[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 081037
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN 08 MAY 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA... GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN
COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...

TROPICAL WAVE ABOUT 1100 NM E OF FRENCH GUIANA ALONG 33W S OF
11N MOVING W 10 KT. TIMESECTIONS FROM DAKAR AND SAL SUGGESTED A
WEAK WAVE PASSAGE ABOUT TWO DAYS AGO...AND SATELLITE IMAGERY
INDICATES A SURGE OF LOW-LEVEL MOISTURE MOVING NWWD OUT OF THE
ITCZ BETWEEN 31W-36W. ISOLATED SHOWERS/TSTMS FROM 1N-6N BETWEEN
30W-34W.

TROPICAL WAVE CENTERED S OF HISPANIOLA ALONG 70W/71W S OF 16N
MOVING W ABOUT 10 KT. THE 24-HR MOVEMENT OF THE WAVE APPEARS TO
HAVE SLOWED DOWN A BIT AS IT MOVES THROUGH A WEAKER PRES
GRADIENT DUE TO THE FRONT LOCATED OVER THE W ATLC. ISOLATED
SHOWERS HAVE BEEN OCCASIONALLY POPPING E OF THE AXIS FROM
14N-17N BETWEEN 69W-72W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 14N0 6N20W 8N32W...THEN ALONG 5N35W
3N40W 3N50W 1N55W. SCATTERED MODERATE CONVECTION WITHIN 75 NM OF
THE COAST OF SIERRA LEONE. WIDELY SCATTERED MODERATE FROM 3N-8N
BETWEEN 17W-26W. NUMEROUS MODERATE S OF 4N BETWEEN 41W-52W...
SOME OF WHICH IS MOVING INLAND NEAR THE AMAZON DELTA.

...DISCUSSION...

GULF OF MEXICO...
BROAD HIGH PRES AT THE SFC HAS SETTLED IN ACROSS THE NE GULF AND
FLORIDA AND HAS BROUGHT IN A DRIER AIR MASS OVER THE AREA WITH
DEWPOINTS DROPPING INTO THE LOWER 60S TO THE LOW/MID 50S EVEN
OVER THE E GULF WATERS. HOWEVER...THE HIGH HAS SHIFTED FAR
ENOUGH TO THE E TO ALLOW MOIST RETURN FLOW TO SET UP OVER THE W
GULF INTO TEXAS AND NE MEXICO WHERE DEWPOINTS ARE NOW PUSHING
70F. VISIBILITIES IN THE AREA HAVE NOT FALLEN ENOUGH TO SUPPORT
FOG DEVELOPMENT BUT CEILINGS OVER S TEXAS HAVE DROPPED TO NEAR
1000 FT WITH PATCHY DRIZZLE DUE TO THE MOIST AIR MASS. IN
ADDITION...AREAS OF SMOKE CONTINUE TO DRIFT ACROSS THE BAY OF
CAMPECHE UP THE E COAST OF MEXICO...AND THESE PARTICULATES ARE
ENHANCING THE DEVELOPMENT OF THE LOW CLOUDS. UPPER LEVEL
WESTERLY FLOW RUNS ACROSS THE REGION WITH SOME HIGH CLOUDINESS
ZIPPING ACROSS THE BAY OF CAMPECHE ALONG THE SUBTROPICAL
JET...BUT A RIDGE EXTENDING FROM THE N/CNTRL GULF UP THE
MISSISSIPPI VALLEY IS HELPING TO PRODUCE MOSTLY DRY AND TRANQUIL
CONDITIONS ACROSS THE REST OF THE AREA. THERE IS NO SIGNIFICANT
PATTERN CHANGE EXPECTED THROUGH THE MIDDLE OF THE WEEK...SO
GENERALLY DRY CONDITIONS WILL CONTINUE WITH LOW CLOUDS/DRIZZLE
STILL OCCURRING ACROSS SE TEXAS AND NE MEXICO. AREAS OF SMOKE
ORIGINATING FROM SRN MEXICO MAY ALSO BE PICKED UP IN THE
LOW-LEVEL FLOW AND BROUGHT IN OVER NE MEXICO AND S TEXAS.

