[Tropical] Tropical Weather Discussion

Sat Aug 2 00:48:23 CDT 2014

AXNT20 KNHC 020548
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT AUG 02 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
0515 UTC.

...SPECIAL FEATURES...
TROPICAL STORM BERTHA IS CENTERED NEAR 15.8N 64.0W AT 02/0600
UTC OR ABOUT 120 NM SSE OF SAINT CROIX AND ABOUT 195 NM SE OF
SAN JUAN PUERTO RICO MOVING WNW AT 19 KT. ESTIMATED MINIMUM
CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 45
KT WITH GUSTS TO 55 KT. SCATTERED MODERATE CONVECTION IS FROM
15N-18N BETWEEN 61W-64W...WITH ISOLATED MODERATE CONVECTION
ELSEWHERE FROM 13N-19N BETWEEN 59W-65W. SEE LATEST NHC
INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS
MIATCPAT3/WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS.

...TROPICAL WAVES...
TROPICAL WAVE EXTENDS FROM A 1012 MB LOW CENTERED AT THE
SOUTHERN EXTENT OF THE WAVE AXIS NEAR 11N25W TO 19N28W MOVING W
AT 15 KT. THE WAVE COINCIDES WITH A BROAD 700 MB TROUGH BETWEEN
25W-36W WITH A MAXIMUM IN 850 MB RELATIVE VORTICITY CENTERED IN
THE VICINITY OF 16N29W. ISOLATED MODERATE CONVECTION IS FROM 08N-
10N BETWEEN 24W-31W.

TROPICAL WAVE EXTENDS FROM 10N41W TO 17N46W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH 700 MB TROUGHING EXTENDING THE LENGTH OF
THE WAVE AXIS WITH 850 MB RELATIVE VORTICITY FIELDS INDICATING
MAXIMUM LOW-LEVEL ENERGY REMAINING E OF THE WAVE IN ASSOCIATION
WITH A CYCLONIC CIRCULATION EMBEDDED WITHIN THE MONSOON TROUGH
FOCUSED ON A 1012 MB LOW CENTERED NEAR 10N36W. THE WAVE HAS NO
SIGNIFICANT DEEP CONVECTION OCCURRING ALONG THE AXIS...HOWEVER
SCATTERED MODERATE CONVECTION IS OCCURRING FROM 10N-11N BETWEEN
37W-40W TO THE NW OF THE LOW.

TROPICAL WAVE EXTENDS FROM 10N65W TO 18N69W MOVING W AT 15 KT.
THE WAVE COINCIDES WITH VERY SUBTLE 700 MB TROUGHING AND HAS
BECOME MORE DIFFICULT TO TRACK DUE TO NORTHWESTERLY UPPER LEVEL
FLOW. RELATIVELY DRY AND STABLE CONDITIONS EXIST ACROSS THE
CENTRAL CARIBBEAN SEA WITH VERY LITTLE EVIDENCE IN THE WAY OF A
SIGNATURE ON VISIBLE AND INFRARED IMAGERY OF THE WAVE LOCATION.
NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS
TIME.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N17W
TO 10N20W TO A 1012 MB LOW PRES NEAR 11N25W TO A 1012 MB LOW
PRES NEAR 10N36W TO 05N40W. THE INTERTROPICAL CONVERGENCE ZONE
AXIS EXTENDS FROM 05N40W TO 04N51W. WIDELY SCATTERED MODERATE
CONVECTION IS FROM 06N-08N BETWEEN 19W-23W AND FROM 03N-05N
BETWEEN 36W-42W. ISOLATED MODERATE CONVECTION IS FROM 05N-10N
BETWEEN 24W-32W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY
OVER THE GREAT LAKES AND MID TO LOWER MISSISSIPPI RIVER VALLEY
THIS EVENING THAT SUPPORTS A FEW WEAK IMPULSES OF ENERGY MOVING
EASTWARD WITHIN THE BASE OF THE TROUGHING ALONG 30N. THE WESTERN
IMPULSE IS ANALYZED AS 1013 MB SURFACE LOW CENTERED ACROSS
LOUISIANA WITH A COLD FRONT EXTENDING SW TO 29N95W AND INLAND
ACROSS SOUTHERN TEXAS AS A STATIONARY FRONT. ISOLATED SHOWERS
AND TSTMS ARE OCCURRING N OF 28N BETWEEN 91W-95W. FARTHER
EAST...THE OTHER IMPULSE OF ENERGY IS ANALYZED AS A 1014 MB LOW
CENTERED OVER THE FLORIDA PANHANDLE NEAR 31N84W. AS OF 02/0300
UTC A SURFACE TROUGH EXTENDS FROM THE LOW GENERALLY SOUTHWARD
ACROSS THE INTERIOR OF THE FLORIDA PENINSULA TO NEAR THE TAMPA
BAY REGION AND INTO THE GULF WATERS SW TO 23N89W. EARLIER
CONVECTION ACROSS THE FLORIDA PENINSULA CONTINUES TO DIMINISH...
HOWEVER ISOLATED SHOWERS REMAIN FROM 25N-28N BETWEEN 81W-83W.
ISOLATED SHOWERS ARE ALSO OCCURRING WITHIN 90 NM EITHER SIDE OF
THE BOUNDARY ACROSS THE SE GULF WATERS. OTHERWISE...A WEAK RIDGE
AXIS EXTENDS FROM THE NORTH-CENTRAL GULF WATERS SW TO THE EAST-
CENTRAL MEXICO COAST BETWEEN TAMPICO AND TUXPAN. LOOKING
AHEAD...THE SYNOPTIC PATTERN IS EXPECTED TO CHANGE LITTLE OVER
THE NEXT 36 TO 48 HOURS AS THE FRONTAL BOUNDARY ACROSS THE NW
GULF BECOMES MOSTLY STATIONARY ALONG THE GULF COAST AND RIDGING
PREVAILS ACROSS MUCH OF THE SOUTHERN TWO-THIRDS OF THE GULF
THROUGH EARLY NEXT WEEK.

