[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 311757
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT MON MAR 31 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1715 UTC.

...THE ITCZ/THE MONSOON TROUGH...
THE MONSOON TROUGH MEANDERS ACROSS W AFRICA ALONG 11N-12N TO
NEAR 12N11W THEN DIVES SW TO THE COAST NEAR 08N13W...WHERE BROAD
CYCLONIC FLOW PREVAILS. THE TROUGH AND ITCZ DO NOT APPEAR TO BE
CONNECTED ATTM. THE ITCZ BEGINS NEAR 04N12W AND CONTINUES TO
02N22W TO 00N29W TO 02S34W TO SOUTH AMERICA NEAR 01S50W.
SCATTERED MODERATE CONVECTION IS NOTED IN A NARROW LINE WITHIN 60
NM OF ITCZ AXIS BETWEEN 12W AND 16W. OTHERWISE...ASSOCIATED
CONVERGENCE LEADING TO SIGNIFICANT CONVECTION IS CONFINED TO S
OF THE EQUATOR....BUT SCATTERED TO NUMEROUS MODERATE TO STRONG
CONVECTION HAD BEGUN TO INCH BARELY ACROSS THE EQUATOR W OF 35W.

...DISCUSSION...

GULF OF MEXICO...
A BROAD UPPER LEVEL TROUGH PREVAIL ACROSS THE NE PACIFIC AND W
HALF OF U.S. WITH A STRONG JET OF AROUND 100 KT MOVING THROUGH
THE BASE AND ACROSS NRN BAJA CALIFORNIA AND THE DESERT SW OF THE
U.S. THE UPPER FLOW THEN QUICKLY DIVERGES ACROSS TEXAS AND
OKLAHOMA...WITH SW FLOW FILLING INTO BACK SIDE OF MID-UPPER
LEVEL TROUGH ACROSS CENTRAL GULF EXTENDING FROM FL PANHANDLE TO
YUCATAN PENINSULA A WEAKENING MIDDLE LEVEL EMBEDDED WITHIN TROUGH
WAS SEEN NEAR 26N87W AND TRAILED THE UPPER TROUGH AXIS SOME 120-
150 NM. ISOLATED CONVECTION IS BEING TRIGGER TO THE E OF TROUGH
AXIS BETWEEN 24-25N...WHERE SUFFICIENT LLVL MOISTURE EXISTS. AT
THE SURFACE...HIGH PRESSURE CENTERED ACROSS THE OHIO VALLEY
EXTENDS A RIDGE S AND SW INTO THE GULF...BEHIND THE COLD FRONT
THE SWEPT THROUGH SE PORTIONS OVER THE PAST 36 HOURS. RECENT
SCAT PASSES AND OBS SHOW ELY WINDS AROUND 15 KT PREVAILING E OF
86W...WITH E TO SE WINDS 10-15 ACROSS SW AND CENTRAL PORTIONS.
SELY RETURN FLOW AROUND 15 KT HAS SET UP ACROSS NW PORTIONS AND
INTO THE TEXAS COAST IN ADVANCE OF DEEP LAYERED LOW PRES
SHIFTING INTO THE NRN PLAINS. THE RIDGE IS EXPECTED TO SHIFT
SLIGHTLY E-SE DURING THE NEXT 24 HOURS WITH WINDS VEERING SE TO
S ACROSS THE ENTIRE W HALF OF THE GULF. MOISTURE IS RATHER
LIMITED ATTM PER RECENT TPW LOOPS BUT WILL INCREASE FAR W
PORTIONS DURING THE NEXT 24 HOURS.

CARIBBEAN...
THE UPPER TROUGH ACROSS THE GULF LOOKS TO BE EXITING THE E COAST
OF YUCATAN PENINSULA ATTM YIELDING SW FLOW ALOFT ACROSS THE
CARIB DOWNSTREAM AND ACROSS THE GREATER ANTILLES.
OTHERWISE...UPPER FLOW IS GENERALLY ZONAL EXCEPT SW ACROSS FAR
SE PORTIONS. DRY MIDDLE LEVELS AND SUBSIDENCE IS SUGGESTED BY
WATER VAPOR IMAGERY S OF 15N. AT THE SURFACE A WEAK PRES
GRADIENT PREVAILS ACROSS THE BASIN WITH LIGHT TO MODERATE TRADES
COVERING THE ENTIRE BASIN...EXCEPT FOR THE LLVL JET
REGION...WHERE RECENT ASCAT PASSES INDICATE 20 KT TRADES S OF
13.5N AND W OF 70W...WITH PEAK WINDS AROUND 25 KT OFF THE COAST
OF COLOMBIA.

THE REMNANTS OF THIS WEEKENDS COLD FRONT WERE LINGERING ACROSS
NW PORTIONS THIS MORNING...EXTENDING FROM ERN CUBA NEAR 20.5N77W
BECOMING DIFFUSE ACROSS THE CAYMAN ISLANDS TO THE YUCATAN COAST
NEAR 20N. LITTLE CLOUD COVER OR WEATHER IS CURRENTLY ASSOCIATED
WITH THIS DYING BOUNDARY AND IS EXPECTED TO DISSIPATE IN THE
NEXT 12 HOURS. AS THE E COAST RIDGE SHIFTS E-SE DURING THE NEXT
24 HOURS...THE PRES GRADIENT WILL INCREASE SOMEWHAT ACROSS THE
BASIN AND INCREASE WINDS SLIGHTLY...WITH STRONG TRADES EXPANDING
ACROSS S CENTRAL PORTIONS. THE TAIL END OF THE FRONT ACROSS THE
ATLANTIC WILL DRIFT SE INTO THE WINDWARD PASSAGE THROUGH WED
NIGHT AND AID IN UPSTREAM CONVERGENCE ACROSS HISPANIOLA AND THE
E TIP OF CUBA DURING THIS TIME...INCREASE LLVL MOISTURE AND
RAIN CHANCES.

