Tropical Weather Discussion
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
000
AXNT20 KNHC 241106
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN APR 24 2016

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
1045 UTC.

...THE ITCZ/THE MONSOON TROUGH...

THE MONSOON TROUGH PASSES THROUGH THE COASTAL AREAS OF GUINEA-
BISSAU NEAR 12N16W TO 07N20W. THE ITCZ CONTINUES FROM 07N20W TO
04N30W AND 01N42W. CONVECTIVE PRECIPITATION...ISOLATED TO WIDELY
SCATTERED MODERATE AND LOCALLY STRONG WITHIN 60 NM TO 120 NM ON
EITHER SIDE OF 06N11W 04N26W 02N39W 02N52W. SCATTERED STRONG FROM
THE EQUATOR TO 01N BETWEEN 02W AND 04W.

...DISCUSSION...

...THE GULF OF MEXICO...

AN UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN MEXICO NEAR
28N102W. UPPER LEVEL SOUTHWEST-TO-WEST WIND FLOW IS MOVING FROM
THE WESTERN SECTIONS OF THE GULF OF MEXICO...INTO THE CENTRAL
SECTIONS. THE SOUTHWEST-TO-WEST WIND FLOW IS BEING PUSHED INTO
THE AREA OF ALREADY-EXISTING UPPER LEVEL CYCLONIC WIND
FLOW...THAT IS ACCOMPANYING THE ATLANTIC OCEAN 32N73W-TO-
BAHAMAS TROUGH.

COMPARATIVELY DRIER AIR IN SUBSIDENCE IS APPARENT IN WATER VAPOR
IMAGERY TO THE NORTH AND NORTHWEST OF THE LINE THAT PASSES
THROUGH 25N78W 27N86W...TO THE COAST OF SOUTHEASTERN LOUISIANA
ALONG 90W.

THE SURFACE PRESSURE GRADIENT IS COMPARATIVELY WEAK AT THE
MOMENT. A WEAK 1017 MB HIGH PRESSURE CENTER IS ALONG THE
SOUTHWEST COAST OF LOUISIANA NEAR 30N93W. A WEAK 1016 MB HIGH
PRESSURE CENTER IS OFF THE SOUTHEASTERN COAST OF LOUISIANA NEAR
29N89W...BASED ON SURFACE OBSERVATIONS.

FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE IN THE AREA WHOSE
BOUNDARIES ARE FROM 27N NORTHWARD AND FROM 88W WESTWARD...

MVFR CONDITIONS...KHHV. VFR/NO CEILINGS ELSEWHERE.

LOW LEVEL CLOUD CEILINGS AND WEATHER...FOR THE COASTAL PLAINS OF
THE U.S.A. FROM THE DEEP SOUTH OF TEXAS TO FLORIDA...

TEXAS...LIGHT RAIN IN WESLACO. IFR IN HARLINGEN. THUNDER IS
BEING OBSERVED CLOSE TO BROWNSVILLE. THUNDER AND LIGHT RAIN HAVE
BEEN OBSERVED IN ROBSTOWN DURING THE LAST HOUR. THUNDER AND
LIGHT RAIN IN THE CORPUS CHRISTI METROPOLITAN AREA. LOUISIANA...
MVFR IN GALLIANO. MISSISSIPPI AND ALABAMA...VFR/NO CEILINGS.
FLORIDA...LIFR IN PERRY. IFR AT THE TAMPA EXECUTIVE AIRPORT.
LIFR IN PUNTA GORDA.

...THE CARIBBEAN SEA...

AN UPPER LEVEL RIDGE PASSES THROUGH NORTHERN COLOMBIA... THROUGH
NORTHERN NICARAGUA AND ACROSS HONDURAS...INTO GUATEMALA. UPPER
LEVEL ANTICYCLONIC WIND FLOW SPANS THE CARIBBEAN SEA.

A SURFACE TROUGH IS ALONG 82W/83W FROM 14N TO 21N. CONVECTIVE
PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM 15N TO 19N BETWEEN
79W AND 85W.

CONVECTIVE PRECIPITATION...NUMEROUS STRONG HAS BEEN OCCURRING IN
EXTREME NORTHWESTERN VENEZUELA AND IN NORTHERN COLOMBIA...SINCE
24/0215 UTC...FROM 06N TO 11N BETWEEN 72W AND 77W. WIDELY
SCATTERED TO SCATTERED STRONG IS FROM 07N TO 11N BETWEEN 78W AND
82W. A SURFACE TROUGH IS ALONG 11N74W 09N78W BEYOND 08N83W.

...HISPANIOLA...

UPPER LEVEL ANTICYCLONIC WIND FLOW IS MOVING ACROSS THE ISLAND.
THE WIND FLOW IS FROM THE SOUTHWEST IN THE WESTERN HALF OF THE
ISLAND...AND FROM THE NORTHWEST ACROSS THE EASTERN HALF OF
HISPANIOLA.

SURFACE OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI...FEW
CUMULONIMBUS CLOUDS...AND A CLOUD CEILING AT 4000 FEET...VFR...
AT 24/0000 UTC. FOR THE DOMINICAN REPUBLIC...BARAHONA...
SCATTERED LOW LEVEL CLOUDS...VFR...AT 24/0000 UTC. SANTO
DOMINGO...SCATTERED LOW LEVEL CLOUDS AND A CLOUD CEILING WHOSE
BASE IS AT 7000 FEET...VFR. SCATTERED HIGH LEVEL CLOUDS...VFR.
LA ROMANA...FEW LOW LEVEL CLOUDS...VFR...AT 24/0300 UTC. PUNTA
CANA...SCATTERED LOW LEVEL CLOUDS...VFR. SANTIAGO...LIGHT RAIN
AND A CLOUD CEILING WHOSE BASE IS AT 1600 FEET...MVFR. PUERTO
PLATA...FEW LOW LEVEL CLOUDS AND A MIDDLE LEVEL CLOUD CEILING
WHOSE BASE IS AT 14000 FEET...VFR.

