[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 181806
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT FRI JUL 18 2008

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1745 UTC.

...SPECIAL FEATURES...

THE CENTER OF TROPICAL STORM BERTHA AT 18/1500 UTC IS NEAR
36.2N 52.3W MOVING NORTHEAST OR 40 DEGREES 16 KT. THE ESTIMATED
MINIMUM CENTRAL PRESSURE IS 995 MB. THE MAXIMUM SUSTAINED WIND
SPEEDS ARE 55 KT WITH GUSTS TO 65 KT. PLEASE READ THE LATEST NHC
FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC
AND THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE
DETAILS. THE FORECAST IS FOR BERTHA TO CHANGE IN STRENGTH ONLY
A LITTLE BIT DURING THE NEXT 24 HOURS. IT IS POSSIBLE THAT BERTHA
MAY BEGIN TO LOSE TROPICAL CHARACTERISTICS LATE ON SATURDAY.
BERTHA IS FORECAST TO START TO BECOME EXTRATROPICAL IN 36 HOURS.
TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 175 MILES/280 KM
FROM THE CENTER. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG
THUNDERSTORMS FROM 36N TO 38N BETWEEN 50W AND 53W. WIDELY
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
WITHIN 30 NM ON EITHER SIDE OF 31N55W 28N59W 26N64W...AND FROM
28N TO 31N BETWEEN 64W AND 70W IN A SURFACE TROUGH.

AN EASTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 69W/70W SOUTH OF
19N MOVING WEST 15 TO 20 KT. THE WAVE RUNS FROM THE SOUTHEASTERN
DOMINICAN REPUBLIC TO NORTHWESTERN VENEZUELA. A 1008 MB LOW
PRESSURE CENTER IS ALONG THE WAVE NEAR 14N. SATELLITE IMAGES
INDICATE THAT THIS AREA CONTINUES TO BECOME BETTER-ORGANIZED.
AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT IS SCHEDULED
TO INVESTIGATE THIS SYSTEM THIS AFTERNOON IN ORDER TO DETERMINE
IF A TROPICAL DEPRESSION OR TROPICAL STORM HAS FORMED. ALL
INTERESTS IN THE CENTRAL AND WESTERN CARIBBEAN SEA SHOULD
CONTINUE TO MONITOR THE PROGRESS OF THIS SYSTEM. PLEASE CONSULT
STATEMENTS FROM YOUR LOCAL WEATHER OFFICE FOR INFORMATION
SPECIFIC TO YOUR AREA. STRONG SHOWERS AND THUNDERSTORMS ARE FROM
16N TO 18N BETWEEN 68W AND 71W...AND FROM 14N TO 15N BETWEEN 70W
AND 71W. OTHER SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 12N
TO 18N BETWEEN 68W AND 75W.

A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 86W SOUTH OF 22N
MOVING WEST 10 TO 15 KT. A 1009 MB LOW PRESSURE CENTER IS ALONG
THE WAVE NEAR 15N. THE SURFACE TO LOW LEVEL CYCLONIC FLOW AND
SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS
AROUND THIS SYSTEM COVER THE CARIBBEAN SEA FROM PANAMA AND
COSTA RICA TO 20N BETWEEN 80W AND 91W. STRONG SHOWERS AND
THUNDERSTORMS COVER AND/OR HAVE BEEN IN BELIZE...AND IN COASTAL
SOUTHWESTERN NICARAGUA. SHOWERS AND THUNDERSTORMS ARE IN THE
WATERS FROM 15N TO 18N BETWEEN 81W AND 86W. CONVECTIVE DEBRIS
CLOUDS AND POSSIBLY LINGERING PRECIPITATION ARE WITHIN 100 NM
TO THE EAST OF THE NICARAGUA COAST. THIS SYSTEM IS CAPABLE OF
PRODUCING STRONG GUSTY WINDS IN SECTIONS OF THE NORTHWESTERN
CARIBBEAN SEA. IT IS POSSIBLE THAT HEAVY RAINS MAY SPREAD ACROSS
SECTIONS OF HONDURAS...NICARAGUA....BELIZE AND GUATEMALA FOR
THE NEXT DAY OR TWO. THIS ACTIVITY MAY CAUSE LIFE-THREATENING
FLASH FLOODS AND MUDSLIDES.

