Tropical Weather Discussion
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000
AXNT20 KNHC 260001 AAA
TWDAT

TROPICAL WEATHER DISCUSSION...AMENDED
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON AUG 25 2014

AMENDED FOR UPDATED TROPICAL STORM CRISTOBAL INFORMATION

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.

...SPECIAL FEATURES...
TROPICAL STORM CRISTOBAL IS CENTERED NEAR 25.0N 72.0W AT 26/0000
UTC OR ABOUT 575 NM SW OF BERMUDA MOVING E AT 2 KT. ESTIMATED
MINIMUM CENTRAL PRESSURE IS 990 MB. MAXIMUM SUSTAINED WINDS ARE
55 KT WITH GUSTS TO 65 KT. SCATTERED MODERATE AND ISOLATED
STRONG CONVECTION IS FROM 22N-25N BETWEEN 70W-73W. SCATTERED
MODERATE CONVECTION IS ELSEWHERE WITHIN 150 NM EITHER SIDE OF A
LINE FROM 29N67W TO 18N76W. SEE LATEST NHC FORECAST/ADVISORY
UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM 14N27W TO 20N26W MOVING W AT 10-15
KT. THE WAVE REMAINS EMBEDDED WITHIN FAIRLY ZONAL EASTERLY FLOW
ALOFT AND IS FAIRLY DIFFICULT TO TRACK AT THIS TIME. NO
SIGNIFICANT CONVECTION IS NOTED WITH THE WAVE AT THIS TIME.

TROPICAL WAVE EXTENDS FROM 12N41W TO 20N42W MOVING W AT 15-20
KT. A 1010 MB LOW IS ANALYZED AT THE SOUTHERN EXTENT OF THE WAVE
AXIS THAT REMAINS EMBEDDED WITHIN THE ITCZ AXIS WITH 850 MB
RELATIVE VORTICITY MODEL FIELDS INDICATING A MAXIMUM FROM 09N-
14N BETWEEN 37W-48W. ISOLATED MODERATE CONVECTION IS FROM 11N-
14N BETWEEN 39W-47W.

TROPICAL WAVE EXTENDS FROM 10N51W TO 17N53W MOVING W AT 10-15
KT. THIS WAVE REMAINS ON THE LEADING EDGE OF A SAHARAN AIR LAYER
APPROACHING THE LESSER ANTILLES AND EASTERN CARIBBEAN SEA. NO
SIGNIFICANT DEEP CONVECTION IS OCCURRING WITH THE WAVE AT THIS
TIME.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO
13N20W TO 14N31W. THE INTERTROPICAL CONVERGENCE ZONE AXIS
EXTENDS FROM 14N31W TO 12N38W TO 08N43W TO 05N52W. NO
SIGNIFICANT CONVECTION OCCURRING ALONG THE MONSOON TROUGH OR
ITCZ AT THIS TIME.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM OVER CENTRAL
MEXICO NEAR 20N100W N-NE TO A FOCUS OF MID-LEVEL ENERGY OVER THE
MISSISSIPPI RIVER DELTA REGION NEAR 28N90W. WHILE WEATHER
ASSOCIATED WITH THE INVERTED TROUGH AXIS OVER THE WESTERN GULF
REMAINS FAIRLY QUIET...CLOSER TO THE MID-LEVEL ENERGY...
SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF 26N BETWEEN 88W-
94W...INCLUDING INLAND LOUISIANA...WESTERN MISSISSIPPI...AND SW
ARKANSAS THIS EVENING. MUCH OF THE GULF CONVECTION IS FOCUSED
ALONG A STATIONARY FRONT EXTENDING FROM THE SOUTHERN FLORIDA
PENINSULA NEAR 26N81W W-NW TO 29N91W. OTHER ISOLATED SHOWERS AND
TSTMS ARE OCCURRING ACROSS THE EASTERN GULF N OF 23N BETWEEN 80W-
88W. THIS SURFACE TROUGHING IS LARGELY AN WESTWARD EXTENSION OF
LOWER SURFACE PRESSURES ASSOCIATED WITH TROPICAL STORM CRISTOBAL
CENTERED IN THE SW NORTH ATLC. OTHERWISE...THE REMAINDER OF THE
GULF IS UNDER THE INFLUENCE OF N-NE WINDS IN THE RANGE OF 10 TO
20 KT. THE WIND FIELD SURROUNDING THE SURFACE TROUGHING IS
FORECAST TO SHARPEN THROUGH THE OVERNIGHT HOURS INTO TUESDAY
WITH THE GLOBAL MODEL GUIDANCE INDICATING CYCLOGENESIS OCCURRING
ACROSS THE WESTERN GULF WATERS BY EARLY WEDNESDAY. ANY LOW
PRESSURE AREA THAT DOES MATERIALIZE IS EXPECTED TO REMAIN WEAK
AND CONTINUE DRIFTING WESTWARD INTO INLAND NE MEXICO AND
SOUTHERN TEXAS LATE THURSDAY INTO FRIDAY.

