[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 232337
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST SUN DEC 23 2007

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN
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
2315 UTC

...THE ITCZ...

ITCZ AXIS IS CENTERED ALONG 7N11W 4N24W 5N40W 4N52W. SCATTERED
MODERATE CONVECTION IS WITHIN 120 NM N OF THE AXIS BETWEEN
35W-39W.

...DISCUSSION...

THE GULF OF MEXICO...
STRONG COLD FRONT CONTINUES TO PRESS SOUTHEASTWARD ANALYZED FROM
THE BIG BEND AREA OF FLORIDA TO THE BAY OF CAMPECHE ALONG 30N83W
24N87W 18N94W...AT 21Z. DOPPLER RADAR AND LIGHTNING DATA ARE
DEPICTING JUST ABOUT NO ACTIVITY NEAR THE BOUNDARY SO ONLY LOW
CLOUDS AND LIGHT SHOWERS ARE EXPECTED WITHIN 60 NM EITHER SIDE N
OF 27N AND WITHIN 90 NM W OF THE FRONT S OF THERE...MOST DENSE
IN THE BAY OF CAMPECHE WHERE THE GREATEST WIND FUNNELING EXISTS.
SPEAKING OF WINDS...GALE WARNING HAS BEEN DISCONTINUED IN THE SW
GULF WITH BUOY AND SCAT DATA SUPPORTING NLY 20-30 KT WINDS AT
THE MOMENT. CURRENT TEMP REPORTS ARE IN THE 60'S F JUST BEHIND
THE FRONT AND FALLING INTO THE LOWER 50'S ACROSS THE N GULF
COAST. WARM AND HUMID AHEAD OF THE FRONT...MID AND UPPER 70'S
ACROSS CENTRAL AND S FLORIDA. MODEL GUIDANCE SUGGESTS WEAKENING
AND SLOWING OF THE FRONT...STALLING OVER SOUTH FLORIDA AND THE
SE GULF TOMORROW AT THIS TIME AS THE BOUNDARY LOSES UPPER
SUPPORT.

THE CARIBBEAN SEA...
AMPLIFIED MID TO UPPER LEVEL RIDGING IS SITUATED ABOVE THE
ENTIRE REGION ENHANCING DRY AIR ALOFT ESPECIALLY N OF 17N WHERE
THE UPPER FLOW IS CONFLUENT BETWEEN TROUGHS NW AND NE OF THE
REGION. THIS STABLE ENVIRONMENT IS SUPPRESSING DEEP CLOUD
DEVELOPMENT AND PROVIDING WIDESPREAD FAIR WEATHER. THE ONLY AREA
OF ORGANIZED SHOWER/TSTM ACTIVITY IS IN THE SW CARIB NEAR THE
COAST OF PANAMA...S OF 10N BETWEEN 76W-82W...WHERE PRONOUNCED
LOW-LEVEL CONVERGENCE EXISTS. PATCHY DEBRIS HIGH LEVEL CLOUDS
ARE ROTATING AROUND THE RIDGE CONFINED S OF 14N. THE SFC PRES
PATTERN IS RATHER WEAK DUE TO BROAD TROUGHING N OF THE AREA.
THIS HAS ALLOWED ELY TRADES TO BE LIGHT TO MODERATE E OF 70W
WITH SOME INCREASE AND BACKING OUT OF THE NE W OF 70W
...ESPECIALLY NEAR THE COAST OF COLOMBIA.

THE ATLANTIC OCEAN...
BROAD VERTICALLY STACKED LOW PRES AREA IS SLIDING E IN THE
ATLC...ANALYZED 1013 MB NEAR 27N60W. THIS LOW SITS ALONG A SFC
TROUGH FROM 31N45W TO 24N73W. LOW CLOUD TURNING IS VERY APPARENT
NEAR THE W EDGE OF THE TROUGH AND SFC DATA MAY SUGGEST A VERY
WEAK LOW DEVELOPING THERE. A WEAKENING COLD FRONT EXTENDS SSW
FROM THE LOW TO 22N67W. NEARLY ALL OF THE ASSOCIATED DEEP
CLOUDINESS AND EMBEDDED SCATTERED SHOWERS AND TSTMS LIE TO THE E
OF THE SFC CENTER...IN AN UPPER DIFFLUENT ZONE...N OF 22N
BETWEEN 46W-60W AND FROM 18N-21N BETWEEN 56W-59W E OF A SLOW
MOVING SMALL SCALE LOW-LEVEL INVERTED TROUGH. TIGHT PRES
GRADIENT BETWEEN THE LOW AND STRONG HIGH PRES TO THE N IS
PRODUCING GALE FORCE E TO NE WINDS N OF THE LOW/TROUGH. MODELS
ARE IN GOOD AGREEMENT IN SHOWING THIS LOW PRES TROUGH SHIFTING E
AND FILLING WHICH SHOULD ALLOW THE GALE EVENT TO COME TO AN END
WITHIN 18 HOURS. STACKED HIGH PRES RIDGING HAS BUILT INTO THE
FAR W ATLC...AHEAD OF THE GULF FRONT...PRODUCING QUIET
CONDITIONS W OF 75W.

MUCH OF THE BASIN E OF 45W REMAINS TRANQUIL THIS EVENING DUE SFC
HIGH PRES RIDGING...ANCHORED BY A 1026 MB HIGH NEAR 37N17W...AND
WIDESPREAD ZONAL FLOW ALOFT. ONLY PATCHY MULTI-LAYER CLOUDINESS
AND ISOLATED SHOWERS DOT THE REGION.

$$
CANGIALOSI




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