[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 311737
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN 31 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 OVER THE E CARIBBEAN ALONG 62W S OF 20N MOVING W
5-10 KT. WAVE REMAINS UNDER SOME WESTERLY SHEAR ASSOCIATED WITH
A DEEP LAYERED TROUGH OVER THE CENTRAL ATLC WHICH IS DISPLACING
ASSOCIATED CONVECTION E OF THE WAVE AXIS AND LIMITING
DEVELOPMENT. CURRENTLY...SCATTERED MODERATE CONVECTION PRIMARILY
E OF THE LESSER ANTILLES FROM 9N-18N BETWEEN 53W-61W.
HOWEVER...THIS ACTIVITY WILL LIKELY SPREAD WESTWARD ACROSS THE
ISLANDS AND WILL BE ASSISTED LATER TODAY AND TONIGHT BY
IMPROVING DYNAMICS/LIFT ASSOCIATED WITH A MIDDLE TO UPPER LEVEL
SHORTWAVE TROUGH DROPPING SEWD OVER HISPANIOLA.

TROPICAL WAVE LOCATED OVER THE W CARIBBEAN AND CENTRAL AMERICA
ALONG 83W S OF 18N MOVING SLOWLY W NEAR 5 KT. SCATTERED
SHOWERS/WIDELY SCATTERED MODERATE CONVECTION ACCOMPANY THE WAVE
S OF 19N BETWEEN JAMAICA AND 85W.  THIS ACTIVITY WILL CONTINUE
TO SPREAD WESTWARD OVER CENTRAL AMERICA DURING THE NEXT DAY OR
TWO.

...ITCZ...

ITCZ AXIS IS ALONG 13N10W 8N20W 7N30W 8N50W 11N60W 10N70W 8N80W.
NUMEROUS MODERATE TO STRONG CONVECTION FROM 6N-11N BETWEEN
30W-50W.

...DISCUSSION...

GULF OF MEXICO...
DRY/TRANQUIL WEATHER REMAINS YET ANOTHER DAY OVER THE GLFMEX
WITH DEEP LAYERED RIDGING IN CONTROL. RIDGE IS ANCHORED BY A
LARGE MID/UPPER LEVEL ANTICYCLONE JUST W OF FLORIDA WITH RIDGE
AXIS EXTENDING NE OVER THE W ATLC. SUBTROPICAL JET AND
ASSOCIATED PACIFIC MOISTURE RIDES UP AND OVER THE RIDGE INTO THE
CENTRAL UNITED STATES KEEP UPSTREAM DISTURBANCES AND ASSOCIATED
WEATHER N OF THE AREA. AT THE SURFACE...RIDGE EXTENDS FROM THE W
ATLC ACROSS N FLORIDA ALONG 28N THEN NW OVER LOUISIANA INTO E
TEXAS. RETURN FLOW OVER THE W GULF INTO CENTRAL TEXAS IS HELPING
TO PRODUCE INCREASING CONVECTION OVER INTERIOR PORTIONS OF TEXAS
ALONG A STATIONARY FRONT. AN AMPLIFYING MIDDLE TO UPPER LEVEL
TROUGH MOVING THROUGH THE SW UNITED STATES AND NW MEXICO WILL
SWEEP QUICKLY EWD PUSHING THE FRONTAL BOUNDARY OFF THE SE TEXAS
COAST LATE MONDAY INTO TUESDAY.  SCATTERED SHOWERS/THUNDERSTORMS
WILL BEGIN DEVELOPING AHEAD OF THE FRONT OVER THE NW GLFMEX
MONDAY.

