[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 091712
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON 09 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1645 UTC.

...TROPICAL WAVES...

TROPICAL WAVE ABOUT MIDWAY BETWEEN AFRICA AND THE WINDWARD
ISLANDS ALONG 39W S OF 15N MOVING W 10-15 KT. VISIBLE IMAGES
SHOW AN INVERTED-V SIGNATURE FROM THE ITCZ TO THE APEX OF THE
WAVE.  THE WAVE IS NOT CAUSING ANY CONVECTION OUTSIDE OF A FEW
TSTMS WITHIN 60 NM OF 6N39W.

W CARIBBEAN TROPICAL WAVE ALONG 78W/79W S OF 17N MOVING W 10-15
KT.  LONG-TERM SATELLITE LOOPS SUGGEST THE WAVE IS RESPONSIBLE
FOR ENHANCED SHOWERS/POSSIBLE TSTM ACTIVITY S OF JAMAICA BETWEEN
77W-81W N OF 15N.  IN ADDITION SCATTERED MODERATE CONVECTION IN
THE FAR SW CARIBBEAN S OF 10N MAY BE INFLAMED DUE TO THE WAVE'S
PRESENCE.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 10N12W 5N22W 3N29W 6N38W 3N44W
3N51W.  ISOLATED MODERATE BETWEEN 4N-8N FROM 10W-20W AND WITHIN
60 NM OF THE ITCZ FROM 22W-30W.  ANOTHER TROPICAL WAVE HAS
PROBABLY LEFT THE AFRICAN COAST AND MAY BE ADDED BETWEEN DAKAR
AND SAL AT 1800 UTC.

...DISCUSSION...

GULF OF MEXICO...
WEATHER PATTERN IS STUCK IN PLACE WITH GENERALLY ELY WINDS IN
THE E GULF AND SLY WINDS IN THE W GULF.  DEWPOINTS ARE SLOWLY
RISING AS THE SPRING AIRMASS MODIFIES OVER THE WARMER GULF/ATLC
WATERS.  LEFTOVER MOISTURE FROM YESTERDAY'S TSTMS ARE STILL
RESPONSIBLE FOR A FEW TSTMS N OF 28N W OF 90W..SPARKED BY A
MID/UPPER TROUGH OVER THE MISSISSIPPI VALLEY.  OTHERWISE THE
UPPER PATTERN IN THE GULF IS RATHER ZONAL WITH MODERATE/STRONG
SUBSIDENCE PRODUCING DRY CONDITIONS ALOFT S OF 27N.  A FEW
ISOLATED TSTMS ARE POSSIBLE THRU THE WEEK IN THE EXTREME
NORTHERN GULF FROM THE UPPER TROUGH... OTHERWISE MOSTLY DRY
CONDITIONS ARE EXPECTED.  SMOKE CONTINUES TO BE A PROBLEM OVER
THE W GULF FROM THE BAY OF CAMPECHE NWD TO THE MEXICO/TEXAS
BORDER W OF 90W...AND LOW-LEVEL SELY FLOW MAY BRING SOME OF THIS
AIR INLAND OVER NE MEXICO TODAY.