CARIBBEAN...
A WEAK UPPER LEVEL TROF/SHEAR AXIS HAS SET UP OVER THE W
CARIBBEAN FROM HAITI TO JAMAICA TO NICARAGUA WITH SWLY FLOW TO
THE E OF THIS FEATURE DRAGGING LARGE AMOUNTS OF TROPICAL
MOISTURE NEWD ACROSS THE CNTRL CARIBBEAN AND HISPANIOLA. THE
LARGE CLUSTER OF TSTMS THAT HAD DEVELOPED OVER THE SW CARIBBEAN
YESTERDAY APPEARS TO HAVE WEAKENED BUT NEW TSTMS ARE DEVELOPING
WITH SCATTERED MODERATE CONVECTION FROM 11N-14N BETWEEN 79W-82W.
OTHER ISOLATED SHOWERS HAVE BEEN DEVELOPING OVER THE HIGH
TERRAIN OF HISPANIOLA DUE TO A SFC TROF IN THE AREA.
ELSEWHERE...BOTH THE NW AND E CARIBBEAN ARE COVERED BY
RELATIVELY DRY AIR MASSES...AND ONLY A FEW LOW-LEVEL TRADE
SHOWERS ARE NOTED MOVING ACROSS ANTIGUA...GUADELOUPE...AND
DOMINICA. ALSO...THE LARGE CLUSTER OF NUMEROUS MODERATE/STRONG
CONVECTION THAT WAS LOCATED OVER NW COLOMBIA HAS DISSIPATED AND
SHIFTED SWD TO THE PACIFIC COAST. MOISTURE VALUES ARE EXPECTED
TO INCREASE OVER THE ENTIRE AREA OVER THE NEXT SEVERAL DAYS
WHICH WILL INCREASE THE LIKELIHOOD OF SHOWERS/TSTMS.

ATLANTIC...
THE STRONG COASTAL NOR'EASTER THAT HAS BEEN AFFECTING THE U.S.
EAST COAST IS NOW LOCATED ABOUT 150 NM SE OF CAPE COD BUT THE
ASSOCIATED UPPER TROF SAGS DOWN INTO THE REGION WITH A LARGE
AREA OF DRY AIR SWEEPING OVER THE W ATLC WATERS. A COLD FRONT
ENTERS THE AREA E OF BERMUDA ALONG 32N61W 25N65W 22N75W AND A
PRE-FRONTAL SFC TROF EXTENDS NE OF HISPANIOLA ALONG 19N71W
26N64W. DIFFLUENCE ALOFT E OF THE FRONT AND TROF IS PRODUCING
WIDELY SCATTERED MODERATE CONVECTION IN A NARROW BAND ABOUT 120
NM E OF THE BOUNDARIES. AN UPPER RIDGE IS CENTERED FARTHER
DOWNSTREAM ALONG 50W AND IS PUSHING MOST OF THE UPPER LEVEL
MOISTURE N OF THE AREA...LEAVING A LARGE AREA OF MODERATE/STRONG
SUBSIDENCE FROM 9N-25N BETWEEN 20W-60W. AN UPPER TROF LIES ALONG
THE LEADING EDGE OF THIS DRY AIR ALONG 32N21W 20N25W 13N40W WITH
A 100 KT JET LIFTING NEWD ACROSS THE CANARY ISLANDS. THIS IS
PULLING HIGH CLOUDS OUT OF THE TROPICS NEWD TOWARDS THE CANARIES
AND THE MOROCCAN COAST. AN UPPER LEVEL ANTICYCLONE IS EMBEDDED
DEEP WITHIN THE TROPICS NEAR 7N26W WITH A RIDGE AXIS EXTENDING
EWD TOWARDS SIERRA LEONE AND LIBERIA...AND WWD ALONG THE N COAST
OF S AMERICA TO ERN VENEZUELA.

$$
BERG


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