CARIBBEAN SEA...
THE PRIMARY FEATURE ACROSS THE CARIBBEAN THIS EVENING IS
TROPICAL STORM BERTHA THAT CONTINUES TO IMPACT THE LESSER
ANTILLES AND TRACK NW TOWARDS THE MONA PASSAGE DURING THE NEXT
24 HOURS. BERTHA CONTINUES TO MOVE NW ON THE EASTERN PERIPHERY
OF AN UPPER LEVEL LOW CENTERED NEAR 14N64W. NORTHWESTERLY FLOW
ALOFT BETWEEN THIS UPPER LEVEL LOW AND AN UPPER LEVEL
ANTICYCLONE CENTERED NEAR 12N77W CONTINUE TO PROVIDE MUCH OF THE
CENTRAL AND REMAINDER OF THE EASTERN CARIBBEAN W OF 65W WITH
MOSTLY CLEAR SKIES AND STABLE CONDITIONS. FINALLY...AN UPPER
LEVEL LOW IS CENTERED OVER THE NW CARIBBEAN NEAR 18N85W THAT IS
ADVECTING MOISTURE NORTHWARD FROM THE EAST PACIFIC REGION
BETWEEN 80W-85W. THIS MOISTURE ALONG WITH THE INSTABILITY
ASSOCIATED WITH THE UPPER LEVEL LOW IS GENERATING SCATTERED
SHOWERS AND ISOLATED TSTMS NE OF A LINE FROM SW HISPANIOLA NEAR
18N73W TO OFFSHORE OF WESTERN CUBA NEAR 21N84W. OTHER ISOLATED
SHOWERS ARE NOTED NEAR THE CENTER OF THE UPPER LEVEL LOW NEAR
18N85W. OTHERWISE...TRADES NOT DISRUPTED BY THE CIRCULATION OF
BERTHA ARE FORECAST IN THE RANGE OF 15 TO 25 KT WITH THE
STRONGEST WINDS EXPECTED GENERALLY S OF 15N BETWEEN 69W-77W.

...HISPANIOLA...
CURRENTLY...EARLIER CONVECTION IS CONTINUING TO DIMINISH WITH
ONLY ISOLATED SHOWER AND TSTM ACTIVITY REMAINING ACROSS FAR
WESTERN PORTIONS OF THE ISLAND AND THE ADJACENT COASTAL WATERS
IN THE WINDWARD PASSAGE. BY MID-DAY SATURDAY INTO EARLY
SUNDAY...TROPICAL STORM BERTHA IS FORECAST TO TRACK THROUGH THE
MONA PASSAGE REGION AND SKIRT THE NORTHEASTERN COAST OF
HISPANIOLA. WHILE BERTHA IS EXPECTED TO REMAIN AT TROPICAL STORM
STRENGTH...HEAVY RAINFALL AND THE POTENTIAL FOR FLASH FLOODING
AND MUDSLIDES ACROSS THE ISLAND ARE ADDITIONAL IMPACTS EXPECTED
FROM BERTHA.

ATLANTIC OCEAN...
AN UPPER LEVEL RIDGE IS CENTERED OVER THE EAST-CENTRAL FLORIDA
PENINSULA NEAR 28N80W THAT IS PROVIDING OVERALL FAIR CONDITIONS
THIS EVENING ACROSS THE SW NORTH ATLC N OF 26N W OF 75W. TO THE
SE HOWEVER...A MIDDLE TO UPPER LEVEL LOW CENTERED NEAR 26N72W
HAS CONTINUED TO DRIFT W-NW DURING THE PAST 24 HOURS AND IS
GENERATING A BROAD AREA OF WIDELY SCATTERED SHOWERS AND ISOLATED
TSTMS FROM 20N-28N BETWEEN 69W-76W. THIS UPPER LEVEL ENERGY IS
EXPECTED TO CONTINUE A WESTWARD MOVEMENT THROUGH MONDAY LIKELY
BRINGING HIGHER PROBABILITY PRECIPITATION CHANCES TO THE BAHAMAS
AND FLORIDA PENINSULA FOR THE DURATION OF THE WEEKEND. FARTHER
EAST..A BROAD MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 31N54W
THAT SUPPORTS A 1016 MB LOW CENTERED NEAR 29N52W. A SURFACE
TROUGH EXTENDS WEST FROM THE LOW TO 28N60W. ISOLATED SHOWERS ARE
OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. OTHERWISE...
THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A
SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED NW OF THE
AZORES NEAR 42N43W. THE RIDGE AXIS EXTENDS FROM THE HIGH SE TO
34N30W THEN SOUTH-SOUTHEAST TO 22N48W.

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

$$
HUFFMAN

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