[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 232340
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST WED JAN 23 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 3N9W 4N6W 5N18W 4N30W CROSSING
THE EQUATOR NEAR 40W TO 2S44W. SCATTERED MODERATE CONVECTION IS
S OF 4N W OF 42W.

...DISCUSSION...
GULF OF MEXICO...
SLOW MOVING COLD FRONT EXTENDS ACROSS CENTRAL FLORIDA INTO THE
MID-GULF NEAR 28N88W THEN STATIONARY THROUGH THE N MEXICAN
COAST...JUST S OF BROWNSVILLE TEXAS...AND ALONG THE E SLOPES OF
THE SIERRA MADRE MOUNTAINS. A WEAK LOW APPEARS TO BE FORMING
ALONG THE FRONT NEAR 27N96W JUST E OF BUOY 42020 WHICH IS
REPORTING AN INCREASE IN NLY WINDS AND A 2-3 MB LOWER PRES THAN
THE SURROUNDINGS. DOPPLER RADAR DEPICTS SCATTERED SHOWERS ALONG
AND TO THE N OF THE FRONT. A LINGERING SFC TROUGH S OF THE FRONT
ALONG 85W/86W HAS JUST ABOUT DISSIPATED AND IS PRODUCING LITTLE
SIGNIFICANT WEATHER. THE FRONT HAS VERY LITTLE UPPER SUPPORT AT
THE MOMENT DUE TO WIDESPREAD ZONAL FLOW ALOFT LOCATED ABOVE THE
ENTIRE REGION AND MOST OF THE SOUTHERN U.S. THIS UPPER FLOW HAS
ADVECTED HIGH LEVEL MOIST PACIFIC AIR ACROSS THE ZONE. MODEL
GUIDANCE SHOWS THE FRONT REMAINING IN PLACE OR EVEN LIFTING N
THROUGH TOMORROW UNTIL AN UPPER TROUGH DIGS OVER THE EASTERN
U.S. ENERGIZING THE BOUNDARY DRIVING IT QUICKLY THROUGH THE
REGION TOMORROW NIGHT. A BRIEF COOLER AND DRIER AIRMASS IS
EXPECTED TO BUILD INTO THE AREA BEHIND THE FRONT.

CARIBBEAN SEA...
ALL QUIET IN THE CARIB 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 72W...CLOSER TO THE ATLC FETCH...AND S
OF 17N W OF 80W 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...
WEAK COLD FRONT EXTENDS FROM 32N74W ACROSS CENTRAL FLORIDA AND
INTO THE GULF. PLUME OF PACIFIC MOISTURE COUPLED WITH LOW-LEVEL
CONVERGENCE NEAR THE FRONT IS PRODUCING MULTILAYER CLOUDS AND
SHOWERS N OF 27N W OF 67W. A GRADUALLY WEAKENING STALLED
BOUNDARY LIES FARTHER E ALONG 32N32W 28N41W 29N59W. SCATTERED
SHOWERS ARE MOST ORGANIZED N OF THE FRONT FROM 28N-32N BETWEEN
54W-58W TRIGGERED BY A WEAK UPPER SHORTWAVE IN THE VICINITY. THE
REMAINDER OF THE TROPICAL PORTION OF THE ATLC WATERS W OF 40W IS
VERY QUIET THIS EVENING DOMINATED BY A SUBSIDENT ENVIRONMENT.
IN THE E ATLC...UPPER CUT OFF IS STILL SPINNING ALBEIT WEAKER
NEAR 32N25W. SCATTERED SHOWERS ARE OCCURRING IN THE UPPER
DIFFLUENT ZONE N OF 28N BETWEEN 15W-22W...WHICH INCLUDES THE
CANARY AND MADEIRA ISLANDS. THE ASSOCIATED SFC CENTER CONTINUES
ITS SWD MOTION ANALYZED NEAR 20N34W 1012 MB AT 18Z...BUT WILL
LIKELY BE DRAWN AS OPEN TROUGH AT 00Z BASED ON THE CLOUD
STRUCTURE. ANOTHER SFC TROUGH LIES FARTHER E FROM 15N18W TO
27N25W. A 1920 Z QSCAT PASS SHOWED THE ASSOCIATED WIND SHIFT
VERY NICELY...HOWEVER...LITTLE OTHER WEATHER EFFECTS ARE
RELATED.

$$
CANGIALOSI




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