[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 240004
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SUN MAY 23 2010

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2355 UTC...

...SPECIAL FEATURES...

A BROAD DEEP LAYER TROUGH IS OVER THE WESTERN ATLANTIC. AN UPPER
LEVEL LOW IS EMBEDDED IN THIS TROUGH...NOTED ON WATER VAPOR
IMAGERY...AND SUPPORTS A 1007 MB SURFACE LOW CENTER NEAR 24N70W.
A SURFACE TROUGH CROSSES THE LOW CENTER ALONG 29N68W 24N70W
21N70W. MARINE OBSERVATIONS NEAR THE LOW CENTER INDICATE 8 FT TO
12 FT SEAS. GALE FORCE WINDS ARE DEVELOPING NORTHEAST OF THE LOW
CENTER FROM 25N TO 32N BETWEEN 65W AND 70W. THIS SYSTEM IS BEEN
FURTHER ENHANCED BY THE FORMATION OF A UPPER LEVEL LONGWAVE
SOUTHWEST OF THE SYSTEM. WHILE THE CURRENT LOW SHIFTS
SOUTHWARD...SATELLITE IMAGERY SUGGESTS THAT A SECOND LOW IS
DEVELOPING TO THE NORTH OF THE CURRENT LOW AND IT IS EXPECTED TO
BE ADDED TO THE SURFACE UNIFIED MAP BETWEEN 24/0000 UTC AND
24/0600. COMPUTER MODELS SUGGEST THE SECOND LOW WILL STRENGTHEN
AND MOVE NORTHWEST TO NEAR 30N71W OVER THE NEXT 24 HOURS. MOST
OF THE CONVECTION IS FOUND EAST OF THE SYSTEM FROM 19N TO 32N
BETWEEN 55W AND 71W. MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS
ARE NORTH EAST OF THE LEEWARD ISLANDS FROM 17N TO 24N BETWEEN
57W AND 62W.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 23W FROM 3.5N TO 9N MOVING WEST AT 10 KT.
THIS WAVE IS MOVING ALONG WITH THE ITCZ EMBEDDED IN AN AREA OF
MAXIMUM DEEP LAYER MOISTURE. SCATTERED MODERATE CONVECTION IS
FROM 5N TO 9N BETWEEN 20W AND 25W.

TROPICAL WAVE IS ALONG 42W FROM 3N TO 9N MOVING WEST AT 12 KT.
THIS WAVE IS EMBEDDED IN AN AREA OF MAXIMUM DEEP LAYER MOISTURE
IN TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED MODERATE TO STRONG
CONVECTION IS WEST OF THE WAVE FROM 5N TO 9N BETWEEN 42W AND
47W.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 9N13W 7N20W 5N30W 6N40W 5N50W. ASIDE
OF AREAS OF CONVECTION ASSOCIATED WITH TROPICAL
WAVES...SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS
WITHIN 60 NM ON EITHER SIDE OF THE ITCZ. STRONG CONVECTION IS
OVER THE WESTERN AFRICA COAST INCLUDING NORTHERN
LIBERIA...SIERRA LEONE...AND GUINEA.

...DISCUSSION...

GULF OF MEXICO...
FAIR WEATHER IS NOTED ACROSS MOST OF THE AREA AS UPPER LEVEL
RIDGE OF HIGH PRESSURE COVERS THE GULF OF MEXICO MOVING DRY
STABLE AIR ALOFT ACROSS THE BASIN. A SURFACE 1017 MB HIGH
PRESSURE SYSTEM IS FOUND OVER THE NORTHERN GULF NEAR 29N88W.
ANTI-CYCLONIC FLOW AROUND THIS FEATURE IS MOVING SOME LOW LEVEL
MOISTURE FROM THE FAR WESTERN ATLANTIC INTO THE NORTHEAST GULF.
THIS AREA OF MOISTURE IS ADVECTING ACROSS THE NORTHERN FLORIDA
PENINSULA...INCLUDING THE PANHANDLE. THE COMBINATION OF LOW
LEVEL MOISTURE...DIURNAL HEATING...AND INSTABILITY OVER THIS
REGION IS PRODUCING A FEW ISOLATED SHOWERS AND POSSIBLE
THUNDERSTORMS OVER THE NORTHERN FLORIDA PENINSULA AND PANHANDLE
NORTH OF 29N. COMPUTER MODELS INDICATE THE CONVECTION IN THIS
REGION MAY LINGER OVER THE NEXT 24 HOURS. ELSEWHERE ACROSS THE
BASIN...NO SIGNIFICANT CHANGES ARE EXPECTED OVER THE NEXT 24 HRS.

CARIBBEAN SEA...
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LONGWAVE ENTERING THE
NORTH-NORTHWEST CARIBBEAN PROVIDING STRONG SUBSIDENCE NORTH OF
17N WEST OF 73W. THE EDGE LINE OF THIS UPPER LEVEL LONGWAVE IS
FROM 19N69W TO 14N80W GENERATING SCATTERED SHOWERS WITHIN 70 NM
ON EITHER SIDE OF THE LINE CROSSING THE NORTH AND CENTRAL
CARIBBEAN...ALSO INCLUDING HISPANIOLA...JAMAICA AND PUERTO RICO.
AS THE LONGWAVE CONTINUES TO ENTER THE NORTHERN CARIBBEAN...LOOK
FOR DRY STABLE AIR TAKING OVER THE REGION NORTH OF 16N WEST OF
71W OVER THE NEXT 24 TO 36 HOURS. A SURFACE TROUGH OS OVER THE
FAR SOUTHWEST BASIN WEST OF 78W SOUTH OF 15N GENERATING
SCATTERED MODERATE TO HEAVY SHOWERS AND POSSIBLE THUNDERSTORMS
IN THIS REGION. THE REMAINDER OF THE BASIN IS EXPERIENCING
GENERALLY FAIR WEATHER.

ATLANTIC OCEAN...
A 1007 MB SURFACE LOW IS OVER THE WESTERN ATLANTIC NEAR 24N70W.
A SURFACE TROUGH CROSSES THE LOW CENTER ALONG 29N68W 24N70W
21N70W. THIS SYSTEM COMBINED WITH SIGNIFICANT DEEP LAYER
MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY IS
PRODUCING MODERATE TO STRONG CONVECTION FROM 19N TO 32N BETWEEN
55W AND 71W. FOR FURTHER DETAILS REGARDING THE LOW PRESSURE
SYSTEM SEE SPECIAL FEATURES DISCUSSION ABOVE. THE FAR WESTERN
ATLANTIC WEST OF THE SURFACE LOW/TROUGH IS EXPERIENCING FAIR
WEATHER CONDITIONS. THE REMAINDER OF THE CENTRAL AND EASTERN
ATLANTIC IS DOMINATED BY AN UPPER LEVEL RIDGE SUPPORTING A
SURFACE 1028 MB HIGH NEAR 34N37W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$

GARCIA




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