Tropical Weather Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | 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 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
AXNT20 KNHC 221804
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST MON DEC 22 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.

...SPECIAL FEATURE...

...GALE-FORCE WINDS ARE FORECAST IN THE GULF OF MEXICO...

A COLD FRONT...THAT CURRENTLY IS ORGANIZING ITSELF IN THE
NORTHERN SECTIONS OF TEXAS...IS FORECAST TO MOVE OFF THE TEXAS
GULF OF MEXICO COAST ON TUESDAY AFTERNOON.

THE 42-HOUR FORECAST SHOWS THAT THE COLD FRONT WILL EXTEND FROM
30N92W TO 22N97W.  GALE-FORCE NORTHWEST WINDS AND SEA HEIGHTS TO
8 FEET WILL COVER THE GULF OF MEXICO TO THE SOUTH OF 26N TO THE
WEST OF THE FRONT.

PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND
THE OFFSHORE FORECAST...MIAOFFNT4/FZNT24 KNHC...FOR MORE
DETAILS.

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

THE MONSOON TROUGH PASSES THROUGH THE COASTAL SECTIONS OF SIERRA
LEONE NEAR 8N13W TO  8N14W. THE ITCZ CONTINUES FROM 8N14W TO
8N27W 5N34W 6N40W AND 3N45W. CONVECTIVE PRECIPITATION...NUMEROUS
STRONG FROM 5N TO 7N BETWEEN 36W AND 41W. WIDELY SCATTERED
MODERATE TO ISOLATED STRONG ELSEWHERE FROM 10N SOUTHWARD FROM
60W EASTWARD.

...DISCUSSION...

...FROM THE WESTERN ATLANTIC OCEAN...ACROSS FLORIDA...INTO THE
GULF OF MEXICO...AND INCLUDING THE REST OF THE GULF OF MEXICO...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH IS DEVELOPING IN THE
CENTRAL SECTIONS OF THE U.S.A. THIS TROUGH IS ORGANIZING ITSELF
AND IT EVENTUALLY WILL BE SUPPORTING THE COLD FRONT THAT IS
FORECAST TO MOVE INTO THE NORTHWESTERN GULF OF MEXICO WATERS ON
TUESDAY AFTERNOON. THIS IS THE COLD FRONT THAT WILL BRING GALE-
FORCE WINDS INTO THE GULF OF MEXICO. PLEASE READ THE SPECIAL
FEATURES SECTION.

CURRENTLY...A STATIONARY FRONT EXTENDS FROM AN ATLANTIC OCEAN
1014 MB LOW PRESSURE CENTER THAT IS NEAR 32N78W...TO GEORGIA
NEAR 31N81W. A WARM FRONT CONTINUES FROM SOUTHEASTERN
GEORGIA...ACROSS THE FLORIDA PANHANDLE NEAR 30N85W...IN THE
NORTHERN GULF OF MEXICO WATERS AND COASTAL PLAINS...ACROSS
SOUTHEASTERN LOUISIANA...TO THE TEXAS GULF COAST ALONG 95W FROM
29N TO 30N. LOW LEVEL CLOUD CEILINGS AND AREAS OF RAIN SHOWERS
ARE IN THE U.S.A. GULF OF MEXICO COASTAL PLAINS. CONVECTIVE
PRECIPITATION IN THE ATLANTIC OCEAN...BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE TO THE
NORTHWEST OF THE LINE 26N80W 27N70W BEYOND 32N60W.

MIDDLE LEVEL TO UPPER LEVEL SOUTHWESTERLY WIND FLOW SPANS THE
GULF OF MEXICO.

FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N
TO THE WEST OF 88W...

LOW LEVEL CLOUD CEILINGS ARE BEING REPORTED AT...KVAF...KGBK...
KATP...AND KSPR.

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

LOW LEVEL CLOUD CEILINGS AND VISIBILITIES OF 3 MILES OR LESS AND
FOG COVER THE INTERIOR LOCATIONS OF THE DEEP SOUTH OF TEXAS. LOW
LEVEL CLOUD CEILINGS COVER THE REST OF THE COASTAL PLAINS OF
TEXAS...INTO LOUISIANA...AND EVENTUALLY TO THE FLORIDA
PANHANDLE. AREAS OF RAINSHOWERS...SOME WITH THUNDER...ARE IN
MISSISSIPPI AND IN THE FLORIDA PANHANDLE...FROM PERRY FLORIDA
WESTWARD. THE WARM FRONT IS IN THE NORTHERN GULF OF MEXICO...
FROM THE AREA OF THE UPPER TEXAS GULF COAST TO THE WESTERN
SECTIONS OF THE FLORIDA PANHANDLE. LOW LEVEL CLOUD CEILINGS
CONTINUE FROM BROOKSVILLE FLORIDA TO THE TAMPA-SAINT PETERSBURG
METROPOLITAN AREA...AND TO PUNTA GORDA FLORIDA.

...THE CARIBBEAN SEA...

