Much Cooler Weather Ahead

For the first time in over 2 weeks the 6-10 temperature forecast is showing normal to below across parts of the Midwest. We kick over to a cool pattern by next weekend. However, the biggest relief will comes in Sunday as a strong cold front pushes through all of the Midwest and drops temps and dew points for Labor Day! Some strong to severe thunderstorms are also likely as the front crashes into the tropical air mass that has encompassed the area for weeks

More Hot and Humid Weather for the Midwest

Hot and Humid weather for next week! A chance of thunderstorms will also persist just about every day in northern parts of the Midwest. Many places in the Northern Plains will see highs up into the 100s, 90s for just about everybody else....as the Jet Stream lifts north into Canada ushering a Gulf area of high pressure that will continue to pump warm moist air up into the Midwest all week.  A couple fronts will move through, but the main one comes in around Labor Day!

Severe Weather Updates for Today/Tonight

Severe Threat for August 21st

A sharp cold front will move through the Midwest tomorrow afternoon and evening. Along with the temporary relief to the heat and humidity, the threat of a severe weather outbreak is looming larger and larger. Computer models are spitting out some high severe threat numbers and with enough daytime heating storms will pop. Tornado parameters are low, so the main threat will be large hail and damaging winds. Be sure to check tomorrow, if any updates are needed.

Major Warm up Signals a Summer Comeback

Summer will makes its stand by next week.  The jet stream will finally lift north after its stubborn ridge pattern for over a month, which has been keeping us cool and below normal for weeks.  With the jet stream shifted into Canada winds will shift into a more southerly fashion and pump warm moist air up from the Gulf.  The moisture will likely be enhanced due to the heavy rains in the Southern Plains over the last week as the Gulf air mass rushes north over these areas.  With that being said the humidity will be turned on, and with temps in the 90s to 100s, heat indexes will be over 100 in much of the Midwest by the middle of next week!

Official Midwest Winter Forecast for 2013!

Well here we go, after weeks of contemplation and sifting through models we finally have a solid winter forecast. To sum up, it will be winter's harshest stance in awhile. Nearly all long range models are showing an active storm track through the core of the midwest, leading to many cold snaps and winter storms.  This goes along with our analog winter forecast from September. We have had a very warm 6-8 weeks across much of North America, and this has lead to stratospheric warming in higher up latitudes. This phenomenon actually leads to a prolonged stretch of cool weather across our area. Usually in a season forecast you will hear something about La nina, or El Nino. Warming and cooling of the Pacific ocean, respectively. However, this year models are hinting at near average ocean surface temperatures, so this factor is relatively low.  Now we move on to the North Atlantic Oscillation (NAO, Current model projection) it is a measure of "blocking" through height annomilies in Greenland. Basically we need a negative value for strong winter storms to come up from the south. A negative value gives us kinks in the jet stream which leads to drastic temperature differences from coast to coast (usually cold for the Midwest).  With that being said, we are expecting multiple negative NAO values this winter! Finally, we took into account many long range computer models: Find Some Here! to get our final product. Enjoy! Be sure to tell you friends and "Like" us on Facebook Click Here for more updates this season, looks like we will have a lot of work to do this year


Discussion From September:

Winter forecasts and any seasonal forecasts for that matter can be very difficult because weather computer models will never fully agree on one set solution. Well, it is far too early to start rationally sifting through models to find what this winter will bring. This is why many in the weather world (including the CPC) are starting to use analog years with increasing popularity. Analog years are weather based data sets that compare well to what is currently observed during the season. The observations are used find the years that a given variable coincides with.

Basically, they are the years with similar weather conditions. Thanks to NOAA, NCEP, and Dr. D'Aleo, three analog years were found (2010, 2009, 1978), with the main variable being that of ocean patterns. With the most heavily weighted being that of 2009. With a good memory, you may remember 2009 shattered snowfall records for many cities in the Midwest. It was a year for the record books.
The ESRL (an agency of NOAA) lets anyone input data and years to construct a "forecast" based on how such years were documented. This is how I developed these maps and
forecasts you see on the page.

Preliminary Forecast:
Below normal temperatures appear to be the rule of thumb this time around. It looks like the jet stream will stagger south, allowing for ample cool Canadian air masses to surge south throughout the season. With that being said, precipitation appears to be in the normal category, based on analog years. CPC agrees with me here. With the colder temperatures, this would signal more snow and less rain/sleet/ice.



Be sure to keep it here to Midwestweather.org for updates on the winter forecast and posts about the weather that impacts your life!!

Northeast and East Central Wisconsin Tornado Outbreak August 6-7, 2013 Recap

One last Recap for the Northeast Wisconsin tornado outbreak of 2013: This will go down in history the worst day outbreak of all time for this region!

