The crazy evolution of a thunderstorm outlook

There is a moderate risk for severe thunderstorms today from the Dakotas to northern Minnesota. How we got to this point is rather circuitous. Let’s take a look at the past 24 hours of SPC outlooks. I don’t think I’ve seen one of these things change so much pre-storm in a very long time. Here is what we started with yesterday morning:

A slight risk, covering most of Minnesota and a lot of the central Dakotas. Furthermore, they had the best threat for severe storms around the North Dakota/South Dakota and Minnesota tri-state.

After a shift change and perhaps the usage of a hallucinogen, Sunday afternoon’s update gave us this moderate risk, with a center about 150 miles to the east-southeast.

And now, thunderstorms were going to be significantly stronger.

Whoa! 45% and hatched, when we only had 30% earlier. And there isn’t much of an overlap, either.

So obviously, something changed, the onus was now on the Twin Cities, St. Cloud and Rochester to be prepared for — Oh, wait. This was the outlook from the overnight.

So we’re back into North Dakota and northern Minnesota, which, initially, wasn’t even in a slight risk for yesterday’s updates. This time, the center shifted about 175 miles to the northwest. Was the threat for significant weather still high? Why yes, yes it was.

Where are we at now with the morning update, you may ask. Pretty similar to the overnight outlook, actually, but greatly elongated.

The only thing is that the threat for strong winds seems to be sneaking back deeper into Minnesota, practically to Wisconsin.

http://www.spc.noaa.gov/products/outlook/day1probotlk_1300_wind.gif?1405956293553

Actually, that’s a pretty significant change, increasing the coverage of significant severe weather like that. There is also a 5% tornado threat now in North Dakota and northwest Minnesota. that really grew over the course of the past two updates.

Expect the afternoon update to push the focus into Iowa.

Boise, Idaho to Phoenix, Arizona

I’m surprised to find out that our journey from Idaho to Phoenix will only take two days. It seems longer than that. The two towns are 908 miles apart, and in fact, the primary connector is a US highway, so speeds will be limited to 60.5mph, and our first day will only net us 483 miles. This is going to be a fairly barren drive, but what will the weather hold?

DAY ONE (Monday)
Boise
Boy, there isn’t much going on between Boise and Phoenix, is there? Beautiful drive, but make sure you hit the restroom whenever you have a chance. As for significant weather, it should remain confined to the first few hours of the trip. There could be a splash of rain or an isolated thunderstorms around the Sun Valley. I think our best bet, however, will be for showers or storms between Twin Falls, Idaho and Wells, Nevada. Rain is highly unlikely south of Wells, but will be possible from Boise to Twin Falls as well. I wish there was a better place for us to stop, but we’re just going to call it a day in, oh, I don’t know Seaman Range HP? What he heck is an HP? Maybe the Highest point? Just plan on camping off by the side of Nevada 318 in southern Nevada.

DAY TWO (Tuesday)
It’s going to be CRAZY hot driving from southern Nevada to Phoenix. Like, don’t slow down, because your tires will melt to the road if we slow down hot. Sunny skies, a quick trip through Vegas and maybe a cactus at the side of the road, but nothing in terms of climate for our drive on Tuesday. Find some air conditioning though, seriously.
phoenix

Phoenix, Arizona

I almost called it Phoenix, Missouri, which would have been wrong. So much Missouri on the brain.

At 851AM, PT, Phoenix was reporting a temperature of 91 degrees with mostly cloudy skies. Before 9am and with clouds, all with temperatures already in the 90s, today will be a very warm one, and little change is in order going forward.
Thermal low pressure looks to be the most significant feature with monsoonal thunderstorms remaining in the higher terrain. Extra sun will mean even warmer temperatures as the weekend continues.
Tomorrow – Sunny, High 106, Low 81
Tuesday – Even hotter. High 109, Low 82

TWC: Tomorrow – Mostly Sunny High 107, Low 83
Tuesday – Partly Cloudy High 112, Low 84

AW: Tomorrow – Very warm with intervals of clouds and sunshine High 106, Low 84
Tuesday – Partly sunny and hot High 110, Low 85

NWS: Tomorrow – Sunny High 106, Low 82
Tuesday – Partly Sunny High 109, Low 84

WB: Tomorrow – Mostly sunny. HIgh 107, Low 83
Tuesday – Partly cloudy. High 108, Low 85

