[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 221752
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI 22 OCT 2004

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN
SECTIONS OF SOUTH AMERICA...AND ATLC 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
1715 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ADDED ALONG 46W S OF 16N MOVING W 15 KT.
LONG-TERM SATELLITE LOOPS SHOW A COHERENT LOW/MID LEVEL WAVE
TRACEABLE FOR A FEW DAYS.  ISOLATED MODERATE FROM 10N-15N
BETWEEN 44W-47W.

TROPICAL WAVE PREVIOUSLY ALONG 60W IS WEAKENING AND CAN NO
LONGER BE TRACKED DUE TO THE ILL-DEFINED LOW PRESSURE SYSTEM
NEAR HISPANIOLA.  ITS REMNANTS COULD BE ENHANCING SHOWERS IN THE
E CARIBBEAN E OF 65W THOUGH.

W CARIBBEAN TROPICAL WAVE ALONG 84W S OF 16N MOVING W 10 KT.
WAVE MIGHT BE RESPONSIBLE FOR SOME TSTMS NEAR NICARAGUA
OTHERWISE WIDELY SCATTERED MODERATE OVER COSTA RICA W OF 84W.

...ITCZ...
ITCZ AXIS IS ALONG 7N12W 5N30W 9N45W 10N62W.  AXIS NOT
PARTICULARLY WELL-DEFINED W OF 57W.  WIDELY SCATTERED MODERATE
WITHIN 75/90 NM OF AXIS BETWEEN 18W-27W.  SCATTERED MODERATE
BETWEEN 4N-8.5N BETWEEN 35W-45W.  ISOLATED MODERATE WITHIN 75 NM
OF AXIS BETWEEN 52W-57W.

...DISCUSSION...
GULF OF MEXICO...
WARM WEATHER CONTINUES IN THE WESTERN GULF STATES WHILE SLIGHTLY
COOLER/DRIER AIR IS FILTERING INTO THE EASTERN GULF.  THESE
MILDER CONDITIONS ARE BEING BROUGHT DOWN BY A COLD FRONT WHICH
IS THROUGH S ALABAMA INTO THE FLORIDA STATES THEN INTO THE
CENTRAL BAHAMAS.  MID/UPPER RIDGE IS SITTING OVER NE MEXICO WITH
STRONG SUBSIDENCE LIMITING ANY SHOWER ACTIVITY IN THE GULF
EXCEPT ISOLATED SPOTS NEAR THE COLD FRONT.  A NEW COLD FRONT IS
FORECAST TO MOVE INTO THE GULF ON SUN THOUGH IT IS EXPECTED TO
HANG UP IN THE NW GULF AND MAKE A DEEPER PUSH THRU THE E GULF IN
THE MEDIUM-RANGE.  THE FRONT SHOULD INCREASE RAIN CHANCES FOR
LATE TOMORROW ALONG THE GULF COAST INTO SAT NIGHT W OF FLORIDA.

SUBTROPICAL ATLC W OF 60W AND CARIBBEAN SEA...
A DEEP-LAYERED TROUGH FROM ABOUT 32N70W SSW THRU THE CENTRAL
BAHAMAS... E CUBA AND JAMAICA INTO NICARAGUA IS RESPONSIBLE FOR
THE PUSH OF DRIER AIR INTO THE TROPICS.  VERY DRY AIR AT THE
MID/UPPER LEVELS IS KEEPING ANY CONVECTION QUITE SHALLOW AND
MOSTLY OVER LAND IN A DIURNAL HEATING FASHION.  AHEAD OF THE
TROUGH... UNSETTLED WEATHER IN LIFT/DIVERGENCE IS OCCURRING OVER
THE W ATLC WITH ISOLATED MODERATE FROM 21N-32N BETWEEN 60W-70W.
SURFACE OBSERVATIONS INDICATE THAT A WEAK 1008 MB LOW HAS
DEVELOPED NEAR E DOMINICAN REPUBLIC AROUND 18N69W.  THIS LOW
DOES NOT APPEAR TO HAVE ANY POTENTIAL FOR TROPICAL DEVELOPMENT
WITH STRONG SHEAR PRESENT... HOWEVER IT WILL CONTINUE SPREADING
MOISTURE FROM THE SOUTH OVER THE LEEWARD ISLANDS INTO PUERTO
RICO WITH A GREATER-THAN-AVERAGE CHANCE FOR RAIN OVER THE NEXT
FEW DAYS.  FARTHER S IN THE CARIBBEAN... ANOTHER WEAK LOW MAY BE
FORMING OFFSHORE OF COLOMBIA NEAR 11.5N77.5W.  OBSERVATIONS
ALONG NW COLOMBIA SHOW S TO SW WINDS... WHICH ARE BASICALLY A
TOTAL REVERSAL OF THE CLIMATOLOGICAL AVERAGE.  IN ANY EVENT THIS
AREA IS EXPERIENCING STRONG SHEAR AS WELL BUT IT FORECAST TO LET
UP SOME BY THE BEGINNING OF NEXT WEEK.  WIDELY SCATTERED
MODERATE S OF 15N BETWEEN 74W-78W.  OTHER ADDITIONAL HEAVY RAINS
ARE S OF PUERTO RICO WITH SCATTERED MODERATE FROM 14N-16.5N
BETWEEN 63W-68W AND MORE ISOLATED ACTIVITY IS IN THE LESSER
ANTILLES E OF 64W.  WET WEATHER IS LIKELY TO CONTINUE FOR THE
NORTHERN LESSER ANTILLES INTO PUERTO RICO FOR THE WEEKEND WITH
PERHAPS SOME IMPROVEMENT FOR THE WINDWARD ISLANDS.

SUBTROPICAL ATLC E OF 60W AND TROPICAL ATLC...
A LARGE RIDGE IN THE MID/UPPER LEVELS DOMINATES THIS AREA W OF
35W WITH A HIGH CENTER CLOSE TO BARBADOS AND RIDGE AXIS FROM
ALONG THE NORTHERN VENEZUELAN COAST TO 20N50W THEN N TO 32N48W.
WEAK SHORTWAVE NEAR 23N62W IS ENHANCING WIDELY SCATTERED
MODERATE CONVECTION FROM 22N-29N BETWEEN 53W-60W.  THIS AREA IS
ALONG A BROAD SURFACE TROUGH RUNNING FROM JUST N OF PUERTO RICO
TO 22N50W.  A VERY MOIST ENVIRONMENT COUPLED WITH THE LOW-LEVEL
DISTURBANCE IS PRODUCING WIDELY SCATTERED MODERATE FROM 17N-23N
BETWEEN 43W-50W.  TROUGH IS OVER THE E ATLC FROM THE MADRAS
ISLANDS TO JUST NW OF THE CAPE VERDES NEAR 20N28W.  HOWEVER THIS
FEATURE IS QUITE DRY WITH NO ASSOCIATED CONVECTION.  HIGH
PRESSURE AT THE SURFACE CONTROLS THE E ATLC WITH A 1020 MB
CENTER NEAR 26N32W SW TO 14N52W W TO 14N64W.  AN AMPLIFIED
PATTERN IS FORECAST OVER THE AREA FOR THE FORESEEABLE FUTURE
WITH A DEEP TROUGH NEAR BERMUDA... STRONG RIDGING IN THE CENTRAL
ATLC AND TROUGHING PERSISTING W OF AFRICA.

$$
BLAKE

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