4 things to know about the weather for the first week of October

We're moving out of a very dry (and hot until this past week) September into October, which typically means fall begins in earnest. Average highs drop from 80° to 70° over the course of the month, record highs drop into the 80s, and morning lows in the 40s become more likely, especially the latter half of October. With a taste of dry air and fall weather this past week, what does the first week of October bring? Here are 4 things you need to know:

1. A gorgeous weekend is ahead! Highs will generally be near 80° or so with lows near 60° in the city and back into the 50s outside the loop. Clouds will stick around, especially during the daylight hours this afternoon and tomorrow, but more sun will be expected on "Sun"-day. Humidity levels remain comfortable as dewpoints stay in the 50s. Open the windows in the evenings and pop that sunroof! There are also plenty of outdoor activities that you can take advantage of.

2. The cool temperatures of the past few days will give way to warmer air next week. Fortunately, we're not talking about a string of 90s, but mid to upper 80s for the middle of next week will be warm enough as humidity creeps back up just a a bit as well. Dry weather continues.

High temperatures for Wednesday, October 5, according to the American GFS model. (WxBell)

3. A cold front will move through mid-to-late next week (likely Thursday), which will bring our next chance of rain and possibly a few thunderstorms. It looks to be a quick hitter though, so no prolonged rainfall is expected to help with our recent deficit. Behind it, slightly cooler and drier air again works its way into the Mid-South.

The surface forecast for next Thursday morning from the NWS shows a cold front moving toward the Mid-South, which will provide our next chance of rain. (NOAA/NWS/WPC)

4. And as a bonus, outside the Mid-South, eyes are on Major Hurricane Matthew which is churning it's way through the southern Caribbean Sea. It's moving west off the coast of South America (yes, that is pretty far south for a Caribbean storm), but will make a hard right turn and head north towards Jamaica and Cuba early next week then into the Bahamas by the middle of next week.

Latest forecast track for Hurricane Matthew from the National Hurricane Center

Significant impacts are possible in all of those locations as no noticeable weakening is expected until it interacts with the island of Cuba. It remains to be seen how much effect Cuba has on it. After the Bahamas, the east coast of the U.S. needs to keep a close eye on Matthew's track. Some models take it towards the Outer Banks of North Carolina, then turn it east, but it is still a long ways out from that. More detail can be found on the MWN Tropical Page.

Based on the output of many meteorological computer models, the potential paths of Matthew are shown above. These "spaghetti plots" change routinely and are not all possible options.

Enjoy the fall weekend!

Erik Proseus
MWN Meteorologist

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Another hot weekend, then FALL arrives!

Tired of the heat? Yeah, me too.  If you can hold out another couple days, I have great news!

Despite fall officially starting on Thursday morning (you didn't try balancing an egg on end at 9:21am did you?), summer weather continues for a few more days. Thursday's high of 95° came within a degree of the record and we'll threaten the record high of 96° again today, as well as the 95° records both Saturday and Sunday. High pressure ridging aloft more typical of mid-summer is to blame. I'm over it...

Mid-afternoon temperatures on Friday are well above normal for many areas east of the Rockies under the dominance of high pressure aloft. (Wright-Weather.com)

But by Monday, we'll start to see the major pattern shift as a massive upper-level trough over the western U.S. this weekend, upstream from our large ridge of high pressure, begins shifting east. It'll flatten out some as the main low pressure area goes by well to our north. However, it will be enough to push a cold front slowly south through the region Monday and Tuesday, resulting in a chance of showers and a "seepage" of more autumn-like air into the Mid-South.

The European model shows the upper level pattern (500 mb/18,000 feet) on Saturday morning dominated by a large trough of low pressure in the west and huge ridge of strong high pressure in the east, centered over the Mid-South. Weather systems moving across the U.S. roughly follow the black line. (PivotalWeather.com)

According to the European model (and GFS, not shown), as the low in the image above lifts northeast into southeast Canada by Tuesday morning, the eastern U.S. ridge flattens, allowing cooler air to drop south. Meanwhile, a ridge builds back to the west. As it shifts east later next week, temperatures will warm back up, but likely not to the levels we see this weekend. (PivotalWeather.com)

The rain chances with this front, despite there being a fairly large temperature gradient across it, will be fairly low thanks to most of the moisture remaining to our west in the southern plains and the dynamics associated with low pressure heading well to our north. Severe weather is not on the docket. The best rain chances will be Monday into Monday evening (and even then only about 30%). We could use some rain, so the little we might get will likely just set the stage for continued dryness next week as cooler high pressure builds in.

The Short-Range Ensemble Forecast (SREF) model data shows probabilities, including this map of probabilities of 0.10" of rain through Monday afternoon. The best rain chances over the next few days occur to our west. The SREF indicates only about a 30% chance we'll see 0.10" of rain with Monday's front. (WeatherBell)

Behind the front, we'll see temperatures more akin to "normal" for late September - cool mornings in the 50s (especially outside the city) and highs in the upper 70s to near 80. Mid-range model data has some disagreement in the strength of the cool air though. If the American GFS model wins out, outlying areas COULD see some lows in the upper 40s by mid-week. For now, that seem a bit of a stretch.

The GFS Ensemble Forecast System (GEFS) consists of multiple iterations of the American GFS model. Above, the average high and low temperatures from the GEFS members show a very welcome shift from summerlike temperatures to fall early next week. Note that its European counterpart (not shown) is similar but not as cool especially for morning lows, next week. (WeatherBell)

In the long-term, it appears this current streak of 90s may be our last for this year, but above normal temperatures are expected to return by early October.  The good news is that "above normal" for that time of year puts us in the 80s and humidity values are expected to remain tolerable. Here's to the arrival of fall next week!

From NOAA's Climate Prediction Center, there is a high probability that temperatures return to "above average" for the first week in October for most of the country east of the Rockies. (NOAA/CPC)

Erik Proseus
MWN Meteorologist

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Follow MWN on Facebook, Twitter, and Google+
Visit MemphisWeather.net on the web or m.memphisweather.net on your mobile phone.
Download our iPhone or Android apps, featuring StormWatch+ severe weather alerts!

MWN is a NOAA Weather Ready Nation Ambassador

Meteorologist Erik Proseus is an NWA Digital Seal Holder