Dick Faurot's Weather Blog: Warmer Days Ahead, Also a Few Showers

Friday, March 6th 2015, 8:15 pm
By: News On 6

Nice warm-up today.

Notice the max/min temperature map for the state, courtesy of the OK Mesonet. The afternoon temperatures are generally 10-15 degrees or so warmer than yesterday - and the weekend will be even warmer yet.

Before getting around to those details, thought a brief explanation of the cause of these temperature swings would be in order.

As mentioned yesterday, the last 10 days or so have been the 2nd coldest on record for those dates, and the last time we were that cold we wound up with the coldest March on record.

The reason for the recent cold snap and the reason why more of it is not expected this time around lie in the meanderings of the upper level jet stream.

Notice the map from the morning of Feb 28, which shows the winds at around the 40,000' level or approximating the jet stream. I have put some arrows on the map to emphasize the direction of the upper level flow - the colors represent where the winds are strongest at that level.

At that time, there was a strong northerly component coming across Western Canada deep into the US before curving off to the east. Flow of that nature typically is favorable for arctic air to penetrate much further south than it normally would and that has certainly been the case; this is what we refer to as a strongly amplified flow.

However, that pattern will change and that is what is now occurring.

Notice the second map, valid for this coming Thursday morning for the same level - arrows and colors are the same as before. Notice that the flow aloft is now much more zonal, or west to east, instead of the north to south, amplified flow from earlier. That pattern keeps the coldest air bottled up well to the north and we warm up.

Notice there is also a split flow off the west coast with a southerly component to the jet stream diving well south of us. That type of flow is representative of disturbances aloft that can occasionally provide some showers or storms depending on just how far south it is located.

For this weekend, one of those systems will be passing by to the south of us and will bring lots more cloud cover by Sunday and perhaps a few showers, mainly for the far southern counties, for late in the day and into Sunday night or early Monday.

Other than that, it is basically a dry forecast.

The primary forecast challenge is temperatures on any given day. Sunny skies and SW surface winds should get us well into the 60s Saturday after starting the day at or below freezing.

More cloud cover and less sunshine on Sunday will slow down the daytime warm-up with highs near 60 but we should start off closer to 40 that morning.

Going into the following week, a more E to SE surface wind component will also provide a bit of a limit to how warm we will go, but with lots of sunshine, we will still be much warmer than normal each day.

As you can see on our forecast page, our chances of any precipitation will be in the slim to none category through that forecast cycle as well.

Not only that, but the 8-14 day guidance also suggests normal to above normal temperatures and a relatively quiet weather pattern going through the middle of March as you can see on the last two maps.

So, stay tuned and check back for updates.

Dick Faurot