[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 100621
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN JUL 10 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 0000 UTC SURFACE ANALYSIS AND
SATELLITE IMAGERY THROUGH 0545 UTC.

...SPECIAL FEATURE...
AT 1 AM EDT...0500Z...THE CENTER OF HURRICANE DENNIS WAS LOCATED
NEAR 27.0N 85.6W OR ABOUT 235 MILES SOUTH OF PANAMA CITY FLORIDA
AND ABOUT 310 MILES SOUTHEAST OF BILOXI MISSISSIPPI. DENNIS IS
MOVING NORTHWESTWARD NEAR 14 MPH. A GRADUAL TURN TOWARD THE
NORTH-NORTHWEST IS EXPECTED TODAY. THIS MOTION WILL BRING THE
CENTER OF DENNIS ACROSS THE NORTHERN GULF COAST LATER TODAY.
REPORTS FROM AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT
INDICATE THAT MAXIMUM SUSTAINED WINDS HAVE INCREASED TO NEAR
135 MPH...WITH HIGHER GUSTS. THIS MAKES DENNIS A CATEGORY FOUR
HURRICANE ON THE SAFFIR-SIMPSON SCALE. SOME ADDITIONAL
STRENGTHENING IS POSSIBLE BEFORE LANDFALL. HURRICANE FORCE WINDS
EXTEND OUTWARD UP TO  40 MILES FROM THE CENTER...AND TROPICAL
STORM FORCE WINDS EXTEND OUTWARD UP TO 230 MILES. HURRICANE
FORCE WINDS ASSOCIATED WITH DENNIS MAY OCCUR AS FAR AS 150 TO
175 MILES INLAND ALONG THE TRACK OF THE HURRICANE. AN AIR FORCE
HURRICANE HUNTER PLANE RECENTLY REPORTED A MINIMUM CENTRAL
PRESSURE OF 937 MB...27.67 INCHES. STORM SURGE FLOODING OF 14 TO
17 FEET ABOVE NORMAL TIDE LEVELS...ACCOMPANIED BY LARGE AND
DANGEROUS BATTERING WAVES...IS POSSIBLE NEAR AND TO THE EAST OF
WHERE THE CENTER OF DENNIS CROSSES THE NORTHERN GULF COAST ON
SUNDAY. STORM SURGE WILL GRADUALLY DECREASE ALONG THE LOWER
FLORIDA KEYS TONIGHT. A STORM SURGE OF 2 TO 4 FEET IS POSSIBLE
ALONG THE SOUTHWESTERN COAST OF FLORIDA TONIGHT AND SUNDAY
MORNING. DENNIS IS EXPECTED TO PRODUCE TOTAL RAINFALL
ACCUMULATIONS OF 5 TO 8 INCHES FROM THE FLORIDA PANHANDLE...
SOUTHERN ALABAMA...AND SOUTHERN MISSISSIPPI NORTHWESTWARD
INTO NORTHERN MISSISSIPPI...WITH ISOLATED MAXIMUM AMOUNTS OF
12 INCHES POSSIBLE NEAR WHERE DENNIS MAKES LANDFALL ON THE GULF
COAST. ADDITIONAL RAINFALL ACCUMULATIONS OF 2 TO 4 INCHES ARE
POSSIBLE OVER THE FLORIDA WEST COAST...WITH 1 TO 3 INCHES
POSSIBLE OVER THE REMAINDER OF THE FLORIDA PENINSULA AND
KEYS...AS WELL AS OVER CUBA. PLEASE SEE THE LATEST NHC PUBLIC
ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC AND THE
FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC
FOR MORE DETAILS. HURRICANE DENNIS HIT CUBA AS A CATEGORY FOUR
SYSTEM. IT LEFT CUBA AND ENTERED THE STRAITS OF FLORIDA/THE
SOUTHEASTERN GULF OF MEXICO AS A CATEGORY ONE FEATURE...AND NOW
IT HAS RETURNED AS A CATEGORY FOUR HURRICANE AGAIN. THE PRESSURE
HAS FALLEN TO 941 MB. THERE IS NO CHANGE TO THE TRACK FORECAST
PHILOSOPHY.  DENNIS IN ON THE SOUTHWEST SIDE OF A MID/UPPER
LEVEL RIDGE EXTENDING FROM THE WESTERN ATLANTIC NORTHWESTWARD
INTO THE OHIO VALLEY...AND EAST OF A MID/UPPER-LEVEL TROUGH
EXTENDING FROM ARKANSAS SOUTH-SOUTHWESTWARD TO JUST OFF THE
TEXAS COAST.  THIS COMBINATION SHOULD KEEP DENNIS ON A GENERAL
NORTHWESTWARD TO NORTH-NORTHWESTWARD TRACK FOR AT LEAST
2 DAYS...WITH THIS MOTION BRINGING THE STORM INLAND ON SUNDAY.
TRACK MODEL GUIDANCE IS TIGHTLY CLUSTERED IN CALLING FOR
LANDFALL IN THE PENSACOLA FLORIDA-PASCAGOULA MISSISSIPPI
AREA...AND THE OFFICIAL FORECAST TRACK IS BASICALLY DOWN THE
MIDDLE OF THE CLUSTER JUST A LITTLE TO THE LEFT OF THE PREVIOUS
FORECAST.  AFTER LANDFALL...DENNIS SHOULD SLOW AND GRADUALLY
RECURVE INTO THE WESTERLIES OVER THE MID-MISSISSIPPI AND OHIO
VALLEYS. A SOLID AREA OF NUMEROUS STRONG SHOWERS AND
THUNDERSTORMS SURROUNDS DENNIS FROM 26N TO 28N BETWEEN 84W
AND 86W. OTHER SHOWERS AND THUNDERSTORMS STRETCH FROM THE
SOUTHEASTERN GULF WATERS NEAR 24N TO SOUTHERN GEORGIA BETWEEN
80W AND 88W. IT SHOULD BE NOTED THAT THE HURRICANE FORCE WINDS
ARE CONFINED TO A VERY SMALL AREA NEAR THE CENTER ALTHOUGH
DENNIS HAS A VERY LARGE OUTER WIND FIELD.

