Month: September 2020

We’ve got a lot of moving parts in the forecast for the next week or so, with each one helping shape what the next one will do. The first big item is our late week front, which seems to be on track. The second item is the tropical disturbance off Mexico that many of you have expressed interest or concerns in, so we’ll explain how those two interact and what it could mean.

Today

Wednesday should be a sunny, hot day. We should see at least a few showers and storms crop up, perhaps more likely north and west of Houston. But I think most of us will be dry. Look for highs in the low- to mid-90s area-wide.

Thursday

For tomorrow, a disturbance in the upper atmosphere is going to approach southeast Texas. We should see more cloud cover Thursday, and we may even have showers in the area by sunrise. As the day goes on, we’ll call it partly to mostly cloudy with scattered thunderstorms developing. After a morning low in the muggy 70s, look for highs in the low-90s or a touch cooler north and west.

Friday to Sunday and cold front

Last week’s cold front was an “in your face” type of frontal passage, where once the front passed your backyard, you knew it was there. I’m not sure this next front will be quite like that. Look for perhaps some showers Thursday night and Friday morning. They’ll drop south on Friday and any more organized storms should focus south of I-10 to the coast before dissipating late. The front itself will lag a bit, but it is expected to pass the northern half of the area Friday morning and afternoon, and it should eventually reach the coast by Friday night or early Saturday. Instead of a sharp change, we will likely see a gradual drop in humidity and clearing later Friday into Saturday.

Look for Friday morning lows in the 70s still, followed by highs near 90° Friday afternoon. Then on Saturday, look for morning lows in the 60s in suburbs and outlying parts of the area to around 70 in Houston and mid- to upper-70s along the coast. Sunday morning should be similar.

Both Saturday and Sunday look like fine early autumn or late summer days with ample sunshine. A few morning clouds are possible Saturday south of Houston. We will still see highs in the upper-80s to near 90°, but the humidity will be tolerable.

Can the front fail? It’s plausible that the front doesn’t push quite as aggressively offshore, but trends since yesterday have been toward a slightly stronger push and the front basically dissolving 100 to 200 miles offshore. So we think that this is real.

See full post

The Atlantic is full. No room at the inn, folks. We’re fresh out of vacancy. If only that were true. Since our last tropical update last Tuesday, we’ve added <checks notes> three more storms. We’re running about three weeks ahead of 2005’s pace and the last name on the list is Wilfred before we shift over to the Greek alphabet. You can argue all day about how many of the storms have been minimal, but a storm is a storm and 2020 is certainly in a unique place based on our historical records. Incidentally, if you want to look back at an interesting analog year to this one, check out 1971.

This is when it occurred last in September 1971, from Neil Frank. Six active with another about to form. 🙂 pic.twitter.com/yxZSsEze7D

— David Roth (@DRmetwatch) September 14, 2020

It was also a year full of mostly minor to moderate storms, including Fern in South Texas and Edith near Cameron, LA. But it included six active systems (including Fern & Edith) at once with one additional in the pipeline. Ginger on that map above is noteworthy for being the longest lived modern Atlantic tropical system. It lasted from September 10th through October 7th, before eventually reaching land in North Carolina. That track map is something to behold. Even better, it was drawn by local hurricane legend Neil Frank.

At present, we are monitoring four systems, none of which are a concern for Houston. There are also two “invests,” neither of which are a serious concern for us either. Plus, we have one “untagged” Gulf disturbance.

We’ll do our best to sift through the morass for you, starting with that current lineup of storms and then talking the hypothetical systems.

Hurricane Sally

Eric covered Sally earlier today, and not much has changed. Sally remains a category 1 storm with 85 mph winds. It is going to meander just offshore of the Gulf for the next day or so before beginning to move along north and northeast. Water trumps wind in terms of greatest threats with Sally, as persistent onshore flow will keep coastal areas inundated for awhile.

Meanwhile, heavy rainfall will repeatedly pelt southern Mississippi, Alabama, the Florida Panhandle, and eventually Georgia and the Carolinas leading to widespread and potentially severe flash flooding.

See full post

Good morning. This post will discuss our rain chances toward the end of the week, a modest cool front this weekend, and also dig into Hurricane Sally, which is nearing the northern Gulf of Mexico coast and will bring devastating flood impacts there.

Tuesday

Today is going to be just plain hot. Most (but not all, I know) readers are dearly looking forward to the end of summer. But we’re not going to find it today, with clear skies and high temperatures pushing up into the mid-90s. We’ll see slight northerly winds on the back side of Sally’s circulation, but it’s going to be just plain humid and summer-like. Overnight temperatures will likely push into the upper 70s across the metro area to low 80s right on the coast. There is a slight chance, perhaps 20 percent, of some afternoon and evening showers to provide some relief.

