With the potential for heavy rain, we’re putting a Stage 1 flood alert in place for coastal areas later this week

In brief: Houston faces a couple of warm (almost hot?) days before clouds and rain chances increase to end the week. The period of Thursday night into Friday looks to be the wettest time, and there is the potential for several inches of rainfall, especially south and west of Houston. To that end we are instituting a Stage 1 flood alert for areas along and south of Interstate 10 on Thursday and Friday.

Tuesday

Take a little extra time as there is a fair bit of fog this morning on roadways. It should clear out by mid-morning at the latest, leaving sunny skies. This combination of sunshine and a warm flow will allow high temperatures to spike this afternoon into the upper 80s, with some west and southwest parts of Houston likely reaching 90 degrees. This will be aided by dewpoints in the upper 50s, so while it will be quite warm, it won’t be super humid by Houston standards (that’s dewpoints in the 70s). Given the calm winds, there is also the potential for high ozone levels in the atmosphere today. Low temperatures tonight will drop into the mid-60s for most locations.

Wednesday

Expect a healthy chance of fog again on Wednesday morning. As moisture levels in the atmosphere increase, we’ll see more clouds on Wednesday. This should help to limit high temperatures in the mid-80s, with another warm night.

Thursday and Friday

We are continuing to watch an evolving situation with the potential for heavy rainfall to end the week. And I know many of you are as well, with the Texas Children’s Houston Open golf tournament at Memorial Park Golf Course running from Thursday through Sunday. The good news is that, I think, the weekend should be OK. But what of Thursday and Friday?

NOAA rainfall forecast for now through Friday night. (Weather Bell)

An upper-level disturbance will lift into the area beginning Thursday and find high atmospheric moisture levels to work with. This is a fairly potent system in that it has the potential to drop 6 to 10 inches of rain somewhere in Texas later this week. However, at this time the majority of our guidance now indicates that the best chance for the highest amounts will be southwest of Houston, near the Matagorda Bay area, or perhaps further south. But that does not mean the Houston area is out of the woods as uncertainty remains.

Rain chances will start to increase on Thursday, but the potential for heavy rainfall appears to be highest on Thursday night and Friday. As for our expectations in Houston, my best guess at this point is that we will see widespread accumulations between 1 and 4 inches, with higher isolated totals. The chances for higher accumulations appear to be greater closer to the coast. For that reason, we are instituting a Stage 1 flood alert for areas in Houston along and south of Interstate 10 on Thursday and Friday. Please note we may continue to modify this as better data becomes available.

(Space City Weather)

The bottom line is that you should prepare for the possibility of some disruptive rainfall on Thursday night and Friday, but it is by no means a certainty. Expect temperatures in the 70s, with cloudy skies when it is not raining, and plenty of humidity.

Saturday and Sunday

As the upper low lifts north of the area, rains should end on Friday night or Saturday morning, and we should be left with partly sunny skies for the weekend. Expect highs both days in the low- to mid-80s with a fair bit of humidity. So if you have outdoor activities, at this point, they look fine. Nights will be warm and muggy, in the upper 60s for most locations.

Next week

Most of next week looks fairly warm and muggy as well, with highs likely in the 80s somewhere and warm nights as we get into April.

Heavy rainfall will be possible later this week in the Houston region

In brief: Some areas of Houston got hit by Sunday night’s storms, and others did not. We will now experience a few days of calmer weather this week before the chance for heavy rainfall on Thursday and Friday of this week. The details of that forecast remain hazy, but it’s something to watch.

Rainfall needed

For central and northwest areas of the Houston region, Sunday night’s storms brough some much needed rainfall, with one or more inches in an area roughly between Highway 290 and I-45 North. Much of the rest of the metro area got significantly less. That could change during the second half of this week, with the combination of an upper-level system and plenty of moisture in the atmosphere bringing a healthy chance of rain to the forecast. It is still too early to say whether this is a case in which most of Houston receives about 1 inch of rain, or whether some areas are at risk of 4 to 6 inches. We will be watching it closely.

Estimated rainfall totals from Sunday night’s storms. (HCOEM)

Monday

Last night’s storms were prompted by a weak front sagging into the area, and this has helped push lows down to near 60 degrees this morning for much of Houston. This is likely to be the “coldest” we get for the next week at least. Highs today will reach the lower 80s, with mostly sunny skies and mostly calm winds. The onshore flow will return later this afternoon or this evening, so lows are unlikely to fall below the low 60s tonight.

