[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 172346
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT MAY 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 33W S OF 11N MOVING W 5-10 KT. A
LOW-AMPLITUDE INVERTED-V SIGNATURE IS OBSERVED ON LATEST VISIBLE
SATELLITE IMAGERY FOR THE DAY. SCATTERED SHOWERS AND ISOLATED
TSTMS ARE WITHIN 180 NM EITHER SIDE OF AXIS S OF 8N. THE WAVE IS
WELL DEFINED ON THE MIMIC-TPW PRODUCT FROM CIMSS. THE HOVMOLLER
DIAGRAM ALSO SHOWS THE WWD PROPAGATION OF THIS WAVE.

TROPICAL WAVE IS ALONG 55W/56W S OF 11N MOVING W 10 KT. THE WAVE
COUPLED WITH THE ITCZ IS GENERATING CLUSTERS OF MODERATE TO
ISOLATED STRONG CONVECTION OVER THE GUYANAS REGION AND COASTAL
WATERS. A BULGE OF MOISTURE IS SEEN ON THE MIMIC-TPW PRODUCT
ASSOCIATED WITH THE WAVE.

TROPICAL WAVE IN THE SW CARIBBEAN ALONG 79W/80W S OF 10N MOVING
W NEAR 10 KT. THE WAVE AXIS CROSSES THE ISTHMUS OF PANAMA INTO
THE EPAC. MODERATE TO STRONG CONVECTION IS BEHIND THE WAVE
AFFECTING EASTERN PANAMA AND NORTHERN COLOMBIA. A DIFFLUENT
PATTERN ALOFT IS ENHANCING THIS CONVECTIVE ACTIVITY.

..THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 4N20W 5N30W 3N45W AND INTO NE
BRAZIL NEAR 2N52W. CLUSTERS OF SCATTERED MODERATE/ISOLATED
STRONG CONVECTION ARE FROM 2N-5N BETWEEN 13W AND 16W...AND NEAR
4N21W. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM N OF AXIS
BETWEEN 25W-30W. SIMILAR CONVECTION IS WITHIN 200 NM N OF THE
AXIS BETWEEN 40W-49W.

...DISCUSSION...

GULF OF MEXICO...
A WEAK STATIONARY FRONT STRETCHES ACROSS THE GULF THIS EVENING.
AS OF 21Z...THE FRONT ENTERS THE REGION THROUGH CENTRAL FLORIDA
AND EXTENDS ALONG THE CENTRAL GULF NEAR 25N90W TO THE BAY OF
CAMPECHE NEAR COATZACOALCOS WHERE THERE IS A CLUSTER OF MODERATE
CONVECTION. MULTILAYERED CLOUDS WITH EMBEDDED SHOWERS AND
ISOLATED TSTMS ARE BEHIND THE FRONTAL BOUNDARY COVERING A GOOD
PORTION OF THE GULF. THE FRONT WILL WEAKEN AND DISSIPATE SUN
WITH A WEAK SFC HIGH PRES BUILDING ALONG THE CENTRAL GULF. AHEAD
OF THE FRONT...SFC RIDGING IS PROVIDING A VERY WARM AND HUMID
DAY OVER SOUTH-CENTRAL FLORIDA AND THE REMAINDER OF THE GULF
WATERS. UNUSUAL SWLY WINDS ASSOCIATED WITH THE SFC RIDGE ARE
BLOWING OVER SOUTH FLORIDA ALLOWING TEMPERATURES TO CLIMB INTO
THE 90S ALONG THE EAST COAST WITH MIAMI BREAKING THE RECORD MAX
TEMP FOR THIS DATE...REACHING 94 DEGREES (PREVIOUS RECORD WAS 93
IN 1985). ALOFT...A LARGE UPPER-LEVEL HIGH REMAINS CENTERED OVER
THE CARIBBEAN SEA NOW NEAR JAMAICA EXTENDING A RIDGE OVER MOST
OF THE GULF...BUT PARTICULARLY THE EASTERN HALF. A DEEP LAYERED
TROUGH/LOW IS OVER TEXAS AND N MEXICO. SWLY WINDS BETWEEN THESE
TWO UPPER LEVEL FEATURES CONTINUE TO TRANSPORT ABUNDANT UPPER
LEVEL MOISTURE FROM THE EPAC THROUGH MEXICO INTO THE GULF WATERS
AND THE SE CONUS. THESE WINDS ARE ALSO ENHANCING CONVECTION OVER
SOUTH-CENTRAL MEXICO AND THE BAY OF CAMPECHE.

CARIBBEAN SEA...
A SFC TROUGH...REMNANTS OF A FRONTAL BOUNDARY...EXTENDS ACROSS
THE CARIBBEAN FROM THE VIRGIN ISLANDS...OVER THE SOUTHERN TIP OF
HISPANIOLA...AND ACROSS JAMAICA. SCATTERED SHOWERS ARE WITHIN 60
NM OF THE TROUGH. A PLUME OF TRANSVERSE HIGH CLOUDS EXTENDS FROM
THE SE CARIBBEAN THROUGH THE LESSER ANTILLES INTO THE TROPICAL
ATLC ASSOCIATED WITH STRONG SWLY UPPER LEVEL WINDS. OTHERWISE...
THE REMAINDER OF THE REGION IS EXPERIENCING FAIR WEATHER UNDER
THE INFLUENCE OF A MID/UPPER RIDGE ANCHORED ON A HIGH NEAR
JAMAICA AND UPPER TROUGHING OVER THE E CARIBBEAN. WEAK HIGH
PRES N OF THE AREA COMBINED WITH THE REMNANTS OF THE FRONT IS
PRODUCING LIGHT TO MODERATE TRADE WINDS ACROSS THE REGION.

ATLANTIC OCEAN...
A COUPLE OF COLD FRONTS ARE OVER THE FORECAST REGION. THE FIRST
ONE ENTERS THE AREA NEAR 31N70W THEN CONTINUES SW TO CENTRAL
FLORIDA WHERE IT BECOMES STATIONARY. SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ARE WITHIN 120 NM AHEAD OF THE BOUNDARY N
OF 29N. EXPECT THE FRONT TO MOVE RAPIDLY E AND DISSIPATE LATE
TONIGHT. MOSTLY CLEAR CONDITIONS HAVE MOVED INTO THE W ATLC
BEHIND THE FRONT. FARTHER EAST...A WEAKER COLD FRONT ENTERS THE
CENTRAL ATLC NEAR 31N44W AND EXTENDS ALONG 28N46W TO 23N53W
WHERE IT CONTINUES AS A SFC TROUGH OVER THE VIRGIN ISLANDS AND
INTO THE CARIBBEAN SEA. MULTILAYERED CLOUDS WITH EMBEDDED
SHOWERS ARE WITHIN 200 NM AHEAD OF THE FRONT N OF 24N. A LARGE
SFC RIDGE ANCHORED BY A 1025 MB SFC HIGH SOUTH OF THE AZORES
DOMINATES THE REMAINDER OF THE ATLC.
ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE DISCUSSION
AREA. THE UPPER TROUGH OVER THE CENTRAL ATLC SUPPORTS THE WEAKER
COLD FRONT. OVER THE DEEP TROPICS...AN ELONGATED RIDGE WITH AXIS
ALONG 10N REMAINS IN PLACE.

$$
GR







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