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AXNT20 KNHC 302348
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT SAT AUG 30 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC.


...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 10N30W TO 20N26W MOVING W AT 10-15 KT. THE WAVE COINCIDES WITH BROAD 700 MB TROUGHING ALOFT BETWEEN 23W-34W AND MAXIMUM MOISTURE VALUES ON TOTAL PRECIPITABLE WATERS IMAGERY FROM 06N-16N BETWEEN 25W-31W. ISOLATED MODERATE CONVECTION IS FROM 07N-12N BETWEEN 28W-34W.

TROPICAL WAVE EXTENDS FROM 08N47W TO 18N45W MOVING W AT 15 KT. THE WAVE HAS MOVED WEST OF A 1010 MB LOW EMBEDDED WITHIN THE MONSOON TROUGH NEAR 10N43W WITH CYCLONIC TURNING OF THE LOW- LEVEL CLOUD FIELD NOTED ALONG THE WAVE AXIS IN THE VICINITY OF 14N47W. SCATTERED MODERATE CONVECTION IS FROM 08N-12N BETWEEN 41W-46W.

TROPICAL WAVE EXTENDS FROM 11N59W TO 19N55W MOVING W AT 15 KT. THE WAVE REMAINS EMBEDDED WITHIN A BROAD 700 MB TROUGH ALOFT BETWEEN 50W-60W. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 12N88W TO 22N85W MOVING W AT 20-25 KT. THE MOST IMPRESSIVE WAVE NOTED ACROSS THE BASIN...IT COINCIDES WITH A 700 MB TROUGH AXIS EXTENDING FROM THE WINDWARD PASSAGE REGION NEAR 20N74W TO SOUTHERN BELIZE NEAR 16N89W. MOST OF THE LOW-LEVEL MOISTURE CONVERGENCE IS EAST OF THE WAVE AXIS SUPPORTING SCATTERED MODERATE CONVECTION FROM 13N-22N BETWEEN 81W-87W...WITH ISOLATED MODERATE CONVECTION ELSEWHERE FROM 12N- 22N BETWEEN 78W-92W.


...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM A 1012 MB LOW CENTERED NEAR 09N32W TO A 1012 LOW CENTERED NEAR 10N43W TO 08N48W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N48W TO 06N57W. SCATTERED MODERATE CONVECTION IS FROM 06N-12N BETWEEN 34W-40W.


...DISCUSSION...

GULF OF MEXICO... SOUTH-SOUTHWESTERLY FLOW ALOFT IS NOTED OVER THE WESTERN GULF AND LOWER MISSISSIPPI RIVER VALLEY REGION THIS EVENING BETWEEN AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 28N90W AND AN UPPER LEVEL TROUGH WITH AXIS EXTENDING FROM THE CENTRAL PLAINS TO BASE OVER THE TEXAS BIG BEND REGION NEAR 29N101W. MOISTURE ADVECTION ALOFT ALONG WITH S-SE RETURN FLOW AT THE SURFACE ON THE WESTERN PERIPHERY OF A RIDGE ACROSS THE BASIN IS GENERATING SCATTERED SHOWERS AND TSTMS NW OF A LINE FROM THE FLORIDA PANHANDLE NEAR 30N87W TO THE MEXICO COAST NEAR TUXPAN... INCLUDING INLAND PORTIONS OF THE LOWER MISSISSIPPI RIVER VALLEY... AND ALABAMA THIS EVENING. FARTHER SOUTHEAST...A TROPICAL WAVE IS ANALYZED ACROSS THE NW CARIBBEAN SEA INCLUDING THE YUCATAN CHANNEL REGION. THE WAVE CONTINUES TO PROVIDE FOCUS FOR SCATTERED SHOWERS AND ISOLATED TSTMS S OF 23N BETWEEN 84W- 91W...INCLUDING PORTIONS OF THE YUCATAN PENINSULA. OTHERWISE... THE UPPER LEVEL RIDGING IS PROVIDING DRY AND RELATIVELY STABLE CONDITIONS TO THE EASTERN GULF AND FLORIDA PENINSULA THIS EVENING WITH THE EXCEPTION OF A FEW SHOWERS AND TSTMS OCCURRING ACROSS THE CENTRAL FLORIDA PENINSULA IN THE VICINITY OF 27N82W. THE SURFACE RIDGE AXIS IS FORECAST TO SHIFT NORTHWARD SLIGHTLY DURING THE NEXT 24 TO 48 HOURS AS THE TROPICAL WAVE BEGINS TO INFLUENCE THE SW GULF WATERS. GLOBAL MODEL CONTINUE TO SUGGEST WEAK CYCLOGENESIS ACROSS THE SW GULF WATERS WITH THE PRIMARY IMPACT BEING INCREASED CONVECTION AND SE WINDS IN THE RANGE OF 15 TO 25 KT ACROSS THE SW GULF S OF 25N W OF 90W TUESDAY AND WEDNESDAY.

