[Tropical] Tropical Weather Discussion

Tue May 27 01:03:21 CDT 2014

AXNT20 KNHC 270604
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0545 UTC.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 08N31W TO 01N32W 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/ISOLATED
STRONG CONVECTION IS WITHIN 60 NM OF THE WAVE S OF 02N. ISOLATED
MODERATE CONVECTION IS ELSEWHERE WITHIN 120 NM OF THE WAVE
AXIS...EXCEPT FOR SCATTERED MODERATE CONVECTION WITHIN 120 NM
EITHER SIDE OF THE THE WAVE FROM 04N TO 06N.

TROPICAL WAVE EXTENDS FROM 10N54W TO INLAND THE COAST OF S
AMERICA AT THE BORDER OF GUYANA AND SURINAME. THE WAVE IS ALSO
MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH A BROAD 700 MB
TROUGH ALOFT AND SUBTLE CYCLONIC TURNING OF THE LOW-LEVEL CLOUD
FIELD BETWEEN 50W-55W AS WAS OBSERVED IN LAST VISIBLE IMAGERY
FROM YESTERDAY...AND AS CURRENTLY SEEN IN IR SHORTWAVE IMAGERY.
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM OF THE WAVE FROM
07N TO 09N. ISOLATED MODERATE CONVECTION IS ELSEWHERE WITHIN 300
NM EITHER SIDE OF THE WAVE AXIS.

TROPICAL WAVE EXTENDS FROM 13N69W SSW INLAND VENEZUELA AT
12N70W...MOVING W AT 15 KT. SSMI TOTAL PRECIPITABLE WATER
IMAGERY SHOWS A PATCH OF DEEP MOISTURE ASSOCIATED WITH THE WAVE
TO THE S OF 14N BETWEEN 65W AND 71W. 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 FROM 02N-08N
BETWEEN 22W-29W...AND 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 A MEAN AXIS ROUGHLY ALONG 92W/93W. 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 IS
AIDING IN THE ADVECTION OF UPPER LEVEL MOISTURE ACROSS MUCH OF
THE NW AND N CENTRAL GULF SECTIONS. ISOLATED STRONG TSTM
CLUSTERS MOVING SE ARE APPROACHING THE SE TEXAS COAST. SIMILAR
ACTIVITY IS OVER NE MEXICO AS WELL. SCATTERED 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. ELSEWHERE...CONDITIONS ARE FIR 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 79W. 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...AN 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
SHOWER 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.

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...LOW-LEVEL MOISTURE ADVECTION...
AND OROGRAPHIC EFFECTS. DIURNAL TYPE SHOWER/TSTM ACTIVITY IS
EXPECTED TO DEVELOP OVER MAINLY THE INTERIOR PORTION OF THE
ISLAND TODAY...BUT SHOULD BE SOMEWHAT CAPPED AS DRY AIR ALOFT
BEGINS TO FILTER IN OVER THE ISLAND.

ATLANTIC OCEAN...
A 1024 MB HIGH IS CENTERED JUST N OF THE BASIN AT 33N69.5W WITH
A RIDGE WSW TO NE FLORIDA. A WEAKENING COLD FRONT EXTENDS FROM
32N52W SW TO 26N65W TO 26N71W...WHERE IT BEGINS TO DISSIPATE TO
THE NW BAHAMAS. A MID TO UPPER TROUGH EXTENDS FROM 32N69W SW TO
THE WINDWARD PASSAGE...AND TO 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 ISOLATED TSTMS ARE ALONG AND WITHIN 60 NM N OF THE FRONT
BETWEEN 68W AND 75W. THE FRONT WILL CONTINUE TO WEAKEN OVER THE
NEXT 24 HOURS.

A 1031 MB HIGH IS OVER THE EASTERN ATLC NEAR 34N32W WITH A RIDGE
SW TO NEAR 28N53W. IT IS BRINGING FAIR WEATHER OVER THAT PART OF
THE ATLC. A TIGHT SURFACE PRESSURE GRADIENT IS PRODUCING A GALE
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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