[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 041203
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE SEP 04 2007

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...SPECIAL FEATURES...

POTENTIALLY CATASTROPHIC HURRICANE FELIX MAKES LANDFALL IN
EXTREME NORTHEASTERN NICARAGUA AT CATEGORY FIVE STRENGTH. FELIX
IS CENTERED NEAR 14.3N 83.2W OR VERY NEAR PUNTA GORDA NICARAGUA
ABOUT 10 MI NNE OF PUERTO CABEZAS AT 04/1200 UTC...MOVING W AT
14 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 935 MB. MAXIMUM
SUSTAINED WIND SPEED IS 145 KT WITH GUSTS TO 175 KT. SEE LATEST
NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS
INCLUDING THE LATEST WATCH AND WARNING INFORMATION. FELIX HAS
CROSSED CAYOS MISKITOS AND IS NOW MAKING LANDFALL IN NE
NICARAGUA. OUTER RAINBANDS OF HEAVY RAIN/ THUNDERSTORMS HAVE
BEEN OVER PORTIONS OF NICARAGUA AND HONDURAS FOR THE PAST FEW
HOURS AND COULD PRODUCE LIFE-THREATENING FLASH FLOODS AND MUD
SLIDES. CONDITIONS WILL CONTINUE TO DETERIORATE OVER THE
REMAINDER OF HONDURAS AS FELIX CONTINUES ON ITS WESTWARD TRACK.
RAINFALL AMOUNTS OF 5 TO 10 INCHES ARE EXPECTED ACROSS N
NICARAGUA AND MUCH OF HONDURAS WITH POSSIBLE AMOUNTS OF UP TO 20
INCHES IN ISOLATED AREAS. SCATTERED/NUMEROUS STRONG CONVECTION
IS FROM 12N-17N BETWEEN 81W-85W.

AS OF 04/0900 UTC...A 1010 MB LOW PRESSURE AREA IS OFF THE E
FLORIDA COAST CENTERED NEAR 30N77W WITH A SURFACE TROUGH
EXTENDING SW ACROSS THE FLORIDA KEYS  TO JUST W OF KEY WEST
FLORIDA. A SECOND SURFACE TROUGH EXTENDS NE FROM THE LOW ALONG
31N73W TO 30N67W. THIS SYSTEM CURRENTLY DOES SHOW ANY TROPICAL
CHARACTERISTICS ONLY DISORGANIZED CLOUDINESS AND SHOWERS. IT
DOES HAVE THE POTENTIAL FOR TO ACQUIRE TROPICAL OR SUBTROPICAL
CHARACTERISTICS OVER THE NEXT FEW DAYS AS IT DRIFTS EASTWARD.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 27N-30N
BETWEEN 71W-76W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE
FROM 25N-28N BETWEEN 76W AND THE FLORIDA E COAST AND N OF 28N TO
THE N SURFACE TROUGH.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 30W S OF 20N MOVING W 10-15 KT WITH A
WEAK 1012 MB LOW ALONG THE WAVE NEAR 14N. BROAD LOW/MID LEVEL
INVERTED-V CURVATURE COVERING THE AREA S OF 23N FROM THE CAPE
VERDE ISLANDS TO 40W WITH A VERY SMALL LOW LEVEL CENTER. NO
ASSOCIATED SHOWERS OR DEEP CONVECTION.

TROPICAL WAVE IS ALONG 61W/62W S OF 22N MOVING W NEAR 10 KT.
WAVE HAS A CLASSIC BROAD INVERTED-V CURVATURE COVERING THE AREA
FROM 53W-65W. A MID LEVEL ROTATION IS TO THE E OF THE WAVE AXIS
NEAR 17N59W. HOWEVER...DUE TO THE DRY STABLE AIR OVER THE REGION
THERE IS NO ASSOCIATED DEEP CONVECTION WITH ONLY ISOLATED
SHOWERS FROM 15N-19N BETWEEN 60W-63W MAINLY OVER THE LEEWARD
ISLANDS.

TROPICAL WAVE IS ALONG 91W/92W S OF 22N MOVING W NEAR 10 KT.
WAVE IS MOSTLY OVER S MEXICO AND INTO THE E PACIFIC REGION WITH
SOME SCATTERED SHOWERS/ISOLATED THUNDERSTORMS MOVING IN THE BAY
OF CAMPECHE S OF 22N E OF 96W.

...THE ITCZ...
ITCZ AXIS IS CENTERED ALONG 13N14W 14N27W 11N31W 7N46W 9N60W. A
WEAK 1012 MB LOW IS JUST N OF THE ITCZ AXIS NEAR 10.5N40.5W.
THIS LOW WAS PREVIOUSLY IN THE SPECIAL FEATURES BUT HAD LOST ALL
CONVECTION AND WAS ONLY A SMALL LOW LEVEL SWIRL. HOWEVER...
SCATTERED MODERATE/ISOLATED STRONG CONVECTION HAS RE-DEVELOPED
FROM 9N-11N BETWEEN 37W-42W. CLUSTERS OF SCATTERED MODERATE TO
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 5N-10N
BETWEEN 31W-49W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE
FROM 3N-7N BETWEEN 10W-18W.

DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL RIDGE EXTENDS ACROSS MEXICO OVER E TEXAS AND
LOUISIANA TO THE MISSISSIPPI VALLEY COVERING THE W GULF W OF
93W. AN UPPER HIGH IS OVER THE NE GULF NEAR 26N86W COVERING THE
E GULF INDUCING AN INVERTED UPPER LEVEL TROUGH EXTENDING FROM
THE E BAY OF CAMPECHE ACROSS THE CENTRAL GULF OF MEXICO
ENHANCING ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE ALONG
91W/92W. THIS SCENARIO IS ALSO PRODUCING ENOUGH UPPER LEVEL
DIFFLUENCE OVER THE GULF TO GENERATE SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ALONG THE NW GULF FROM 24N-28N W OF 94W...THE N
GULF N OF 28W E OF 92W TO THE W COAST OF FLORIDA. THE SURFACE
TROUGH THAT EXTENDS ACROSS THE FLORIDA KEYS DESCRIBED INT HE
SPECIAL FEATURES IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS
OVER THE FLORIDA BAY FROM 24N-27N BETWEEN 82W-84W. THE REMAINDER
OF THE AREA REMAINS RELATIVELY TRANQUIL WITH POSSIBLE WIDELY
ISOLATED LOW LEVEL SHOWERS WITH LIGHT SURFACE WINDS.

CARIBBEAN SEA...
HURRICANE FELIX IS THE MAIN FOCUS THIS MORNING AS IT MOVES
INLAND OVER CENTRAL AMERICA MAKING LANDFALL IN A FEW HOURS. FOR
MORE DETAILS ON FELIX REFER TO THE SPECIAL FEATURE SECTION
ABOVE. UPPER HIGH ASSOCIATED WITH FELIX IS PRODUCING GOOD
OUTFLOW OVER FELIX IN ALL QUADRANTS FROM 74W-88W. THE ITCZ AXIS
EXTENDS INTO THE E PACIFIC REGION ACROSS N PORTION OF SOUTH
AMERICA AND PANAMA GENERATING CLUSTERS OF SCATTERED SHOWERS/
THUNDERSTORMS S OF 13N FROM 68W-78W AND IS BEING DRAWN TOWARD
FELIX. NE UPPER WINDS COVER MOST OF THE E CARIBBEAN WITH A WEAK
UPPER INVERTED TROUGH EXTENDING FROM VENEZUELA NEAR 10N65W
ACROSS THE LESSER ANTILLES TO NEAR 19N57W. DRY STABLE AIR IS
FILTERING IN THE WAKE OF FELIX OVER THE E CARIBBEAN CLEARING
SKIES WITH THE EXCEPTION OF SOME ISOLATED LOW LEVEL SHOWERS OVER
THE E CARIBBEAN BROUGHT IN BY THE MODERATE EASTERLY TRADE WINDS.

ATLANTIC OCEAN...
A SHORTWAVE UPPER TROUGH EXTENDS THROUGH 32N77W SW TO CENTRAL
FLORIDA NEAR LAKE OKEECHOBEE. THE 1010 MB LOW AND SURFACE
TROUGHS MENTIONED IN THE SPECIAL FEATURES ABOVE ARE ASSOCIATED.
AN UPPER HIGH COVERS THE REMAINDER OF THE W ATLC W OF 58W. AN
UPPER TROUGH EXTENDS INTO THE CENTRAL ATLC THROUGH 32N57W TO
NEAR 23N54W ENVELOPING THE UPPER LOW THAT WAS PREVIOUSLY IN THE
REGION. A SURFACE TROUGH EXTENDS THROUGH 32N53W TO NEAR 29N62W
GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 28N TO
THE SURFACE TROUGH BETWEEN 52W-58W. ISOLATED SHOWERS DOT THE
AREA N OF 26N FROM 58W-61W. THE REMAINDER OF THE ATLC IS
DOMINATED BY THE TYPICAL E/W UPPER RIDGE EXTENDING FROM OFF
AFRICA TO NEAR 50W CENTERED ROUGHLY ALONG 23W/24W. ABUNDANT DRY
AIR ALOFT COVERS THE ATLC E OF 50W WITH A SURFACE RIDGE
EXTENDING THROUGH 32N28W WSW TO A 1019 MB HIGH NEAR 26N68W WITH
LIGHT TO MODERATE EASTERLY TRADE WINDS ACROSS THE ATLC.

$$
WALLACE


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