[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 222345
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE MAY 22 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL
ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 04N27W TO 12N25W MOVING W NEAR 15 KT.
LOW-LEVEL CYCLONIC TURNING IS EVIDENT IN THE VICINITY OF THE
WAVE AXIS BETWEEN 24W-29W. TOTAL PRECIPITABLE WATER IMAGERY
INDICATES A LARGE AREA OF ENHANCED MOISTURE AROUND THE WAVE FROM
02N-13N BETWEEN 16W-27W WITH SAHARAN DUST WRAPPED AROUND THE
NORTHERN PERIPHERY OF THE WAVE. WITH THE DUST INHIBITING ANY
DEEP CONVECTION...ONLY ISOLATED SHOWERS ARE OCCURRING FROM
02N-09N BETWEEN 24W-29W.

TROPICAL WAVE EXTENDS FROM 06N51W TO 13N50W MOVING W NEAR 15 KT.
THE WAVE IS EMBEDDED WITHIN A BROAD AREA OF DEEP LAYERED
MOISTURE BETWEEN 44W-53W AS EVIDENT IN TOTAL PRECIPITABLE WATER
IMAGERY. THE WAVE REMAINS EMBEDDED WITHIN THE REGION OF THE ITCZ
AND ON THE SOUTHERN PERIPHERY OF A STRONG CENTRAL ATLC RIDGE
ANCHORED BY A 1027 MB HIGH CENTERED NEAR 32N52W. SCATTERED
MODERATE CONVECTION IS FROM 07N-11N BETWEEN 48W-55W AND IS MORE
LIKELY ASSOCIATED WITH THE ITCZ DESCRIBED BELOW.

...ITCZ/MONSOON TROUGH...

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N15W TO
06N27W TO 03N35W TO 08N51W TO 07N58W. ISOLATED MODERATE
CONVECTION IS FROM 01N-05N BETWEEN 11W-23W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER LEVEL LOW IS CENTERED OVER NORTHERN ALABAMA NEAR 33N85W
AND EXTENDS BROAD UPPER LEVEL TROUGHING SOUTHWARD TO A BASE NEAR
24N90W. WATER VAPOR IMAGERY INDICATES THAT MOST OF THE FLOW
ALOFT IS EMBEDDED WITHIN DRY AIR AND STRONG SUBSIDENCE WHICH IS
SUPPORTING A SURFACE RIDGE OVER MUCH OF THE GULF W OF 85W. THE
RIDGE IS ANCHORED BY A 1017 MB HIGH CENTERED NEAR 24N96W. LIGHT
ANTICYCLONIC WINDS ARE OCCURRING IN CLOSE PROXIMITY OF THE HIGH
CENTER ITSELF...WHILE NORTHEAST WINDS IN THE RANGE OF 10 TO 15
KT ARE OCCURRING ON THE EASTERN PERIPHERY OF THE RIDGE BETWEEN
83W-94W. OVER THE EASTERN GULF AND FLORIDA PENINSULA...WEAK
SURFACE TROUGHING PERSISTS EXTENDING FROM THE SW NORTH ATLC
SOUTHWESTWARD TO A 1009 MB LOW CENTERED IN THE GULF OF HONDURAS
IN THE NW CARIBBEAN SEA NEAR 17N86W. THIS SURFACE FEATURE...
ALONG WITH THE ADVECTION OF MIDDLE TO UPPER LEVEL MOISTURE EAST
OF THE TROUGH AXIS IS PROVIDING FOCUS FOR ISOLATED SHOWERS AND
TSTMS OVER THE SOUTHERN FLORIDA PENINSULA AND SE GULF EAST OF A
LINE FROM 28N81W TO THE NORTHERN YUCATAN PENINSULA NEAR 22N89W.
THE SURFACE RIDGE IS FORECAST TO SLIDE EAST OF 90W AND WEAKEN
GRADUALLY BY THURSDAY AS SOUTHERLY RETURN FLOW RE-ESTABLISHES
ACROSS THE WESTERN GULF. WHILE THE RIDGE ERODES...THE LOW
CENTERED IN THE NW CARIBBEAN SEA IS EXPECTED TO MOVE NORTHEAST
AND IMPACT THE STRAITS OF FLORIDA LATE THURSDAY INTO FRIDAY AS
IT CONTINUES INTO THE SW NORTH ATLC BY THE WEEKEND.