THE GFS MODEL FOR 250 MB SHOWS THAT A RIDGE WILL EXTEND FROM
NORTHERN COLOMBIA TOWARD THE YUCATAN CHANNEL. EXPECT NORTHWEST
WIND FLOW ACROSS HISPANIOLA DURING DAY ONE. EXPECT WESTERLY WIND
FLOW DURING DAY TWO. THE GFS MODEL FOR 500 MB SHOWS THAT A
TROUGH WILL BE TO THE WEST OF HISPANIOLA AT THE START OF DAY
ONE. THE WIND WILL COME FROM THE SOUTHWEST AT THE START OF DAY
ONE...AND THEN IT WILL SWITCH TO WESTERLY AND THEN FROM THE
NORTHWEST BY THE END OF DAY ONE. THE TROUGH WILL DISSIPATE AND
IT WILL BE REPLACED BY AN EAST-TO-WEST ORIENTED RIDGE...GIVING
THE WEST-TO-NORTHWEST WIND FLOW. EXPECT WESTERLY WIND FLOW
DURING DAY TWO...AS THE EAST-TO-WEST ORIENTED RIDGE REMAINS IN
PLACE ACROSS PARTS OF THE CENTRAL CARIBBEAN SEA. THE GFS MODEL
FOR 700 MB SHOWS THAT AN ATLANTIC OCEAN-TO-CARIBBEAN SEA EAST-TO-
WEST ORIENTED RIDGE WILL BE A BIT TO THE SOUTH OF HISPANIOLA
DURING DAY ONE. EXPECT SOUTHWEST WIND FLOW ACROSS HISPANIOLA
DURING DAY ONE. THE RIDGE WILL REMAIN IN PLACE DURING THE FIRST
6 TO 12 HOURS OF DAY TWO...SENDING MORE SOUTHWEST WIND FLOW
ACROSS THE AREA. WESTERLY WIND FLOW WILL COVER HISPANIOLA FOR
THE NEXT 6 TO 12 HOURS OR SO...FOLLOWED BY SOUTHWEST WIND FLOW
AGAIN AS THE ATLANTIC OCEAN-TO-CARIBBEAN SEA EAST-TO-WEST
ORIENTED RIDGE RETURNS BY THE END OF DAY TWO.

...THE ATLANTIC OCEAN...

A SURFACE TROUGH IS JUST TO THE EAST OF THE FLORIDA COAST...
ALONG 79W/80W FROM 24N TO 27N. CONVECTIVE PRECIPITATION...
RAINSHOWERS ARE POSSIBLE IN LOW LEVEL CLOUDS FROM 26N TO 30N
BETWEEN 78W AND THE FLORIDA EAST COAST.

A DEEP LAYER TROUGH PASSES THROUGH 32N73W...TO 25N76W JUST TO
THE EAST OF THE BAHAMAS. COMPARATIVELY DRIER AIR IN SUBSIDENCE
IS APPARENT IN WATER VAPOR IMAGERY TO THE NORTH AND NORTHWEST OF
THE LINE THAT PASSES THROUGH 32N67W 28N70W 25N78W 27N86W...TO
THE COAST OF SOUTHEASTERN LOUISIANA ALONG 90W. THE TROUGH IS
SUPPORTING A COLD FRONT THAT PASSES THROUGH 32N70W TO 29N72W AND
27N76W. A SURFACE TROUGH IS WITHIN 60 NM TO 120 NM TO THE EAST
OF THE FRONT ALONG 30N70W 28N73W 26N76W. CONVECTIVE
PRECIPITATION...WIDELY SCATTERED MODERATE TO ISOLATED STRONG IS
FROM 27N NORTHWARD BETWEEN 64W AND 69W.

BROAD CYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN FROM 25N
NORTHWARD BETWEEN AFRICA AND 60W. AN UPPER LEVEL CYCLONIC
CIRCULATION CENTER IS NEAR 41N41W. A 989 MB LOW PRESSURE CENTER
IS NEAR 42N42W. A STATIONARY FRONT IS ALONG 32N27W TO 25N40W AND
21N50W 20N60W...AND TO 21N71W IN THE SOUTHEASTERN BAHAMAS. A
SLOWLY-MOVING SECOND COLD FRONT PASSES THROUGH 32N40W TO 30N43W
AND 29N50W. CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO
ISOLATED STRONG FROM 24N TO 27N BETWEEN 34W AND 37W...AND FROM
24N TO 26N BETWEEN 66W AND 68W. BROKEN TO OVERCAST MULTILAYERED
CLOUDS AND POSSIBLE RAINSHOWERS ARE ELSEWHERE WITHIN 400 NM TO
500 NM TO THE SOUTH OF THE LINE 30N30W 27N43W 27N60W 25N75W
24N80W.

A SURFACE RIDGE IS TO THE EAST OF THE COLD FRONT/STATIONARY
FRONT...PASSING THROUGH 32N20W...TO A 1019 MB HIGH PRESSURE
CENTER THAT IS NEAR 26N29W...TO 20N45W AND 19N53W.

A SURFACE RIDGE IS TO THE WEST OF THE COLD FRONT/STATIONARY
FRONT...ALONG 32N59W...TO A 1018 MB HIGH PRESSURE CENTER THAT IS
NEAR 28N58W...AND TO 25N47W AND 27N37W.

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

$$
MT



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.