[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 061039
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT MON APR 06 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 1015 UTC.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 6N10W 3N17W CROSSING THE EQUATOR
NEAR 22W AND EXTENDING TO 2S30W INTO NE BRAZIL NEAR 3S42W.
SCATTERED MODERATE CONVECTION IS FROM 1N TO 6N BETWEEN 11W AND
15W. SCATTERED MODERATE CONVECTION IS S OF 3N BETWEEN 20W AND
25W.

...DISCUSSION...

THE GULF OF MEXICO...
A STRONG FRONT FOR THIS TIME OF YEAR IS ON THE MOVE EXTENDING
FROM THE FLORIDA PANHANDLE TO S MEXICO ALONG 30N85W 24N90W
18N95W. STRONG N WINDS FOLLOW THE FRONT DUE TO THE TIGHT PRES
GRADIENT BETWEEN IT AND A 1038 MB HIGH BUILDING S FROM CANADA.
WINDS ARE ESTIMATED TO BE UP TO GALE FORCE BEHIND THE FRONT OVER
THE SW WATERS...WHERE LOCAL TOPOGRAPHY PROVIDES AN ENHANCEMENT.
THESE WINDS HAVE ELEVATED SEAS TO 10 FT ACROSS THE NW GULF BUOYS
AND LIKELY A FEW FT HIGHER OVER THE SW GULF WHERE THE FETCH IS
GREATER AND WINDS ARE LIKELY STRONGER. LITTLE SIGNIFICANT
MOISTURE IS ASSOCIATED WITH THE FRONT...IN PART CAPPED BY
WIDESPREAD STABILITY IN THE MID-LEVELS. THE AIR IS SUBSTANTIALLY
COOLER AND DRIER W OF THE FRONT WITH TEMPS IN THE 40'S/50'S F
AND DEWPTS IN THE 30'S F OVER THE N GULF COAST (COMPARED WITH
70'S F TEMPS AND DEWPTS OVER MUCH OF FLORIDA). THE BOUNDARY IS
EXPECTED TO CLEAR THE ENTIRE AREA BY THIS EVENING.

THE CARIBBEAN SEA...
A WEAK SFC TROUGH IS MOVING SLOWLY W CENTERED ALONG 68W N OF
15N. SATELLITE IMAGERY AND SAN JUAN DOPPLER RADAR SHOW AN AREA
OF LOW-MID LEVEL CLOUDINESS WITH EMBEDDED SCATTERED SHOWERS AND
ISOLATED TSTMS N OF 14N BETWEEN 63W-69W. FAIR WEATHER DOMINATES
THE REMAINDER OF THE REGION ENHANCED BY A STRONGLY SUBSIDENT
ENVIRONMENT BETWEEN AMPLIFIED UPPER RIDGING OVER THE TROPICAL
EPAC AND TROUGHING OVER THE CENTRAL ATLC. RECENT QSCAT DATA AND
SFC OBS DEPICT LIGHT TO MODERATE TRADES...EXCEPT FOR THE GULF OF
HONDURAS AND NEAR THE COAST OF COLOMBIA. LOOKING AHEAD...THE
WEAK TROUGH MENTIONED IS EXPECTED TO CONTINUE W-NW MOVING OVER
HISPANIOLA LATER TODAY. MEANWHILE...A STRONG FRONT FOR THIS TIME
OF YEAR IS EXPECTED TO MOVE INTO THE NW CARIBBEAN TONIGHT.

THE ATLANTIC OCEAN...
IR IMAGERY AND LIGHTNING DATA DEPICT AN AREA OF SCATTERED
SHOWERS AND TSTMS BETWEEN THE SE CONUS AND BERMUDA N OF 28N
BETWEEN 71W-76W. THIS ACTIVITY IS BEING TRIGGERED BY A MID-LEVEL
VORTICITY MAXIMUM THAT IS DIVING SE INTO A TROUGH OVER THE
CENTRAL ATLC. THAT TROUGH IS PROVIDING SOME SUPPORT FOR A
QUASI-STATIONARY FRONT THAT EXTENDS FROM 32N60W TO 24N69W.
UPPER DIFFLUENCE E OF THE TROUGH AXIS IS PRODUCING ISOLATED
SHOWERS AND TSTMS N OF 23N BETWEEN 56W-60W. FARTHER E...AN
ELONGATED UPPER TROUGH EXTENDING ALONG 29N/30N E OF 40W IS
PROVIDING VERY LIMITED SUPPORT FOR A BENIGN WEAK SFC TROUGH
ALONG 32N44W 26N42W. THIS FEATURE WILL LIKELY DISSIPATE LATER
TODAY. OVER THE DEEP TROPICS...THE MAIN FEATURE IS A LARGE UPPER
HIGH CENTERED NEAR 10N17W. ONLY ASSOCIATED EFFECTS EXIST ON ITS
WRN PERIPHERY WHERE UPPER SLY FLOW AND AN OVERALL DIFFLUENT
PATTERN IS GENERATING AND SPREADING MOISTURE N FROM THE ITCZ S
OF 11N BETWEEN 40W-56W.

$$
CANGIALOSI



This weather bulletin was brought to you by:
www.nashvilleweather.net