6:20 am CT Friday: Hurricane Delta has completed its north turn and is now steaming toward the Louisiana coast. Delta is a large storm in size, and as a result, we are seeing some rain here in the Houston area, especially on the east side. But Delta will exit quickly tonight, setting the stage for a sunny weekend but also the return of heat.

Hurricane Delta Update

As of the 4 am CT advisory, Hurricane Delta still had 120 mph maximum sustained winds, supported by observations from aircraft investigating the storm. Since that advisory, little has changed for the most part, but Delta is now moving into an area of high shear and cooler water temperatures.

In addition, the southern side of the storm is beginning to feel the effects of drier air being swept off Texas and Mexico in the wake of its passage. The GFS model image below is valid for Noon today and shows drier air (brown) getting dragged into the southern half of the storm. Delta is likely to come ashore fairly lopsided, with a potent northern half and a much more frazzled and weaker southern half.

So this storm has likely peaked in intensity over the Gulf and will slowly weaken up to landfall. That said, it remains a dangerous storm, as the large size of it will allow for a storm surge in Louisiana that is more significant than the storm’s landfall intensity will probably suggest. In addition, the expansive tropical storm force wind field (which now has a radius of 160 miles north and east of the center) will allow for damaging winds in weakened, vulnerable parts of Louisiana. So for southwest Louisiana, this remains a serious storm.

Local impacts from Delta

We have already begun to see tides increase on the Upper Texas coast. San Luis Pass is just on the cusp of minor flooding this morning.

We are now past high tide, so this will likely level off now or perhaps rise just a little more. A similar story is playing out in Galveston. Tidal levels on our slice of the Texas coast will probably be similar to what we saw with Hanna and Laura and lower than what was experienced with Beta. Watch for the risk of some minor flooding from the Galveston Bay side in Bolivar and Galveston itself later today with winds shifting behind Delta.

Rain continues to circulate in from the east, and most of the eastern half of the Houston metro has seen about a quarter-inch so far.

Total rainfall in the Houston area should be under an inch for most folks, and no flooding is expected in our area. Look for upwards of 2 to 4 inches in the Golden Triangle, with minimal flooding issues expected and 6 to 8 inches in Lake Charles, where street flooding could be a bit more serious of a problem.

Winds at Galveston are gusting just a bit under tropical storm force this morning (35 mph as of 6 AM). We could see sustained winds or gusts to tropical storm force (45 mph or so) along the immediate Gulf coast. In Houston, wind gusts will be unlikely to get much past 25 or 30 mph, and no serious issues are expected due to wind for the vast majority of the region. Winds in the Beaumont area could gust to 40 to 50 mph, with slightly higher winds closer to the coast. In Lake Charles,  winds could gust as high as 50 to 70 mph for a time later today, with hurricane conditions on the immediate coast of southwest Louisiana, in addition to a significant storm surge on the immediate Gulf coast there.

Eric and I continue to send our thoughts and best wishes to our neighbors in the east. Even a best case scenario outcome with Delta is still a pretty bad day for southwest Louisiana, and they will continue to need our help in recovery.

After Delta: Weekend

With Delta moving off to the north tonight and tomorrow, the Houston area is going to clear out quickly in its wake. Saturday should be a lovely day, albeit a bit warm. Expect sunshine with highs in the upper-80s. Humidity should be tolerable. More sunshine will follow Sunday, but temperatures are going to crank up and so will the humidity. Sunday is going to feel like a summer day, with highs in the low to mid-90s.

For the holiday on Monday, expect more of the same, with at least low-90s and sunshine.

Tuesday & beyond

A cold front is likely to press into the area later on Monday, but how far south it gets is an open question. While a few showers will be possible, we expect this wash out over us, which should lead to a slight cooldown in temperatures and slightly lower humidity. By the end of the week, we may see a more robust cold front enter the picture, driving in more pleasant weather for next weekend, but even that is not a guarantee at this point. More on this for you on Monday.

Our next update on Delta will be posted by 2:30 pm CT today.

1:45pm CT Update: Good afternoon folks. We promised an update on Hurricane Delta today, but to be honest there are no significant forecast changes to report. As expected, the storm’s wind field is expanding, and its maximum sustained winds have increased slightly, to 105 mph today. Confidence in the forecast track bringing Delta to southwestern Louisiana late Friday afternoon or evening remains high—all of the 12z model guidance today supports this. The National Hurricane Center’s track is on point.