Summary:
A line of severe thunderstorms raced across Wisconsin during the late night and early morning hours of August 6-7, 2013, producing wind damage and tornadoes in the east-central part of the state. Hundreds of homes, businesses and farm buildings were damaged. Thousands of trees and power lines were downed, leaving tens of thousands of people without power. Two injuries were reported during the storm.

Six tornadoes occurred within the large area of straight-line winds, all within about 45 minutes. Below is a map of the long track twisters that hit the populated area.

Map ID	Start	End	EF-Scale	Comments
1	1 mi SW of New London, 12:23 am	Greenville, 12:33 am	EF2	Significant damage at church south of New London. Hundreds of trees impacted homes in Hortonville. Peak wind estimated at 115 to 120 mph. Image at right is of the church on the south side of New London.
2	5 mi SW of New London, 12:25 am	1 mi S of Hortonville, 12:30 am	EF1	Two injuries occurred at Huckleberry Campground, where camping trailers were blown over. About 100 trees were damaged. Peak wind estimated at 90 to 95 mph.
3	2 mi N of Greenville, 12:35 am	2 mi NE of Forest Junction, 12:52 am	EF1	Considerable damage on the north side of Appleton near the Northland Mall. Roof damage at mall and nearby businesses. Thousands of trees were damaged, some falling onto homes in a nearby neighborhood. Peak wind estimated at 100 to 110 mph. Image at right is one of many homes that sustained damage from fallen trees in Appleton.
4	Mackville, 12:38 am	3 mi ESE of Greenleaf, 12:53 am	EF1	Numerous trees and farmsteads sustained damage along the path of this tornado. Several homes were damaged by fallen trees and two homes had damage to garages. Peak wind estimated at 95 to 105 mph.
5	4 mi WSW of Freedom, 12:40 am	4 mi E of Maribel, 1:10 am	EF1	Thousands of trees and dozens of farmsteads sustained damage along a 30+ mile long path (damage was sporadic along the path). Peak winds estimated of 95 to 105 mph. Image at right is a farm house, barn and silo that sustained damage near Freedom.
6	2 SW of Pilsen, 1:06 am	3 SE of Pilsen, 1:09 am	EF1	Several dozen trees were uprooted or damaged along the path of this tornado. In addition, the storm damaged a silo and two barns. Peak winds estimated of 90 to 100 mph.

Credit: NWS Green Bay

Severe Weather Possible for Nebraska and Northern Iowa

|Severe Thunderstorms Today|


Mainly in Nebraska and Northern Iowa. The SPC has issued a slight risk for severe weather in the area. Main threat being damaging winds and large hail. The activity will probably get going in just a couple hours. Be sure to monitor local watches and warnings throughout the afternoon.

Recap of Wisconsin Tornado Outbreak

Mother Nature threw out a Major Tornado Outbreak in Wisconsin yesterday morning. A total of at least 5 tornadoes struck a densely populated area in northeast wisconsin Wednesday.  The tornadoes were spun up ahead of a bow echo (see radar).  These tornadoes are classified as mesovortex tornadoes, they occur when straight line winds get so strong a twisting motion gets going, acceleration takes over and you get a full blown tornado.  Although somewhat rare, at least 5 have now been confirmed by the NWS.  Given the velocity data, the real tally is likely well over 5! Each tornado recorded an estimate wind speed of over 100mph and were classified as EF1 or EF2. The National Weather Service will be out surveying again and may find more confirmation of additional tornadoes. Thanks for all the pictures everyone! Very well appreciated!

Severe Weather Threat for Wisconsin Overnight

Severe Weather threat is beginning to diminish throughout much of the Midwest, except for Wisconsin. A line of thunderstorms is getting its act together in Central Wisconsin and will pose a damaging wind threat for eastern Wisconsin. Another severe thunderstorm watch may be needed relatively soon as these storms head into a favorable environment.

Severe Thunderstorms Expected this Afternoon

SLIGHT RISK OF SEVERE WEATHER across much of the Midwest. The main line of thunderstorms (depicted in the simulated radar) will come with the cold front late this afternoon and into the overnight. The line will develop this afternoon and weaken as they head east late this evening. Damaging winds, large hail and a couple tornados should be expected. Scattered strong to severe storms are also possible in the "slight risk" shaded area in yellow in areas further south this afternoon.

More Fall-like Weather Late Next Week?

Computer models still pinning down another "cold" couple days late next week. A closed area of low pressure appears like it will drift south from Canada into the Midwest. Bringing clouds, showers, and October-like chill. This feature is very similar to the record cold last weekend. The map below is the GFS model for 850mb temps for next Friday, showing highs in the 50s/60s in the Northern Great Lakes. Still 8 days out, but has been consistent from run to run, the question will be how far south the system/cold can make it.