60W. A SURFACE RIDGE COVERS THE W ATLC INTO THE
GULF OF MEXICO W OF 65W ANCHORED BY A 1022 MB HIGH OVER GEORGIA
AND A 1024 MB HIGH INT HE W ATLC. BROAD UPPER TROUGH COVERS THE
REMAINDER OF THE NE ATLC N OF 27N E OF 37W WITH A REMNANT
STATIONARY FRONT N OF THE REGION. A WEAK 1019 MB HIGH IS LOCATED
NW OF THE CAPE VERDE ISLANDS NEAR 21N32W. WESTERLY NEAR ZONAL
UPPER LEVEL FLOW DOMINATES THE TROPICS ENHANCING THE ACTIVITY IN
THE ITCZ SECTION ABOVE.

$$
WALLACE


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