Wednesday

Wednesday should be a lot like Tuesday—hot, mostly sunny, and with only a slight chance of afternoon showers. If you like summer in Houston, you’re in luck!

Thursday and Friday

The overall pattern begins to change by Wednesday night or so, as an atmospheric disturbance nears the area. This should allow for the development of some clouds in the sky, and a healthy chance of rain showers. It appears as though rain chances will be highest on the western side of Houston—some areas may see on the order of half an inch of rain, maybe? Temperatures should moderate slightly, into the low 90s, and overnight lows will drop a few degrees as well.

Saturday and Sunday

We’re now pretty confident that some sort of front will push into Houston on Friday night or Saturday morning, but we still don’t have great confidence in the details. At this point it’s probably best to temper expectations. Yes, we’ll see some noticeably drier air. Yes, this should shave a few points of high and low temperatures. But no, at least right now, we can’t definitely say it will feel like fall in Houston. However, the good news is that we don’t expect to go back to highs in the mid-90s and lows near 80 after this front passes. Summer’s days are numbered as we should see more fronts after this one.

Hurricane Sally

Matt will have all the details on an incredibly action-packed tropics in a post later this morning, and you’ll want to be sure and check that out. Regarding Sally, the good news is that the storm not intensified over night, and remains a Category 1 hurricane with 85 mph winds. As wind shear begins to increase, Sally should not get a whole lot stronger over the next 24 hours before it makes landfall. But that’s where the good news ends.

Sally is only moving to the northwest at 2 mph. At present the storm remains a few dozen miles east of the mouth of the Mississippi River. Two days from now, on Thursday morning, it should still be over southern Alabama. As anyone who lives in Houston knows, this is a recipe for extremely heavy rainfall. This will occur primarily over southern Mississippi, Alabama, and the Florida Panhandle over the next several days, with isolated totals of 20 inches or more possible. A large swath of heavy rain will then traverse Alabama and northern Georgia along Sally’s eventual track. This will of course lead to devastating flooding.

Good morning. The primary weather issues we’re watching this week are the approach of Tropical Storm Sally toward the Louisiana and Mississippi coasts, local rain chances, and the potential for a modest cool front to arrive this weekend. The latter should bring slightly cooler temperatures and some welcome drier air.

Monday

The area of low pressure off the Texas coast that drove widespread showers and thunderstorms on Sunday has moved south, and thus the chance for rain today will be less. Some coastal areas, and locations far west of Houston, may still see scattered showers but for the most part we should be dry. High temperatures should otherwise get into the low- to mid-90s with partly sunny skies. Yes, it will be another hot, summer-like day. Winds will be out of the north at about 10 mph—but this isn’t due to a front or anything, it’s because we’ll be on the backside of distant Sally. More on this storm below. Lows tonight will probably drop into the upper 70s.

Tuesday and Wednesday

As the region remains on the backside of Sally, we should see a persistent, if light northerly wind. This should help to limit cloud cover during the middle of the week. This, in turn, will allow highs to push into the mid-90s on Tuesday and Wednesday with the potential for only some isolated showers. So yeah, hot.

Thursday and Friday

The end of the work week should see a slightly more perturbed atmosphere, and this could push rain chances into the 40 percent range, or so, for both days. We will expect that partly sunny skies will allow highs to reach 90 degrees, or the low 90s.

Saturday and Sunday

It will be a fairly close thing, but for now we generally think a front will reach the coast on Saturday. Our weekend forecast will depend upon the timing and strength of the front, as well as on whether it actually makes it. But overall, we’d anticipate highs somewhere in the upper 80s, with lows of around 70 degrees—areas inland may see 60s but it’s hard to say for sure. The drier air should be noticeable, however, making for pleasant mornings and evenings this weekend. Skies should be partly to mostly sunny.

Tropical Storm Sally

Fortunately we have not seen too much intensification with Sally overnight—this is something we feared might happen. It is now a 65-mph tropical storm. Although Sally still has about a day to intensify, this relative lack of organization means it is mostly likely the system comes ashore as a Category 1 hurricane. The current track, just east of New Orleans, would spare the city the worst in terms of storm surge and winds. Our primary concern remains the potential for very heavy rainfall from southeastern Louisiana through the Mississippi and Alabama coastal areas. Later in the week, the slow-moving Sally could produce very heavy rains across much of the state of Alabama.

The tropics remain incredibly active at this time—Tropical Storm Teddy has formed far out to sea, where it will curve north away from the United States—and we’ll continue to watch things closer to home in the Gulf of Mexico where the waters are quite warm.