From the NHC: Tropical Storm Barry Discussion Number 5
SUMMARY OF 1000 AM CDT…1500 UTC…INFORMATION
———————————————–
LOCATION…27.8N 88.7W
ABOUT 95 MI…150 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 200 MI…320 KM SE OF MORGAN CITY LOUISIANA
MAXIMUM SUSTAINED WINDS…40 MPH…65 KM/H
PRESENT MOVEMENT…W OR 270 DEGREES AT 5 MPH…7 KM/H
MINIMUM CENTRAL PRESSURE…1005 MB…29.68 INCHES
Key Messaging
Key Messages for Barry can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2 and WMO header WTNT32 KNHC.
STORM SURGE: The combination of a dangerous storm surge and the tide will cause normally dry areas near the coast to be flooded by rising waters moving inland from the shoreline. The water could reach the following heights above ground somewhere in the indicated areas if the peak surge occurs at the time of high tide…
Mouth of the Atchafalaya River to Shell Beach…3 to 6 ft
Shell Beach to the Mississippi/Alabama border…2 to 4 ft
Intracoastal City to the Mouth of the Atchafalaya River…2 to 4 ft
Lake Pontchartrain…1 to 3 ft
Surge-related flooding depends on the relative timing of the surge and the tidal cycle, and can vary greatly over short distances. For information specific to your area, please see products issued by your local National Weather Service forecast office.
RAINFALL: Barry is expected to produce total rain accumulations of 10 to 15 inches near and inland of the central Gulf Coast through early next week, with isolated maximum rainfall amounts of 20 inches across portions of eastern Louisiana and southern Mississippi.
WIND: Tropical storm conditions are expected in the Tropical Storm Warning area by Friday. Hurricane conditions are possible within the Hurricane Watch area by Friday night, with tropical storm conditions possible in the Tropical Storm Watch area by Friday night or Saturday.
TORNADOES: A tornado or two are possible tonight and Friday across southern portions of Louisiana and Mississippi.
Watches & Warnings
CHANGES WITH THIS ADVISORY…
A Tropical Storm Warning is now in effect for the Louisiana coast from the Mouth of the Pearl River to Morgan City.
A Storm Surge Warning is now in effect for the Louisiana coast from the Mouth of the Atchafalaya River to Shell Beach.
A Tropical Storm Watch is now in effect for the Mississippi coast east of the Mouth of the Pearl River to the Mississippi/Alabama border…and for Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans.
A Storm Surge Watch is now in effect for the Mississippi coast from the Mouth of the Pearl River to the Mississippi/Alabama border.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT…
A Tropical Storm Warning is in effect for…
* Mouth of the Pearl River to Morgan City
A Storm Surge Warning is in effect for…
* Mouth of the Atchafalaya River to Shell Beach
A Storm Surge Watch is in effect for…
* Shell Beach to the Mississippi/Alabama border
* Mouth of the Atchafalaya River to Intracoastal City
A Hurricane Watch is in effect for…
* Mouth of the Mississippi River to Cameron
A Tropical Storm Watch is in effect for…
* East of the Mouth of the Pearl River to the Mississippi/Alabama border
* Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans
A Tropical Storm Warning means that tropical storm conditions are expected somewhere within the warning area within 36 hours.
A Storm Surge Warning means there is a danger of life-threatening inundation from rising water moving inland from the coastline during the next 36 hours in the indicated locations. For a depiction of areas at risk please see the National Weather Service Storm Surge Watch/Warning Graphic available at hurricanes.gov. This is a life-threatening situation. Persons located within these areas should take all necessary actions to protect life and property from rising water and the potential for other dangerous conditions. Promptly follow evacuation and other instructions from local officials.
A Storm Surge Watch means there is a possibility of life-threatening inundation from rising water moving inland from the coastline in the indicated locations during the next 48 hours.
A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds conditions that make outside preparations difficult or dangerous.
A Tropical Storm Watch means that tropical storm conditions are possible within the watch area generally within 48 hours.
Additional watches and warnings may be required for portions of the northern Gulf coast later today or tonight. Interests elsewhere along the Gulf Coast from the Upper Texas Coast to the Florida Panhandle should monitor the progress of this system.
For storm information specific to your area, including possible inland watches and warnings, please monitor products issued by your local National Weather Service forecast office.
Forecaster Discussion
The low pressure area over the northern Gulf of Mexico has become better organized during the past several hours, with a large convective band in the southern semicircle. The circulation center has also become better defined, although it is still elongated and multiple cloud swirls are seen rotating around the mean center. In addition, Air Force Reserve and NOAA Hurricane Hunter aircraft report flight-level and SFMR winds high enough for an initial intensity of 35 kt. Based on these developments, the system is upgraded to Tropical Storm Barry.
The initial motion is a rather uncertain 270/4. Barry is being steered by a weak low- to mid-level ridge to the north, and a weakness in the ridge is forecast to develop during the next 24-48 h. This should allow the cyclone to turn northwestward and eventually northward. However, there is a large spread in the track guidance. The HWRF and HMON forecast Barry to move almost due north from its current position with a landfall in Mississippi, while the UKMET takes the cyclone to the upper Texas coast. The GFS, ECMWF, and Canadian models lie between these extremes. Overall, there has been a slight eastward shift of the guidance envelope, so the new forecast track is also adjusted slightly to the east. It should be noted, though, that the new track is west of the consensus models.
Barry is being affected by northerly shear, and water vapor imagery indicates mid- to upper-level dry air moving into the cyclone from the northeast. Some moderate shear is now expected to persist until the cyclone makes landfall. Despite this less than ideal environment, the guidance forecasts slow but steady intensification,so the NHC forecast follows this trend. The new intensity forecast is similar to the previous one in calling for Barry to become a
hurricane just before landfall in Louisiana, and it lies between the HCCA and ICON consensus models.
>strong>Key Messages:
1. Barry is expected to bring storm surge, rainfall, and wind hazards to the central Gulf Coast during the next several days.
2. There is a danger of life-threatening storm surge inundation along the coast of southern and southeastern Louisiana where a Storm Surge Warning has been issued. The highest storm surge inundation is expected between the Mouth of the Atchafalaya River and Shell Beach. Residents in these areas should listen to any advice given by local officials.
3. A Tropical Storm Warning and Hurricane Watch are in effect for much of the Louisiana coast and additional watches and warnings could be required later today. Residents in these areas should ensure they have their hurricane plan in place.
4. The slow movement of this system will result in a long duration heavy rainfall threat along the central Gulf Coast and inland through the lower Mississippi Valley through the weekend and potentially into early next week. Flash flooding and river flooding will become increasingly likely, some of which may be significant, especially along and east of the track of the system.
FORECAST POSITIONS AND MAX WINDS
INIT 11/1500Z 27.8N 88.7W 35 KT 40 MPH
12H 12/0000Z 27.8N 89.3W 35 KT 40 MPH
24H 12/1200Z 28.1N 90.0W 45 KT 50 MPH
36H 13/0000Z 28.6N 90.8W 55 KT 65 MPH
48H 13/1200Z 29.4N 91.4W 65 KT 75 MPH
72H 14/1200Z 32.0N 91.8W 30 KT 35 MPH…INLAND
96H 15/1200Z 34.5N 91.5W 25 KT 30 MPH…INLAND
120H 16/1200Z 37.0N 89.5W 20 KT 25 MPH…POST-TROP/REMNT LOW