Tuesday

This will be a warm—borderline hot—day as we see mostly sunny skies and a warm southerly flow. Expect high temperatures in the upper 80s with a few locations possibly hitting 90 degrees. Some slightly drier air (dewpoints in the upper 50s) will help the air warm more rapidly. Winds will generally be light, perhaps at 5 mph from the east. Lows on Tuesday night will drop into the mid-60s.

Tuesday will be hot for much of the area. (Weather Bell)

Wednesday

A few more clouds on Wednesday should help to limit high temperatures in the mid-80s. After Wednesday the region will not see much (any?) sunshine until at least Saturday. Expect another mild night in the mid-60s.

Thursday and Friday

The period of Thursday afternoon through Friday night should bring a high chance of rain as an upper-level system moves into the region. In terms of most impactful rains, with the potential for street flooding, we’re probably looking at late Thursday night into Friday afternoon, but those details will have to wait. These will be cloudy days, with highs mostly in the upper 70s, and muggy evenings. The global models are indicating the potential for a heavy pocket of rainfall, with several inches of rain during this period. However it still is not clear whether this will line up north of the Houston metro area, or more directly over the city and its suburbs. For now I think it’s best to say that we’re going to see some rain during the second half of the work week, and there’s the distinct potential for heavy rainfall and street flooding. We may need to break out the Space City Weather flood scale, but I’m going to hold off on that decision until Tuesday’s post.

Precipitable water levels will be nearly 200 percent of normal levels on Friday, indicating plenty of moisture available for rain showers.

Saturday, Sunday, and beyond

At this point it looks like things will begin to clear up by Saturday, so if you have some outdoor plans this weekend all is not lost. Both days this weekend should see partly sunny skies with highs in the lower 80s, give or take. We cannot rule out some showers each day, but the overall odds appear fairly low. A weak front may arrive by Monday, or so, to bring us some slightly cooler nights. We’ll see!

Odds and ends about springtime in Houston as we cruise through the equinox

In brief: We’re experiencing a chilly morning, and we have one more cold night before we enter a generally warmer pattern. In addition to a mostly spring-like forecast, today’s post includes some musings on the passage of winter, into spring, into summer in Houston.

It’s a cold morning across much of Texas. (Weather Bell)

Thoughts on spring

Last night, a little after 10 pm, I let the dogs out for the final time before bed. As I stood in the dark, enjoying the quietude, I heard it. That characteristic zing of a June bug kamikazeing into the back door. It was the first of the season here, the first of what surely will be thousands over the coming weeks. In Houston, June bugs come in March. It is the way of things, the rite of passage from winter to spring to finally summer.

You can see it in the trees as well. Only a few days ago, leaves were still falling from the trees in my backyard. Now, it is pollen. There is so much pollen. It is the price we pay for shade in the summertime, and a price I will gladly pay. But do you know what did not fall from the tress this year? Acorns. By my fallible memory, we have had two mast years within the last half decade, when the acorns dropped from the trees for weeks on end, carpeting lawns and creating seas of seeds. There seemed to be billions of them. This year, I think I saw maybe one or two. Should we worry about the squirrels?

It is a time to think about such things. Planet Earth spun through the spring equinox this morning at 4:01 am local time. It’s OK, I didn’t wake up for it either. It just means the Sun is directly over the equator today, and that its light is shining equally on both the northern and southern hemisphere of the planet. Although by some definitions the spring equinox marks the beginning of spring, in our area spring more typically runs from late February into the middle of May.

After that, of course, comes summer. But on such a pleasantly crisp morning as we have today, there is no need to think about that quite yet.

Thursday

Temperatures have fallen to about 50 degrees, or a tad cooler, this morning under the influence of cool and dry northerly winds. Dewpoints are exceptionally low. Because of this, and ongoing winds of 10 to 15 mph, and higher gusts, the region will fall under a ‘red flag’ warning this afternoon from 1 to 7 pm. This means that wildfires could spread quickly. Highs this afternoon will reach the upper 60s for most locations under perfectly clear skies.

Winds will be subsiding later this afternoon, and early evening, if you’re headed out to the Houston rodeo. Temperatures will be in the mid-60s before the show, falling to the upper 50s afterward. So, slightly chilly. Low temperatures tonight will fall into the 40s for much of the Houston metro area. This may be the final night in the 40s for many locations this season, but there’s enough spring left in the calendar where I would not want to say that definitively.

