7-11-19: 10PM Advisory from the National Hurricane Center on Tropical Storm Barry

Courtesy: nhc.noaa.gov

From the National Hurricane Center

SUMMARY OF 1000 PM CDT…0300 UTC…INFORMATION
———————————————–
LOCATION…27.9N 89.4W
ABOUT 85 MI…135 KM SSW OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 165 MI…265 KM SE OF MORGAN CITY LOUISIANA
MAXIMUM SUSTAINED WINDS…50 MPH…85 KM/H
PRESENT MOVEMENT…W OR 275 DEGREES AT 3 MPH…6 KM/H
MINIMUM CENTRAL PRESSURE…1001 MB…29.56 INCHES

Forecaster Discussion

Despite the lack of convection over the northern portion of the storm, reconnaissance aircraft data show that Barry has
strengthened this evening. The aircraft has found peak 850 mb flight-level winds of 55 kt, and believable SFMR winds of around 45 kt. Based on these data, the initial wind speed has been increased to 45 kt. The NOAA and U.S. Air Force Reserve aircraft have also reported that the pressure has fallen a couple of millibars since the previous advisory.

The tropical storm continues to be affected by northerly shear and dry mid-level air. Despite the shear, nearly all of the intensity guidance and the global models gradually deepen the cyclone during the next 24-36 hours and the NHC intensity forecast once again calls for strengthening until the cyclone reaches the coast. Although the NHC intensity forecast again does not explicitly show Barry becoming a hurricane, it is still possible for that to occur before landfall. After that time, steady weakening is expected while the center moves inland. The intensity guidance is in relatively good agreement, and the NHC forecast is in best agreement with the latest HFIP-corrected-consensus model.

Barry is moving westward or 275 degrees at about 3 kt. The tropical storm should move slowly westward to west-northwestward around the southern portion of a mid-level ridge tonight and Friday. After that time, a weakness in the ridge should cause Barry to turn northwestward, then northward later in the weekend. The overall track guidance envelope changed little this cycle. The UKMET is still along along the far western side of the envelope, but the 18Z HWRF did shift westward and is closer to the center of the envelope. The NHC forecast track is very close to the previous official forecast, and lies between the GFEX and HCCA consensus models.

Key Messages

1. There is a danger of life-threatening storm surge inundation along the coast of southern and southeastern Louisiana where a Storm Surge Warning is in effect. The highest storm surge inundation is expected between Intracoastal City and Shell Beach. Residents in these areas should listen to any advice given by local officials.

2. The slow movement of Barry will result in a long duration heavy rainfall and flood threat along the central Gulf Coast and inland through the lower Mississippi Valley through the weekend 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.

Courtesy: nhc.noaa.gov

3. Hurricane conditions are expected along a portion of the coast of Louisiana, where a Hurricane Warning has been issued. Residents in these areas should rush their preparations to completion, as tropical storm conditions are expected to arrive in the warning area by Friday morning.

Forecast position & wind

INIT 12/0300Z 27.9N 89.4W 45 KT 50 MPH
12H 12/1200Z 28.0N 89.9W 50 KT 60 MPH
24H 13/0000Z 28.5N 90.7W 55 KT 65 MPH
36H 13/1200Z 29.5N 91.5W 60 KT 70 MPH…NEAR THE COAST
48H 14/0000Z 30.5N 91.9W 45 KT 50 MPH…INLAND
72H 15/0000Z 33.2N 92.0W 30 KT 35 MPH…INLAND
96H 16/0000Z 35.7N 91.2W 20 KT 25 MPH…POST-TROP/REMNT LOW
120H 17/0000Z 38.2N 87.9W 15 KT 15 MPH…POST-TROP/REMNT LOW

 

Courtesy: nhc.noaa.gov

Watches & Warnings
CHANGES WITH THIS ADVISORY…

The Storm Surge Warning has been extended westward to Intracoastal
City.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT…

A Hurricane Warning is in effect for…
* Intracoastal City to Grand Isle

A Tropical Storm Warning is in effect for…
* Mouth of the Pearl River to Grand Isle
* Lake Pontchartrain and Lake Maurepas including metropolitan New Orleans
* Intracoastal City to Cameron

A Storm Surge Warning is in effect for…
* Intracoastal City 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
* Lake Pontchartrain

A Hurricane Watch is in effect for…
* Mouth of the Mississippi River to Grand Isle
* Intracoastal City to Cameron

A Tropical Storm Watch is in effect for…
* East of the Mouth of the Pearl River to the Mississippi/Alabama border

A Hurricane Warning means that hurricane conditions are expected somewhere within the warning area. A warning is typically issued 36 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous. Preparations to protect life and property should be rushed to completion.

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.

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.

Hazards

Key Messages for Barry can be found in the Tropical Cyclone Discussion under AWIPS header MIATCDAT2 and WMO header WTNT42 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…3 to 5 ft
Lake Pontchartrain…2 to 4 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 20 inches over southeast Louisiana and southwest Mississippi, with isolated maximum amounts of 25 inches. These rains are expected to lead to dangerous, life-threatening flooding over portions of the central Gulf Coast into the Lower Mississippi Valley. Over the remainder of the Lower Mississippi Valley, total rain accumulations of 4 to 8 inches are expected, with isolated maximum amounts of 12 inches.

Courtesy: nhc.noaa.gov

WIND: Hurricane conditions are expected in the Hurricane Warning area by Friday night or Saturday morning, with tropical storm conditions expected to begin on Friday. Hurricane conditions are possible within the Hurricane Watch area by Friday night or Saturday morning. Tropical Storm conditions are expected to spread across the Tropical Storm Warning area starting early Friday, with tropical storm conditions possible in the Tropical Storm Watch area by Friday night or Saturday.

TORNADOES: A few tornadoes are possible Friday and Friday night across southeast Louisiana, far southern Mississippi, and the Alabama coast.



Author of the article:


Nick Lilja

Nick is former television meteorologist with stints in Amarillo and Hattiesburg. During his time in Hattiesburg, he was also an adjunct professor at the University of Southern Mississippi. He is a graduate of both Oregon State and Syracuse University that now calls Houston home. Now that he is retired from TV, he maintains this blog in his spare time.