WHAT'S IT GONNA BE BOY, YES OR NO...
Well, the tide (as expected) has turned allowing seasonally cold air to flood the beaches (cornfields) of the Midwest. This is actually a pretty good pop of cold air but the fact the sun is strong and the days have been getting longer the past three months will play in our favor. The same air mass that would have held us well below freezing in January will now lack the same capacity and we'll manage to stay about 20 degrees warmer. Even so, it will be plenty crisp with highs Wednesday and Thursday in the range of 38-44 in most of my area.
Here's the low temperatures we start the day with Wednesday.
Even worse are the wind chills which will range from the upper teens north to the mid 20s south. Nobody's happy about that!
Wind chills Wednesday morning.
Another noteworthy aspect of this air mass is its lack of moisture. Available water vapor over a large part of the central U.S. is at 0.10" of less. That's bone dry.
Water vapor values that low are 15-20 percent of what they typically would be.
Dew points in some areas Thursday morning are in the single digits. We won't have to worry about any significant precipitation for awhile with readings like that. Even so, I can't rule out a few flurries or snow showers later in the day Wednesday with steep lapse rates and cold air aloft squeezing out what precious little moisture there is.
Then, as quickly as it came, the cold air goes. Watch the change in the 500mb jet configuration that allows a major warm-up for Easter weekend.
This brings us to the future and if the EURO is right, is it ever bright. This is the 10 day temperature forecast off the operational Tuesday and no one in their right mind would turn this away. That's an amazing run for the first week of April.
In fact, it looks too good to be true and that raises a red flag. So, the big question is, what's it gonna be boy, yes or no? I think I can safely say the warmth is warranted through Tuesday, maybe even Wednesday. After that, there may be sharks in the water that cut it short towards the middle of next week. This is a situation where I will be very cautious handling this for a couple reasons.
One, everybody would be thrilled to see those 80 degree highs (the warmest in six months) later next week. Knowing that, the last thing I want to do is send the wrong message and have to drastically reverse course on a promise of 80 degree highs.
Secondly, and this is the key meteorological reason, the ensembles of the EURO are about 10-20 degrees cooler than the operational run above. Below you can see the ensembles and the difference between it and the operational run above.
The reason this happens is that the ensembles are composed of 51 individual members. Some do show the 80 degree warmth but others are significantly colder and are down in the 40s for a couple days. That indicates a big range within the 51 members. The purpose of the ensemble is to eliminate that spread by smoothing or averaging the various solutions. It tells me those 80s are not off the table but they are far from a sure thing and that it's "time to stop right now" after Tuesday or I could be praying for the end of time. Thank you Meat Loaf. As we get further out in time the spread should narrow and we can refine the forecast accordingly.
By the way, we have a model blend that incorporates a number of long range models into an outlook of its own. As you can see, its similar to the EURO ensemble and shows the cooling after Tuesday. I'm leaning this way as it's just very difficult to sustain the type of warmth the EURO depicts this early in the season. One little bubble of high pressure and NE winds and the party is over in a hurry. Not to say it can't happen but everything would have to line up just right. Here's hoping.
One thing I do see on the EURO ensembles is enough moisture by next Monday for some elevated CAPE numbers. CAPE stands for convective available potential energy. In other words, there we be instability and that would imply the potential for thunderstorms if we can get the right set-up and forcing. A little early for that but the potential is indicated.
Below you can also see the 51 members of the EURO showing total precipitation. There's nothing indicated for my area until Monday night and then there are a couple opportunities the following 9 days. The control indicates a 15 day rain total of 2.50 and the mean is at 1.40". Again, some members are higher and others lower but that's the middle ground.
Well, anyway these are the things that keep me up at night. All these little details are baked into my thinking. Hopefully, you can see the value of using ensembles when it comes to long range forecasting. It will be fun to see how this plays out in coming days. I really think we are in for some welcome and significant warmth Easter weekend through Wednesday of next week. After that, the results are still to be determined but I expect a healthy cool down by April 9th. Roll weather...TS