CARIBBEAN SEA...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE SE
GULF OF MEXICO WATERS NEAR 25N84W THAT IS PROVIDING THE
CARIBBEAN W OF 70W WITH NE FLOW ALOFT TO 84W THEN SE FLOW ALOFT
PRIMARILY OVER CENTRAL AMERICA AND THE YUCATAN PENINSULA THIS
EVENING. WHILE MUCH OF THE AREA W OF 84W ALOFT REMAINS DRY...
BETWEEN 70W-84W SCATTERED SHOWERS AND TSTMS ARE OCCURRING N OF
15N BETWEEN 70W-80W IN ASSOCIATION WITH A SURFACE TROUGH
EXTENDING FROM THE S-SW PERIPHERY OF TROPICAL STORM CRISTOBAL
NEAR 21N75W SW TO JAMAICA TO 13N82W. AS CRISTOBAL TRACKS NORTH-
NORTHEASTWARD DURING THE NEXT 24 HOURS...THE REMNANT SURFACE
TROUGHING IS FORECAST TO DRIFT WESTWARD AND GRADUALLY DISSIPATE
THROUGH LATE WEDNESDAY. THEREAFTER...MODERATE TO FRESH TRADES
ARE EXPECTED TO RE-ESTABLISH BY THURSDAY. FARTHER EAST...A
SURFACE TROUGH IS ANALYZED FROM GUADELOUPE TO THE VENEZUELA
COAST NEAR 10N62W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING S OF
13N BETWEEN 60W-65W...INCLUDING INLAND PORTIONS OF EASTERN
VENEZUELA. FINALLY...THE MONSOON TROUGH EXTENDS ALONG 09N TO 78W
THEN ALONG THE COAST OF COLOMBIA TO NEAR 11N73W. SCATTERED
SHOWERS AND TSTMS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE
AXIS.

...HISPANIOLA...
TROPICAL STORM CRISTOBAL IS CENTERED WELL NORTH OF HISPANIOLA
HOWEVER...SURFACE TROUGHING EXTENDS FROM EASTERN CUBA NEAR
21N75W TO JAMAICA TO 13N82W. THE LOW-LEVEL MOISTURE CONVERGENCE
ASSOCIATED WITH THE SURFACE TROUGH...MAXIMIZED EAST OF THE
SURFACE TROUGH AXIS...IS PROVIDING HISPANIOLA WITH CONTINUED
SCATTERED SHOWERS AND ISOLATED TSTMS THIS EVENING. AS CRISTOBAL
CONTINUES TO TRACK N-NE DURING THE NEXT 24 HOURS...CONDITIONS
ACROSS THE ISLAND WILL VERY GRADUALLY BEGIN TO IMPROVE BY LATE
THURSDAY INTO FRIDAY. UNTIL THEN...AS PRECIPITATION CONTINUES...
INCREASED PROBABILITY OF FLASH FLOODING AND MUDSLIDES WILL
CONTINUE TO BE POSSIBLE.

ATLANTIC OCEAN...
THE PRIMARY FOCUS FOR THE SW NORTH ATLC CONTINUES TO BE TROPICAL
STORM CRISTOBAL THIS EVENING. ASIDE FROM THE IMMEDIATE STORM
CENTER ITSELF...THE STORM IS SURROUNDED BY A LARGE AREA OF LOWER
PRESSURE GENERALLY W OF 60W REACHING INTO THE GULF OF MEXICO
NEAR 90W. A STATIONARY FRONT EXTENDS FROM BERMUDA NEAR 32N65W TO
30N69W TO 29N75W...AND A SURFACE TROUGH EXTENDS FROM 21N75W
ACROSS EASTERN CUBA TO JAMAICA. WHILE NUMEROUS SHOWERS AND TSTMS
ARE OCCURRING WITHIN 120 NM OF THE CENTER IN THE SE QUADRANT OF
CRISTOBAL...THE FRONT AND SURFACE TROUGH ARE PROVIDING FOCUS FOR
SCATTERED SHOWERS AND TSTMS REACHING FROM JAMAICA AND THE
WINDWARD PASSAGE NE TO BEYOND BERMUDA. THE AREA OF CONVECTION
REMAINS A 300 NM ZONE WITH MORE WIDESPREAD SHOWERS N OF 30N
BETWEEN 56W-70W. OTHERWISE...THE REMAINDER OF THE CENTRAL AND
EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE
ANCHORED BY A 1027 MB HIGH CENTERED SW OF THE AZORES NEAR 34N32W.

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

$$
HUFFMAN



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