[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 110005
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED JAN 10 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...
CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...
NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC
OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N.
THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...
METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2345 UTC.

...THE ITCZ...
ITCZ AXIS IS ALONG 2N AT THE PRIME MERIDIAN...3N15W 2N30W 1N40W
TO THE EQUATOR AT 50W. THE SCATTERED MODERATE CONVECTION THAT
WAS FROM 2S-4N BETWEEN 31W-38W HAS BEEN DIMINISHING IN BOTH
COVERAGE AND INTENSITY OVER THE LAST FEW HOURS...THOUGH
SCATTERED SHOWERS WITH EMBEDDED TSTMS STILL POSSIBLE IN THIS
REGION. SIMILAR SHOWERS/TSTMS NOTED FROM THE EQUATOR TO 2N
BETWEEN 40W-45W.

...DISCUSSION...
GULF OF MEXICO...
SFC HIGH PRESSURE IS WELL ESTABLISHED ACROSS THE GULF THIS
EVENING FROM A 1033 MB CENTER OVER CENTRAL TENNESSEE. THIS IS
PRODUCING 10-20 KT ELY WINDS EXCEPT SE IN THE FAR WRN PORTION.
A SHORT WAVE TROUGH IS MOVING EWD ACROSS THE CENTRAL AND ERN
GULF GENERATING WIDELY SCATTERED SHOWERS. AN UPPER RIDGE COVERS
MEXICO AND THE FAR WRN GULF ANCHORED BY AN UPPER HIGH IN THE
EPAC. BROKEN TO OVERCAST LOW LEVEL CLOUDS WITH EMBEDDED LIGHT
RAIN/DRIZZLE ARE POOLING AGAINST THE SIERRA MADRES AND ADJACENT
SW GULF WATERS WITH THE ONSHORE FLOW. A MORE SEASONABLE AIR MASS
CONTINUES TO COVER THE GULF AND THE STATE OF FLORIDA IN WAKE OF
THE COLD FRONT NOW IN THE NW CARIBBEAN AND SW NORTH ATLC. WARMER
SLY RETURN FLOW WILL GRADUALLY DEVELOP ACROSS THE GULF FROM W TO
E BY THIS WEEKEND IN ADVANCE OF THE NEXT COLD FRONT CURRENTLY
ANTICIPATED TO MOVE INTO THE NW PORTION SUN NIGHT INTO MON.

CARIBBEAN SEA...
FRONTAL BOUNDARY HAS BECOME STATIONARY IN THE NW CARIBBEAN. AS
OF 2100 UTC THE FRONT EXTENDS FROM CENTRAL CUBA THROUGH 18N84W
TO THE GULF OF HONDURAS NEAR 16N87W. A SMALL TEMP/DEWPOINT
DISCONTINUITY STILL EXISTS AROUND THIS BOUNDARY...IN ADDITION TO
A FADING LOW LEVEL CLOUD SIGNATURE. THE CARIBBEAN PORTION OF THE
FRONT WILL LIKELY BECOME DIFFUSE THROUGH TONIGHT. UNTIL
THEN...LIGHT RAIN SHOWERS ANTICIPATED WITHIN 90 NM OF THE FRONT.
SFC FLOW BEHIND THE FRONT IS GENERALLY NE 20-25 KT WITH SLIGHTLY
LIGHTER E TO NE TRADES W OF THE FRONT EXCEPT FOR THE AREA NEAR
THE COLOMBIAN COAST...WHERE 25-30 KT IS EXPECTED. FRESH TO
STRONG TRADES EXPECTED TO INCREASE ESPECIALLY IN COVERAGE ACROSS
THE CARIB THROUGH THE END OF THE WEEK AS STRONG HIGH PRESSURE
BUILDS NORTH OF THE AREA. ALOFT...SHORTWAVE TROUGH FROM THE GULF
IS AFFECTING THE NW PORTION WHILE RIDGING GENERALLY HOVERS OVER
THE REST OF THE CARIB. HOWEVER...OTHER SUBTLE FEATURES LIKELY
THOUGH FAIRLY INSIGNIFICANT AND DIFFICULT TO DISCERN WITH THE
ABUNDANT DRY MID TO UPPER AIR IN PLACE.

ATLANTIC OCEAN...
DEEP LAYER TROUGH EXTENDING SSE FROM THE CANADIAN MARITIMES HAS
AN ASSOCIATED COLD FRONT THAT ENTERS THE AREA 32N61W AND EXTENDS
SW THROUGH THE SE BAHAMAS. THE FRONT REMAINS VOID OF DEEP
CONVECTION THROUGH LIGHT RAIN SHOWERS LIKELY WITHIN 90 NM OF THE
BOUNDARY. A SECONDARY SURGE OF NE WINDS AND DRY/COOLER AIR HAS A
DYING COLD FRONT ENTERING THE AREA AT 32N64W AND EXTENDS SW TO
THE NW BAHAMAS. THE FRONTAL SYSTEM HAS BROUGHT A MUCH MORE
SEASONABLE AIR MASS TO THE AREA WITH ITS NLY FLOW...ALONG WITH A
MODERATE N SWELL THAT PROPAGATED AS FAR SOUTH AS DELRAY FLORIDA
TODAY. THE ASSOCIATED MODERATE NW/N SWELL WILL SPREAD E INTO THE
WEEKEND...REACHING PUERTO RICO BY EARLY FRIDAY. WINDS WILL
GRADUALLY VEER NE TO E AND INCREASE IN THE SW NORTH ATLC OVER
THE NEXT COUPLE OF DAYS...AS STRONG HIGH PRESSURE PUSHES OFF THE
EASTERN SEABOARD. SEE MIAOFFNT3 AND MIAHSFAT2 FOR DETAILS. THERE
A SMALL PATCH OF MOISTURE WITH POSSIBLE SHOWERS IS FROM 19N-22N
BETWEEN 52W-59W WHICH SEEMS ASSOCIATED WITH A WEAK UPPER TROUGH
IN THE VICINITY. MUCH OF THE CENTRAL ATLC IS DOMINATED BY DEEP
LAYER HIGH PRESSURE...WITH UPPER CENTER NEAR 36N36W AND THE 1034
MB SFC CENTER NEAR THE WRN AZORES AT 38N30W. AN UPPER LOW IS
SEEN SPINNING BETWEEN THE MADEIRA AND CANARY ISLANDS THAT HAS AN
UPPER TROUGH EXTENDING SW TO 19N35W. ASSOCIATED SFC LOW IS NEAR
33N18W. THERE IS QUITE A BIT OF MOISTURE WITH POSSIBLE SCATTERED
SHOWERS E OF THE UPPER TROUGH AXIS TO THE COAST OF AFRICA. UPPER
WLY FLOW CONTINUES TO STRETCH HIGH CLOUDS E ACROSS THE DEEP
TROPICS.

$$
WILLIS




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