[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 122357
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED 12 JAN 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N10W 3N20W 2N30W 8N45W 9N60W
6N80W.  WIDELY SCATTERED MODERATE CONVECTION IS FROM 4N-8N
BETWEEN 18W-23W.  ISOLATED MODERATE CONVECTION IS WITHIN 90 NM
OF THE AXIS BETWEEN 30W-55W.

...DISCUSSION...
GULF OF MEXICO...
THE PATTERN OVER THE GLFMEX CONTINUES TO BE DRY/TRANQUIL AS
LARGE SCALE RIDGING MAINTAINS ITS GRIP OVER THE E HALF OF THE
UNITED STATES.  HOWEVER...A DEEP LAYERED TROUGH CURRENTLY
MOVING  ACROSS THE SW UNITED STATES IS EXPECTED TO PUSH THE
RIDGE INTO THE W ATLC ALLOWING A COLD FRONT TO PENETRATE THE NW
GLFMEX TOMORROW.  AMPLE LOW LEVEL MOISTURE ALONG WITH GOOD UPPER
LEVEL DYNAMICS WILL SUPPORT INCREASING SHOWERS/THUNDERSTORMS
ALONG THE FRONT ESPECIALLY N OF 26N ON THURSDAY.  THE FRONT AND
ASSOCIATED SHOWER/THUNDERSTORM ACTIVITY WILL ADVANCE QUICKLY
ACROSS THE GLFMEX REACHING FLORIDA FRIDAY.  ELSEWHERE...A HIGH
PRESSURE RIDGE EXTENDING ACROSS CENTRAL FLORIDA AND THE GLFMEX
ALONG 25N WILL RETREAT SEWD DURING THE NEXT 48 HOURS AS THE
FRONT APPROACHES.  EXPECT WARM SOUTHERLY RETURN FLOW OVER THE W
GLFMEX INTO TEXAS WITH STRONG NLY FLOW DEVELOPING BEHIND COLD
FRONT THU.

CARIBBEAN SEA...
BROAD MIDDLE TO UPPER LEVEL RIDGE COVERS THE CARIBBEAN WITH MEAN
AXIS EXTENDING FROM VENEZUELA NW TO 17N85W.  SW TO WLY FLOW
AROUND THE N PERIPHERY OF THE RIDGE IS ADVECTING UPPER LEVEL
TROPICAL MOISTURE FROM THE E PACIFIC ACROSS CENTRAL AMERICA AND
THE CARIBBEAN E OF A LINE FROM HISPANIOLA TO HONDURAS.
DIVERGENT UPPER LEVEL FLOW JUST E OF NICARAGUA IS SUPPORTING AN
AREA OF ISOLATED MODERATE CONVECTION FROM 11N-14N BETWEEN
81W-83W WITH WIDELY SCATTERED SHOWERS ELSEWHERE OVER THE E
CARIBBEAN ESPECIALLY WITHIN 90 NM EITHER SIDE OF A LINE FROM
TRINIDAD TO 14N80W. FURTHER W...STRONG SUBSIDENCE AND DRY AIR
COVERS THE NW CARIBBEAN N OF A LINE FROM 15N83W TO 19N73W.

ATLANTIC...
A BROAD/FLAT MIDDLE TO UPPER LEVEL RIDGE COVERS ALL BUT THE FAR
E ATLC WATERS WHERE A TROUGH TRAILS SWD FROM N AFRICA TO THE
CAPE VERDE ISLANDS. A NEAR ZONAL PATTERN EXISTS BETWEEN
80W-30W.  UPSTREAM MOISTURE IS RIDING UP AND OVER A LARGE RIDGE
OVER THE E UNITED STATES LEAVING STRONG SUBSIDENCE AND VERY DRY
MIDDLE TO UPPER LEVEL AIR OVER THE ATLC N OF 20N.  THIS PATTERN
IS PRODUCING UNUSUALLY TRANQUIL WEATHER AND A NOTICEABLE ABSENCE
OF SIGNIFICANT CLOUDINESS OVER THE ENTIRE SUBTROPICAL ATLC.   AT
THE LOW LEVELS...A WEAK ELY DISTURBANCE NE OF THE BAHAMAS IS
PRODUCING A SMALL AREA OF SCATTERED SHOWERS FROM 24N-27N BETWEEN
68W-73W. ELSEWHERE...A 1013 MB LOW NEAR THE AZORES TRAILS A WEAK
COLD FRONT SWD ALONG 35N30W TO 30N38W WHERE IT DEGENERATES
INTO A REMNANT FRONTAL TROUGH TO 27N49W. ONLY A FEW ISOLATED
SHOWERS ACCOMPANY THIS FEATURE.  FURTHER W...A MUCH STRONGER
COLD FRONT IS PUSHING SWD OVER THE CENTRAL ATLC FROM 40N34W TO
36N40W 32N50W TO 33N64W NEAR BERMUDA.  ELSEWHERE...A 1032 MB
HIGH IS OFF THE COAST OF PORTUGAL NEAR 36N10W.  A SUBTROPICAL
RIDGE EXTENDS SW TO THE EASTERN ATLC NEAR 30N25W.

$$
FORMOSA





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