[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 151024
TWDAT

TROPICAL WEATHER DISCUSSION...
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE APR 15 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
0945 UTC.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N8W 2N20W 1N30W CROSSING THE
EQUATOR NEAR 43W AND INTO NE BRAZIL NEAR 1S47W. CLUSTERS OF
SCATTERED MODERATE TO STRONG CONVECTION ARE WITHIN 90 NM EITHER
SIDE OF THE AXIS BETWEEN THE WEST COAST OF AFRICA AND 14W.
SIMILAR CLUSTERS OF MODERATE TO STRONG CONVECTION ARE FROM THE
EQUATOR TO 6N BETWEEN 20W-25W. SCATTERED MODERATE TO STRONG
CONVECTION IS WITHIN 160 NM N OF THE AXIS BETWEEN 36W-45W.

...DISCUSSION...

THE GULF OF MEXICO...
AS OF 09Z...THE ONLY REMAINING PORTION OF THE COLD FRONT THAT
HAS BEEN TRAVERSING THE GULF IS IN THE BAY OF CAMPECHE FROM
19N91W ALONG 19N94W TO 22N97W. THE FRONT IS FAIRLY DRY IN THE
GULF WITH ONLY A NARROW BAND OF LOW-LEVEL CLOUDS DEVELOPING
ALONG THE BOUNDARY. COLD AIR STRATOCUMULUS CLOUDS CONTINUE TO
COVER THE GULF. SHIP AND BUOY OBSERVATIONS INDICATED THAT WINDS
IN THE NW GULF HAVE SHIFTED E TO SE AT 5-10 KT. NORTHERLY WINDS
COVER THE REMAINDER OF THE GULF...HOWEVER...THESE TOO ARE
EXPECTED TO VEER SE AND DIMINISH AS HIGH PRESSURE MOVES INTO THE
AREA AND SETS UP RETURN FLOW AROUND THE RIDGE LATER TODAY.
ALOFT...NEAR ZONAL FLOW AT THE BASE OF AN UPPER TROUGH RESULTS
IN STRONG SUBSIDENCE OVER THE NORTHERN GULF WATERS.

THE CARIBBEAN SEA...
A FRONTAL BOUNDARY REMAINS ANCHORED IN THE WESTERN CARIBBEAN. AS
OF 09Z...THE STATIONARY BOUNDARY STRETCHED FROM SE CUBA NEAR
20N77W TO HONDURAS NEAR 16N86W. TO THE NW...A COLD FRONT HAS
ENTERED THE CARIBBEAN AND...AS OF 09Z...WAS ANALYZED FROM SW
CUBA NEAR 22N81W TO THE YUCATAN PENINSULA NEAR 20N87W. NE WINDS
10-15 KT AHEAD OF THE BOUNDARY WILL SHIFT NW AND INCREASE TO 20
KT FOLLOWING THE FRONTAL PASSAGE. LOW CLOUDS AND EMBEDDED
ISOLATED SHOWERS ARE BETWEEN THE TWO BOUNDARIES. FARTHER
EAST...A SFC TROUGH STRETCHING FROM HISPANIOLA TO COLOMBIA
CONTINUES TO MOVE WESTWARD THROUGH THE CARIBBEAN. SCATTERED
SHOWERS ARE WITHIN 120 NM W OF THE AXIS. BROKEN LOW CLOUDS AND
ISOLATED SHOWERS COVER THE CARIBBEAN E OF THE TROUGH. EXPECT
THIS TROUGH TO GRADUALLY DISSIPATE AS IT INTERACTS WITH THE
FRONTAL BOUNDARIES IN THE WESTERN CARIBBEAN. ALOFT...A FLATTENED
UPPER RIDGE RESIDES OVER THE CENTRAL AND WESTERN CARIBBEAN...
KEEPING THE ATMOSPHERE FAIRLY STABLE.

WESTERN ATLANTIC...
THE WEATHER PATTERN IN THE W ATLC IS DEFINED BY THE EXISTENCE OF
TWO COLD FRONTS. AS OF 09Z...THE EASTERN-MOST FRONTAL BOUNDARY
ENTERS THE REGION NEAR 31N66W AND CONTINUES SW OVER THE BAHAMAS
BEFORE CROSSING OVER CUBA NEAR 21N76W. MULTILAYERED CLOUDS WITH
EMBEDDED SHOWERS ARE WITHIN 80 NM BEHIND THE BOUNDARY. THE
SECOND FRONT ENTERS THE W ATLC NEAR 31N71W AND CONTINUES OVER
THE NW BAHAMAS BEFORE CROSSING OVER CUBA NEAR 23N80W. ASSOCIATED
CONVECTION IS MOSTLY CONFINED TO THE AREA N OF 25N...WITH
LIGHTING DATA INDICATING NUMEROUS ISOLATED THUNDERSTORMS JUST N
OF THE DISCUSSION AREA. THE TWO FRONTS ARE EXPECTED TO MERGE AND
FORM A SFC LOW NEAR 30N78W LATE TODAY. STRONG N WINDS BEHIND THE
FRONT ARE EXPECTED TO REACH GALE FORCE TO THE WEST OF THE
DEVELOPING SFC LOW.

CENTRAL AND EASTERN ATLANTIC...
THE CENTRAL AND EASTERN ATLC REMAIN TRANQUIL UNDER THE INFLUENCE
OF A BROAD DEEP-LAYERED RIDGE ANCHORED BY A 1027 MB SFC HIGH
NEAR 30N43W. ANTICYCLONIC FLOW AROUND THE RIDGE CONTINUES TO
TRANSPORT PATCHY CLOUDS ACROSS THE REGION. IN THE DEEP
TROPICS....AN UPPER HIGH IS SITUATED NEAR 9N33W ENHANCING
CONVECTION IN THE ITCZ. WLY FLOW N OF THE UPPER RIDGE AND S OF
AN ELONGATED UPPER TROUGH IS TRANSPORTING UPPER LEVEL
MOISTURE/HIGH CLOUDS FROM S AMERICA TO AFRICA BETWEEN 11N-18N.

$$
WADDINGTON




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