[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 061751
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST TUE MAR 06 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 2315 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 7N10W 5N20W 2N35W CROSSING THE
EQUATOR AT 47W AND INTO COASTAL NE BRAZIL NEAR 1S52W. CLUSTERS
OF SCATTERED MODERATE CONVECTION DOT THE AREA FROM 1N-5N BETWEEN
9W-22W. SIMILAR ACTIVITY IS FROM 2S-EQ BETWEEN 26W-32W...WITHIN
150 NM N OF THE AXIS BETWEEN 33W-37W...AND JUST OFF THE COAST OF
NE BRAZIL FROM EQ-5N BETWEEN 47W-52W.

...DISCUSSION...

THE GULF OF MEXICO...
NICE WEATHER DAY ACROSS THE GULF THIS AFTERNOON WITH COOL AND
DRY CONDITIONS PREVAILING...AS SFC HIGH PRESSURE EXTENDS INTO
THE AREA FROM THE N. A SCATTERED TO BROKEN AREA OF COOL AIR
STRATOCUMULUS CLOUDS NOTED S OF 28N W OF 85W. A LOWER STRATUS
DECK IS SEEN BANKING UP AGAINST THE MEXICO COAST WITH ONSHORE
FLOW IN THE SW BAY OF CAMPECHE S OF 22N. MOSTLY CLEAR SKIES ARE
NOTED ELSEWHERE. SFC WINDS IN THE SRN GULF CONTINUE TO DIMINISH
THOUGH REMAIN NE TO 20 KT S OF 25N AND E OF 87W. SFC HI PRES
RIDGING ALONG THE N GULF COAST WILL DOMINATE THROUGH SAT...WITH
THE WINDS AND SEAS S OF 25N CONTINUING TO SLOWLY RELAX.
ALOFT...BROAD NW FLOW DOMINATES AROUND RIDGING FILLING IN BEHIND
THE LONGWAVE TROUGHING OFF THE EAST COAST. THERE IS A BAND OF
UPPER MOISTURE HUGGING THE N GULF COAST BUT OVERALL VERY DRY MID
TO UPPER AIR DOMINATES THE BASIN.

THE CARIBBEAN SEA...
REMNANT FRONTAL TROUGH EXTENDS FROM ERN CUBA TO NEAR THE ERN TIP
OF HONDURAS ALONG 21N77W 19N81W 16N83W. THIS MORNINGS QUIKSCAT
PASS SHOWED THE BOUNDARY IS MOSTLY MARKED BY WEAK LOW LEVEL
CONFLUENCE AND A SPEED GRADIENT...WITH NLY WINDS 20-25 KT W OF
THE TROUGH AND NE WINDS 15-20 KT E OF THE TROUGH. BROKEN LOW TO
MID CLOUDS WITH EMBEDDED SHOWERS ARE ALSO OVER THE NW CARIB W OF
THE TROUGH. MODERATE TRADES GENERALLY DOMINATE OVER THE CENTRAL
AND ERN CARIB WHICH ARE ADVECTING TYPICAL PATCHES OF LOW LEVEL
MOISTURE WWD...WITH THE MOST CONCENTRATED OF THESE PATCHES NOTED
BETWEEN PUERTO RICO AND THE ABC ISLANDS. MODERATE TO FRESH
TRADES EXPECTED TO TAKE OVER THROUGH THE SECOND HALF OF THE WEEK
AS THE FRONTAL TROUGH DISSIPATES. ALOFT...DEEP LAYER TROUGHING
OFF THE U.S. EAST COAST EXTENDS INTO THE NW CARIB. UPPER HIGH
JUST NE OF THE LEEWARD ISLANDS IS AFFECTING THE ERN CARIB. UPPER
CONFLUENCE BETWEEN THESE FEATURES IS SUPPORTING THE VERY DRY AIR
SEEN IN THE ERN CARIBBEAN.

THE ATLANTIC OCEAN...
A 1030 MB SFC HIGH OVER MISSISSIPPI IS BUILDING INTO THE WRN
ATLC BEHIND THE STATIONARY FRONT THAT ENTERS THE AREA NEAR
31N56W AND CONTINUES SW TO ERN CUBA NEAR 21N76W. OVERCAST DEEP
LAYER CLOUDINESS WITH EMBEDDED SHOWERS ARE WITHIN 120NM NW OF
THE FRONT. SCATTERED TO BROKEN COOL AIR STRATOCUMULUS CLOUDS
ARE ELSEWHERE NW OF THE FRONT EXCEPT FOR CLEAR SKIES JUST
OFFSHORE THE SE U.S. COAST. FRONT IS ASSOCIATED WITH THE DEEP
LAYER TROUGHING OFF THE EAST COAST. THE REMAINDER OF THE CENTRAL
AND ERN ATLC SFC PATTERN IS DOMINATED BY THE SRN PERIPHERY OF
THE 1032 MB HIGH NEAR 32N28N. PATCHES OF LOW TO MID CLOUDS ARE
ROTATING ANTICYCLONICALLY AROUND THIS HIGH. AN UPPER HIGH NE OF
THE LEEWARD ISLANDS NEAR 21N58W HAS RIDGING OVER MUCH OF THE
CENTRAL ATLC. HOWEVER...A DISTINCT MID TO UPPER LOW REMAINS NEAR
22N44W. UPPER DIFFLUENCE BETWEEN THIS LOW AND RIDGING JUST OFF
THE AFRICAN COAST IS SUPPORTING THE MOISTURE RICH REGION SEEN IN
WV IMAGERY FROM 10N-25N E OF 44W. THERE MAY BE SHOWERS JUST S
AND SE OF THE UPPER LOW MAINLY WITHIN 120 NM OF A LINE FROM
8N51W 18N35W...WHERE MOISTURE CONTENT IS HIGHEST AND CLOUD TOPS
ARE COLDEST.

$$
WILLIS




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