CARIBBEAN SEA... A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM THE SW NORTH ATLC NEAR 25N69W SW TO OVER EASTERN CUBA TO 17N85W THAT CONTINUES TO PROVIDE CONCENTRATION OF MIDDLE TO UPPER LEVEL MOISTURE ACROSS THE CARIBBEAN THIS EVENING. MOST OF THE MOISTURE IS FOCUSED W OF 75W AND MORE SPECIFICALLY IN ASSOCIATION WITH A TROPICAL WAVE EXTENDING ALONG 87W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 13N-223N BETWEEN 78W-90W...INCLUDING COASTAL CUBA AND INLAND PORTIONS OF CENTRAL AMERICA AND THE YUCATAN PENINSULA. WHILE THE TROPICAL WAVE IS EXPECTED TO MOVE WEST OF THE AREA OVERNIGHT INTO EARLY SUNDAY...ISOLATED SHOWERS AND TSTMS ARE EXPECTED TO LINGER ACROSS HISPANIOLA...THE WINDWARD PASSAGE REGION...AND JAMAICA. FARTHER EAST...A WEAK TROPICAL WAVE IS FORECAST TO APPROACH 60W OVERNIGHT INTO SUNDAY...HOWEVER EXHIBITS RELATIVELY DRIER CONDITIONS AND A LACK OF ANY DEEP CONVECTION. IN ADVANCE OF THE WAVE...LOW-LEVEL ISOLATED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE SE CARIBBEAN S OF 14N BETWEEN 60W-70W...AND ACROSS THE LEEWARD ISLANDS N OF 16N BETWEEN 61W- 66W THIS EVENING. LOOKING AHEAD...FRESH TO STRONG WINDS W OF 70W WERE NOTED ON EARLIER ASCAT PASSES TO THE EAST OF THE TROPICAL WAVE...AND AS THE TROPICAL WAVE ALONG 87W MOVES WEST OVERNIGHT...THE STRONGER TRADES ARE FORECAST TO REMAIN GENERALLY S OF 17N BETWEEN 70W-80W.


...HISPANIOLA... CURRENTLY OVER THE ISLAND...PLENTY OF MOISTURE AND CLOUDINESS WITH ISOLATED SHOWERS ARE NOTED ON SATELLITE IMAGERY. MOST OF THIS ACTIVITY IS LOCATED SOUTHEAST OF AN UPPER LEVEL TROUGH AXIS EXTENDING NW OF THE ISLAND. WITH THIS UPPER LEVEL FEATURE REMAINING IN PLACE DURING THE NEXT 24 TO 36 HOURS...ISOLATED SHOWER ACTIVITY IS EXPECTED OVERNIGHT INTO SUNDAY. LOW-LEVEL MOISTURE TO THE EAST ALSO CONTINUES TO ADVECT WESTWARD WITHIN MODERATE TO FRESH TRADE WIND FLOW.

ATLANTIC OCEAN... GENERALLY NORTHEASTERLY FLOW ALOFT PREVAILS W OF 70W OVER THE SW NORTH ATLC PROVIDING OVERALL FAIR CONDITIONS AND SKIES THIS EVENING. THE NE FLOW IS LOCATED ON THE SOUTHERN PERIPHERY OF A MIDDLE TO UPPER LEVEL RIDGE CENTERED OFF THE COAST OF THE CAROLINAS NEAR 34N75W AND SUPPORTS A 1023 MB HIGH CENTERED NEAR 28N69W. TO THE NORTH OF THE SURFACE RIDGE ALONG 32N...A DISSIPATING STATIONARY FRONT EXTENDS FROM 32N54W TO 32N72W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING FROM 29N-33N BETWEEN 50W-66W. FURTHERMORE...AN UPPER LEVEL LOW IS CENTERED SOUTH OF THE SURFACE RIDGING NEAR 25N68W THAT CONTINUES TO ADVECT MOISTURE NORTHEASTWARD ON THE EASTERN PERIPHERY OF THE LOW GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 18N-27N BETWEEN 60W-72W. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A WEAK SURFACE RIDGE WITH AXIS EXTENDING FROM A 1023 MB HIGH CENTERED NEAR 33N25W TO A 1022 MB HIGH CENTERED NEAR 27N43W TO THE AFOREMENTIONED 1023 MB HIGH CENTERED NEAR 28N69W. OVERALL FAIR CONDITIONS ACCOMPANY THE RIDGING...HOWEVER A DISSIPATING STATIONARY FRONT DOES DIP INTO THE DISCUSSION AREA NEAR 32N33W EXTENDING SW TO 29N39W IN ASSOCIATION WITH AN UPPER LEVEL LOW CENTERED NEAR 31N37W.

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

$$ HUFFMAN

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