CARIBBEAN...
COMPLEX PATTERN OVER THE CENTRAL TO E CARIBBEAN CONTINUES TO
PRODUCE UNSETTLED/STORMY WEATHER.  MIDDLE TO UPPER LEVEL
SHORTWAVE TROUGH DROPPING SEWD OVER HISPANIOLA IS PROVIDING THE
UPPER LEVEL SUPPORT WHILE A TROPICAL WAVE ENTERING THE E
CARIBBEAN AND A REMNANT FRONTAL BOUNDARY LIFTING N OF THE AREA
PROVIDE COPIOUS TROPICAL MOISTURE. A 40-60 KT JET STREAK FROM
JUST S OF HISPANIOLA NEWD OVER PUERTO RICO IS PROVIDING THE BEST
DYNAMICS/LIFT AND FOCUSING THE MOST INTENSE/NUMEROUS CONVECTION
N OF THE ABC ISLANDS FROM 11N-14N BETWEEN 65W-73W.  SCATTERED
MODERATE CONVECTION IS ELSEWHERE S OF PUERTO RICO BETWEEN
64W-70W.  ADDITIONAL ACTIVITY IS OVERSPREADING THE LESSER
ANTILLES IN ASSOCIATION WITH A TROPICAL WAVE. THE SHORTWAVE
TROUGH WILL BE ROUNDING THE BASE OF A LARGER SCALE TROUGH OVER
THE ATLC LATER TODAY AND TONIGHT REESTABLISHING BROAD TROUGHING
OVER THE NE CARIBBEAN ON MONDAY. THIS PATTERN COMBINED WITH
ABUNDANT LOW LEVEL MOISTURE WILL KEEP SHOWERS/THUNDERSTORMS
ACROSS THE AREA.  OVER THE NW CARIBBEAN...MODERATE TO STRONG
SUBSIDENCE AND VERY DRY AIR IN THE MIDDLE TO UPPER LEVEL IS
GRADUALLY GIVING WAY TO INCREASING LOW LEVEL MOISTURE SPREADING
WESTWARD WITH A TROPICAL WAVE ALONG 83W.  THIS COUPLED WITH A
BUILDING MIDDLE TO UPPER LEVEL RIDGE WILL PROMOTE
SHOWERS/THUNDERSTORMS TONIGHT AND TOMORROW.

SUBTROPICAL ATLANTIC...
LARGE MID/UPPER LEVEL TROUGH COVERS THE ENTIRE ATLC W OF 40W
WITH STRONG SUBSIDENCE AND VERY DRY AIR PREVAILING ALL THE WAY
TO THE SE UNITED STATES COAST. MIDDLE TO UPPER LEVEL RIDGE OVER
THE GLFMEX IS BEGINNING TO BUILD EWD OVER FLORIDA INTO THE FAR W
ATLC NEAR BERMUDA. OVER THE CENTRAL ATLC...A BROAD SWATH OF DEEP
LAYERED MOISTURE ACCOMPANIES A 100 KT SUBTROPICAL JET EXTENDING
FROM 24N45W NE TO BEYOND 32N40W. GOOD UPPER LEVEL DYNAMICS NEAR
THE ENTRANCE REGION OF THE JET IS PRODUCING AN AREA OF SCATTERED
SHOWERS/THUNDERSTORMS WITHIN 250 NM AHEAD OF A COLD FRONT FROM
32N38W TO 25N47W. FRONT CONTINUES SW TO HISPANIOLA AS A
DISSIPATING STATIONARY BOUNDARY ALONG 22N60W 19N69W WITH
SCATTERED SHOWERS AND ISOLATED MODERATE CONVECTION WITHIN 120 NM
EITHER SIDE OF BOUNDARY.  SHOWER/THUNDERSTORM ACTIVITY IS
INCREASING JUST S OF THIS BOUNDARY OR N AND E OF THE LEEWARD
ISLANDS COURTESY OF A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH
MOVING SEWD OVER HISPANIOLA. THIS ACTIVITY SHOULD CONTINUE TO
INCREASE THIS AFTERNOON AND TONIGHT AS A 40-60 KT JET STREAK
LIFTS NEWD FROM THE E CARIBBEAN.  FARTHER E...DEEP LAYERED
RIDGING DOMINATES THE REMAINDER OF THE ATLC E OF 40W WITH
ASSOCIATED SUBSIDENCE AND DRY MIDDLE TO UPPER LEVEL AIR LIMITING
SIGNIFICANT CLOUDS/CONVECTION.

TROPICAL ATLANTIC...
THE MIDDLE TO UPPER LEVEL PATTERN IS COMPRISED OF A FLAT RIDGE
EXTENDING E/W ALONG 10N/11N W OF 40W...CUTOFF LOW IS NEAR
17N38W...AND WEAK RIDGE OVER THE CAPE VERDE ISLANDS.  STRONG WLY
FLOW ASSOCIATED WITH THIS PATTERN PENETRATES WELL INTO THE
TROPICAL BELT TO 10N.   DIFFLUENT FLOW BETWEEN THE RIDGE W OF
40W AND UPPER LOW NEAR 17N38W IS SUPPORTING A LARGE AREA OF
NUMEROUS CONVECTION ALONG THE ITCZ BETWEEN 30W-50W WHILE
MODERATE SUBSIDENCE E OF 30W IS LIMITING ACTIVITY.

$$
RHOME



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