[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 142333
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE 14 DEC 2004

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 ALONG 6N10W 8N35W 9N50W 9N60W.  ISOLATED MODERATE
FROM 6N-10N BETWEEN 25W-40W.  SIMILAR CONVECTION WITHIN 120 NM
OF 5N12.5W.  OTHER ISOLATED SHOWERS ARE FROM 7N-13N BETWEEN
40W-52W.

...DISCUSSION...

GULF OF MEXICO...
BIG PUSH OF COLD AIR HAS SLID THRU FLORIDA AND THE ASSOCIATED
FRONT LIES ACROSS THE FLORIDA STRAITS TO 22N93W THEN S TO THE
SOUTHERN TIP OF THE BAY OF CAMPECHE.  THE FRONTAL BOUNDARY IS
MARKED BY OVERCAST LOW CLOUDS IN THE GULF FOR ABOUT 200 NM AND
SOME SHOWERS ESPECIALLY W OF 88W.  IN THE MID TO UPPER LEVELS...
TROUGH IS FROM N CAROLINA TO THE CENTRAL GULF AND MOVING SE
QUICKLY.  FRONT SHOULD DEPART THE GULF BY EARLY WED WITH GALE
FORCE WINDS IN THE SW GULF DUE TO A STRONG 1044 MB HIGH OVER SW
OKLAHOMA RIDGING SOUTHWARD ALONG THE W GULF COAST DOWN THRU NE
MEXICO.  THE COLDEST NIGHT OF THE SEASON IS EXPECTED FOR MANY OF
THE GULF COAST STATES WITH FREEZING TEMPERATURES INTO CENTRAL
FLORIDA.  A SLOW MODIFICATION OF THE COOL TEMPERATURES SHOULD
OCCUR AS HIGH PRESSURE MOVES EASTWARD OVER THE NEXT COUPLE OF
DAYS... BRINGING WINDS AROUND TO THE NE WITH MORE OF A MARITIME
WIND EXPOSURE RATHER THAN COOL/DRY NW CONTINENTAL FLOW.  THE
NEXT REINFORCING PUSH OF COOLER AIR...ALBEIT WEAK..APPEARS TO
ENTER THE GULF ON FRI.

CARIBBEAN SEA...
PAIR OF WEAK SURFACE TROUGHS CONTINUE TO BE THE WEATHER-MAKERS
FOR THE AREA.  FIRST SYSTEM IS ALONG THE E COAST OF CENTRAL
AMERICA FROM COSTA RICA TO E HONDURAS WITH SURFACE CONVERGENCE
FORCING WIDELY SCATTERED SHOWERS WITHIN 60/90 NM OF THE
COASTLINE.  ZONAL FLOW ALOFT DOMINATES WITH SOME HINTS OF AN
ANTICYCLONIC RIDGING AXIS ALONG 70-75W.  SECOND TROUGH LIES FROM
PUERTO RICO TO ARUBA WITH WIDELY SCATTERED SHOWERS WITHIN 100 NM
MOSTLY W OF THE FEATURE.  A CONTINUATION OF DEEPER MOISTURE IS
ACROSS THE LEEWARD ISLANDS WITH DEEPENING LOW-LEVEL ELY FLOW
SPARKING WIDELY SCATTERED SHOWERS ALONG AND ABOUT 180 NM OF E OF
THE LEEWARD/WINDWARD ISLANDS N OF BARBADOS.  EASTERNMOST TROUGH
SHOULD WEAKEN DURING THE NEXT COUPLE OF DAYS BUT STILL REMAINING
A FOCUSING MECHANISM FOR SHOWERS IN THE CENTRAL CARIBBEAN.
INSTABILITY ALONG WITH HIGH MOISTURE VALUES LOOK LIKELY TO SPAWN
HIGHER-THAN-AVERAGE SHOWER CLUSTERS TIL LATE-WEEK IN THE LEEWARD
ISLANDS.

WEST ATLANTIC...
COLD FRONT HAS PUSHED TO 31N71W SW TO THE STRAITS OF FLORIDA
WITH OVERCAST TO BROKEN LOW CLOUDS BEHIND THE FRONT TO 80W.
UPPER FLOW IS NOW MORE FROM THE WSW ALL THE WAY TO 60W WITH
BROAD-SCALE UPPER DIVERGENCE ENHANCING SHOWERS WITHIN 120 NM OF
21N BETWEEN 53W-63W.  DISSIPATING FRONTAL TROUGH LIES FROM THE
TURKS/CAICOS ISLANDS TO 31N61W WITH ONLY SOME SCATTERED LOW
CLOUDS ALONG THE FRONT.  W ATLC COLD FRONT SHOULD MOVE THRU THE
ENTIRE BAHAMAS BY LATE THU WITH MORE TYPICAL NE FLOW RESUMING.

CENTRAL/EAST ATLANTIC...
BLOCKING PATTERN REMAINS WITH HIGH-OVER-LOW SITUATION IN PLACE.
HIGH IS NEAR 32N41W WITH BROAD LOW CENTERED NEAR 20N45W.
DIVERGENCE AHEAD OF THE LOW FROM AN UPPER JET COMBINED WITH
DEVELOPING RIDGING OVER THE DEEP TROPICS IS LEADING TO THICK
OVERCAST AND WIDELY SCATTERED TSTMS FROM 10N-15N BETWEEN 30W-42W.
ANOMALOUS UPPER RIDGING IS ALONG 10N BETWEEN 20W-40W WITH
COPIOUS UPPER MOISTURE ALONG A JET RIDING THE N SIDE OF THE
RIDGE FROM 14N41W TO 16N32W ACROSS THE CAPE VERDES TO NW
MAURITANIA.  FARTHER E...STRONG CUTOFF DEEP-LAYERED 999 MB LOW
PERSISTS IN THE NE ATLC NEAR 29N20W DRIFTING SE WITH GALE FORCE
WINDS ALONG THE NW SIDE OF THE LOW.  COOL UPPER TEMPERATURES
COMBINED WITH A WARMER THAN AVERAGE OCEAN IS ASSISTING WIDELY
SCATTERED SHOWER DEVELOPMENT N OF 24N E OF 20W WITH SOME RARE
ISOLATED THUNDERSHOWERS IN THE NW CANARY ISLANDS TODAY.  LOW IS
EXPECTED TO MOVE SSE TOWARD WESTERN SAHARA AND SLOWLY FILL FOR
THE NEXT COUPLE OF DAYS....BRINGING A CHANCE OF RAIN TO AREAS IN
NW AFRICA THAT GENERALLY DON'T SEE MUCH RAIN AT ALL.

$$
BLAKE

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