Joe’s Weather Forecast: Challenging forecast week ahead (MON-9/24)

Happy Monday. After just about as good of a weekend of weather that we can possibly have in KC…the work week has started differently. Lots of gray skies are in place this morning and today’s temperatures will be challenging because of the timing of the clouds breaking. Faster=warmer…slower=cooler. So this is just one of the forecast challenges this week…and there are  many including where a front sets up later in the week and weekend and how the temperatures will be affected by not only the front’s location but also the rain chances…because at least when looking at the surface weather maps…it’s tough to see how we don’t get at least some rain from the set-up later in the week or weekend.



Forecast:

Today: A gray morning then variable afternoon clouds. 60s this morning will jump into the 70s when the sun comes out in later today. We could get close to 80° with enough sunshine.

Tonight: Fair skies and mild with lows by daybreak in the 60s

Tuesday: Changeable. A cold front will come into the area around lunch or so. Temperatures will vary greatly from the coolish 60° weather in NW MO and NE KS to near 80° farther south. Once the front passes in the afternoon…temperatures may drop off some 10-20° in about a 1-2 hour timeframe too with the wind shift. So highs may be near 75 on the northside before tanking…near 80° on the southside before dropping and there may be some showers happening as well. Not a lot of rain and more than likely under 1/4″ rain for many.

Wednesday: Nice and cool with morning lows in the 40s and highs in the 60s.



Discussion:

Fall is here and while the weather in KC is typically wonderful for days on end…the weather from the northern US and into Canada gradually changes. One of the main reason this happens in the shrinking daylight that is occurring at a faster rate the farther north you go. For example in Calgary, Canada they’re losing about 4 minutes of daylight per day but in Yellowknife, in the NW Territories about a 2 hour flight from Calgary…6 minutes of daylight are being lost per day and in Barrow, Alaska…some 9-10 minutes are being lost per day!

This dramatic lose of daylight the farther north you go allows temperatures up there to continue to get colder and colder as the days go by. Farther south the lose of daylight is slower…especially in the far southern US. This helps create larger temperatures contrasts, not only at the surface but aloft as well. This strengthens the jet stream as the season progresses. A faster jet stream creates more weather changes and these changes typically move through the Plains in various forms. Stronger cold fronts…bigger surface storms…stronger areas of high pressure with chillier air masses building into the region…and so it goes as we head towards winter.

Cold fronts also surge farther southwards…and so we try this delicate balance between getting returning moisture from the south and well-timed cold fronts from the north. As the fronts go farther and farther south…it’s tougher to get the returning moisture farther north.

This is a common occurrence in March and April as well. When things time out correctly you can get strong thunderstorms and even severe weather. A secondary severe weather season sets up that typically lingers into later October and early November.

So fall is a time of changes and there are typically bigger forecast challenges with these changes and also the potential of changing forecasts. This week is sort of like this.

It’s not so much the weather through Thursday…that seems pretty straight forward…warm today and into lunch tomorrow…then cooler Wednesday>Thursday. We’ll probably tank into the 40s for lows WED>THU AM. Also of note for the gardeners towards far northern MO is the potential of some frost IF we dip low enough. Any temperature near 40° creates that potential…so it’s something worth monitoring for areas well north of KC I think.

Then there is Friday into the weekend and this is where things become challenging. Another cold front is forecast to move towards the area. Both our medium range models have this front…and it will move south of KC later Friday. Behind the front a pretty strong area of higher pressure will be up towards IA…then means that cooler air will be pressing southwards while the warmer air to the south puts up resistance. Usually IF this was winter…it would almost be a no-brainer…cold air almost always wins…during the transition season though it gets tougher for the colder air to press south as far as what typically happens in the winter.

So we’re left with a stationary front of sorts somewhere in MO…and where it sets up means areas farther north are int eh 50s while farther south are in the 80s. That’s the conundrum for the region later in the week and into the weekend. Plus the front could waver south to north…and that complicates things tremendously for forecasting temperatures..

Here are two model portrayals of the potential for Saturday…note how just miles separates the chilly stuff (40s) from the AC weather (80s)

First the GFS model for highs later Saturday:

The Metro is about cut in half…

Now the EURO model…

Note how KC is in the warmer air with the colder air more confined towards the IA border later Saturday.

That means there will be a warm/stationary front somewhere in the region and north of the front is typically where we find more clouds and showery type weather. So there are implications where the front eventually sets up.

Which model is right? Where exactly is the front going to set-up. I can’t really say with accuracy from 5 days out. we should at least dip into the cool air on Friday…beyond that…we’ll see. At some point that cooler air will surge southwards…perhaps later in the weekend or early next week.

People of Cowtown with our feature photo today.

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