Fall is my favorite time of the year, especially when it comes to visiting parks and taking in the fall colors. Due to our very warm September, the leaves have been slow to turn this season. With the cool weather that has finally settled in over the past five days, leaves are beginning to change rapidly.
To the left is the latest fall color map from the Minnesota DNR
, showing many places across northern Minnesota approaching peak color. Colors are still slow to change around the Twin Cities, but I'm starting to see a little more yellow and orange around the metro, including in my back yard.
The weather looks good for much of the next 10 days if you want to take a trip up north or just get out and enjoy fall around the Twin Cities. We'll see slightly warmer temperatures into the upper 60s for the next two days, then our only chance of rain comes Wednesday night into early Thursday morning where MSP could see .25"-.5"
Otherwise dry conditions are expected this weekend into early next week, with a BIG warmup on the way! Highs back into the 70s appear likely this weekend, with southern Minnesota approaching 80° or even warmer on Sunday!
Record Rainfall Across South Carolina
Check out the incredible water vapor loop across the southeastern U.S. from October 1st - today. As you can see below, the combination of a slow moving upper level low across Georgia/Florida and tropical moisture partially related to Hurricane Joaquin, created an atmospheric river which remained nearly stationary across South Carolina this weekend.
This atmospheric river helped to produce record rainfall across many locations in South Carolina. Here is the total rainfall map through this morning across central South Carolina. You can see record amounts of 17"-26" fell from just north of Charleston to near Columbia.
Meteorology speaking, this was an incredible and rare event, that will likely be studied for some time. On a positive note, the weather models - specifically the ECMWF did a very nice job of forecasting these extreme amounts several days in advance. Even the GFS, which struggled with Hurricane Joaquin, did much better in forecasting this event.
Thoughts and prayers are with those affected by this catastrophic flooding.
October has arrived with autumn in full swing across the Upper Midwest, including here in Minnesota. We're off to a cool start to the month in the Twin Cities, but are still only running a few degrees below average, which will continue through the weekend. If it feels even cooler than that, that's largely in part to coming off of our 4th warmest September since records began, and warmest since 1931.
To the left is a look at what I expect for temperature departures from average for the entire month of October. The warmth will continue across the west, with slightly below average temperatures possible across the southeast.
Twin Cities Forecast
I expect near to slightly above average temperatures for October. Even though we will start cool, temperatures will likely rise back above average for the second week and possibly continue into the 3rd week of October, before cooling down again to end the month. Keep in mind that average temperatures decrease rapidly for MSP in the month of October. On October 1st the average high/low is 65°/45°, but these decrease to 51°/34° on October 31st.
Monthly precipitation forecasts are difficult, especially in transition months like October. High pressure is in control across the Midwest to start the month, keeping the Mississippi River valley dry. I expect this pattern to keep this area, including the Twin Cities drier than average for October.
The big story, especially if you live along the east coast, has been the potential track of Hurricane Joaquin. Joaquin is an extremely dangerous category 4 hurricane currently battering the eastern Bahamas with sustained winds of 130 mph and a central pressure of 936 mb. Fortunately all models are now locking onto a solution which keeps this storm well off the east coast.
However, the combination of an upper level low and a stationary front across North and South Carolina will feed into tropical moisture from Joaquin. Record rainfall poses a threat for serious flooding, especially across South Carolina where 10" to even 20" of rain is possible as shown in the WPC 5-day rainfall forecast to the left.
To put this into perspective, Columbia, SC record rainfall for the ENTIRE month of October is 12.09". They could receive amounts close to this by the end of the weekend! Please take the necessary precautions if you live in this area as this will likely become an extremely dangerous situation.
As mentioned before, long range forecasts are difficult in the transition months (fall/spring) due to how rapidly the weather pattern can change. I arrived at my forecast by starting with similar El Nino years, but also by factoring in the PDO, CFSv2 monthly forecast, model ensembles, and operational model forecasts for the first half of October.
When thinking about El Nino here in Minnesota, the first word that comes to everyone's mind is 'warm'. This is true for many (not all) El Nino winters, but is not always true for the fall. I took what I thought were similar years to this year, and the composite temperature anomalies are shown to the left.
The eastern half of the U.S. has seen generally cool October's during moderate to strong El Nino's, but the western half remains average to slightly above average.
This typically changes as you head into the winter months, to a north/south split with warm temperatures across the northern half of the U.S. and cooler temperatures across the southern half.
I will save that for another day when I post my annual winter forecast.