HISPANIOLA...
THE WEAKENING ATLC COLD FRONT EXTENDS SW AND JUST SE OF THE
TURKS AND CAICOS ISLANDS AND INTO E CUBA NEAR THE TOWN OF BANES.
A WEAK PRY FRONTAL TROUGH IS SUGGESTED BY SATELLITE IMAGERY AND
RECENT ASCAT PASSES EXTENDING FROM THE N CENTRAL COAST OF
HISPANIOLA NEAR THE DR-HAITI BORDER. TPW IMAGERY INDICATES THAT
LLVL MOISTURE HAS CONVERGED ACROSS SW PORTIONS OF HAITI...WITH
SUFFICIENT MOISTURE PRESENT TODAY FOR DIURNAL CONVECTION TO
DEVELOP ACROSS THE ISLAND. SWLY SLOW ALOFT WILL LIKELY ENHANCE
THIS CONVECTION AND YIELD ISOLATED STRONG CELLS TODAY...WITH AN
INCREASE IN MOISTURE AND INSTABILITY EXPECTED ON TUE AS THE
GULF OF MEXICO TROUGH SHIFTS E ACROSS 80W.

ATLANTIC...
AN ELONGATED UPPER CYCLONE ACROSS THE NW ATLC ALONG ABOUT 70W IS
SHIFTING E AND GRADUALLY BECOMING DISCONNECTED WITH HIGHER
LATITUDE TROFFING. THIS CYCLONE AND ASSOCIATED TROUGH SUPPORTS A
COLD FRONT THAT EXTENDS INTO THE AREA FROM JUST E OF BERMUDA TO
JUST SE OF THE TURKS AND CAICOS ISLANDS AND INTO E CUBA...AS
DESCRIBED ABOVE. SCATTERED SHOWERS AND TSTORMS WITH WIDELY
SCATTERED TOPS 30-40K FT WERE OCCURRING WITHIN 60 NM E OF THE
FRONT N OF 27N AND WERE MORE ISOLATED BETWEEN 23N AND 27N. A
RECENT 1402 UTC ASCAT PASS SHOWED WNW WINDS 20-25 KT BEHIND THE
FRONT N OF 28N AND WERE GENERATING WNW SWELL WITH COMBINED SEAS
TO 12 FT THERE. ATLC RIDGING BEHIND THE FRONT WAS YIELDING N TO
NE WINDS 15-20 KT DIRECTLY BEHIND THE FRONT S OF 25N. COOLER DRY
AIR AND MOSTLY CLEAR SKIES PREVAILED ELSEWHERE BEHIND THE FRONT
TO THE E COAST OF FL AND THE SE U.S. LIMITED MOISTURE IS
AVAILABLE TODAY ACROSS FLORIDA TO INTERACT WITH THE APPROACHING
UPPER TROUGH.

SHARP UPPER LEVEL RIDGING PREVAILS E OF THIS UPPER CYCLONE...N
OF 30N AND BETWEEN 62W AND 40W. TO ITS E LIES A BROAD UPPER
TROUGH WITH EMBEDDED CYCLONE IN ITS BASE NEAR 40N20W. WATER
VAPOR IMAGERY SUGGESTS A WEAK MID LEVEL TUTT AXIS EXTENDING
FROM THE BROAD BASE TO A DYING MID LEVEL CYCLONE NE OF THE
LEEWARDS NEAR 23N55W. S OF THIS...AN EQUATORIAL RIDGE PREVAILS
YIELDING SW TO W FLOW ALOFT S OF 20N AND INTO W AFRICA. AT LOWER
LEVELS...BROAD CYCLONIC FLOW DOMINATES THE NE ATLC WITH A
WEAKENING COLD FRONT SINKING SE INTO THE FAR NE PORTIONS OF THE
DISCUSSION AREA ALONG 31N E OF 35W. A MODEST RIDGE IS SITUATED
BETWEEN THE TWO ATLC COLD FRONTS...CENTERED ON A 1028 MB HIGH
NEAR 31N46W...WITH RIDGE EXTENDING SE TO NEAR 24N22W. MODERATE
ANTICYCLONIC FLOW DOMINATES MOST OF THE DISCUSSION AREA...WITH
STRONG NE TRADES AROUND 20 KT OCCURRING S OF 14N W OF 40W AND
BLOWING INTO S AMERICA...AND SLY FLOW AROUND 20 KT OCCURRING N
OF 26N WITHIN 300 NM OF W ATLC COLD FRONT. STABLE CONDITIONS
GENERALLY PREVAIL ACROSS THIS REGION...WITH LARGE PATCHES OF BKN
STRATOCU S OF 20N. THE HIGH WILL WEAKEN SLIGHTLY DURING THE NEXT
24 HOURS AS THE W ATLC COLD FRONT DAMS UP AGAINST THE W SIDE OF
THE DEEP LAYERED RIDGE...AND LITTLE CHANGE IN THE OVERALL
SYNOPTIC PATTERN IS EXPECTED IN THE SHORT TERM.

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

$$
STRIPLING


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