[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 300603
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SUN DEC 30 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0515 UTC

...SPECIAL FEATURE...

THE EASTERN ATLANTIC DEEP LAYER CYCLONIC CIRCULATION CENTER
IS MORE OR LESS IN THE SAME SPOT THAT IT HAS BEEN RESIDING FOR
THE LAST WEEK OR SO. THE SUBTROPICAL CLASSIFICATION NUMBER IS
S-T 2.5. A HURRICANE FORECASTER WROTE A DSAAT BULLETIN AT
29/1900 UTC...THIS FEATURE THAT IS ABOUT 950 MILES SOUTHWEST
OF THE AZORES GRADUALLY HAS BEEN ACQUIRING SOME SUBTROPICAL
CHARACTERISTICS DURING THE PAST DAY OR SO. IT HAS BEEN
PRODUCING GALE-FORCE WINDS...MAINLY TO THE NORTH AND EAST
OF ITS CIRCULATION CENTER. IT IS POSSIBLE THAT IT MAY BECOME
A SUBTROPICAL STORM LATER TODAY AS IT REMAINS NEARLY STATIONARY.
FURTHER TROPICAL DISTURBANCE STATEMENTS WILL BE ISSUED AS
NECESSARY. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND
IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE...
UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.
SCATTERED MODERATE TO STRONG SHOWERS AND THUNDERSTORMS ARE
FROM 28.5N TO 30N BETWEEN 33W AND 37W. A THIN LINE OF CLOUDS
AND POSSIBLE SHOWERS STILL IS ALONG 25N34W 20N37W 18N40W 13N50W
10N57W 9N60W AND NOT QUITE TO THE COAST OF EXTREME EASTERN/
NORTHEASTERN VENEZUELA AS IT WAS 16 HOURS AGO. PATCHES OF
MULTILAYERED CLOUDS AND POSSIBLE SHOWERS ARE ASSOCIATED WITH
AN ALREADY-DISSIPATED ATLANTIC OCEAN TROUGH...ORIGINATING FROM
THE DEEP LAYER LOW PRESSURE CENTER WITHIN 180 NM TO 240 NM
NORTH OF 17N46W 12N57W 11N65W 13N71W. THE CLOUDS/POSSIBLE
PRECIPITATION ALONG THE WESTERN END OF THIS LINE ARE IN THE
CARIBBEAN SEA. THE CYCLONE SHOULD MEANDER DURING THE NEXT
36 HOURS BEFORE BEING PUSHED TOWARD THE WEST OR SOUTHWEST
BY A DEVELOPING MIDDLE-OCEAN RIDGE ON MONDAY. THE LATE NIGHT
AND EARLY MORNING HOURS OF TODAY MAY BE THE LAST OPPORTUNITY
FOR THIS SYSTEM TO GAIN A BIT MORE ORGANIZATION TO ITS
PRECIPITATION PATTERN AND MAKE THE TRANSITION TO A NAMED
SUBTROPICAL STORM GIVEN THAT THE VERTICAL SHEAR IS FORECAST
TO INCREASE SUBSTANTIALLY LATER TODAY.

...THE ITCZ...

FROM SOUTHERN LIBERIA TO 2N20W TO 4N33W INTO NORTHEASTERN BRAZIL
NEAR 2N51W. A TROUGH IS ALONG 39W/40W SOUTH OF 15N. ISOLATED
MODERATE TO LOCALLY STRONG THUNDERSTORMS ARE SOUTH OF 9N
EAST OF 54W. UPPER LEVEL SOUTHWESTERLY WIND FLOW IS SOUTH OF
10N60W 12N60W 17N40W 27N18W CROSSING OVER NORTHERN WESTERN
SAHARA.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH IS DIGGING ACROSS TEXAS. THE GULF
OF MEXICO EAST OF 90W IS COVERED BY ANTICYCLONIC FLOW FROM THE
CARIBBEAN SEA RIDGE. THE REST OF THE GULF OF MEXICO IS COVERED
BY A MIXTURE OF THE MIDDLE TO UPPER LEVEL SOUTHWESTERLY WIND FLOW
TO THE EAST OF THE TEXAS TROUGH..AND THE ANTICYCLONIC FLOW JUST
AWAY FROM THE EAST OF 90W RIDGE. ISOLATED MODERATE SHOWERS HAVE
BEEN NORTH OF 28N BETWEEN 88W AND 93W DURING THE LAST FEW HOURS.
A COLD FRONT/STATIONARY FRONT HAS BEEN IN THE GULF OF MEXICO
ALONG 31N84W IN THE FLORIDA PANHANDLE TO 27N90W IN THE NORTH
CENTRAL GULF OF MEXICO...DISSIPATING AND CURVING INTO THE
SOUTHWESTERN CORNER OF THE AREA. ALL THIS HAS BEEN OCCURRING
UNDER THE ANTICYCLONIC FLOW FROM THE CARIBBEAN SEA.

THE CARIBBEAN SEA AND THE REST OF THE ATLANTIC OCEAN...
MIDDLE TO UPPER LEVEL ANTICYCLONIC WIND FLOW EXTENDS FROM
THE WEST CENTRAL CARIBBEAN SEA NORTHWARD IN ORDER TO COVER
THE GULF OF MEXICO EAST OF 90W...AND NORTHEASTWARD BEYOND
32N69W IN ORDER TO COVER THE ATLANTIC OCEAN WEST OF 60W.
UPPER LEVEL MOISTURE THAT HAD BEEN CONFINED MOSTLY TO THE
SOUTHWESTERN CORNER OF THE CARIBBEAN SEA NOW COVERS THE
NORTHWESTERN CORNER OF THE AREA. MIDDLE TO UPPER LEVEL
ANTICYCLONIC FLOW COVERS THE ENTIRE CARIBBEAN SEA BASIN.
SHOWERS ARE POSSIBLE IN BROKEN LOW CLOUDS IN SURFACE EASTERLY
WIND FLOW NORTH OF 14N WEST OF 76W. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND POSSIBLE SHOWERS ARE ASSOCIATED WITH
AN ALREADY-DISSIPATED ATLANTIC OCEAN TROUGH...ORIGINATING FROM
THE DEEP LAYER LOW PRESSURE CENTER...WITHIN 180 NM TO 240 NM
NORTH OF 17N46W 12N57W 11N65W 13N71W. THE CLOUDS/POSSIBLE
PRECIPITATION ALONG THE WESTERN END OF THIS LINE ARE IN THE
CARIBBEAN SEA.

$$
MT




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