[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 051145
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST SAT DEC 05 2015

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
1115 UTC.

...SPECIAL FEATURES...
A STATIONARY FRONTAL BOUNDARY EXTENDS ACROSS THE SW NORTH ATLC
FROM 31N62W W-SW TO THE EXTREME SOUTHERN FLORIDA PENINSULA NEAR
25N80W. NORTH OF THE FRONT...A STRONG PRESSURE GRADIENT PERSISTS
BETWEEN LOWER PRESSURE ACROSS THE GREATER ANTILLES AND
BAHAMAS...AND A RELATIVELY STRONG HIGH PRESSURE SYSTEM AT 1038
MB CENTERED ACROSS THE OHIO RIVER VALLEY. EARLIER EVENING
SCATTEROMETER DATA INDICATED A 120 NM WIDE SWATH OF WINDS
DIRECTLY NORTH OF THE FRONT REACHING NEAR GALE TO GALE FORCE.
THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH 05/1800 UTC.
SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS
MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

A STRENGTHENED PRESSURE GRADIENT IS EXPECTED TO MATERIALIZE
ACROSS THE SW CARIBBEAN SEA WITHIN CLOSE PROXIMITY TO THE COAST
OF COLOMBIA BY 06/0000 UTC. THESE NEAR GALE TO GALE FORCE WINDS
ARE EXPECTED TO PERSIST FOR 12 HOURS AND THEN DECREASE TO A
RANGE OF 20 TO 30 KT. SEE LATEST NWS HIGH SEAS FORECAST UNDER
AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 02N AND THE PRIME MERIDIAN TO
05N14W INTO A 1013 MB LOW NEAR 05N19W TO 04N27W. THE
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N27W TO
03N37W TO THE EQUATOR NEAR 44W. SCATTERED MODERATE CONVECTION IS
FROM THE EQUATOR TO 07N BETWEEN 06W-23W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER LEVEL TROUGHING OVER THE SE CONUS IS SUPPORTING A
WEAK AREA OF LOW PRESSURE ACROSS THE SW NORTH ATLC THAT
STRETCHES ACROSS THE SE GULF WATERS AND REMAINS FOCUSED ALONG A
FRONTAL BOUNDARY EXTENDING FROM THE EXTREME SOUTHERN FLORIDA
PENINSULA NEAR 25N81W TO 21N86W. SCATTERED SHOWERS AND ISOLATED
TSTMS ARE OCCURRING GENERALLY WITHIN 90 NM EITHER SIDE OF THE
FRONT...INCLUDING THE APPROACH TO THE YUCATAN CHANNEL.
OTHERWISE...THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF
A SURFACE RIDGE ANCHORED BY A 1038 MB HIGH CENTERED ACROSS THE
OHIO VALLEY EXTENDING AN AXIS S-SW TO COASTAL TEXAS THEN
SOUTHWARD TO A 1031 MB HIGH CENTERED NEAR TAMPICO MEXICO. UPPER
LEVEL DRYING HAS OCCURRED DURING THE PAST 24 HOURS ACROSS MUCH
OF THE GULF WITH PRIMARY CLOUD COVER CONTINUING TO BE A BROKEN
TO OVERCAST STRATOCUMULUS DECK INDICATING RELATIVELY STABLE
CONDITIONS PREVAIL. FRESH TO STRONG NE WINDS PREVAIL E OF 90W
WHILE MODERATE TO FRESH NE WINDS CONTINUE W OF 90W THIS MORNING.
THIS OVERALL WIND REGIME IS EXPECTED TO PERSIST THROUGH EARLY
SUNDAY.

CARIBBEAN SEA...
UPPER LEVEL RIDGING IS NOTED ON WATER VAPOR IMAGERY OVER THE
WESTERN CARIBBEAN WITH AXIS ANCHORED NEAR 12N80W EXTENDING N-NE
TO BEYOND EASTERN CUBA NEAR 24N75W. UPPER LEVEL DIFFLUENCE
ASSOCIATED WITH THE RIDGING ALOFT IN TANDEM WITH A SURFACE
TROUGH ANALYZED FROM THE YUCATAN CHANNEL NEAR 22N84W SOUTHWARD
INTO A 1017 MB LOW CENTERED NEAR 17N87W IS PROVIDING FOCUS FOR
SCATTERED SHOWERS AND TSTMS ACROSS THE NW CARIBBEAN N OF 15N
BETWEEN 83W-88W. SCATTERED SHOWERS AND TSTMS CONTINUE TO THE SE
ALONG THE NICARAGUA TO PANAMA COAST FROM 09N-16N BETWEEN 80W-
85W. ELSEWHERE...A NORTH-SOUTH ELONGATED UPPER LEVEL LOW IS
CENTERED NEAR 15N69W WITH MIDDLE TO UPPER LEVEL MOISTURE NOTED
ON WATER VAPOR IMAGERY ACROSS THE EASTERN CARIBBEAN E OF 72W.
ISOLATED SHOWERS ARE OCCURRING FROM 11N-20N BETWEEN 63W-72W.
OTHERWISE...FRESH TO STRONG TRADES PREVAIL ACROSS MOST OF THE
BASIN EXCEPT W OF 82W WHERE THE SURFACE TROUGH AXIS IS
GENERATING BROAD MODERATE TO FRESH CYCLONIC FLOW. THE STRONGEST
TRADES ARE NOTED WITHIN CLOSE PROXIMITY TO THE COAST OF COLOMBIA
THIS EVENING.

...HISPANIOLA...
AN UPPER LEVEL LOW IS CENTERED NEAR 15N69W THAT CONTINUES TO
PROVIDE MOSTLY CLEAR SKIES THIS MORNING WITH POSSIBLE ISOLATED
SHOWERS OCCURRING ACROSS THE SOUTHERN AND EASTERN ADJACENT
COASTAL WATERS. THE UPPER LEVEL FEATURE WILL SLOWLY DRIFT
EASTWARD BY LATE SUNDAY AND WEAKEN E OF 68W AS UPPER LEVEL
RIDGING SETTLES IN AND THE OVERALL DRYING TREND CONTINUES.

ATLANTIC OCEAN...
UPPER LEVEL TROUGHING EXTENDS FROM 41N59W W-SW TO OVER THE
CAROLINAS. THE TROUGHING SUPPORTS A STATIONARY FRONT ANALYZED
FROM 31N61W W-SW INTO A 1018 MB LOW NEAR 27N77W THEN TO THE
EXTREME SOUTHERN FLORIDA PENINSULA AND INTO THE SE GULF OF
MEXICO. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING
GENERALLY WITHIN 120 NM EITHER SIDE OF THE FRONT. STRONG TO NEAR
GALE NE WINDS PERSIST AS A STRONG RIDGE ANCHORS ITSELF ACROSS
THE MID-ATLC AND SE CONUS. OTHERWISE...SURFACE RIDGING PREVAILS
ACROSS THE CENTRAL ATLC ANCHORED BY A 1028 MB HIGH CENTERED S OF
THE AZORES NEAR 36N28W. FINALLY...ACROSS THE EASTERN ATLC...A
MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 24N33W. EXTENSIVE
CLOUDINESS COVERS THE EASTERN ATLC FROM 15N-31N E OF 28W DUE TO
DIFFLUENT SOUTHWESTERLY FLOW ALOFT. ISOLATED SHOWERS AND TSTMS
ARE POSSIBLE ACROSS THIS AREA THROUGH LATE SATURDAY.

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

$$
HUFFMAN
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