In terms of local impacts, they remain the same as we posted about this morning. We expect moderate effects in Houston: Decent rain chances, gusty winds on Friday, and seas a few feet higher along the coast. Winds get stronger east of High Island, right along the coast.

Unless there are significant changes in the forecast, our next post will come on Friday morning, by 7:30am CT.

6:45 am CT Thursday: Good morning. We’re tracking near-term weather issues related to Hurricane Delta, which is still expected to come ashore in southwestern Louisiana on Friday afternoon or evening. Then, we can anticipate a sunny, hot weekend before a cool front arrives early next week to usher back fall-like weather into the region. That’s a lot to cover, so let’s jump right in with an update on Delta.

Hurricane Delta

The storm has slowly organized over night and now has 100 mph winds. Overall, the Delta track forecast remains pretty locked in, with the storm moving to the northwest, and commencing a northward turn Thursday night. Along this track, which is is supported by virtually all of the reliable guidance and therefore of high confidence, the storm will very likely come ashore between Cameron, Louisiana, on the eastern side, and White Lake on the west. As you may remember, Hurricane Laura made landfall near Cameron in August as a devastating Category 4 hurricane. Delta will be weaker, and perhaps a dozen or two miles further east, but it will nonetheless bring repeat misery to a region still reeling from catastrophe only six weeks ago. This is truly horrible.

In terms of intensity, forecasters at the National Hurricane Center expect Delta to intensify today, and possibly reach Category 3 before moving over the cooler waters in the northern Gulf of Mexico and encountering higher wind shear. It is forecast to come ashore with 105 mph winds, as a Category 2 hurricane. Let’s briefly address the three main effects from Delta.

Wind

Here’s the latest forecast for maximum wind gusts from Delta. Note, this is not sustained winds, but the maximum winds that may briefly pulse up during Delta’s strongest squalls. These strongest winds will be along, and to the east of the storm’s landfall location.

The strongest winds will occur on Friday. Much of the Houston area is unlikely to see Tropical Storm-force wind gusts, but coastal areas will definitely become quite windy during the day and evening, with the possibility of some gusts reaching 60 mph, especially along Bolivar Peninsula.

Surge

And here’s the National Hurricane Center’s forecast for “peak storm surge,” which represents the combination of surge and high tide for coastal areas. Again, the worst effects will be to the right of the storm’s landfalling location. For Houston, coastal flooding of 1 to 3 feet will be possible generally north of San Luis Pass, including around Galveston Bay and across the Bolivar Peninsula.

Rain

In terms of rainfall, we still have some uncertainties, as there should be a pretty steep rainfall gradient—a line along which, to the west, there will be virtually no rain, and to the east where there will be 1 to 2 inches. We think this line probably will fall somewhere in Houston, but whether it’s along the Interstate 45 corridor, or further east, is difficult to say. Here’s the official forecast for rainfall, but we would rate this as fairly low confidence. In Houston, we should see some outer bands of Delta moving through today, with the heavier rain chances on Friday. We expect no flooding issues in the metro area.

Thursday

Today should see increasing clouds with the aforementioned chance of rain showers, especially on the southern and eastern sides of the region. Despite the mostly cloudy skies this afternoon, expect highs to reach into the upper 80s, with a warm night, and lows only dropping into the 70s. Hello, humidity!

Friday

This will be the day with the most impacts in terms of surf, winds, and rain. Skies will be cloudy, and highs may struggle to reach 80 degrees for most areas. Winds amp up during the day on Friday, with gusty conditions during the afternoon, evening, and overnight hours as Delta pushes through. With the kinds of winds we’re expecting we do not anticipate power outage issues in Houston, although there could possibly be a few problems right on the coast.

Saturday and Sunday

Showers should be ending by late Friday night or Saturday morning, and skies are expected to clear fairly quickly. The weekend will be sunny and warm, with highs in the upper 80s to lower 90 degrees. My sense is that this weekend and early next week are probably the last times Houston will see highs in the 90s in 2020, but that is a guess, not a promise.

Next week

A cool front appears to be on track to arrive on Tuesday to sap some of the region’s heat, with another stronger front probably arriving by or before the weekend.

Our next update will come no later than 2:30pm CT today.

2:35pm CT Wednesday update: Good afternoon, and it’s good to be back. Thanks to Eric for dealing with an absentee site partner for the last couple weeks and getting us from Beta to Delta. I sincerely hope this is the last storm we have to write about for the Gulf this year.

Hurricane Delta is emerging into the Gulf from the Yucatan this afternoon.

