Matt Lanza

Continuing to watch next week’s rain

A quiet morning should transition into another quiet day for Houston, but rumblings remain on the horizon, though unfortunately clarity has not increased much more today.

TODAY

No big issues are anticipated for Friday, with highs in the low 80s and a mix of sun and clouds after any morning low overcast or fog dissipates.

SATURDAY

The first phase in the transition to a more active, unsettled weather pattern unfolds tomorrow. Onshore winds off the Gulf will help pool atmospheric moisture over us. Dewpoints should jump into the upper 60s Saturday, with high temperatures in the upper 70s. It will feel a bit more humid. While a shower or very isolated storm can’t be ruled out, most of us should see quiet weather.

SUNDAY THROUGH MIDWEEK

Not much change today in the forecast for this period. We continue to see an upper level storm system approach us from the west, tapping into rich Gulf moisture (available moisture will be near record levels in this period). These sorts of events are difficult to communicate effectively sometimes, so I’ll try and answer some questions.

When will the rain fall? There will likely be a few periods of thunderstorms or showers between Sunday afternoon and Wednesday. It will not rain the entire time though. Right now, the period from Sunday afternoon into Tuesday stands the best chance for storms of the next 6-7 though.

How much rain will we see? You’re going to see a lot of rainfall maps (including the official NWS one below) over the next few days.

National Weather Service rainfall forecast through next Thursday (as of Friday AM). (Weather Bell)
National Weather Service rainfall forecast through next Thursday (as of Friday AM). (Weather Bell)

Some maps may show big numbers (particularly anyone showing the GFS model, which has been handing out double digit rain amounts southwest of Houston). It’s impossible for sure to say how much rain we see in this sort of situation, but we can use the weather models as guides. So if the models are painting regularly bullseyes of 10″+ of rain, we know potential is there for some significant totals. That said, the places actually seeing that much rain are likely to be isolated and small (10″ rain totals would be the exception rather than the rule). But I can’t tell you today whether it’s Baytown, Bay City, or Brenham that sees these big numbers. As of now, the trends imply that the best risk for this is south and west of Houston and probably south and west of the suburbs. That said, we won’t have high confidence as to where those places will be until about 24-36 hours before the storms hit. Eric’s call yesterday of an average of 2-5″ is about as good as we can do right now, knowing that some places will see quite a bit more. We’ll pin down exactly who that will be Sunday or next week.

Will there be severe weather? As of right now, the Storm Prediction Center has areas west of Houston in a “slight” risk for Sunday, but hasn’t highlighted anyone for Monday and Tuesday as of yet.

Severe weather outlook for Sunday (NOAA, Storm Prediction Center)
Severe weather outlook for Sunday (NOAA, Storm Prediction Center)

From experience, these sorts of setups have four primary severe weather concerns. In order: Flooding, wind, lightning, hail. I think the focus should be on the rain and potential for localized flooding, but we will be watching for damaging winds in stronger storms, definitely a lot of lightning, and even some risk for a few hailers too. You always should have your guard up in spring, but I think the main headline in all this will ultimately be heavy rain and flooding potential.

When does this clear? I don’t think rain chances will leave the forecast much at all next week, but after Tuesday, weather models continue to imply quieter weather (so lower significant rain chances).

Advice: Keep tuned it over the weekend for updates on next week. Follow Eric or myself on Twitter too. We’ll hopefully be able to pin a few more details down by Sunday and certainly Monday morning. If you have plans early next week, don’t cancel, but run through some alternatives, and make sure to stay tuned to the forecast.

MS 150 RIDERS

Unfortunately no change in the MS150 forecast. Saturday should be good, with a solid tailwind. But Sunday will turn progressively stormy between La Grange and Austin, especially in the afternoon. Heavy rain is a good bet, and lightning is very possible. Officials are slated to update the status of the event by 10 A.M. this morning.

Stunning Weather Winding Down

Our lengthy stretch of stellar, stunning, <insert your favorite adjective here> weather will gradually wind down over the next couple days, as we return to more humid weather and some rain chances next week.

TODAY

We’re starting off today pleasant again. Temperatures are generally in the mid 50s region-wide, though a few spots in the city are around 60°, particularly south and east of Downtown. High clouds will continue to stream across the region today.

040816_Sat
Satellite image this morning shows high clouds streaming across Texas. (College of DuPage)

As long as clouds aren’t too thick, we should manage around 80° or lower 80s again. Otherwise, we will be a couple degrees cooler. No issues though, with continued low humidity.

