[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 180604
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST MON FEB 18 2013

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA ENTERING THE E TROPICAL
ATLC THROUGH SIERRA LEONE TO 03N19W WHERE THE ITCZ CONTINUES TO
EQ25W 1N34W EQ40W TO 1S45W. SMALL CLUSTERS OF MODERATE/ISOLATED
STRONG CONVECTION ARE WITHIN 130 NM NORTH AND SOUTH OF THE
MONSOON TROUGH AXIS. SIMILAR CONVECTION IS WITHIN 150 NM NORTH
OF THE ITCZ AXIS BETWEEN 20W AND 34W. SCATTERED MODERATE
CONVECTION IS WITHIN 130 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN
35W AND 43W.

...DISCUSSION...

GULF OF MEXICO...
A 1029 MB HIGH PRES LOCATED OVER NORTHERN FLORIDA NEAR 30N82W IS
PROVIDING ANTICYCLONIC WIND IN THE RANGE OF 20-25 KT WEST OF 90W
AND OF 5-15 KT EAST OF 90W. STRONG SOUTHEASTERLY WIND FLOW IS
BANKING LOW LEVEL CLOUDS WITH ISOLATED SHOWERS ALONG THE COAST
OF MEXICO TO THE E SLOPES OF THE SIERRA MADRE MOUNTAINS.
OVERCAST SKIES WITH POSSIBLE ISOLATED SHOWERS EXTEND
APPROXIMATELY 170 NM OFF THE WEST GULF COASTLINE. IN THE UPPER
LEVEL WESTERLY FLOW MOVES OVER THE WHOLE BASIN AND DRY AIR ALOFT
SUPPORTS FAIR WEATHER OVER THE REMAINDER OF THE GULF. RETURN
FLOW WILL CONTINUE WITHIN THE NEXT 24 HOURS OVER THE ENTIRE
REGION WHILE A NEW FRONT APPROACHES THE NW GULF.

CARIBBEAN SEA...
AS OF 0300 UTC...THE COLD FRONT OVER THE WEST CARIBBEAN STALLED
AND BECAME A STATIONARY FRONT THAT EXTENDS FROM NORTHERN HAITI
NEAR 19N73W TO 18N76W...OVER JAMAICA AND THEN SW TO 17N78W
14N81W 12N82W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 120 NM
EITHER SIDE OF THE FRONTAL BOUNDARY. WEST OF THE STATIONARY
FRONT NORTHERLY WINDS IN THE RANGE OF 20-25 KT DOMINATE.
EASTERLY TRADEWINDS IN THE RANGE OF 15-20 KT SPREAD OVER THE
REMAINDER OF THE CARIBBEAN. IN THE UPPER LEVEL...A TROUGH OVER
THE W ATLC DIPS S OVER THE NW CARIBBEAN N OF 20N SUPPORTING THE
AFOREMENTIONED STATIONARY FRONT. NEAR ZONAL WESTERLY FLOW ALOFT
DOMINATES THE REMAINDER OF THE CARIBBEAN SEA. WATER VAPOR
SATELLITE IMAGERY CONTINUES TO SHOW VERY STRONG SUBSIDENCE AND
DRY STABLE AIR ALOFT E OF 75 ACROSS THE REMAINDER OF THE BASIN.
WITHIN THE NEXT 24 HOURS...THE STATIONARY FRONT SLOWLY WEAKENS.
ISOLATED/SCATTERED SHOWERS ARE EXPECTED TO CONTINUE OVER THE NW
CARIBBEAN WHILE WINDS OVER NW CARIBBEAN SHIFT FROM NORTHERLY
FLOW TO EASTERLY FLOW. STRONGEST WINDS OF 25-30 KT ARE EXPECTED
NEAR THE COAST OF COLOMBIA.

ATLANTIC OCEAN...
THE PREVIOUSLY MENTIONED BROAD UPPER LEVEL TROUGH SUPPORTS A
COLD FRONT THAT ENTERS THE DISCUSSION AREA AT 18/0000 UTC NEAR
30N60W EXTENDING SW TO 25N64W 21N69W AND THEN N OF HAITI WHERE
IT BECOMES STATIONARY. NO CONVECTIVE PRECIPITATION IS ASSOCIATED
WITH THIS FRONT OVER THE W ATLC. HOWEVER ISOLATED SHOWERS ARE
POSSIBLE WITHIN 200 NM WEST OF THE FRONT. E OF THE FRONT...A
1026 MB HIGH PRES IS CENTERED NEAR 29N39W AND IS EXPECTED TO
REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS. THIS SYSTEM
EXTENDS A RIDGE OVER MOST OF THE E AND CENTRAL ATLC. ALOFT...AN
UPPER RIDGE COVERS THE CENTRAL ATLC. A NARROW UPPER TROUGH IS
OVER THE E ATLC WHICH IS SUPPORTING A DISSIPATING COLD FRONT
CURRENTLY LOCATED BETWEEN THE MADEIRA AND THE CANARY ISLANDS.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NR






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