[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 101130
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SUN FEB 10 2008

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1130 UTC

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 7N12W 3N25W 1N34W 2N43W EQ.
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF LINE FROM 2N4W
TO 2N8W. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION ARE
WITHIN 150-180 NM OF THE AXIS BETWEEN 23W AND 35W.

...DISCUSSION...

GULF OF MEXICO...
RATHER FAST MID TO UPPER LEVEL FLOW EVIDENT ACROSS THE CONUS
WITH SHORTWAVE TROUGHS SWEEPING EWD IN STRONG WLY FLOW ALOFT.
THE MOST RECENT SHORTWAVE TROUGH EXTENDS FROM A VORT MAX
CENTERED ABOUT 240 NM OFF THE MID-ATLANTIC COAST/38N72W SWWD TO
A BASE OVER N FLORIDA AND THE ADJACENT NE GULF. MODERATE TO
STRONG UPPER LEVEL SUBSIDENCE IS SWEEPING OFF THE SE COAST AND
EXTENDS WWD ACROSS MUCH OF THE DEEP SOUTH AND NRN GULF IN THE
WAKE OF THE TROUGH. THE TROUGH IS PROVIDING SUPPORT FOR A COLD
FRONT EXTENDING FROM NEAR CEDAR KEY FLORIDA TO THE NE GULF NEAR
28N85W. THIS FRONT WAS MOVING SE AT 20 KT AND IS EXPECTED TO
OVERTAKE A WEAKENING QUASI-STATIONARY FRONTAL TROUGH CURRENTLY
EXTENDING ACROSS EXTREME S FLORIDA OVER THE UPPER KEYS TO THE
SRN GULF NEAR 22N87W LATER TODAY. ALTHOUGH THE FRONTAL TROUGH
APPEARS TO BE LOSING ITS DEFINITION SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE OCCURRING WITHIN 60-90 NM SE OF THE FRONT N OF
27N. THE HEAVIEST ACTIVITY WAS OCCURRING IN THE STRAITS OF
FLORIDA BETWEEN MIAMI AND GRAND BAHAMA ISLAND AND ALSO NEAR THE
N COAST OF CUBA.

CARIBBEAN SEA...
AN UPPER RIDGE EXTENDS ACROSS THE WRN CARIBBEAN FROM PANAMA TO
HISPANIOLA AND CONTINUES NEWD INTO THE SUBTROPICAL ATLC. AN
UPPER LEVEL TROUGH/SHEAR AXIS IS UNDERCUTTING THE RIDGE AND
EXTENDS ACROSS THE NE WINDWARD ISLANDS NEAR GUADELOUPE WWD JUST
TO THE S OF PUERTO RICO AND HISPANIOLA. AN EMBEDDED SMALL MID
LEVEL CYCLONIC CIRCULATION WAS JUST S OF THE MONA PASSAGE NEAR
17N68W. CONFLUENT FLOW WITHIN THE SHEAR AXIS MANIFESTED ITSELF
IN VERY STRONG UPPER LEVEL SUBSIDENCE OVER THE FAR NE PORTION OF
THE WINDWARD ISLANDS AND PUERTO RICO WITH PRONOUNCED SUBSIDENCE
NOTED ELSEWHERE OVER THE CARIBBEAN. THIS SUBSIDENCE WAS LIMITING
ANY THUNDERSTORMS ACROSS THE AREA WITH THE EXCEPTION OF A SMALL
CLUSTER OF ACTIVITY IN THE GULF OF HONDURAS NEAR ROATAN ISLAND.
EXPANSIVE SURFACE RIDGE OVER THE ATLC COUPLED WITH THE LOWER
PRESSURE OVER SOUTH AMERICA IS PRODUCING A RATHER TIGHT PRESSURE
GRADIENT OVER THE SW CARIBBEAN RESULTING IN MODERATE/STRONG
EASTERLY TRADE WINDS ACROSS THE AREA. A 0242 UTC ASCAT PASS
INDICATED 25-30 KT WINDS ALONG THE COAST OF COLOMBIA. THE TRADE
WINDS ARE USHERING IN SOME LOW LEVEL CLOUDS AND WIDELY SCATTERED
LOW TOPPED SHOWERS.

ATLANTIC OCEAN...
THE UPPER LEVEL SHORTWAVE TROUGH MOVING OFF THE MID-ATLANTIC
COAST IS PROVIDING SOME SUPPORT FOR AN EXISTING STATIONARY FRONT
WHICH EXTENDS FROM 32N71W TO 27N77W WHERE IS BECOMES A
DISSIPATING STATIONARY FRONT ACROSS EXTREME S FLORIDA AND THE
UPPER KEYS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN
60 NM SE OF THE FRONT N OF 27N WITH MORE PRONOUNCED ACTIVITY
OCCURRING IN THE STRAITS OF FLORIDA BETWEEN MIAMI AND GRAND
BAHAMA ISLAND AND ALSO NEAR THE N COAST OF CUBA. THIS ACTIVITY
WAS PROPAGATING SWD AT 15 KT. THE CENTRAL ATLC N OF 19N BETWEEN
40W AND 75W IS DOMINATED BY AN EXPANSIVE DEEP LAYERED RIDGE AND
EMBEDDED ANTICYCLONE NEAR 24N60W. THE SURFACE RIDGE IS ANCHORED
BY A 1024 MB HIGH NEAR 28N53W. AN UPPER LEVEL TROUGH OVER THE
FAR E ATLC EXTENDS FROM AN UPPER LEVEL LOW N OF THE CANARY
ISLANDS NEAR 32N15W ACROSS THE W COAST OF MAURITANIA AND WESTERN
SAHARA THEN TURNS WSWWD THROUGH 20N22W 18N35W THEN UNDERCUTS THE
RIDGE NOTED ABOVE THROUGH 18N50W TO THE NE WINDWARD ISLANDS.
ASSOCIATED WEAKENING COLD FRONT EXTENDS FROM A 1008 MB LOW OVER
GRAND CANARY ISLAND NEAR 28N16W ALONG 27N14W THEN SW ALONG
21N20W TO 20N22W. SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS ARE N OF 29N FROM THE MAINLAND OF MOROCCO
TO 35N BETWEEN 8W-14W. AN E/W UPPER RIDGE EXTENDS ACROSS THE
TROPICAL ATLC ALONG 4N/5N TO 40W AND A WEAKENING JETSTREAM WITH
WINDS OF 90 TO 110 KT IS ALONG THE N PERIPHERY OF THE RIDGE
WITHIN 150 NM OF LINE FROM 14N35W TO INLAND OVER W AFRICA NEAR
19N16W/MAURITANIA.

$$
COBB







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