Flip-Flopping Forecast

We have gone from a forecast of very little snow last night, to predictions of two to four inches this morning, and back to last night's forecast this afternoon. Not uncommon for an early season storm, as they are typically much harder to forecast. Still, this doesn't fill me with a lot of confidence for the upcoming winter season forecasts.

Interesting Saturday

Tomorrow's weather could be quite interesting, and could upset a lot of people. The current forecast calls for rain changing to snow in the afternoon, with minor (if any) accumulation. But one of the computer models has been very consistent in bringing the precipitation a little more to the north, as well as producing some more impressive snowfall accumulations. If this model verifies, there could be isolated reports of three to five inches of snow. That isn't the official forecast right now, but the afternoon forecaster at La Crosse noted that the forecast has a high bust potential, meaning anything could happen. The forecasts this week haven't been exactly spot-on, so I don't think snow accumulations tomorrow are out of the question. We'll see.

Brisk

This is probably the most appropriate word to describe the weather today. The cold front blasted through the region this morning after a night of steady rainfall. It is currently cloudy, windy, and cold, with a temperature of about 38 degrees. It is dry now, but there has been occasional light precipitation this afternoon. I did see a few flakes of snow, but not many (just enough to officially make it the first snow of the season). Overall it seems like there was less snow than anticipated with this system, but I suspect there were a few more flakes up on the ridgetops (we miss all the good/more-exciting weather here in the valley). Should be some scattered snow showers about the region until Friday. Otherwise, brisk.

Snow Soon

It now appears highly likely that the first snowflakes of the season will fall sometime on Wednesday. A very unusual weather scenario for mid-October is beginning to take shape across the continent. A strong Arctic cold front is pushing south out of Canada, and some unseasonably cold air is behind it. As this front continues southward, it will help create a very large and intense low pressure system that will move northeast across the area tomorrow.

The first effects of this storm will begin tonight, as rain is expected to develop during the evening and continue overnight. As the system strengthens, winds will increase to 20-30 miles per hour tomorrow, with gusts up to 40 mph. The cold front is expected to be approaching the area by morning, and should move through during the day. Temperatures will begin to fall sharply as the front passes, with readings expected to drop from the 40s down into the 30s by late in the day. This will effectively change any precipitation to snow. A mix of rain and snow is forecast for much of the day Wednesday, with a changeover to all snow by Wednesday night. Exactly how much snow falls will be highly dependent on the amount of moisture still available when the changeover occurs. If there is enough moisture around yet, the snow could fall pretty fast. If moisture is limited, it may be no more than flurries. Nonetheless, the warm ground should prevent any accumulations. Isolated rain or snow showers could continue through Thursday night, with high temperatures struggling to reach the 40s.

Overall this will be a very sudden transition to more November-like conditions, and will be especially shocking after the mild conditions of the weekend. It could be much worse though--up to 8 inches of snow is expected in the arrowhead region of Minnesota.

Major Changes Ahead

A major change in the weather is coming. A strong cold front is forecast to move south across the northern United States around mid-week, with unseasonably cold Arctic air moving in behind it. This will likely keep high temperatures in the 40s on Thursday and possibly Friday, as low temperatures tumble into the 20s. The first snowflakes of the season will also be possible late Wednesday. It will be very interesting to see how this situation plays out, as there are indications in the computer models that this could be a record-breaking event. A few of the models are even showing solutions that are nearly impossible to achieve for a storm system this time of year (i.e. anomalously cold temperatures and low pressures). This could be a very November-like storm, and is definitely something to keep an eye on.

Overnight Hail

There were several reports of large hail around the region late last night and early this morning, but overall it wasn't nearly the significant severe outbreak that had been predicted. The atmosphere remained capped most of the night, with most of the thunderstorms not developing until the early morning hours. This overhyped outbreak really served as the perfect end to the severe weather season (severe storms are still possible later in October and November, but become increasingly unlikely), as it followed the trend established by previous blown forecasts. Hard to say why this has happened, but hopefully next year's forecasts will be much better. If anything, this proves how little we know about the dynamics of the atmosphere. In the end, Mother Nature will basically do whatever she wants, regardless of what the forecasts say.

Here We Go Again......

Update--6:33 p.m.: Three hours into a tornado watch and not even a hint of a thunderstorm developing. The atmosphere remained capped, which is the problem that has plagued almost every other potential severe weather outbreak this season. The cap could still break, and if it does, storms will rapidly develop and become severe. Another watch-and-wait situation.

Morning entry: There is a moderate risk for severe thunderstorms today. An area of low pressure is forecast to move along a warm front that is currently situated across the region, and this should be the focus for storms later this afternoon. Currently, storms are expected to develop around mid-afternoon, probably across southeastern Minnesota and northeastern Iowa, and then move eastward into Wisconsin. Wind shear is expected to be quite significant, so supercell thunderstorms appear likely, enhancing the threat for tornadoes. Large hail and strong winds are also possible. Overall, the best threat time appears to be between 3 and 10 p.m.

However....... I have lost count of the number of times I have heard this same tune this year. It seems that every time the conditions seem to have come together for a major outbreak, everything fizzles out. Hard to say if the same thing will happen today. The temperature isn't rising very fast this morning thanks to some clouds, which could limit the instability later this afternoon. It is hard to ignore the strong ingredients in place that would support some dangerous storms, and it seems as if these ingredients will all come together later today.

Indian Summer

Indian Summer has arrived right on schedule. Temperatures climbed into the middle 70s yesterday and are poised to reach the middle 80s today. This will probably be a few degrees short of the record highs in most locations, but with dewpoint temperatures increasing into the 60s it will definitely feel much more like July or August than early October. However, with the warmer temperatures comes a threat for thunderstorms, some of which could be severe. A cold front will drop south towards the region this afternoon, and storms should develop ahead of it. The best chances for severe thunderstorms today will be between 3 and 9 p.m., with the biggest threats being large hail and gusty winds. There may be a better chance for severe storms on Tuesday. The front is expected to get hung up across the area tonight, and again sink southward tomorrow. If the conditions come together just right, supercell thunderstorms will be possible tomorrow afternoon and evening, creating an enhanced threat for severe weather, including isolated tornadoes. October is certainly not the most favorable month for severe weather in Wisconsin, but it has been known to happen. After the front finally moves south, temperatures will cool slightly, but are expected to remain above normal through the weekend.