After a brutally cold November across much of the eastern U.S. you may be asking yourself: A winter forecast now? Winter is already a month old! Although we have had a very early taste of winter this year, I have taken my time to come up with this forecast. My winter forecast covers meteorological winter December-February, but I like to include March as well, because here in Minnesota winter rarely ends at the end of February. Long range forecasts are not easy, and after successful forecasts the last two years (only missed MSP's total snowfall by 1.2" last year - Winter Forecast 2013-2014
), this year's forecast has been the most difficult. To further complicate things a very warm middle of December is expected across much of the U.S. BUT you'll see that does not necessarily translate to a warm winter. Just two years ago on 12/3/12 MSP saw a high of 55, and much of the U.S had a warm December. Temperatures remained mostly below average after that, and the spring included 18" of snow in April with snow continuing into May!
ENSO - Is El Nino finally here?
When creating a long range winter forecast it is necessary to start by taking a look at the El Nino - Southern Oscillation (ENSO). Very strong correlations to weather patterns can be made when an El Nino or La Nina is present. After two straight winters of ENSO neutral conditions, we are very close to seeing a weak El Nino. When El Nino is present, mild, drier, Pacific air is much more likely to spread across the northern U.S. increasing the chances of having a more mild winter in places like Minnesota. However, not every El Nino means Minnesota will have a warm winter, with the most recent cold El Nino being the winter of 2009-2010. I believe ENSO will stay at minimum in the neutral range, with a weak El Nino likely verifying over the next few months.
The Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) are two key teleconnections to monitor during the winter. When the AO is negative, this brings very cold air to the central/eastern U.S., whereas a positive AO usually brings the opposite conditions. The NAO is similar, however, the temperature correlations are not quite as strong. A negative NAO typically brings increased precipitation to the central U.S.
So far this autumn the AO has been largely negative since the beginning of October. This is the opposite of last year, and was responsible for sending very cold, arctic air southward throughout the month of November.
New research has shown strong correlations between an above average Siberian snow pack in October producing a negative AO throughout the winter. The Siberian snow pack was well above average in October 2014, and approached record levels. Because of this, I believe the AO will remain largely negative throughout the winter. The NAO has been more neutral over the past few weeks, and I expect this to remain in the neutral to negative phase throughout the winter.
After combining the factors above (weak El Nino, negative AO, neutral to negative NAO, and adding a currently positive Pacific Decadal Oscillation - PDO) I have come up with 3 winters that I think will strongly correlate to the upcoming winter December - March. They are 1969-70, 1976-77, and 1979-80. As you can see, this is not good news for the eastern half of the U.S. if you are looking for a warm winter.
Taking a look at precipitation anomalies over the same winters show near average snowfall across the northern U.S. with a dry Ohio valley, and a wet southeastern U.S. The west coast, especially in the northwest, experienced drier than average conditions.
November 2014 compared to November 1969, 1976, 1979
The left image above shows the November 2014 temperature departure from normal, while the right image combines the temperature departure for 1969, 1976, and 1979. Can you see the similarities? These analogue years also had very cold Novembers across the eastern 2/3rd of the U.S, including a very cold deep south.
December 1969, 1976, 1979
Taking a look back at December in the analogue years, you can see a warm December, especially across the western U.S. and northern plains was not out of the ordinary. The effect of El Nino was evident in these months, but overall did not keep much of the northern plains from experiencing below average temperatures for the remainder of the winter.
We are off to well below average start to December in Minnesota, but next week's warmup has been well advertised. Record high temperatures are possible late next week at MSP. After a warm middle of the month, temperatures are likely to fall back below average to end December. This means MSP may finish close to average for the month, which would fall in line with the December analogues I have chosen.
2014-2015 Winter Prediction
Here is a look at what I expect temperature departures from average to look like across the U.S this winter. The eastern U.S, and especially the Great Lakes region, will feel the effects of a negative AO with below average temperatures likely December - March.
The effects of a weak El Nino are prevalent across the northwest, where above average temperatures appear likely.
The effects of a weak El Nino are also prevalent when looking at my precipitation forecast for this winter. In typical El Nino winters, you see increased precipitation in California and across the southern U.S while the northern U.S. remains drier compared to average.
The below average precipitation forecast for the Great Lakes and Ohio valley are mainly due to the expectation of northwest flow and well below average temperatures.
Northern Plains and the Twin Cities
Overall, I expect near average snowfall across the northern plains including the Twin Cities.
Total snowfall prediction for the Minneapolis-St. Paul International airport: 53"
This means a drier winter compared to the last two winters where MSP received around 70". 53" seems like a lot less, but it is nearly right on our 30 year climatological average of 54". 53" includes the 9.4" we received in November. That leaves us with around 44" December-March, with the most snow coming in what is climatologically our snowiest months January and March. Last spring was a slight improvement over the previous spring due to less snow in April. I do think we warm up more quickly this spring, with warmer weather possible late March and continuing into April.