Low temperature forecast for Friday morning. (Weather Bell)

Friday

This will be another sunny day, but temperatures will be warmer, in the mid-70s. We’ll also see those northerly winds swing around to come from the south, perhaps gusting up to 20 mph or so during the afternoon hours. As a result, lows on Friday night will only drop into the upper 50s.

Saturday

The first half of the weekend has no weather concerns, aside from some southerly winds gusting up to 20 mph or so. We’re going to see highs of around 80 degrees, with mostly sunny skies. With a warmer flow in place, lows on Saturday night will only drop into the mid-60s.

Sunday

Clouds should start to build on Saturday evening or night in response to increasing moisture levels in the atmosphere. Sunday looks to be a warmer, more humid day in the 80s. The region will see the potential for some light showers during the afternoon ahead of an advancing cold front. It’s a weak front, but it still could spark some scattered thunderstorms on Sunday night. Overall rain accumulations look fairly low for most locations, on the order of a tenth of an inch of rain, or two.

Next week

Monday is likely to be cooler as a modest amount of drier air filters in from the northeast. Let’s call it mid-70s, with the possibility of nighttime temperatures in the 50s. Most of the rest of next week should see highs in the 80s with lows in the 60s. There is a decent signal for rain showers from Wednesday night through Friday. An inch or so of rain sure would help us out, but it’s too far out to have absolute confidence in any such forecast. We’ll see.

Sharply drier air moves in behind a front today, but our weather turns warmer next week

In brief: A robust front will bring much drier air into the Houston region today, and a couple of chilly nights in the upper 40s. After that Houston will likely experience warmer weather for the rest of March: think 80s with some humidity rather than the 70s we’ve had for much of the month. Summer is not here, but it is on the horizon.

It is not difficult to find the cold front as of 7 am CT on this map of dewpoint temperatures. (Weather Bell)

Wednesday

Temperatures across much of the metro area this morning are in the range of 65 to 70 degrees, which is rather warm for mid-March. It’s also fairly sticky outside. However, this will end later this morning, as a fairly strong front moves into the area. We’ll feel this both in the form of northwesterly winds, gusting up to 20 or 25 mph, as well as much drier air. As skies clear out later today, with the drier air, expect high temperatures in the vicinity of 80 degrees.

Unfortunately for rodeo-goers, those winds will not let up much this evening. In fact, they should peak during the overnight hours, perhaps gusting up to about 30 mph. So be prepared for that. Temperatures after the show will be in the 60s, before lows tonight ultimately drop into the mid- to upper 40s for much of the metro area away from the coast.

Thursday

This will be a sunny and pleasant day, with low humidity and highs of around 70 degrees. During the morning hours, at least, we should still see some modestly gusty winds. However by the afternoon these winds will likely slacken. Thursday night will be chilly again, with much of the region likely dropping into the upper 40s. Will this be the last time that parts of the Houston region get into the 40s this season? I think that’s quite possible.

Most of Houston will drop into the 40s on Thursday morning. (Weather Bell)

Friday

Expect a sunny, pleasant day with highs in the mid-70s. Winds will turn southerly, gusting at times up to 20 mph. Expect overnight lows to only reach about 60 degrees with the warmer, southerly flow.

Saturday

The first half of the weekend brings more sunshine, with highs around 80 degrees. Dewpoints should still be in the 50s, so it will not feel too humid outside. Yet. Lows on Saturday night only drop into the mid-60s.

Sunday, Monday, and next week

With a more humid flow, expect temperatures to reach into the lower- to mid-80s on Sunday with likely increasing cloudiness. The question then is to what extent a slug of drier air will slide down from the northeast into the region. This is known as a “backdoor” front because instead of blowing down from the northwest, it edges in from the northeast. It’s likely that this system will generate a decent chance of rain, perhaps on the order of 50 percent during the period of Sunday afternoon through Monday morning. Accumulations don’t look that high, probably on the order of tenths of an inch.

Temperatures on Monday and Tuesday will depend on the extent to which the backdoor opens, and the amount of cooler and drier air that moves in. Perhaps we’ll have a couple of days in the 70s, with lows in the upper 50s. Maybe it will be a tad warmer. Most of the rest of next week should see highs in the 80s, however, with a decent amount of humidity. So it goes in Houston as we get nearer the end of March: fewer fronts and more humidity.