CARIBBEAN SEA...
MUCH OF THE CARIBBEAN BASIN W OF 64W IS UNDER THE INFLUENCE OF
AN UPPER LEVEL RIDGE AXIS EXTENDING FROM AN UPPER LEVEL
ANTICYCLONIC CIRCULATION CENTERED OVER SOUTHERN GUATEMALA NEAR
14N91W. THE UPPER LEVEL RIDGE AXIS EXTENDS E-NE TO 15N80W THEN
NE TO BEYOND 20N70W. MUCH OF THE AREA ENCOMPASSED BENEATH THIS
UPPER LEVEL RIDGING IS AN AREA OF MAXIMUM UPPER LEVEL DIFFLUENCE
AS WELL AS OVERALL WEAK TROUGHING AT THE SURFACE. A SURFACE
TROUGH IS ANALYZED FROM WESTERN CUBA NEAR 23N83W TO A 1009 MB
LOW CENTERED NEAR 17N86W. SCATTERED SHOWERS AND TSTMS ARE
OCCURRING MOSTLY TO THE EAST OF THE SURFACE TROUGH FROM 13N-23N
BETWEEN 76W AND THE SURFACE TROUGH. ISOLATED SHOWERS ARE ALSO
OCCURRING WITHIN 150 NM WEST OF THE SURFACE TROUGH AXIS...
HOWEVER DRIER AIR ALOFT IS LIMITING OVERALL DEVELOPMENT THIS
EVENING. THIS OVERALL SYNOPTIC SETUP FOR THE WESTERN CARIBBEAN
IS UNLIKELY TO CHANGE OVER THE NEXT FEW DAYS AS GLOBAL MODELS
SUGGEST AND THE FORECAST INDICATES THE LOW PRESSURE IN THE GULF
OF HONDURAS IS TO DRIFT NORTHEASTWARD INTO THE FLORIDA STRAITS
BY LATE THURSDAY INTO FRIDAY. E OF 75W...EAST-SOUTHEAST TRADES
IN THE RANGE OF 15 TO 25 KT PERSIST AS SURFACE RIDGING EXTENDS
SOUTHWESTWARD FROM THE CENTRAL ATLC ACROSS THE EASTERN
CARIBBEAN. ISOLATED SHOWERS ARE NOTED ON SATELLITE IMAGERY
OCCURRING ACROSS THE LESSER ANTILLES...PUERTO RICO...AND
HISPANIOLA THIS EVENING.

ATLANTIC OCEAN...
WATER VAPOR IMAGERY INDICATES ADVECTION OF DEEP LAYERED TROPICAL
MOISTURE DUE TO SOUTHWESTERLY FLOW ALOFT N OF 20N W OF 60W OVER
THE SW NORTH ATLC. WITH THIS SOUTHWESTERLY FLOW ALOFT EXTENDING
INTO THE NW CARIBBEAN SEA...SCATTERED SHOWERS AND WIDELY
SCATTERED TSTMS ARE OCCURRING OVER MUCH OF THE SW NORTH ATLC
THIS EVENING WITHIN 300 NM EITHER SIDE OF A LINE FROM 22N78W TO
32N66W. THE SURFACE TROUGHING ACROSS THE SW NORTH ATLC IS
FORECAST TO PERSIST THROUGH THE REMAINDER OF THE WEEK AS A LOW
OVER THE NW CARIBBEAN SEA DRIFTS NORTHEASTWARD INTO THE WESTERN
SW NORTH ATLC OFFSHORE ZONES OVER THE WEEKEND. FARTHER EAST...
THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD
SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED NEAR 32N52W. A
COLD FRONT SKIRTS THE NORTHERN STRIP OF THE DISCUSSION AREA
BETWEEN 30W-47W...ANALYZED FROM 32N30W TO 31N38W TO 32N47W.
ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE
FRONT.

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

$$
HUFFMAN




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