[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 101756
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST WED JAN 10 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...
NORTHEASTERN 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...THE ITCZ...
ITCZ AXIS IS ALONG 2N AT THE PRIME MERIDIAN...5N13W 3N24W 4N30W
1N40W 1N51W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 1S-2N
BETWEEN 33W-37W. SIMILAR CONVECTION IS ALSO FOUND FROM 2N-4N
BETWEEN 22N-25W.

...DISCUSSION...
GULF OF MEXICO...
DEEP LAYERED TROUGH IS OVER THE EASTERN SEABOARD MOVING INTO THE
W ATLC N OF 28. THE ASSOCIATED COLD FRONT...THAT CLEARED THE
GULF YESTERDAY CURRENTLY EXTENDS ACROSS THE W ATLC...E CUBA AND
THE NW CARIBBEAN. A SHORT WAVE TROUGH IS MOVING EWD ACROSS THE
CENTRAL GULF GENERATING WIDELY SCATTERED SHOWERS. AN UPPER RIDGE
COVERS MEXICO ANCHORED BY AN UPPER HIGH IN THE EPAC. BROKEN TO
OVERCAST LOW LEVEL CLOUDS WITH EMBEDDED LIGHT RAIN/DRIZZLE ARE
POOLING AGAINST THE SIERRA MADRE DEL SUR IN MEXICO BY MODERATE
TO STRONG NE WINDS. A MUCH COOLER AND SEASONABLE AIR MASS COVERS
THE ENTIRE GULF AND THE STATE OF FLORIDA IN THE WAKE OF THE COLD
FRONT MENTIONED ABOVE. SURFACE RIDGE REMAINS IN PLACE WITH A
1030 MB HIGH ALONG THE NE COAST OF MEXICO NEAR 23N98W AND A
LARGER 1033 MB HIGH INLAND OVER THE SE US. SURFACE WINDS ARE
BEGINNING TO WEAK FROM WEST TO EAST ACROSS THE GULF AND WILL
BECOME MORE EASTERLY LATER TODAY AS THE SURFACE RIDGE GRADUALLY
MOVES E ACROSS THE SE US. SLY RETURN FLOW WILL DEVELOP ON FRI
AHEAD OF THE NEXT COLD FRONT THAT IS FORECAST TO MOVE OFF THE
TEXAS COAST ON SUN.

CARIBBEAN SEA...
BASED ON LATEST VIS SATELLITE IMAGERY AND SURFACE OBSERVATIONS
THE COLD FRONT ACROSS THE W ATLC AND E CUBA HAS BEEN EXTENDED SW
ACROSS THE CARIBBEAN FROM 21N78W TO 17N85W. COLD AIR
STRATOCUMULUS CLOUDS NOTICED BEHIND THE COLD FRONT IMPLY THAT A
COOL AND DRIER AIR MASS HAS INVADED THE NW CARIBBEAN. THE FRONT
IS EXPECTED TO BECOME DIFFUSE IN THE NEXT 6 HOURS. UPPER RIDGE
COVERS MUCH OF THE CARIBBEAN WHILE A WEAKENING UPPER TROUGH IN
THE CENTRAL ATLC ENTERS THE NE CARIBBEAN THROUGH THE VIRGIN
ISLANDS. STRONG SUBSIDENCE AND VERY DRY UPPER AIR REMAIN IN
CONTROL OF THE CARIBBEAN. TYPICAL PATCHES OF LOW LEVEL MOISTURE
WITH EMBEDDED SHOWERS ARE SEEN MOVING INTO CENTRAL AMERICA...
PARTICULARLY OVER HONDURAS AND NICARAGUA UNDER A NE WIND FLOW.
TRADE WINDS ARE EXPECTED TO INCREASE AGAIN THU THROUGH SUN AS
HIGH PRES BUILD N OF THE AREA AND MOVES E. THE STRONGEST WINDS
OF 20-30 KT WILL BE FOUND JUST OFF THE COAST OF COLOMBIA.

ATLANTIC OCEAN...
DEEP LAYERED TROUGH IS OVER THE EASTERN SEABOARD MOVING INTO THE
W ATLC N OF 28. THE ASSOCIATED COLD FRONT ENTERS THE AREA NEAR
NEAR 31N64W THEN CONTINUES SW ACROSS THE CENTRAL BAHAMAS/E CUBA
INTO THE NW CARIBBEAN. A REINFORCING COLD FRONT EXTENDS FROM A
1000 MB LOW MOVING NE WELL N OF THE REGION THROUGH 32N65W TO
27N80W. A 60-80 NM WIDE BAND OF MAINLY LOW CLOUDS WITH ISOLATED
SHOWERS IS ASSOCIATED WITH THE LEADING COLD FRONT WHILE THE
SECOND ONE REMAINS EMBEDDED WITHIN MUCH DRIER AIR AND NOT
PRODUCING ANY SHOWERS. THE UPPER TROUGH IN THE CENTRAL ATLC IS
RAPIDLY DETERIORATING AND EXTENDS FROM A ILL-DEFINED UPPER LOW
NEAR 25N55W DIPPING S INTO THE NE CARIBBEAN. VERY BROAD UPPER
RIDGE ANCHORED WELL N OF THE REGION CONTINUES TO ERODE THE UPPER
TROUGH THAT LINGERS IN THE CENTRAL ATLC AND COVERS THE ATLC N OF
20N FROM 30W-50W. NARROW UPPER TROUGH IS OVER THE FAR E ATLC
EXTENDING FROM AN UPPER LOW NEAR THE MADEIRA ISLANDS SW ALONG
23N23W 18N67W. A BAND OF TRANSVERSE HIGH CLOUDS IS JUST SE OF
THE UPPER TROUGH AND RUNS FROM NEAR 15N30W NE INTO WEST AFRICA.
A SURFACE TROUGH PROBABLY REFLECTION OF THE LOW/TROUGH EXTENDS
FROM A 1020 MB LOW NEAR 36N14W TO 31N17W. THE TROPICS REMAINS
DOMINATED BY STRONG WESTERLY UPPER FLOW. AT THE SURFACE...HIGH
PRESSURE DOMINATES THE ATLC E OF 60W ANCHORED BY A 1035 MB HIGH
NEAR THE AZORES. PATCHES OF LOW LEVEL MOISTURE ARE UNDER THE
INFLUENCE OF THIS FEATURE.

$$
GR




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