[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 141103
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SAT MAR 14 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N5W 1N17W CROSSING THE EQUATOR
NEAR 24W EXTENDING TO 2S32W INTO NE BRAZIL NEAR 5S39W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 2N-5N BETWEEN
6W-14W. SCATTERED MODERATE CONVECTION IS S OF 3N BETWEEN 28W-30W.

...DISCUSSION...

GULF OF MEXICO...
DIFFLUENT WESTERLY FLOW ALOFT IS PRESENT ACROSS THE WESTERN GULF
REGION. DEEP LAYER ATMOSPHERIC LIFT IN THIS FLOW IS SUPPORTING A
SURFACE COLD FRONT IN THE W GULF THAT EXTENDS FROM S LOUISIANA
NEAR 30N92W TO 26N94W TO 22N96W AND A SURFACE STATIONARY FRONT
THAT EXTENDS FROM 22N96W TO THE COAST OF MEXICO NEAR 20N97W. LOW
LEVEL CONVERGENCE AND DEEP LAYER ATMOSPHERIC LIFT ARE SUPPORTING
SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THE FRONTS. TO THE
NW OF THE FRONTS...NW TO N SURFACE WINDS OF 15 TO 20 KT ARE
OCCURRING...WHERE A RELATIVELY COOLER AND DRIER AIRMASS IS
PRESENT. THIS COOLER AIR IS OVER RELATIVELY WARMER WATERS...
RESULTING IN LAYERS OF SCATTERED TO OVERCAST STRATOCUMULUS
CLOUDS TO THE NW OF THE FRONTS. TO THE SE OF THE FRONTS...DEEP
LAYER DRY AIR IS RESULTING IN GENERALLY FAIR WEATHER CONDITIONS
ACROSS MUCH OF THE CENTRAL AND SE GULF.

CARIBBEAN SEA...
STRONG SURFACE HIGH PRESSURE BUILDING SOUTHWARD OVER THE W
ATLC WILL MAINTAIN MODERATE TO STRONG TRADES OVER MUCH OF THE
CARIBBEAN SEA THROUGH MONDAY. GENERALLY FAIR WEATHER CONDITIONS
ARE OCCURRING ACROSS MUCH OF THE CARIBBEAN REGION...WHERE DEEP
LAYER DRY AIR IS PRESENT. HOWEVER...THE TRADE WINDS ARE
ADVECTING PATCHES OF LOW LEVEL MOISTURE WESTWARD ACROSS THE
CARIBBEAN...WITH SCATTERED SHOWERS EMBEDDED WITHIN THESE PATCHES
OF LOW LEVEL MOISTURE. THE GREATEST CONCENTRATION OF THESE
SHOWERS IS FROM 15N-19N BETWEEN 75W-81W. ALSO...INCREASED UPPER
LEVEL MOISTURE IS STREAMING NORTHEASTWARD ACROSS PORTIONS OF THE
SW CARIBBEAN.

ATLANTIC OCEAN...
SOUTHWESTERLY FLOW ALOFT IS PRESENT ACROSS THE FAR W ATLC. DEEP
LAYER ATMOSPHERIC LIFT IN THIS FLOW IS SUPPORTING A SURFACE
STATIONARY FRONT EXTENDING FROM THE E FLORIDA PENINSULA NEAR
30N81W TO 31N78W TO 32N76W TO NE OF THE DISCUSSION AREA. LOW
LEVEL CONVERGENCE AND DEEP LAYER ATMOSPHERIC LIFT ARE SUPPORTING
SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THIS FRONT. TO THE
SE OF THIS FRONT...AN UPPER LEVEL RIDGE IS IN PLACE. DEEP LAYER
DRY AIR AND ATMOSPHERIC STABILITY IN THE VICINITY OF THIS UPPER
LEVEL RIDGE ARE RESULTING IN GENERALLY FAIR WEATHER CONDITIONS
TO THE SE OF THE FRONT. FARTHER TO THE E...AN UPPER LEVEL TROUGH
IS N OF 25N BETWEEN 28W-39W...WITH AN UPPER LEVEL LOW NEAR
31N36W. THE UPPER LEVEL LOW AND UPPER LEVEL TROUGH ARE
ASSOCIATED WITH A 1003 MB SURFACE LOW NEAR 29N37W...A
DISSIPATING SURFACE STATIONARY FRONT EXTENDING FROM 14N41W TO
23N33W TO 31N32W...AND A SURFACE OCCLUDED FRONT EXTENDING FROM
31N32W TO 32N35W TO 31N39W. ATMOSPHERIC INSTABILITY...UPPER
LEVEL DIFFLUENCE...AND LOW LEVEL CONVERGENCE IN THE VICINITY OF
THE SURFACE LOW AND SURFACE FRONTS ARE SUPPORTING SCATTERED
SHOWERS AND THUNDERSTORMS N OF 26N BETWEEN 28W-37W. THIS
ACTIVITY IS BEING SUPPORTED BY UPPER LEVEL DIVERGENCE IN THE NE
QUADRANT OF A 100-110 KT UPPER LEVEL JET MAXIMUM LOCATED SE OF
THE UPPER LOW. THE SURFACE LOW IS FORECAST TO MOVE NORTHEASTWARD
DURING THE NEXT DAY AND BE LOCATED NEAR 32N32W AS A 1007 MB
SURFACE LOW AT 15/0600 UTC. FARTHER TO THE E...SUBSIDENCE
ASSOCIATED WITH A SURFACE RIDGE IS RESULTING IN FAIR WEATHER
CONDITIONS ACROSS THE E ATLC. ACROSS THE TROPICAL ATLC...AN
UPPER LEVEL RIDGE IS S OF 13N E OF 51W WITH AN UPPER LEVEL HIGH
NEAR 10N21W. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE UPPER
LEVEL HIGH AND UPPER LEVEL RIDGE IS ENHANCING THE CONVECTION
ASSOCIATED WITH THE ITCZ.

$$
COHEN




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