[Tropical] Tropical Weather Discussion

Tue May 27 05:59:20 CDT 2014

AXNT20 KNHC 271100
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE MAY 27 2014

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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1045 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 07N32W TO 01N33W MOVING W AT 15-20
KT. THE WAVE REMAINS LARGELY LOW-AMPLITUDE AND EMBEDDED WITHIN
THE ITCZ AXIS. WEAK 700 MB TROUGHING ALOFT AND TRACES OF LOW-
LEVEL VORTICITY AT 850 MB ARE NOTED ON GLOBAL MODEL FIELDS IN
THE VICINITY OF THE WAVE AXIS. SCATTERED MODERATE CONVECTION
WITH WARMING CLOUD TOP TEMPERATURES IS LESS SCATTERED THAN
OBSERVED 3 TO 6 HOURS...AND IS PRESENT WITHIN 60-75 NM OF THE
WAVE AXIS. THIS WAVE IS LIKELY TO BECOME FURTHER SUPPRESSED
THROUGH THE NEXT 24 HOURS AS IT CONTINUES WESTWARD UNDER THE
SOUTHERN PERIPHERY OF ATLC HIGH PRESSURE TO ITS N.

TROPICAL WAVE EXTENDS FROM 10N55W SSW TO INLAND THE COAST OF
GUYANA AT 06N56W. THE WAVE IS ALSO MOVING W AT 15-20 KT. FIRST
MORNING VISIBLE IMAGERY SHOWS A SUBTLE CYCLONIC TURNING OF THE
LOW-LEVEL CLOUD FIELD BETWEEN 53W-59W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM W OF THE
WAVE FROM 07N TO 09N. ISOLATED SHOWERS AND TSTMS ARE S OF 07N E
OF THE WAVE TO 52W.

TROPICAL WAVE EXTENDS FROM 13N71W S TO INLAND VENEZUELA MOVING W
AT ABOUT 16 KT. SSMI TOTAL PRECIPITABLE WATER IMAGERY SHOWS A
PATCH OF DEEP MOISTURE TRAILING THE WAVE TO NEAR 66W. 700 MB
STREAMLINE ANALYSIS SUGGESTS CONVERGENCE WITHIN THE AREA OF DEEP
MOISTURE. ISOLATED SHOWERS AND TSTMS WITHIN 240 NM E OF THE WAVE.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR
12N16W TO 09N21W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 09N21W TO 04N30W WHERE IT ENDS BRIEFLY. IT RESUMES
AT 02N34W TO EQUATOR AT 40W...AND TO THE COAST OF SOUTH AMERICA
NEAR 01S49W. ISOLATED MODERATE CONVECTION IS SEEN FROM 02N-07N
BETWEEN 25W-29W. SCATTERED MODERATE CONVECTION IS NOTED FROM
JUST N OF THE EQUATOR TO 04N ELSEWHERE W OF 34W.

...DISCUSSION...

GULF OF MEXICO...
A SURFACE RIDGE EXTENDING FROM THE WESTERN ATLC HIGH ACROSS THE
FAR NORTHERN AND CENTRAL GULF PORTIONS IS THE MAIN SYNOPTIC
FEATURE OVER THE AREA. THE RIDGE IS SUPPORTED BY RIDGING ALSO IN
THE UPPER LEVELS WITH AN AXIS ROUGHLY ALONG 93W/94W. AT THE
SURFACE...ANTICYCLONIC FLOW IS RESULTING IN GENERALLY AND E-SE
FLOW OF 10-15 KT OVER MUCH OF THE AREA...WITH THE EXCEPTION OF
THE FAR WESTERN GULF WHERE A TIGHTER PRES GRADIENT BETWEEN THE
RIDGE AND LOW PRESSURE OVER WESTERN TEXAS IS INDUCING SE 15-20
KT WINDS THERE. A JET STREAM BRANCH CROSSING THE NW GULF IS
AIDING IN THE ADVECTION OF UPPER LEVEL MOISTURE ACROSS MUCH OF
THE NW AND N CENTRAL GULF SECTIONS. ISOLATED STRONG TSTM
CLUSTERS EARLIER NOTED ALONG THE SOUTHERN TEXAS COAST AND OVER
NE MEXICO HAVE JUST ABOUT DISSIPATED. ISOLATED SHOWERS AND
ISOLATED TSTMS ARE OVER THE FAR NW WATERS MOVING E. THIS
ACTIVITY IS EXPECTED TO GRADUALLY SPREAD EASTWARD OVER THE NEXT
24 HOURS OR SO...WHILE SCATTERED SHOWERS AND TSTMS MOVE INTO THE
WESTERN GULF AHEAD OF A TROUGH THAT APPROACHES THE TEXAS COAST
AS THE RIDGE WEAKENS. ELSEWHERE...CONDITIONS ARE FAIR WITH JUST
SMALL POCKETS OF LOW LEVEL MOISTURE IN THE FORM OF LOW CLOUDS
WITH ISOLATED SHOWERS MOVING TO THE NW UNDER THE SOUTHERN
PERIPHERY OF THE RIDGE.

