[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 161152
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT FRI MAY 16 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
1015 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ALONG 29W S OF 11N MOVING W 15-20 KT.
SATELLITE IMAGERY SHOWS A BROAD AREA OF LOW LEVEL CYCLONIC
TURNING ALONG THE WAVE NEAR 5N. SCATTERED SHOWERS AND TSTMS ARE
WITHIN 150 NM ON EITHER SIDE OF THE WAVE AXIS. MORE SHOWER AND
TSTM ACTIVITY IS OBSERVED BEHIND THE WAVE AXIS FROM 2N-7N
BETWEEN 22W AND 25W. THIS CONVECTIVE ACTIVITY IS BEING ENHANCED
BY UPPER DIFFLUENCE ASSOCIATED WITH AN UPPER-LEVEL HIGH LOCATED
NEAR 7N21W.

A TROPICAL WAVE IS ALONG 49W/50W S OF 11N MOVING W 10-15 KT. AN
INVERTED-V PATTERN IS FAIRLY WELL DEFINED ON SATELLITE IMAGERY
WITH SOME LOW-LEVEL CYCLONIC TURNING ALONG THE WAVE AXIS NEAR
6N. SCATTERED SHOWERS AND TSTMS ARE WITHIN 160 NM ON EITHER SIDE
OF THE AXIS BETWEEN 4N-8N. THE SSMI-DERIVED TOTAL PRECIPITABLE
WATER PRODUCT FROM CIMSS SHOWS A FAIR LOW-LEVEL MOISTURE SURGE
NORTH ALONG 49W SUPPORTING THE POSITION OF THE WAVE.

AN ILL-DEFINED TROPICAL WAVE IS ALONG 73W/74W OVER N COLOMBIA S
OF 13N MOVING W 10-15 KT. A SMALL BULGE OF MOISTURE ON THE MIMIC
TPW ANIMATION N OF THE GUAJIRA PENINSULA SUGGESTS THE PRESENCE
OF THIS WAVE THAT IS ENHANCING SOME SHOWER/TSTM ACTIVITY ACROSS
N COLOMBIA. HOWEVER...NO OTHER AVAILABLE DATA CAN CURRENTLY
CONFIRM OR DENY THE PRESENCE OF THIS FEATURE ESPECIALLY AS IT
MOVES OVER THE HIGH TERRAIN OF W COLOMBIA. FOR THE TIME
BEING...THE WAVE HAS BEEN EXTRAPOLATED WESTWARD IN ORDER TO KEEP
CONTINUITY WITH PREVIOUS MOTION.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 9N13W 9N20W 6N27W 3N31W 2N36W 4N47W.
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 NM OF A
LINE FROM 2N10W TO 3N19W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 5N-7N BETWEEN 11W-15W. SIMILAR CONVECTION IS
WITHIN 90 NM OF A LINE FROM 9N19W TO 3N25W.

...DISCUSSION...

GULF OF MEXICO...
UPPER LEVEL RIDGE CENTERED IN THE NW CARIBBEAN SEA CONTINUES TO
TRANSPORT MOISTURE FROM THE EPAC ACROSS MEXICO AND S TEXAS INTO
THE W GULF. UPPER LEVEL TROUGH OVER THE SW CONUS SUPPORTS COLD
FRONT WHICH ENTERS THE GULF NEAR ATCHAFALAYA BAY LOUISIANA AND
EXTENDS ACROSS THE NW GULF INLAND S OF BROWNSVILLE. SCATTERED
SHOWERS AND THUNDERSTORMS CONTINUE ACROSS THE NW GULF AS FRONT
CONTINUES TO SLOWLY MOVE EASTWARD. A PRE-FRONTAL TROUGH EXTENDS
FROM NEAR 26N94W TO NEAR TUXPAN MEXICO AND IS AIDING IN
CONVECTIVE ACTIVITY AS WELL. THIS PATTERN IS PRODUCING SOUTHERLY
15-20 KT WINDS ACROSS MUCH OF THE GULF AHEAD OF FRONTAL
BOUNDARY. A 1020 MB SURFACE HIGH PRESSURE CENTERED IN THE W ATLC
WITH ASSOCIATED RIDGE ACROSS THE STRAITS OF FLORIDA AND THE SE
GULF IS PROVIDING FAIR WEATHER E OF 85W. THE FRONT CURRENTLY IN
THE NW GULF IS FORECAST TO EXTEND FROM NORTH FLORIDA TO NEAR
27N86W BY FRIDAY NIGHT AND BECOME STATIONARY WEAKENING ON
SATURDAY.

CARIBBEAN SEA...
THE TAIL END OF A COLD FRONT FROM THE CENTRAL ATLC REMAINS
ACROSS PUERTO RICO AND S HISPANIOLA WHERE IT IS PRODUCING BROKEN
LOW/MID CLOUDS AND MAINLY LIGHT SHOWERS. THE REMAINDER OF THE
BASIN IS FAIRLY TRANQUIL DUE TO THE PRESENCE OF A MID/UPPER
RIDGE OVER THE W AND CENTRAL CARIBBEAN AND UPPER TROUGHING OVER
THE E CARIBBEAN. THIS UPPER PATTERN IS PRODUCING MODERATE TO
STRONG SUBSIDENCE SUPPRESSING THE DEVELOPMENT OF ANY SIGNIFICANT
CONVECTION. FRESH TRADE WINDS REMAIN ACROSS MUCH OF THE
CARIBBEAN SEA AND ARE EXPECTED TO INCREASE SLIGHTLY DURING THE
WEEKEND AS W ATLC RIDGE GRADUALLY BUILDS IN ACROSS THE GREATER
ANTILLES.

ATLANTIC OCEAN...
AN UPPER-LEVEL TROUGH EXTENDS ALONG 54W N OF 20N OVER THE
CENTRAL ATLC. THIS SUPPORTS A COLD FRONT THAT ENTERS THE
DISCUSSION AREA NEAR 32N50W THROUGH 25N52W TO S OF SAINT CROIX.
LOW-LEVEL CONVERGENCE ALONG THE FRONTAL BOUNDARY COUPLED WITH A
DIFFLUENT PATTERN ALOFT IS PRODUCING A 200 NM WIDE BAND OF
SCATTERED SHOWERS AND TSTMS E OF THE FRONT N OF 23N. A 1020 MB
SURFACE HIGH PRESSURE LOCATED NEAR 29N71W IS BEHIND THE FRONT
PRODUCING MOSTLY FAIR WEATHER ACROSS THE BAHAMAS AND CUBA. THIS
HIGH IS FORECAST TO MOVE ESE OVER THE W ATLC DURING THE NEXT 24
HOURS. THE REMAINDER OF THE CENTRAL AND E ATLC IS DOMINATED BY A
1023 MB SURFACE HIGH LOCATED NEAR 32N38W. THE TIGHT PRESSURE
GRADIENT BETWEEN THE HIGH AND THE AFOREMENTIONED FRONT IS
PRODUCING SOUTHERLY WINDS OF 20-30 KT WITHIN 300 NM E OF THE
COLD FRONT N OF 27N. IN THE UPPER LEVELS...A RIDGE/TROUGH/RIDGE
PATTERN DOMINATES THE DISCUSSION AREA. IN THE DEEP TROPICS...AN
ELONGATED RIDGE REMAINS BETWEEN AFRICA AND THE WINDWARD ISLANDS
WITH AXIS ALONG 10N ENHANCING CONVECTION ALONG THE ITCZ.

$$
HUFFMAN




This weather bulletin was brought to you by:
www.nashvilleweather.net