I hope everyone was able to get outside today, finish yard work, enjoy the grass one more time, or even just enjoy above freezing temperatures because everything changes tomorrow. Winter officially begins in the Twin Cities tomorrow, a good 2 1/2 weeks before Thanksgiving! Not exactly what most people want to hear after two consecutive long, cold, winters. However, for a number of snow lovers, or just for people who enjoy massive snow storms, tomorrow will be an awesome day.
To the left is my final forecast for this storm which will begin overnight tonight and continue into the early morning hours on Tuesday.
Storm total forecast for MSP: 12"
- Light snow is currently developing across northern South Dakota this evening, and will continue to expand and intensify in coverage overnight. Snow will reach western Minnesota around midnight, and extend into the Twin Cities between 4-6am tomorrow morning.
- Snow will quickly become heavy in the Twin Cities between 6am-10am creating a difficult morning commute.
- The difficult portion of this forecast is figuring out how far north the freezing line will reach tomorrow morning. It's possible temperatures aloft rise above freezing as far north as I-94, decreasing overall amounts across the south metro. This could cause a brief period of sleet, rain, or freezing rain to fall across the south metro, mainly between 10am-1pm. This is why I held overall snow accumulations across the south metro down slightly.
- If the majority of the metro remains all snow through the day tomorrow, my forecast may be too low. The 12-16" band would likely need to shift southward to encompass the entire metro.
- Mixed precipitation will likely fall across southern Minnesota throughout the day tomorrow, especially from a Mankato - Faribault line and southward. This is why you see a sharp decrease in snow accumulations as you head south.
- Snow will once again become heavy in the Twin Cities tomorrow afternoon/evening and slowly taper off into the late evening. The evening commute in the Twin Cities will be a NIGHTMARE.
- 12-16" of snow is likely across the north metro, with spotty amounts near 20" possible. The south metro will range from 8-12", with amounts decreasing as you head south.
- As I mentioned previously, the cold air behind this system is significant, especially for early November. Record breaking lows near or below 0 will be possible throughout the week and into next weekend. Welcome to January two months early!
I sat down last night, ready to crank out my 2014-2015 winter predictions, but just couldn't take my eyes off of our impending snow storm for late Sunday night into Monday. Judging by the forecast below, how can you blame me? I will put my focus into this storm over the next two days, and plan to release my winter forecast later this week. If you want a sneak preview of what this winter is going to look like? It will be COLD, again. I'm sorry, I'm only the messenger.
Sunday night into Monday
Snow will develop and move through southern North Dakota and northern South Dakota tomorrow evening. This will continue to expand across all of South Dakota and move into Minnesota overnight Sunday into early Monday morning.
Snow will really pick up across the Twin Cities metro early Monday morning and become heavy during the morning rush hour. The heaviest snow is likely to fall in the Twin Cities between 7am-3pm, with accumulations of 8-12" possible. I will not be surprised if a number of locations pick up close to a foot in and around MSP. This is my preliminary forecast, with my final forecast coming tomorrow.
I am 100% confident that heavy snow will fall near the areas outlined. There is still some uncertainty on where exactly the heaviest snow will accumulate, especially with a northward trend in the models this morning. Although this northward trend is noted, I like to call it 2 day model wobble, and it happens with nearly every forecasted storm. All week the models had kept the heaviest snow near or to the south of the Twin Cities metro, so the actual solution will likely end up somewhere in the middle. This would still put MSP near the heaviest axis of snow.
One other component of this storm that jumps out at me is the overall track. It moves southeast out of Montana/Wyoming, then takes on a more easterly to northeasterly component as it moves near the Iowa/Minnesota border. Here is where the system taps into more gulf moisture and throws it over very cold air. Does this sound familiar? This is very similar to what our heaviest snow storms have done over the past several years, including the one that took down the Metrodome roof with 17.1" of snow on December 10th/11th, 2010.
The last thing I, and most other meteorologists are 100% certain of, is the strength of the cold air behind this system. Especially with a deep snowpack, we could see near record cold over the next week. MSP could see low temperatures near 0 on Wednesday morning, and again into next weekend!
A moderate risk for severe weather continues across Kansas, Nebraska, and Iowa today. All severe modes are possible, with the highest threat of tornadoes along the warm front in southeastern Nebraska and far southwestern Iowa.
The image to the left shows the forecasted STP (Significant Tornado Parameter) at 5pm this evening. Very high numbers are forecasted for southeastern Nebraska, especially for the Lincoln and Omaha areas.