A MIDDLE LEVEL TO UPPER LEVEL RIDGE STARTS ALONG 73W AT THE
NORTHERN COAST OF COLOMBIA...IT PASSES ACROSS HISPANIOLA...AND
BEYOND 32N70W IN THE ATLANTIC OCEAN.  MIDDLE LEVEL ANTICYCLONIC
WIND FLOW SPANS THE CARIBBEAN SEA.

COMPARATIVELY DRIER AIR IN SUBSIDENCE IS APPARENT IN WATER VAPOR
IMAGERY...EVERYWHERE EXCEPT FOR THAT PART THAT IS TO THE
NORTHWEST OF 22N81W IN CUBA...TO 18N88W IN THE YUCATAN PENINSULA
OF MEXICO.

RAINSHOWERS ARE POSSIBLE IN THE CARIBBEAN SEA WATERS...IN
SURFACE-TO-LOW LEVEL TRADE WIND FLOW...FROM 18N SOUTHWARD
BETWEEN 60W AND 70W...FROM 12N NORTHWARD BETWEEN 70W AND
80W...AND FROM 80W WESTWARD. THE 24-HOUR RAINFALL TOTAL IN
INCHES FOR THE PERIOD ENDING AT 22/1200 UTC...ACCORDING TO THE
PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES ARE...0.23 IN
GUADELOUPE...AND 0.11 IN TRINIDAD.

THE MONSOON TROUGH IS ALONG 4N/5N FROM 75W IN COLOMBIA...BEYOND
84W INTO THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...
RAINSHOWERS ARE POSSIBLE...IN TRADE WIND FLOW...FROM 13N
SOUTHWARD FROM 80W WESTWARD.

...HISPANIOLA...

MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND FLOW IS CROSSING
HISPANIOLA. A RIDGE PASSES DIRECTLY ACROSS HISPANIOLA.

CLOUD CONDITIONS AND PREVAILING WEATHER...FOR PORT-AU-PRINCE IN
HAITI...FEW LOW LEVEL CLOUDS. FOR THE DOMINICAN REPUBLIC...FEW
LOW LEVEL CLOUDS IN BARAHONA. SCATTERED LOW LEVEL CLOUDS IN
SANTO DOMINGO AND IN LA ROMANA. FEW LOW LEVEL CLOUDS ARE IN
PUNTA CANA. FEW LOW LEVEL CLOUDS ARE IN SANTIAGO AND IN PUERTO
PLATA.

THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT THE CURRENT RIDGE
WILL REMAIN ACROSS HISPANIOLA FOR THE NEXT 36 HOURS OR SO. THE
RIDGE WILL SHIFT WESTWARD AFTER THAT TIME. THE GFS MODEL
FORECAST FOR 500 MB SHOWS THAT BROAD ANTICYCLONIC WIND FLOW WILL
COVER HISPANIOLA...WITH AN ANTICYCLONIC CIRCULATION CENTER ON
TOP OF HISPANIOLA AND/OR NEAR HISPANIOLA...FOR THE NEXT 48
HOURS. THE GFS MODEL FORECAST FOR 700 MB SHOWS THAT
SOUTHEASTERLY WIND FLOW WILL CROSS HISPANIOLA FOR THE NEXT 48
HOURS.

...THE REST OF THE ATLANTIC OCEAN...

A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N42W TO
28N37W. THIS TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH
32N37W TO 31N38W. CONVECTIVE PRECIPITATION...WIDELY SCATTERED TO
SCATTERED MODERATE AND ISOLATED STRONG FROM 27N NORTHWARD
BETWEEN 33W AND 48W.

SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN FROM
24N NORTHWARD BETWEEN 45W AND 70W. A 1024 MB HIGH PRESSURE
CENTER IS NEAR 32N61W.

A SURFACE TROUGH IS ALONG 24N61W 22N63W 19N64W. CONVECTIVE
PRECIPITATION...BROKEN TO OVERCAST MULTILAYERED CLOUDS AND
POSSIBLE RAINSHOWERS ARE FROM 20N TO 24N BETWEEN 60W AND 68W.

A MIDDLE LEVEL TO UPPER LEVEL RIDGE EXTENDS FROM HISPANIOLA
BEYOND 32N70W. MIDDLE LEVEL TO UPPER LEVEL ANTICYCLONIC WIND
FLOW COVERS THE ATLANTIC OCEAN FROM 20N NORTHWARD BETWEEN 34W
AND 80W.

A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS
NEAR 26N17W. CYCLONIC WIND FLOW IS MOVING AROUND THE CIRCULATION
CENTER FROM 20N NORTHWARD BETWEEN AFRICA AND 34W. NO SIGNIFICANT
DEEP CONVECTIVE PRECIPITATION IS APPARENT IN SATELLITE IMAGERY.

AN EASTERN ATLANTIC OCEAN SURFACE RIDGE PASSES THROUGH 32N27W TO
26N35W. BROAD SURFACE ANTICYCLONIC WIND FLOW COVERS THE ATLANTIC
OCEAN FROM 20N NORTHWARD BETWEEN AFRICA AND 38W.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://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.