CARIBBEAN SEA...
A LOW AMPLITUDE TROPICAL WAVE IS OVER THE SOUTH CENTRAL
CARIBBEAN AND VENEZUELA AS DESCRIBED ABOVE UNDER TROPICAL WAVES.
IN THE UPPER LEVELS...BROAD UPPER LEVEL RIDGING COVERS THE SEA W
OF 78W. NW TO N STRONG UPPER LEVEL WINDS ARE OVER THIS PORTION
OF THE SEA. ASSOCIATED MODERATE SUBSIDENCE IS KEEPING SKIES
GENERALLY CLOUD FREE THERE WITH ONLY SCATTERED LOW CLOUDS MOVING
WESTWARD IN THE TRADES WITH POSSIBLE ISOLATED SHOWERS. TO THE E
OF THE RIDGE...A MID/UPPER LEVEL TROUGH WITH A RATHER SHARP AXIS
IS SEEN ON WATER VAPOR IMAGERY TO STRETCH FROM THE WINDWARD
PASSAGE SW TO 14N75W AND TO ACROSS NW COLOMBIA. A NE TO SW JET
STREAM BRANCH TO THE E OF THE TROUGH IS TRANSPORTING DEEP
ATMOSPHERIC MOISTURE NEWD ACROSS MUCH OF THE EASTERN CARIBBEAN
SEA. ISOLATED TO WIDELY SCATTERED SHOWERS AND TSTMS ARE POSSIBLE
WITH THIS MOISTURE. THE TROUGH WILL SLOWLY MOVE EASTWARD THROUGH
THE NEXT 24 HOURS. THIS SHOULD BRING AN INCREASE OF MOISTURE
WITH SCATTERED SHOWERS AND TSTMS ACROSS MUCH OF THE EASTERN PART
OF THE SEA...INCLUDING PUERTO RICO AND MOST OF THE LESSER
ANTILLES AS ADDITIONAL MOISTURE FROM A TROPICAL WAVE PASSING
ACROSS THE FAR SOUTHERN WATERS BECOMES ENTRAINED INTO THE SW
FLOW ALOFT IN ADVANCE OF THE AFOREMENTIONED MID/UPPER TROUGH.

TRADE WINDS OF 15-20 KT ARE OVER MUCH OF THE CENTRAL PART OF THE
CARIBBEAN...WHILE TRADES OF 10-15 KT ARE PRESENT ELSEWHERE.

...HISPANIOLA...
CURRENTLY...ONLY ISOLATED SHOWERS ARE POSSIBLE ACROSS HISPANIOLA
DUE TO PERSISTENT E-SE WINDS ALONG WITH LOW-LEVEL MOISTURE
ADVECTION...AND OROGRAPHIC LIFT. A SMALL POCKET OF SCATTERED
SHOWERS AND TSTMS HAS RECENTLY FORMED JUST W OF HAITI...AND OVER
THE WINDWARD PASSAGE AIDED BY MAINLY A MID/UPPER TROUGH IN THAT
VICINITY. THIS ACTIVITY SHOULD CONTINUE THROUGH TONIGHT...THEN
DIMINISH AS THE TROUGH SHIFTS FURTHER E. THE TROUGH SHOULD AID
IN THE DEVELOPMENT OF SHOWER/TSTM ACTIVITY OVER SOME AREAS OF
THE INTERIOR PORTION THROUGH WED...BUT SHOULD BE SHORT-LIVED AS
DRY AIR ALOFT IN THE WAKE OF THE TROUGH BEGINS TO FILTER IN OVER
THE ISLAND.

ATLANTIC OCEAN...
A 1024 MB HIGH IS AT 32N62W WITH A RIDGE WESTWARD TO A 1021 MB
HIGH OVER SE GEORGIA. A COLD FRONT MOVING SLOWLY E AND
WEAKENING EXTENDS FROM 32N51W SW TO 29N55W...WHERE IT BECOMES
STATIONARY TO 26N62W TO 27N66W WHERE IT IS DISSIPATING TO
26N74W. A MID TO UPPER LEVEL TROUGH EXTENDS FROM 32N57W W TO
NEAR 32N69W...THEN SW TO A WEAK CYCLONIC CIRCULATION AT
28N73W...AND SW TO THE WINDWARD PASSAGE. FROM THERE IT EXTENDS
FURTHER SW WELL ACROSS THE CENTRAL CARIBBEAN SEA. THIS FEATURE
IS SUPPORTING THE FRONT WHILE ALSO ENHANCING LIFT ALONG AND NEAR
ITS WESTERN SEGMENT. AS A RESULT...SCATTERED SHOWERS AND TSTMS
ARE QUITE ACTIVE ALONG AND WITHIN 120 NM N OF THE FRONT BETWEEN
67W AND 72W. THE FRONT WILL CONTINUE TO WEAKEN...AND EVENTUALLY
DISSIPATE WITHIN THE NEXT 24 HOURS...OR SHORTLY AFTERWARDS.

A 1030 MB HIGH IS OVER THE EASTERN ATLC NEAR 34N32W WITH A RIDGE
SW TO NEAR 28N49W. IT IS BRINGING FAIR WEATHER OVER THAT PART OF
THE ATLC. ONLY SCATTERED TO BROKEN STRATOCUMULUS CLOUDS MOVING
WSW ARE NOTED OVER THAT PORTION OF THE ATLC. A TIGHT SURFACE
PRESSURE GRADIENT IS PRODUCING GALE FORCE WINDS ALONG THE COAST
OF MOROCCO NEAR 31N10W. AN UPPER LEVEL RIDGE IS OVER THE CENTRAL
ATLANTIC BETWEEN 40W AND 60W WITH ITS MEAN CENTER AT 14N46W. AN
UPPER LEVEL TROUGH IS OVER THE E ATLANTIC N OF 18N E OF 35W WITH
DRY CONDITIONS ALOFT IN THAT AREA KEEPING A CAP ON MOISTURE AND
PRECIPITATION OVER THAT AREA.

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

$$
AGUIRRE

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