After being one of the quickest intensifying storms on record, Delta has taken a beating over the last 18-24 hours and, while it’s holding its own, maximum sustained winds of 100 mph may be a bit generous here. Either way, Delta is now back over warm water with relatively low wind shear, so odds favor it beginning to reintensify tonight.

The track forecast has continued to nudge a bit farther west, however that trend appears to be stable or ending now, and I think we’re close to the maximum for how far west Delta will track.

The last big holdout, the European model, which had been advertising landfall near the Texas/Louisiana border has shifted east by a good 25 miles or more today, and virtually all reliable model guidance now has Delta’s landfall occurring between Cameron, LA and the western edge of Vermilion Bay, or very close to/slightly east of where Laura made landfall. A word of advice: Don’t focus too closely on every wobble and maneuver Delta makes over the next 24-48 hours. While there is still a small degree of uncertainty on the exact track of Delta, the odds that there would be a significant enough shift to detrimentally impact the Houston area is very, very, very small. We all brace ourselves for The Turn™ during these events, and it will happen.

As far as intensity goes, modeling has been slowly easing up on the excitement since last night. Some of that is likely due to what happened to Delta on approach into the Yucatan and land interaction. But as of this afternoon, virtually all intensity forecasts are for this to not get above a category 3 storm in the Gulf before it weakens on approach to the coast. Wind shear is going to likely increase significantly, and the storm will encounter cooler water as well beginning tomorrow night or Friday morning.

That said, the biggest change with Delta over the next couple days will likely be the expansion of its wind field. Larger storms usually have lower intensity ceilings, but they compensate for that by spreading tropical storm or hurricane force winds out over a larger area. You can see this wind field expansion on the HWRF model by looking at 10 meter winds (winds experienced at ground level will be somewhat lower than shown here). The map at left is this evening’s forecast, while the map at right is for Friday afternoon. Both maps are at the same spatial scale, and you can see how the tropical storm force wind field (green, yellow, red) basically doubles in size as Delta comes north.

Hurricane force winds are in purple here also. So despite Delta perhaps being weaker, it will likely have impacts spread over a large swath of Louisiana and perhaps eastern Texas, with a significant surge once again possible along and east of where the center goes.

Speaking of surge, the first National Hurricane Center surge outlook was posted today, showing the potential for as much as 11 feet of surge above ground level if Delta comes ashore at high tide on Friday.

These surge values are rough, though certainly not quite as catastrophic as those seen in Hurricane Laura. But 11 feet of water is a bad day, and unfortunately, the areas around Vermilion Bay that were hammered during Laura are going to get another significant event with Delta.

Locally in the Galveston Bay area, we expect surge impacts to be more like Laura than Beta, with minor overwash possible near Bolivar and perhaps down Bluewater Highway south of Galveston into Brazoria County. Surge should not be much worse than 1 to 3 feet above normally dry ground. Storm Surge Watches have not been posted in our area, but they are hoisted east of High Island. Tropical Storm Watches have been posted from San Luis Pass to High Island.

Will we see tropical storm force winds in the Houston or Galveston areas? My hunch right now is that we won’t see this in Houston. Galveston always has a chance to briefly get to tropical storm force gusts or even sustained winds at times. But this would be mostly a Friday issue. At this point we don’t expect significant problems from wind in the Houston or Galveston areas.

For folks in southwest Louisiana and around the Beaumont/Port Arthur areas, the story is a little less clear. Assuming the wind field does expand as expected, we would likely see tropical storm force gusts and perhaps a period of sustained tropical storm force winds (35-55 mph) in the Beaumont or Port Arthur areas. In Lake Charles, which is still far from recovered from Laura, we expect about an 80 percent chance of sustained tropical storm force winds (greater than or equal to 39 mph) and about a 30 percent chance of sustained hurricane force winds (greater than or equal to 74 mph). This will not be another Laura in Lake Charles by any means whatsoever, however given that many, many structures in the city have not yet been repaired, this does have the potential to produce some considerable damage, particularly the farther west it comes ashore.

As far as rainfall goes, we don’t expect to see much more than perhaps a few outer bands in the Houston and Galveston areas. Rain totals will be manageable and no flooding is expected in our area.

In Louisiana, up to about 6 to 8 inches will be possible along and east of where the center comes ashore, which could cause minor to moderate flooding issues but really isn’t all that bad as far as these storms go. Delta will be a quick mover and out of there by Saturday morning.

Unless something dramatic changes this evening, our next update will be our regularly scheduled update on Thursday morning.