[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 201141
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SUN 20 MAR 2005

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHEASTERN 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 8N10W 3N21W 2N40W 1N50W. SCATTERED/
MODERATE/STRONG CONVECTION IS WITHIN 90/120 NM OF LINE FROM THE
COAST OF AFRICA NEAR 5N3W ALONG 1N7W 2N12W TO THE ITCZ AXIS NEAR
6N14W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE
WITHIN 100 NM N OF THE AXIS AND WITHIN 180 NM S OF THE AXIS
BETWEEN 16W-24W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE S
OF 10N FROM 30W-52W.

...DISCUSSION...

GULF OF MEXICO...
DEEP LAYERED TROUGH COVERS THE GULF WITH YET ANOTHER POTENT S
STREAM SHORTWAVE DISTURBANCE MOVING E OUT OF TEXAS ACROSS THE SE
UNITED STATES AND IS THE CURRENT WEATHER MAKER AS IT MOVES OVER
LOUISIANA. ATTENDANT FRONTAL BOUNDARY IS STILL INLAND OVER THE
MISSISSIPPI VALLEY THROUGH TEXAS AND WILL BE IN THE GULF LATER
THIS TODAY. WEAK SURFACE RIDGE PREVAILS OVER THE E HALF OF THE
GULF AND FLORIDA WITH A 1019 MB HIGH CENTERED ALONG THE NW COAST
OF FLORIDA NEAR 29N83W. GENERALLY COOL/DRY CONDITIONS PREVAIL
ACROSS THE E GULF COURTESY OF THE CONTINENTAL AIRMASS. STRONG
SHOWERS/THUNDERSTORMS ARE WITHIN 45 NM OF LINE FROM 27N93W TO
INLAND OVER LOUISIANA TO NEAR 31N92W. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS OVER THE NW GULF N OF 27N W OF 90W. THE SHORTWAVE
AND ASSOCIATED SHOWER/THUNDERSTORM ACTIVITY SHOULD MOVE INTO THE
CENTRAL GULF LATER TODAY. THEREAFTER...THE PROGRESSION OF THE
PATTERN WILL BE SLOWER OVER THE FOLLOWING 24 HOURS.
NONETHELESS...UNSETTLED/WET CONDITIONS MAY EXIST OVER THE N GULF
THROUGH TUE.

CARIBBEAN...
PERSISTENT MID/UPPER LEVEL RIDGE REMAINS ANCHORED OVER THE W
TROPICAL ATLC WITH RIDGE AXIS EXTENDING E/W ALONG 15N/16N. THERE
IS A SOME UPPER LEVEL MOISTURE MOVING AROUND THE W PERIPHERY
OF THE RIDGE FROM OVER CENTRAL AMERICA TO OVER E CUBA.
HOWEVER...MOST OF THE AREA CONTINUES TO BE DOMINATED BY STRONG
SUBSIDENCE AND DRY/STABLE CONDITIONS ALOFT. DRY CONDITIONS ALSO
PREVAIL IN THE LOWER LEVELS LIMITING SHOWER ACTIVITY SAVE SOME
ISOLATED ACTIVITY ALONG A REMNANT STATIONARY FRONT OVER E TIP OF
CUBA AND OVER HONDURAS AND THE SURROUNDING AREA. MOISTURE WILL
REMAIN PRIMARILY LIMITED OVER MOST OF THE AREA THROUGH THE
WEEKEND MAINTAINING THE VERY DRY PATTERN WHICH HAS PREVAILED FOR
SEVERAL WEEKS.

ATLANTIC...
STRONG MID/UPPER LEVEL RIDGING OVER THE CARIBBEAN WATERS IS
PRODUCING MAINLY SW FLOW OVER THE W ATLC...WITH A LOW/MID LEVEL
SHORTWAVE TROUGH ALONG 75W. A 1009 MB LOW IS OFF THE U.S. E
COAST NEAR 32N76W WITH A WEAK COLD FRONT EXTENDING W TO THE
COAST OF GEORGIA. THIS SYSTEM IS PRODUCING OVERCAST CLOUDINESS
WITH SCATTERED SHOWERS/THUNDERSTORMS N OF 31N FROM BERMUDA TO
75W. A SECOND SHORTWAVE TROUGH IS N OF 30N OVER THE CENTRAL ATLC
WITH ATTENDANT COLD FRONT EXTENDING SW FROM A 998 MB LOW N OF
THE AREA NEAR 33N33W ALONG 27N48W TO 24N63W THEN DISSIPATING
STATIONARY TO THE E TIP OF CUBA. MOST OF THE UPPER LEVEL
DYNAMICS/SUPPORT WITH THIS SYSTEM IS FOCUSED WELL N OF THE AREA
BUT LOW LEVEL MOISTURE POOLING IS PRODUCING A NARROW BAND OF
ISOLATED SHOWERS EXTENDING UP TO 90 NM E OF FRONT. BEHIND THE
FRONT...BROKEN COLD AIR STRATOCUMULUS CLOUDS TO 65W. FURTHER
E...AN ELONGATED SURFACE RIDGE SPANS ACROSS MUCH OF THE
CENTRAL/EASTERN ATLC FROM THE CANARY ISLANDS SW TO A 1020 MB
HIGH LOCATED NEAR 20N34W THEN NW TO 23N53W. A WEAK 1019 MB HIGH
IS NW OF THE CENTRAL ATLC FRONT NEAR 29N62W. THERE IS NO
LARGE-SCALE PRECIPITATION OVER THE E HALF OF THE SUBTROPICAL
ATLC. FURTHER S...MODERATE SUBSIDENCE IN THE UPPER LEVELS AND
DRY AIR IN THE LOWER LEVELS MOVING OFF W AFRICA IS LARGELY
SUPPRESSING CLOUDS AND PRECIPITATION OVER THE AREA INCLUDING THE
N PORTION OF THE TROPICAL ATLC.

$$
WALLACE


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