This is the HRRR (High Resolution Rapid Refresh model) showing the simulated radar at 5pm. A line of severe thunderstorms is expected to quickly develop this afternoon and move east/northeastward. As I mentioned above, any storms that can remain discrete and move along the warm front, are most likely to produce tornadoes, and the possibility of large, destructive tornadoes. If you live in southeastern Nebraska, especially from Lincoln to Omaha, please pay close attention to the weather this evening and take any tornado warnings very seriously.
One thing that could limit the widespread tornado potential, is if these storms go linear quickly. There would still be the potential for embedded supercells to produce tornadoes, but severe straight line winds could become a bigger threat. This is especially likely as these storms continue to move into Iowa late this evening and into the overnight hours.
Meanwhile back here in the Twin Cities, heavy rain will become likely overnight tonight. The heaviest rains may remain just southeast of the metro, where 1-3" of rain is possible through tomorrow morning.
Happy Mother's day to my mom and all of the other moms out there!
Scary mother's day shaping up tomorrow, with a moderate risk for severe weather out across Iowa, Nebraska, and Kansas. Everything is in place for severe weather, including the possibility of large destructive tornadoes, especially along the warm front in Nebraska/Iowa. If you live in this area or have friends and family in this area, please be aware of the weather tomorrow afternoon/evening.
As of 4:30 pm heavy sleet is moving back into the Twin Cities metro. This will change over to all snow over the next hour or two and become heavy at times tonight. As you can see I've made some slight changes to the forecast I posted last night. There's no doubt this has been a challenging forecast for many meteorologists today.
Storm total forecast for MSP: 6"
- Snow is really beginning to pick up to the west of the Twin Cities and will continue to develop towards the metro this evening. 6-8" with remains likely just to the west and northwest of the metro.
- My forecast remains consistent from last night as I still expect to see 4-8" across much of the Twin Cities metro. Most of the heavy snow will fall across MSP between 6pm - 2am. Drier air will work into the metro after 2am, limiting accumulations beyond that time.
- The biggest change to the forecast comes late this evening and into the overnight hours just to the south and southeast of the Twin Cities. As the main surface low pushes northward a very heavy band of snow will develop from Albert Lea - Owatonna - Red Wing. 6-8" with possibly a few higher amounts will fall within this band overnight with thundersnow possible.
- The snow will exit the entire state of Minnesota by late tomorrow morning. The morning rush hour could be very difficult, but temperatures will rise above freezing during the day and should help to make for a much easier evening commute.
- As I mentioned yesterday enjoy the snow while it lasts because it won't be around long. We'll still see temperatures rise into the 50s and 60s, with even 70 a possibility next week. Enjoy!
From a personal standpoint I really hope this is the last snowfall forecast I post on this website this spring. From a meteorological standpoint a very impressive storm system will take aim at the entire Mississippi River valley Thursday into Friday. For tomorrow, a moderate risk for severe weather is out for the lower Mississippi River valley including much of southern Missouri and all of Arkansas. The potential is there for all modes of severe weather including damaging winds, hail, and tornadoes.
The biggest challenge in forecasting snow on the northern side of this system is how much energy will be focused on producing thunderstorms to the south and how much energy will be left over to develop heavy snow to the north. One model (NAM) really winds this system up with a potent closed low which produces a prolonged period of heavy snow through and just north of the Twin Cities. The other models are much more progressive with this system in pushing it more quickly to the northeast, leaving the heaviest snow totals to northern Wisconsin. Below is a timeline of what to expect from this system.
Storm total forecast for MSP: 7"
- Temperatures will remain near or above freezing at MSP overnight tonight. Rain, possibly mixed with sleet will develop and move northward tomorrow morning. A rumble of thunder may even be possible as heavier rain moves into metro early tomorrow afternoon.
- Snow will develop and become heavy at times across eastern South Dakota into western and central Minnesota early tomorrow afternoon.
- Snow will spread eastward into the metro tomorrow evening, with the northern and western suburbs seeing the fastest changeover to snow. Snow will become heavy in the Twin Cities late tomorrow evening into the early morning hours on Friday. Friday morning's commute could be an ugly one.
- I think much of the Twin Cities metro will see 6-8" of snow with the southeastern suburbs seeing closer to 4-6" due to a longer period of rain/sleet. Higher amounts closer to 9" are possible to the northwest from Willmar to St. Cloud to Duluth.
This may be a great time to enjoy what could be our last snow storm of the season - sorry no guarantees though. If you're completely fed up with winter and snow, there is a reason to be optimistic. This snow won't last long as temperatures quickly rise back into the 40s this weekend and 50s early next week. We may even have another shot at 60 next Wednesday, and our first 70 of the spring next Thursday. The snow may frustrate you for the next few days, but a week from now it will feel like a distant memory.