[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 242335
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU JAN 24 2008

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...
THE ITCZ AXIS IS CENTERED ALONG 5N9W 2N25W 1N39W CROSSING THE
EQUATOR NEAR 44W TO 2S48W. SCATTERED MODERATE CONVECTION IS
MAINLY INLAND OVER NE BRAZIL S OF THE EQUATOR. OTHERWISE NO
SIGNIFICANT CONVECTION ALONG THE AXIS.

...DISCUSSION...
GULF OF MEXICO...
SLOW MOVING OR NEARLY STALLED FRONT IS DRAPED ACROSS THE REGION
FROM CENTRAL FLORIDA TO S MEXICO ALONG 28N83W 26N93W 20N97W THEN
NWD ALONG THE E SLOPES OF THE SIERRA MADRE MOUNTAINS. A SERIES
OF FRONTAL WAVES ARE EVIDENT ALONG THE BOUNDARY ANALYZED 1016 MB
NEAR 27N86W...25N95W AND ALONG THE COAST OF S MEXICO NEAR
21N97W. DENSE MULTILAYER CLOUDINESS AND SCATTERED SHOWERS ARE
NOTED N OF THE FRONT. SCATTERED CLOUDS AND ISOLATED SHOWERS ARE
WITHIN 120 NM S OF THE FRONT E OF 90W. TIGHTENED PRES GRADIENT
BETWEEN THE FRONT AND 1036 MB HIGH PRES OVER THE MIDWEST IS
PRODUCING 20-25 KT N TO NE WINDS NORTH OF THE FRONT. THIS
BOUNDARY HAS MOVED LITTLE OVER THE PAST 24 HOURS BUT THAT IS
ABOUT TO CHANGE AS AN MID TO UPPER TROUGH OVER THE GREAT LAKES
DIGS SOUTHEASTWARD DRIVING THE BOUNDARY THROUGH THE CENTRAL AND
E GULF BY TOMORROW MORNING. A COOLER AND DRIER AIRMASS IS
EXPECTED TO BUILD BEHIND THE BOUNDARY. MODEL GUIDANCE SHOWS THE
A WEAK FRONTAL LOW...LIKELY SPUN UP BY THE TAIL END OF THE
CURRENT BOUNDARY...DEVELOPING IN THE NW GULF LATE TOMORROW.

CARIBBEAN SEA...
THE CARIBBEAN REMAINS QUIET THIS EVENING BENEATH A WEAK UPPER
SHORTWAVE OVER THE NW PORTION AND A MODEST MID TO UPPER RIDGE
ELSEWHERE. SUBSIDENCE IS WIDESPREAD REGION WIDE AS NOTED IN
WATER VAPOR IMAGES. THIS DRY SINKING ENVIRONMENT IS CAPPING THE
TYPICAL STREAMS OF LOW-LEVEL CLOUDS DRIVEN FROM THE TROPICAL
ATLC WATERS ACROSS THE CARIB SEA BY THE TRADES. BRIEF QUICK
MOVING SHOWERS ARE LIKELY EMBEDDED IN SOME OF THE PATCHES
ESPECIALLY S OF 17N E OF 75W...CLOSER TO THE ATLC FETCH...AND S
OF 16N W OF 82W WHERE THE LOW LEVEL FLOW IS CONFLUENT NEAR THE
CENTRAL AMERICA COAST. TRADE WINDS ARE QUITE BRISK 20-25
KT...EXCEPT TO 30 KT NEAR THE N COAST OF COLOMBIA.

ATLANTIC...
LARGE MID TO UPPER TROUGH OVER THE ERN CONUS IS SUPPORTING A
COLD FRONT FROM 32N75W THROUGH CENTRAL FLORIDA AND ACROSS THE
GULF. BROKEN MULTILAYER CLOUDINESS AND ISOLATED SHOWERS ARE N OF
THE FRONT. DEEPER MOISTURE...IN THE FORM OF SCATTERED TSTMS LIE
TO THE E OF THE FRONT N OF 28N BETWEEN 65W-72W TRIGGERED BY A
PREFRONTAL TROUGH AND DIFFLUENCE ALOFT BETWEEN THE
AFOREMENTIONED MID-UPPER TROUGH/EMBEDDED SHORTWAVE ALONG 77W AND
AN AMPLIFIED RIDGE EXTENDING NWD FROM THE CARIBBEAN. ABUNDANT
DRY SINKING AIR ALOFT COVERS THE BULK OF THE CENTRAL ATLC S OF
25N EMBEDDED IN THE RIDGE EXTENDING WELL E TOWARD THE CAPE VERDE
ISLANDS.

LARGE MID TO UPPER TROUGH COVERS THE NE PART OF THE ATLC
DISCUSSION AREA ANCHORED BY AN UPPER LOW CENTERED NEAR 35N25W. A
SMALLER WEAKER UPPER LOW IS CENTERED NEAR 29N35W GENERATING
SCATTERED SHOWERS WITHIN 180 NM OF THE CENTER. A PAIR OF
ASSOCIATED SFC TROUGHS CONTINUE TO WEAKEN...ONE ALONG 36W FROM
16N-20N AND THE OTHER ANALYZED FROM 20N22W TO 27N25W. BESIDES
FOR WIND SHIFTS AND AN ISOLATED SHOWER OR TWO NEAR THE SFC
TROUGHS THE REMAINDER OF THE REGION REMAINS QUIET UNDER THE
INFLUENCE OF THE SOUTHERN PERIPHERY OF STRONG SFC HIGH PRES OVER
THE MID-LATITUDES AND ZONAL FLOW ALOFT.

$$
CANGIALOSI




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