...TROPICAL WAVES...

1012 MB LOW PRESSURE CENTER NEAR 11N25W MOVING WEST 10 TO 15 KT.
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS IN THE ITCZ FROM 9N
TO 10N BETWEEN 20W AND 22W.

TROPICAL WAVE ALONG 37W/38W SOUTH OF 17N MOVING WEST 10 TO
15 KT. SCATTERED MODERATE TO ISOLATED STRONG SHOWERS AND
THUNDERSTORMS FROM 10N TO 13N BETWEEN 37W AND 44W...AND ITCZ
PRECIPITATION FROM 6N TO 8N BETWEEN 37W AND 40W.

TROPICAL WAVE ALONG 66W/67W SOUTH OF 17N MOVING WEST 10 TO
15 KT. THIS WAVE IS MOVING THROUGH THE AREA OF AN ATLANTIC-
TO-CARIBBEAN SEA MIDDLE TO UPPER LEVEL TROUGH...FROM 23N62W
TO 16N66W TO THE NORTHWESTERN COAST OF VENEZUELA NEAR 11N69W.
ISOLATED MODERATE SHOWERS FROM 13N TO 15N BETWEEN 65W AND 68W.

...THE ITCZ...

ITCZ 11N14W 10N19W 11N24W...11N27W 11N37W...10N41W 7N50W 10N64W.
STRONG SHOWERS AND THUNDERSTORMS IN A FEW INDIVIDUAL CELLS OR
AREAS FROM 8N TO 11N BETWEEN 16W AND 28W. WIDELY SCATTERED
MODERATE TO ISOLATED STRONG SHOWERS AND THUNDERSTORMS WITHIN
100 NM ON EITHER SIDE OF 8N29W 7N35W 6N43W...BECOMING MORE
ISOLATED MODERATE TO LOCALLY STRONG SHOWERS AND THUNDERSTORMS
FROM THE EQUATOR TO 8N BETWEEN 43W AND 54W.

...DISCUSSION...

GULF OF MEXICO...
HURRICANE DENNIS DOMINATES THE WEATHER STORY FOR THE EASTERN
GULF OF MEXICO...THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA
INCLUDING THE YUCATAN CHANNEL AREA...AND THE ATLANTIC OCEAN
WATERS ADJACENT TO FLORIDA AND OVER THE BAHAMAS. AN UPPER LEVEL
RIDGE RUNS FROM WESTERN CUBA INTO THE SOUTHWESTERN CARIBBEAN
SEA. THE MIDDLE TO UPPER LEVEL TROUGH FROM 24 HOURS AGO...
WHETHER OR NOT IT IS IN PART THE SAME OR ONLY PARTIALLY
SIMILAR...NOW EXTENDS FROM THE UPPER TO MIDDLE TEXAS COAST TO
THE SOUTH CENTRAL GULF. MIDDLE TO UPPER LEVEL DRY AIR COVERS THE
GULF EVERYWHERE WEST OF HURRICANE DENNIS. THE SURFACE STATIONARY
FRONT ACROSS THE SOUTHEASTERN U.S.A. FROM 16 TO 24 HOURS AGO HAS
DISSIPATED.

THE CARIBBEAN SEA...
HURRICANE DENNIS DOMINATES THE WEATHER STORY IN THE NORTHWESTERN
CORNER OF THE AREA...INCLUDING THE YUCATAN CHANNEL. AN UPPER
LEVEL RIDGE RUNS FROM WESTERN CUBA INTO THE SOUTHWESTERN
CARIBBEAN SEA. A MIDDLE TO UPPER LEVEL TROUGH ORIGINATES IN THE
ATLANTIC OCEAN NEAR 26N58W AND EXTENDS TO 22N60W...ENTERING
THROUGH THE NORTHEASTERN CORNER TO 13N67W...BRINGING WITH IT
MIDDLE TO UPPER LEVEL DRY AIR WITHIN 100 NM ON EITHER SIDE OF
IT. THE 66W/67W TROPICAL WAVE BRINGS ISOLATED MODERATE SHOWERS
FROM 13N TO 15N BETWEEN 65W AND 68W.

THE ATLANTIC OCEAN...
UPPER LEVEL NORTHERLY FLOW SPINS AWAY FROM THE CIRCULATION
AROUND HURRICANE DENNIS...INTO THE ATLANTIC WATERS FROM THE
BAHAMAS TOWARD CUBA. WEAKER MIDDLE LEVEL ANTICYCLONIC FLOW MOVES
TOWARD THE BAHAMAS AND EASTERN FLORIDA FROM THE ATLANTIC
OCEAN...AS IT SHOOTS WESTWARD AND AWAY FROM A 23N61W MIDDLE TO
UPPER LEVEL CYCLONIC CIRCULATION CENTER. THIS CYCLONIC CENTER IS
PART OF THE ATLANTIC-TO-VENEZUELA TROUGH. MIDDLE TO UPPER LEVEL
TROUGH THROUGH 32N35W TO 27N43W. BROAD SURFACE ANTICYCLONIC FLOW
IS FOUND FROM 20N TO 30N BETWEEN AFRICA AND 80W.

$$
MT


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