Potential Tropical Cyclone Two Likely to Become a Tropical Depression or Storm Today

Figure 1. Official forecast track for Potential Tropical Cyclone Two as of the 7 AM EDT intermediate advisory. Image: NHC

Potential Tropical Cyclone (PTC) Two is likely to become a tropical depression later today, and attain the name “Barry” by tomorrow.

Analysis

A reconnaissance aircraft this morning found a minimum central pressure of 1003 millibars, indicating that PTC Two has strengthened a bit. However, the center is still fairly broad/not well defined, likely as a result of some northerly shear.

Model guidance

All model guidance continues to indicate PTC Two will become a tropical cyclone later today.

Track

Some good news for Texas: the east trend continued overnight, and a Louisiana landfall looks most probable. The reason for this is because model guidance is seeing a stronger weakness in ridging to the north.

Latest track guidance for PTC Two. East trend that started yesterday continued overnight/this AM. pic.twitter.com/1rsIlBxxj0

— Gulf Coast Storm Center (@GCSCWX) July 11, 2019

Here are the various model solutions for track as of the 00z model cycle:

ECMWF: landfall in Vermilion Bay, LA Saturday morning.

GFS: landfall in Grand Isle, LA tomorrow night/early Saturday (1 AM CDT Saturday to be specific).

UKMET: landfall in southeast Texas late Saturday.

At this point, the UKMET is an extreme outlier.

The TVCN consensus model favors a Morgan City, LA landfall late tomorrow night/early Saturday, and is essentially on top of the official forecast track (see figure 1).

Intensity

Since a farther east track is now likely, PTC Two will have less time over water. As a result, the trend among model guidance has been down with regard to intensity.

Figure 2. GFS predicted 6-hour precipitation and MSLP valid at 1 AM CDT Saturday, showing Barry making landfall near Grand Isle, LA. Image: Tropical Tidbits

ECMWF: strong tropical storm or category 1 hurricane.

GFS: strong tropical storm or category 1 hurricane (see figure 2).

UKMET: Category 2 or 3 hurricane.

The UKMET is clearly an outlier in respect to intensity, too. This is likely because it is farther west with its predicted track, resulting in more time over water.

The IVCN consensus model favors a strong tropical storm.

The official forecast from the National Hurricane Center is for soon-to-be Barry to peak as a category 1 hurricane right before landfall.

Impacts

At this point, it is looking like heavy rain/flooding will be the primary impact.

Figure 3. Latest 7-day precipitation forecast for Potential Tropical Cyclone Two. Image: NHC/WPC

The latest 5-day quantitative precipitation forecast (QPF) from the Weather Prediction Center is calling for a swath of 15 – 20″ of rain for southeast Louisiana (see figure 3). Placement is subject to change with any shifts in track, however.

Storm surge will also be an issue, even with a weaker storm.

Other impacts will include:

tropical storm, and possibly hurricane force, winds;
waterspouts/tornadoes with outer bands/squalls;
high seas, dangerous surf;
a high risk for rip currents.

Based on the trend toward a weaker, less consolidated storm, the worst of the impacts will probably be near and east of the center.

It should also be noted that impacts will be felt inland as the storm tracks north after landfall.

Timing

Figure 4. Most likely arrival of tropical storm force winds. Image: NHC

Tropical storm force winds will likely begin to arrive along the northern Gulf Coast by tomorrow evening (see figure 4).

Watch and warning summary

A Hurricane Watch is in effect from the Mouth of the Pearl River to Intracoastal City.
A Storm Surge Watch is in effect from the Mouth of the Pearl River to Cameron.
A Tropical Storm Watch is in effect from the Mouth of the Pearl River to Intracoastal City.