[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 290001
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON OCT 28 2013

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
2230 UTC.

...TROPICAL WAVES...
A VERY POSITIVELY TILTED TROPICAL WAVE IS ANALYZED ACROSS THE
EXTREME NE CARIBBEAN AND TROPICAL N ATLC FROM NEAR 18N63W TO
13N61W TO 08N56W...AND IS INTERACTING WITH AN ELONGATED UPPER
CYCLONE EXTENDING NE TO SW JUST E OF THE LESSER ANTILLES. DEEP
LAYERED RIDGING TO THE E OF THE WAVE AND CENTERED ACROSS THE E
ATLC HAS AIDED IN MAINTAINING A STRONG LOW TO MID TROPOSPHERIC
JET WITH THIS WAVE...WITH 25-30 KT SUGGESTED BY THE GFS AT 700
HPA WITH AND BEHIND THIS WAVE. THE NORTHERN PORTION OF THE WAVE
IS RACING WWD 15-20 KT WHILE THE SOUTHERN PORTION HAS SLOWED AS
IT INTERACTS WITH THE NEAR EQUATORIAL TROUGH OFF S AMERICA.
SCATTEROMETER PASSES TODAY INDICATED A LARGE AREA OF 25 KT WINDS
WITH AND BEHIND THE WAVE FROM 11N TO 18N...WHERE SEAS AREA
LIKELY 8-10 FT. SCATTERED MODERATE ISOLATED STRONG CONVECTION
WAS NOTED WITH THE WAVE...AND E OF THE UPPER CYCLONE FROM 07N TO
13N BETWEEN 50W AND 57W. ISOLATED TSTORMS AND SHALLOW CONVECTION
WAS NOTED ACROSS THE E CARIB E OF 65W. THE WAVE WILL CONTINUE TO
MOVE QUICKLY WWD DURING THE NEXT 12 TO 24 HOURS WITH FRESHENING
WINDS AND BUILDING SEAS EXPECTED ACROSS THE E CARIB.

...THE ITCZ/THE MONSOON TROUGH...
THE MONSOON TROUGH EXITS THE W COAST OF AFRICA ALONG THE COAST
OF SENEGAL NEAR 13.5N18W AND CONTINUES SW TO NEAR 12N20W...WHERE
IT TRANSITIONS TO ITCZ...CONTINUING W-SW THROUGH 08N35W TO
05N46W TO 07.5N56W. ISOLATED TO WIDELY SCATTERED MODERATE
CONVECTION WITH ISOLATED STRONG CONVECTION WAS NOTED WITHIN 120
NM NW AND 210 NM SE OF BOTH THE TROUGH AND ITCZ E OF 36W.

...DISCUSSION...

THE GULF OF MEXICO...
SURFACE RIDGING REMAINS ACROSS MOST OF THE BASIN...ANCHORED BY A
1024 MB HIGH OVER N GEORGIA...WHILE NEAR ZONAL FLOW DOMINATING
THE BASIN TODAY IS BECOMING MORE AMPLIFIED AS UPPER RIDGING IS
SHIFTING E OFF OF MEXICO AND INTO THE W GULF ALONG 95W. REMNANT
LOW LEVEL MOISTURE FROM AN OLD FRONTAL BOUNDARY LINGERING IN THE
NW CARIBBEAN SEA HAS BEEN DRAGGED WWD BY A LOW TO MID LEVEL
TROUGH NOW ACROSS THE BAY OF CAMPECHE ALONG 93W...WITH SCATTERED
ACTIVE EVENING CONVECTION ACROSS MUCH OF THE YUCATAN
PENINSULA...AND ISOLATED SHALLOW TO MODERATE CONVECTION N OF THE
YUCATAN BEHIND THE TROUGH ALONG NEAR 23N. THE SURFACE RIDGING IS
FORECAST TO PERSIST BEYOND TUE...WITH THE LOW TO MID LEVEL
TROUGH SHIFTING WWD INTO SW PORTIONS TUE. A LOW PRESSURE SYSTEM
IS EXPECTED TO DEVELOP OVER THE SOUTHERN PLAINS WITH A COLD
FRONT REACHING THE TEXAS COAST EARLY FRI.