CARIBBEAN...
WIDESPREAD CIRRUS CONTINUES OVER THE CARIBBEAN BASIN THIS
MORNING AS TRPCL MOISTURE IS ADVECTED IN FROM THE E PAC AND FROM
TSTMS IN THE SW CARIBBEAN.   PERSISTENT SHOWERS/TSTMS HAVE BEEN
OCCURRING OVER THE SW CARIBBEAN FOR THE PAST FEW DAYS AND
ISOLATED TSTMS HAVE ALSO BEEN HUGGING THE COASTS OF PANAMA AND
COSTA RICA WITH AN UPPER TROUGH ALONG 82W S OF 18N ENHANCING THE
CONVECTION. A STATIONARY FRONT NEAR HISPANIOLA IS DISSIPATING
AND MOISTURE FROM THE SYSTEM SHOULD REMAIN OVER THE ISLAND FOR
THE REST OF THE WEEK. SW FLOW ALOFT CONTINUES OVER THIS ISLAND
WITH IMPULSES IN THE FLOW HELPING TO FORM WIDELY SCATTERED
SHOWERS/TSTMS OVER THE HIGH TERRAIN...LIKELY FOR THE REST OF THE
WEEK.  STRONGER AND MORE WIDESPREAD CONVECTION IS ANTICIPATED BY
WED NIGHT INTO THE WEEKEND AS MOISTURE OVER THE CARIBBEAN
INCREASES DRASTICALLY DUE TO A BROAD UPPER TROUGH OVER THE W
ATLC DIPPING INTO THE REGION.  SOME OF THIS CONVECTION IS ALSO
LIKELY TO SPREAD OVER PUERTO RICO AND THE NRN LEEWARD
ISLANDS...POSSIBLY LEADING TO FLASH FLOODING/MUDSLIDES DURING
THE WEEK ESPECIALLY IN THE STEEPER TERRAIN OF ALL THESE ISLANDS.

ATLANTIC...
1020 MB HIGH IS SITTING OVER GRAND BAHAMA ISLAND WITH MOSTLY
LIGHT WINDS N OF 26N W OF 70W IN THE AREA.  STRONG SUBSIDENCE IS
IN THE MID/UPPER LEVELS...ATTRIBUTABLE TO A BROAD UPPER TROF
OVER THE W ATLC W OF 60W. A COLD FRONT HAS MOVED WELL AHEAD OF
THE ACTUAL LOW AND ENTERS THE AREA NEAR 32N57W TO 25N61W
STATIONARY TO 21N66W DISSIPATING TO CENTRAL HISPANIOLA.
DIFFLUENCE ALOFT AHEAD OF THE UPPER TROF IS GENERATING WIDELY
SCATTERED MODERATE CONVECTION UP TO 120 NM E OF THE FRONT N OF
26N WITH OTHER ISOLATED SHOWERS FROM HISPANIOLA E TO THE NRN
LEEWARD ISLANDS. THIS BOUNDARY OR A WEAKENED VERSION WILL REMAIN
NEAR THESE ISLANDS DURING THE UPCOMING WEEK PROVIDING THE FOCUS
MECHANISM FOR POTENTIALLY HEAVY RAINFALL BY LATE WED. A SECOND
COLD FRONT IS SWEEPING SWD AROUND THE LOW INTO THE AREA ALONG
32N65W 28N68W DISSIPATING TO 28N74W AND IS BRINGING IN SLIGHTLY
DRIER AIR INTO THE REGION. UPPER LEVEL RIDGING IS LOCATED OVER
THE CNTRL ATLC ALONG 48W WITH A SFC RIDGE FROM A 1022 MB HIGH
NEAR 31N45W SW TO 20N60W AND SE TO 23N30W THEN NE TO THE CANARY
ISLANDS.  BROAD UPPER TROUGH CONTROLS THE E ATLC... WITH A GALE
LOW NEAR THE AZORES DOING LOOPS NEAR THE ISLANDS,  THE LOW IS
THE SAME LOW THAT CAUSED GALE FORCE WINDS S OF 31N LAST WEEK AND
IS STUCK BENEATH AN UPPER HIGH W OF SPAIN.  A WEAK SFC TROF
ATTACHED TO A SPIRALING LOW NEAR THE AZORES IS JUST EDGING INTO
THE AREA ALONG 32N20W 27N31W AND IS ONLY BRINGING IN BROKEN
STRATOCUMULUS SWD TO 26N.  VISIBLE SATELLITE IN THE E ATLC ALSO
SUGGESTS DUST BLOWING OFFSHORE OF AFRICA... THIS TIME MOSTLY N
OF DAKAR TO 22N E OF THE CAPE VERDE ISLANDS.

$$
BLAKE

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