WN: Tomorrow – Mostly Sunny High 106, Low 82
Tuesday – Partly Cloudy High 109, Low 84

I can’t even imagine that. We have heat advisories here in the Twin Cities and it’s 20 degrees warmer in Phoenix.
Phoenix

Rain steers clear of the Show Me State

Two forecasts in a row in Missouri, both with a shot of rain according to some outlets, but two dry verifications. The anticipation for rain was more universal in Springfield, but it was just as dry there as it was in Columbia. WeatherNation was the only provider that had a dry forecast, but their temperature forecast was subpar. The differentiator was a combination of two things. Those who had a warm forecast on Friday afternoon and those who hedged cooler on Saturday morning ended up earning the top spots. The Weather Channel edged out Victoria WEather and the Weather Service to earn the victory.
Actuals: Friday – High 78, Low 60
Saturday – High 82, Low 57

Grade: B

A sure sign of a cool summer

This is the current hazard map for the Twin Cities NWS office.
Heatwatch

Temperatures are going to warm up for the beginning of next week, and dew points will climb into the 60s, leading to heat indices around 100, leading to an excessive heat watch. Certainly, excessive heat is in the eye of the beholder, much like freeze watches or wind chill advisories. They aren’t going to be issuing these advisories or watches in St. Louis or Dallas, and they don’t continue to issue them if the warning area should have acclimated to a particular temperature by that point in the season. Like, the 3rd day below freezing in a row, the 3rd stretch of 90s in a season, whatever.

So anyways, what I’m trying to say is that these heat indices reflect the fact that Minneapolis is just not used to the 90s, and these warm temperatures this week will be a bizarre aberration –
screwy temp trends

Whoa, wait. Nope! Temperatures in the Upper Midwest will be very close to normal for this time of year. It will even be a bit cooler than normal just east of town. Admittedly, this is the 6-10 day graphic, and will be valid after the temperatures spike on Monday, but if temperatures cool off this dramatically, and we are getting our first advisory in late July, well, it’s been a cool summer in Minneapolis.

Masterful in Missouri

There was some model guidance that insisted upon a weak wave moving through the southern Plains before turning north into the Mid Mississippi Valley on Thursday, but right thinking forecasters recognized that that guidance was nonsense. Half of the forecasters in Columbia called for rain, and were wrong, while the other half, including Accuweather, who missed by a mere 2 degrees on their temperatures, properly foresaw high pressure squashing any convective development and preventing rain showers. As you may have figured, Accuweather’s solid performance and easily won the top spot.
Actuals: Thursday – High 79, Low 54
Friday – High 80, Low 59

Grade: A

Springfield, Missouri to Carson City, Nevada

Our trip is deceptively long on this occasion, covering 3 1/2 days and 1795 miles through the Rockies and Great Basin. Thanks to our use of the one interstate through much of the drive, we will have a pace of about 64.85mph, which will lead to a daily goal of 518.8 miles on Saturday through Monday, leaving a little chunk of Nevada for Tuesday. We have a lot of open country in our future, so we’d best be on our way.

DAY ONE (Saturday)
Springfieldmo
Many people don’t appreciate the featureless terrain of Kansas and Nebraska, but I for one am a big fan. The open road with the windows down and tunes blaring is one of the most pleasurable sensations in life. We will get to experience it in full on Saturday as warm temperatures and sunny skies will have infiltrated the Plains. The drive through western Missouri and Nebraska will be pretty easy, and will end in Overton, Nebraska, in the western part of the state

DAY TWO (Sunday)
There isn’t much going on synopticly for us to contend with from Overton west through Nebraska and in southern Wyoming. Monsoonal thunderstorms develop late in the afternoon, and shouldn’t cause too many problems until about 4pm. Even then, we may not see any storms, because they will be extremely isolated, and mostly will be south of I-80 anyways. Still west from Rawlins we might need the wipers. Our drive will be through in Point of Rocks, which is just east of Rock Springs.

DAY THREE (Monday)
High pressure over the Great Basin will do wonders for our travel route. Not only will we be driving through much of the route before daily convection kicks off, but the ridge will help stabilize the Great Basin and thunderstorms will be shunted north of Salt Lake City and northern Nevada. Good luck getting any radio stations in this part of the world though for that whole windows down tunes blaring thing. The day will end west of Winnemucca in the tiny oasis of Valmy.