SURFACE OBSERVATIONS AND SATELLITE IMAGES INDICATE THAT
A 1012 MB LOW PRESSURE SYSTEM LOCATED JUST OFF THE COASTS
OF GEORGIA AND SOUTH CAROLINA IS BECOMING BETTER ORGANIZED.
ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR FURTHER
DEVELOPMENT...AND IT IS POSSIBLE THAT A TROPICAL DEPRESSION
MAY FORM TODAY OR TOMORROW. AN AIR FORCE RESERVE HURRICANE
HUNTER AIRCRAFT IS SCHEDULED TO INVESTIGATE THIS SYSTEM
TOMORROW IF NECESSARY.  ALL INTERESTS ALONG THE COASTS OF
GEORGIA...SOUTH CAROLINA...AND NORTH CAROLINA SHOULD MONITOR
THE PROGRESS OF THIS SYSTEM.  LOCALLY HEAVY RAINFALL IS POSSIBLE
IN THESE AREAS DURING THE NEXT COUPLE OF DAYS AS THIS SYSTEM
MOVES SLOWLY NORTHEASTWARD NEAR THE COAST. PLEASE CONSULT
STATEMENTS FROM YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST
OFFICE FOR INFORMATION SPECIFIC TO YOUR AREA. SCATTERED MODERATE
TO STRONG SHOWERS AND THUNDERSTORMS NOW ARE FROM 29N TO 32N
BETWEEN 76W AND 81W.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 48W/49W SOUTH OF 19N
MOVING WEST 15 KT. THIS WAVE IS NOT MAKING THE HEADLINES THAT
THE CARIBBEAN SEA WAVES HAVE ENJOYED. IT SHOWS UP IN VISIBLE
SATELLITE IMAGERY. NO DEEP CONVECTIVE PRECIPITATION ACCOMPANIES
THIS WAVE.

...THE ITCZ...
14N17W 7N25W 4N36W 9N54W 9N63W. SCATTERED MODERATE SHOWERS TO
ISOLATED STRONG THUNDERSTORMS FROM 4N TO 8N BETWEEN 23W AND 31W.
ISOLATED MODERATE SHOWERS FROM 5N TO 13N BETWEEN AFRICA AND
23W...AND SOUTH OF 6N BETWEEN 35W AND 52W. ISOLATED MODERATE
SHOWERS AND POSSIBLE THUNDERSTORMS TO THE SOUTH OF A MIDDLE TO
UPPER LEVEL TROUGH AT THE WESTERN END OF THE ITCZ FROM 8N TO 12N
BETWEEN 54W AND 62W.

...DISCUSSION...

THE GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH RUNS FROM EAST TEXAS TO THE LOWER
TEXAS COAST TO MEXICO ABOUT 120 NM NORTHWEST OF THE ISTHMUS OF
TEHUANTEPEC. ISOLATED MODERATE SHOWERS ARE IN COASTAL MEXICO
FROM 22N TO 25N BETWEEN 98W AND 99W. A MIDDLE TO UPPER LEVEL
RIDGE RUNS FROM THE YUCATAN PENINSULA TOWARD THE NORTH CENTRAL
GULF OF MEXICO COAST OF THE U.S.A. A MIDDLE TO UPPER LEVEL
CYCLONIC CIRCULATION CENTER IS NEAR 22N76W IN THE WATERS BETWEEN
THE SOUTHERN BAHAMAS ISLANDS AND EASTERN CUBA. CYCLONIC FLOW
HAS BECOME MOVED INTO THE EASTERN AND SOUTHEASTERN GULF WATERS.

THE CARIBBEAN SEA...
ONE TROPICAL WAVE IS ALONG 86W. THE CLOUDS AND PRECIPITATION
ACCOMPANYING THE 86W TROPICAL WAVE ALREADY COVER CENTRAL
AMERICA. THIS PRECIPITATION MAY CAUSE LIFE-THREATENING FLASH
FLOODS AND MUDSLIDES. A SECOND TROPICAL WAVE IS ALONG 69W/70W.
AN AIR FORCE RESERVE UNIT RECONNAISSANCE AIRCRAFT IS SCHEDULED
TO INVESTIGATE THIS SYSTEM THIS AFTERNOON IN ORDER TO DETERMINE
IF A TROPICAL DEPRESSION OR TROPICAL STORM HAS FORMED. ALL
INTERESTS IN THE CENTRAL AND WESTERN CARIBBEAN SEA SHOULD
CONTINUE TO MONITOR THE PROGRESS OF THIS SYSTEM. PLEASE CONSULT
STATEMENTS FROM YOUR LOCAL WEATHER OFFICE FOR INFORMATION
SPECIFIC TO YOUR AREA. STRONG SHOWERS AND THUNDERSTORMS ARE FROM
16N TO 18N BETWEEN 68W AND 71W...AND FROM 14N TO 15N BETWEEN 70W
AND 71W. OTHER SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 12N
TO 18N BETWEEN 68W AND 75W. A MIDDLE TO UPPER LEVEL CYCLONIC
CIRCULATION CENTER IS NEAR 22N76W IN THE WATERS BETWEEN THE
SOUTHERN BAHAMAS ISLANDS AND EASTERN CUBA. CYCLONIC FLOW COVERS
THE AREA FROM JAMAICA NORTHWARD BETWEEN HISPANIOLA AND THE
YUCATAN CHANNEL.

THE ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM 28N72W TO A CYCLONIC
CIRCULATION CENTER NEAR 22N76W TO THE CARIBBEAN SEA NEAR
JAMAICA. A MIDDLE TO UPPER LEVEL TROUGH IS CONNECTED BY ONE
CYCLONIC CIRCULATION CENTER NEAR 28N48W TO A SECOND CYCLONIC
CENTER NEAR 17N56W TO BARBADOS. THIS TROUGH IS EMBEDDED
IN/SURROUNDED BY DRY AIR IN SUBSIDENCE.

$$
MT







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