[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 191743
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON MAY 19 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS TITLED ALONG 41W/42W S OF 13N MOVING W 10-15
KT. VIS SATELLITE IMAGERY SHOWS SOME CYCLONIC TURNING ALONG THE
WAVE AXIS NEAR 8N. THIS FEATURE IS WELL DEFINED ON THE MIMIC-TPW
PRODUCT FROM CIMSS. SCATTERED SHOWERS AND ISOLATED TSTMS ARE
WITHIN 180 NM EITHER SIDE OF THE WAVE AXIS.

A TROPICAL WAVE IS IN THE CARIBBEAN SEA ALONG 65W/66W S OF 13N
MOVING W 10 KT. MUCH OF THE WAVE IS NOW INLAND OVER SOUTH
AMERICA...WHICH WILL MAKE IT DIFFICULT TO TRACK FOR THE NEXT
COUPLE OF DAYS. THIS WAVE MAY BE ENHANCING CONVECTION W OF THE
AXIS OVER WRN VENEZUELA.

..THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 5N10W 4N23W 3N36W 4N44W 3N51W.
CLUSTERS OF MODERATE TO STRONG CONVECTION ARE FROM EQUATOR TO 8N
BETWEEN 4W-15W. PART OF THIS ACTIVITY IS AFFECTING SW AFRICA
INCLUDING LIBERIA. THIS CONVECTIVE ACTIVITY MAY BE ASSOCIATED
WITH A NEW TROPICAL WAVE. UPPER DIFFLUENCE ASSOCIATED WITH AN
UPPER HIGH LOCATED OVER W AFRICA NEAR 12N15W IS HELPING TO
INDUCE THIS ACTIVITY.

...DISCUSSION...

THE GULF OF MEXICO...

A SFC TROUGH...REMNANTS OF FRONTAL BOUNDARY IS ALONG THE GULF.
AS OF 1500Z...THE TROUGH EXTENDS FROM N FLORIDA TO THE CENTRAL
GULF NEAR 24N90W TO THE BAY OF CAMPECHE WHERE IT IS GENERATING
A CLUSTER OF MODERATE CONVECTION. LIGHTNING DATA SHOWS SCATTERED
TSTMS IN THIS AREA. A 140 NM BAND OF LOW/MID CLOUDS WITH
EMBEDDED SHOWERS AND TSTMS IS ALSO ASSOCIATED WITH THE TROUGH
OVER N-CENTRAL FLORIDA. THE STRONGEST ACTIVITY IS CURRENTLY OVER
THE TAMPA BAY AREA. A WEAK 1015 MB HIGH IS BEHIND THE TROUGH AXIS
NEAR THE MEXICAN COAST BETWEEN TAMPICO AND TUXPAN. ALOFT...
STRONG SW FLOW DOMINATES MUCH OF THE GULF OF MEXICO MOISTENING
THE MID AND UPPER LEVELS SE OF A LINE FROM NE MEXICO TO N
FLORIDA. THESE WINDS ARE ALSO ENHANCING CONVECTION OVER THE BAY
OF CAMPECHE. MODERATE TO STRONG SUBSIDENCE IS OVER THE NORTHERN
GULF WATERS. SFC WINDS ARE MAINLY LIGHT ACROSS THE REGION DUE TO
THE WEAK FRONT AND A 1015 MB HIGH OVER THE WESTERN GULF. THE SFC
TROUGH IS FORECAST TO DISSIPATE TONIGHT THROUGH TUE. THE GFS
MODEL KEEPS MOISTURE FROM THIS TROUGH OVER THE BAY OF CAMPECHE
AND PARTS OF THE YUCATAN PENINSULA DURING THE NEXT 12-24 HOURS.

THE CARIBBEAN SEA...

CLUSTERS OF MODERATE TO STRONG CONVECTION HAVE DEVELOPED OVER
THE SW CARIBBEAN POSSIBLY ASSOCIATED WITH THE COLOMBIAN LOW AND
A DIFFLUENT PATTERN ALOFT. A 1011 MB LOW IS ANALYZED NEAR 9N76W.
THIS ACTIVITY IS FORECAST BY THE COMPUTER MODELS TO SPREAD OVER
PARTS OF CENTRAL AMERICA DURING THE NEXT FEW DAYS. PRES GRADIENT
BETWEEN A SFC RIDGE ALONG THE GREATER ANTILLES AND THE COLOMBIAN
LOW IS PRODUCING MODERATE TO FRESH TRADE WINDS ACROSS THE
SOUTH-CENTRAL CARIBBEAN. A QUIKSCAT PASS FROM AROUND 11Z SHOWED
ELY WINDS OF 20 TO 25 KT IN THIS AREA. THESE WINDS VEER SE OVER
THE NW WATERS IN RESPONSE TO THE TROUGH IN THE GULF OF MEXICO. A
MID/UPPER LEVEL RIDGE CONTINUES TO COVER MOST OF THE BASIN WHILE
A SMALL UPPER LOW IS JUST SOUTH OF PUERTO RICO NEAR 16N66W.
THESE UPPER FEATURES ARE PRODUCING MODERATE TO STRONG SUBSIDENCE
IN THE IMPLIED DRY AND STABLE AIR MASS. AS USUAL...FRAGMENTS OF
LOW LEVEL CLOUDS WITH EMBEDDED SHALLOW SHOWERS ARE MOVING ACROSS
THE NE CARIBBEAN.

THE ATLANTIC OCEAN...

THE SFC TROUGH THAT LIES OVER THE GULF OF MEXICO AND N FLORIDA
EXTENDS NEWD OVER THE FAR NW PORTION OF THE FORECAST AREA.  THIS
FEATURE IS GENERATING SOME SHOWER ACTIVITY MAINLY N OF 27N AND
WEST OF 70W. SFC HIGH PRES CENTERED S OF THE AZORES NEAR 32N27W
DOMINATES THE WEATHER PATTERN ACROSS THE REMAINDER OF THE REGION
WITH THE EXCEPTION OF A WEAK TROUGH THAT RUNS FROM 31N42W TO
25N47W. THERE IS SOME SHOWERS ACTIVITY NEAR THE NORTHERN END OF
THIS TROUGH. PATCHES OF LOW LEVEL CLOUDS AND MAINLY LIGHT WINDS
ARE SEEN UNDER THE INFLUENCE OF THIS SYSTEM. A SFC RIDGE EXTENDS
SW ENVELOPING THE BAHAMAS...THE GREATER ANTILLES AND THE NE
CARIBBEAN. PRES GRADIENT BETWEEN THE AZORES HIGH AND LOWER PRES
OVER AFRICA IS PRODUCING A SWATH OF MODERATE TO STRONG NELY
WINDS NEAR THE AFRICAN COAST BETWEEN THE CANARY AND THE CAPE
VERDE ISLANDS. THESE CONDITIONS WILL PERSIST OVER THE NEXT FEW
DAYS. IN THE MID AND UPPER LEVELS...A LARGE SCALE RIDGE LIES
OVER MUCH OF THE CENTRAL AND WESTERN ATLANTIC ANCHORED ON A HIGH
NEAR 22N63W. THIS BROAD SYSTEM IS PROVIDING DRY STABLE AIR ALOFT
ACROSS MUCH OF THE AREA W OF 50W. AN UPPER-LEVEL TROUGH ENTERS
THE AREA NEAR 31N33W THEN CONTINUES SW TO 10N50W. SCATTERED
SHOWERS ARE JUST AHEAD THE TROUGH AXIS.

$$
KB/GR


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