DAY FOUR (Tuesday)
The end of the road will be pretty uneventful. No, really, until you get to Reno, there isn’t much going on in Nevada. Our arrival in Carson City will be to sunny skies and elevation cooled air.
Carson City

Springfield, Missouri

So many Springfields, so little time! Today we venture to Springfield, Missouri. Sorry if you were wondering about Springfield, IL, or Springfield, MA, or….

At 352pm CDT, the temperature at Springfield, MO was 74 degrees under fair skies. A slow-moving mid-level disturbance has been kicking up plenty of showers and thunderstorms over the Southern Plains as it treks slowly towards the east. This feature is at the southern tip of an overall upper-level trough that has brought record-setting cold to the central and eastern US, with highs only topping out in the 60s and low 70s in portions of KS/OK in the last couple days. Some rain showers are slowly moving in from the west as this feature moves through, and some could linger past midnight into the early morning hours of Friday. They shouldn’t stick around long as they continue eastward, but should lead to a cloudy start to the day Friday. Temps should creep towards the mid 70s once again as only brief bursts of sun get through during the afternoon hours. Luckily, this feature will continue eastward over the TN Valley on Saturday, making way to mostly sunny skies under high pressure for Saturday, a good start to the weekend!

Friday: A brief, early morning shower possible, dry for remainder of day but stays mostly cloudy. High 77, Low 58.
Saturday: Mostly sunny. High 82, Low 60.

TWC: Friday: Chance of morning showers, then partly cloudy. High 78, Low 58.
Saturday: Partly cloudy. High 83, Low 59.

AW: Friday: An A.M. shower, mostly cloudy. High 74, Low 58.
Saturday: Partly sunny and warmer. High 80, Low 60.

NWS: Friday: Slight chance of early morning rain shower, partly sunny during the day. High 76, Low 58.
Saturday: Partly sunny. High 81, Low 59.

WB: Friday: chance of a morning thunderstorm, then partially clearing. High 73, Low 59.
Saturday: Partly sunny. High 81, Low 61

WN: Friday: Partly cloudy. High 75, Low 61.
Saturday: Partly cloudy. High 81, Low 64.

It’s dry right now, but we see some of those rain showers moving in from the west. This shouldn’t affect many of our plans as we move into the weekend however.

SpringRAD

Columbia, Missouri

Taking a quick look at central Missouri and the home of hte University of Missouri with our forecast today.

At 154pm, CT, Columbia was reporting a temperature of 73 degrees with mostly cloudy skies. An upper level trouggh is departing, which means that a return to more seasonable warmth is on its way, beginning as soon as they can see some clearing skies.
As high pressure builds over the Great Lakes, the Gulf will open up on the western flank, with warm, humid air being drawn through Missouri. Lee troughing over the southern Rockies will be able to develop and begin approaching the Ozarks by tomorrow evening. Some guidance suggests available vorticity that really doesn’t make much sense given the upper level dynamics. Guidance that doe make sense insists a lee trough attempting to advance into the southern Plains will be squashed south towards the Gulf of Mexico, while Colummbia will see mostly clouy skies, but will otherwise stay dry, if a bit on the muggy side.
Tomorrow – Mostly sunny, increasing clouds, High 80, Low 57
Friday – Mostly cloudy, High 79, Low 60

TWC: Tomorrow – Partly Cloudy High 80, Low 57
Friday – Mostly Sunny High 78, Low 59

AW: Tomorrow – Partly sunny and pleasant High 79, Low 55
Friday – Partly sunny and nice High 80, Low 60

NWS: Tomorrow – A 20 percent chance of showers after 1pm. Partly sunny High 76, Low 56
Friday – Mostly sunny High 78, Low 59

WB: Tomorrow – Partly cloudy in the morning…then mostly cloudy with a 20 percent chance of showers in the afternoon. High 76, Low 56
Friday – Partly cloudy. High 78, Low 59

WN: Tomorrow – Partly Cloudy with Isolated Showers High 75, Low 55
Friday – Partly Cloudy Hgh 79, Low 59

A few outlets are buying into the shower and storm threat tomorrow evening, but I think if there is anything, it would be on Friday morning. More likely, there won’t be a drop. Satellite showws some good old fashioned cumulus clouds.
Columbia

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