WEEKEND

After another relatively pleasant morning, Saturday should be similar to Friday, with sun and high clouds. Temperatures will again be contingent on how thick the cloud cover is, but we’ll likely be a few degrees cooler than Friday regardless; say upper 70s for now. I can’t fully rule out a shower tomorrow afternoon, but the odds would be very low. The best chance would be north and west of town.

Saturday afternoon dewpoints in the 50s means another day of comfortable, low humidity. (Weather Bell)
Saturday afternoon dewpoints in the 50s means another day of comfortable, low humidity. (Weather Bell)

On Sunday, onshore flow will have been established pretty persistently. This will bring warm, moist air off the Gulf, and the humidity will edge upwards. There will likely be some clouds around, mixed with sun. A chance of showers exists, but it is a low chance. Temperatures will press back to near 80 degrees.

NEXT WEEK

Monday will carry a low chance of showers, along with clouds and sun and temperatures again around 80°. If you’re attending the Astros home opener, I’d probably lean 60/40 on the roof being closed right now. Hopefully we get it open for a few games next week though.

Forecast confidence plunges Tuesday, Wednesday, and Thursday. I expect showers and storms to become more numerous, but the key to unlocking rain chances is trying to time upper level storm systems that we just can’t do 4+ days out (I’ve seen the heaviest rain shift 12 hours and 100 miles around Texas between weather model runs the last couple days). But I think there’s a good chance some heavy rain will return to the forecast for parts of the area midweek next week (though not every single day). Behind that, we should briefly return to nice spring weather and low humidity for late week. These “nice” windows of weather are going to get shorter and shorter as our typical summer pattern develops. Enjoy it while you still can.

MS-150

As Eric told you yesterday, mild temperatures are expected right now. No changes there or on the idea of a tail wind being dominant. However, the bigger issue may be rain. Some models indicate thunderstorms next Sunday between Houston and Austin. This is very much a “let’s wait and see” forecast right now. All options are still on the table, so stay tuned!

Final Four-cast in a word: Swish

The humidity is just about outta here, after a summer-like Thursday. After tonight, we’re setting up for 3-4 straight chamber of commerce days for early April. If you have plans to take part in one of the many big events going on around the region this weekend, you’re in luck.

TODAY

The only blemish in the forecast will be today. Radar shows the bulk of the area is quiet right now. But showers and embedded storms are scattered about much of Texas this morning.

Widely scattered showers and a few storms from Hill Country to Houston this morning. (Intellicast)
Widely scattered showers and a few storms from Hill Country to Houston this morning. (Intellicast)

Today should be one of those days where it could rain or briefly pour at virtually any time, though the bulk of the day may end up dry. Any storms today could drop some small hail, and you’ll likely notice an uptick in winds later this afternoon and evening. Severe weather is unlikely however.

Temperatures today will be tricky. We are already in the 50s to low 60s this morning in spots north of I-10 and mid 60s south of I-10. With clouds and showers and a slowly exiting cold front, I don’t expect to see a big jump this afternoon, so highs around 70 at best (upper 60s more likely) should be expected.

The rain should clear by later this afternoon or evening, and the humidity will press downward. Low temps tonight should bottom out in the low 50s, with a few upper 40s possible outside the Beltway. Gusty winds will make it feel a few degrees cooler, so a jacket will likely be in order tonight and Saturday morning.

Saturday AM forecast lows (Weather Bell)
Saturday AM forecast lows (Weather Bell)

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Almost finished with the rain risks

Eric touched on the flooding issues for our friends to the east in the Sabine River basin yesterday. Check that post and visit the NWS Lake Charles website for the latest. Locally, here are the latest flood gauge levels and forecasts around Houston.

We got away with a mostly quiet Thursday. Judging by the weather model trends, today will hopefully have a similar outcome.

TODAY

The upper low over Mexico the last couple days is projected to end up over South Central Texas this afternoon. That means we are slowly drawing closer to the end of this frustrating weather pattern.

Upper level low moves over South Texas this afternoon and evening. (Weather Bell)
Upper level low moves over South Texas this afternoon and evening. (Weather Bell)

 

There will still be a few spokes of energy pivoting around the upper low today, so we will still carry a chance of showers or a thunderstorm throughout the day (showers this morning are popping up west of Houston already). But the heaviest storms will be in Eastern Louisiana and Mississippi. There will also likely be areas of showers/storms on the periphery of the upper low in interior Texas (basically north, west, and south of us). That puts us in between. So I’ll put an optimistic spin on things and say, “Yes, a chance of showers or storms through the day today, but I will lean toward the bulk of the day not being too bad.” We’ll see if that works out.

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