CARIBBEAN SEA...
A FLAT UPPER RIDGE DOMINATES THE CARIBBEAN AND IS ANCHORED ON AN
UPPER ANTICYCLONE OVER THE YUCATAN NEAR 19N90W AND EXTENDS
ACROSS THE GREATER ANTILLES. WHILE THE TROPICAL WAVE ACROSS THE
FAR E CARIB IS CURRENTLY IMPACTING AREAS E OF 65W...MODERATE ELY
TRADES GENERALLY DOMINATED THE REMAINDER OF THE BASIN...EXCEPT
IN THE VICINITY OF THE CARIB LOW LEVEL JET OFFSHORE OF W
VENEZUELA AND COLOMBIA. A DISSIPATING STATIONARY FRONT LINGERS
ACROSS NW PORTIONS FROM CENTRAL CUBA TO THE E COAST OF YUCATAN
JUST N OF BELIZE...BUT IS ILL DEFINED IN SATELLITE IMAGERY DUE
TO AMPLE CONVECTION OCCURRING ACROSS NW PORTIONS ASSOCIATED WITH
A SURFACE TROUGH ALONG 82W. A BROAD ZONE OF MOISTURE CONVERGENCE
S OF THE FRONT AND JUST W OF THIS TROUGH PREVAILS N OF 15N
BETWEEN 80W AND 86W...WHERE SCATTERED MODERATE TO STRONG
CONVECTION IS OCCURRING. LOOK FOR THIS MOISTURE AND ACTIVE
CONVECTION TO SHIFT WWD AND INTO THE YUCATAN AND CENTRAL AMERICA
DURING THE NEXT 24 HOURS. MEANWHILE...THE N PORTION OF THE
TROPICAL WAVE WILL MOVE QUICKLY W ACROSS THE E CARIBBEAN AND NE
CARIB ISLANDS TONIGHT THROUGH TUE MORNING AND REACH 72W BY TUE
EVENING.

HISPANIOLA...
AN UPPER LEVEL SHORT WAVE TROUGH IS CURRENTLY SWEEPING EWD
ACROSS W CUBA AND THE NW BAHAMAS...WITH STRONG SE UPPER JET TO
ITS E. INDUCED UPPER DIFFLUENCE CURRENTLY PREVAILS E AND SE OF
THE UPPER TROUGH AND IS SHIFTING EWD ACROSS THE WINDWARD
PASSAGE AND INTO HAITI. THE SHORTWAVE WILL MOVE E OVERNIGHT AND
TUE AND CREATE UNSTABLE CONDITIONS ALOFT ACROSS HISPANIOLA
THROUGH TUE MORNING BUT AS IT SHIFTS ACROSS THE ISLAND
TUE...UPPER CONVERGENCE WILL BEGIN TO STABILIZE THE ATMOSPHERE
THERE. MOISTURE AND LOW LEVEL WIND SURGE ASSOCIATED WITH THE
APPROACHING TROPICAL WAVE WILL REACH THE ISLAND TUE WITH
POTENTIAL FOR SQUALLS AND STRONG TSTMS OCCURRING ACROSS THE
DOMINICAN REPUBLIC AND ADJACENT CARIB WATERS AHEAD OF THE UPPER
TROUGH DURING THE DAY.

ATLANTIC OCEAN...
DEEP LAYERED RIDGING DOMINATES THE BASIN E OF 50W WITH MODERATE
TO FRESH E TO NE TRADES ACROSS MOST OF THE WATERS E OF 50W...AND
ONLY SHALLOW MOISTURE AND LIGHT PASSING SHOWERS NOTED. A
LINGERING STATIONARY FRONT REMAINS ACROSS THE W ATLC FROM 31N61W
THROUGH 26.5N67W TO CENTRAL CUBA NEAR 22N78W. ABUNDANT MOISTURE
PREVAILS ALONG AND S OF THE STATIONARY FRONT THAT APPEARS TO
HAVE BEGUN TO DRIFT NW E OF THE BAHAMAS. LOW LEVEL CONVERGENCE N
OF THE FRONT IS INTERACTING WITH THE APPROACHING SHORTWAVE
TROUGH TO IGNITE SCATTERED MODERATE TO STRONG CONVECTION WITHIN
180 NM NW OF THE FRONT FROM 64W TO 75W...WHICH WILL PERSIST
OVERNIGHT AS UPPER DIFFLUENCE THERE CONTINUES. SURFACE RIDGING
ACROSS THE SE U.S. IS YIELDING A NARROW ZONE OF FRESH NE WINDS
WITHIN 150 NM NW OF THE FRONT THAT EXTENDS WWD THROUGH THE
STRAITS OF FLORIDA. LOOK FOR THE FRONT TO DRIFT NW OVERNIGHT
WITH WINDS BACKING SLIGHTLY TO ITS N...BEFORE THE SHORT WAVE
PICKS UP THE FRONT AND SHIFTS IT EWD TUE.

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

$$
STRIPLING


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