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SPLASH AND DASH STORMS, WITH A SIDE OF HUMIDITY...

Make no mistake about, Monday was a burner. With highs in the range of 85 to 90 and dew points in the 70s, it felt more like 95 to 100. That qualifies it as a dog day of summer. Here are some late day heat index values from the NWS in the Quad Cities. With that much heat and humidity, instability was high but forcing was lacking and most of the thunderstorms avoided my local area. That was not the case where intense thunderstorms battered parts of the upper Midwest. Rainfall amounts were excessive in a band that caught Minneapolis and extended into NW Wisconsin where 4-9" totals were measured. You can see all the reports of flooding in that part of the Midwest. Going forward available water

RAIN FOR SOME THIS WEEK...

The heat is on and it will be a hot, humid week. It begins Monday with low rain chances and hot temperatures: Humidity will is going to be very high... dew points in the 70s is very uncomfortable. That will translate to heat index values in the 90s to near 100 degrees Monday afternoon. There will be little relief today with just a few scattered showers and thunderstorms near and east of the Mississippi. In fact, that's where most of the rain will be this week, in southeastern Iowa and east of the Mississippi. There will be a system that brings in rain Tuesday into Wednesday, but right now there is a lot of uncertainty in terms of where it sets up. Here's a look at the rain on the European mo

IT'S NOT THE HEAT, IT'S THE HUMIDITY

Right now it's kind of both that's going to get you. But the humidity is running high.. something that's pretty typical this time of year. In order to discuss humidity we have to talk about the dew point temperature. Here's an explanation of the dew point from the National Weather Service in La Crosse: "The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to achieve a relative humidity (RH) of 100%. At this point the air cannot hold more water in the gas form. If the air were to be cooled even more, water vapor would have to come out of the atmosphere in the liquid form, usually as fog or precipitation. The higher the dew point rises, the greater the

CLOUDS SEEDED BY METEOROIDS...

Noctilucent clouds over London taken by Phil Halpert June 2020 METEOR CREATED CLOUDS IN THE MESOSPHERE In the summer of 1885, sky watchers around northern Europe noticed something strange. Sunsets weren't the same anymore. The red and orange colors people were used to seeing were still there, but those familiar colors were increasingly joined by rippling waves of luminous blue. At first they chalked it up to Krakatoa which had erupted two years earlier. The explosion of the Indonesian super volcano hurled massive plumes of ash and dust into the atmosphere more than 50 miles high, coloring sunsets for years after the blast. Eventually Krakatoa's ash settled, yet the rippling waves of luminous

UPDATE ON TODAY'S THUNDERSTORM THREAT...

Thunderstorms that developed around the region last night and this morning have largely dissipated or become widely scattered. In the wake of the storms outflow boundaries and residual moisture remain over the area. Breaks for sunshine are also developing which will further increase instability this afternoon. By late afternoon CAPE which measures instability is forecast to be significant, especially south of HWY 20. By late afternoon a surface cold front will drift into the unstable air mass and become the focus for thunderstorm development. It appears that the greatest coverage will be over the southern half of my area later today and into the evening as a line forms and sinks southeast. T

FRIDAY'S STORMS TIED TO OUTFLOW BOUNDARIES...

The satellite image below was taken late Thursday evening. The obvious feature of interest is the thunderstorm cluster that's formed over South Dakota. Experience tells us that despite what models may show, what goes on within the convection structure of thunderstorms tonight can often dictate where tomorrow's storms form. A big factor in determining our weather the next 24 hours is tied to outflow boundaries, a complex and intricate part of forecasting. So lets define outflow and why as as forecasters we should care about its existence During the early stages of a thunderstorm's life cycle, its updraft (the warm, moist air flowing into the storm) feeds the structure and energy it needs to

LEADING THE WAY TO WETNESS...

The Madden Julien Oscillation (MJO) has done a very good job of depicting potential periods of wet weather around the central Midwest the past 30 days, well in advance of the rain itself. What I look for from the MJO ishow it handles the cycle or progression of convective clusters in the tropical Pacific. By observing which of the 8 pases we'll be in at any specific time, I can then correlate the precipitation analogs with that phase to see if it has a tendency to be wet or dry. It's a fascinating way of capturing trends, often before the models even see the.pattern unfolding The last couple of days I've been pushing the idea that my area was going into a 2 week period where precipitation co

THE FUTURE HAS THE POTENTIAL TO BE SOGGY...

The weather improved around the central Midwest Tuesday but as expected there were still a few scattered instability showers and storms. These were most common in the north during the late afternoon and early evening. Doppler shows a few spots may have picked up a 1/4" of rain but in general amounts were 1/10" or less. Lots of places missed the showers altogether. You can see that between the showers and the clouds that produced them, there were pockets of sunshine. Despite the strongest and most direct solar radiation of the year readings remained well below normal in the 70s Up in parts of Minnesota and Wisconsin 3:00 pm readings were in the 60s with mid to upper 50s in northern Michigan.

WHEN IT RAINS, IT REALLY POURS...

We told you last week we were going to get back into a wet and active period. It turns out the forecast was correct but in an understated way. Showers and thunderstorms the past 48 hours have dumped widespread heavy rain around my area, especially in many of my Iowa counties. In some spots, Doppler estimates are indicating as much as 6 inches of rain. Add this on top or what the remnants of tropical storm Christobal produced and some places have had 10-12" of rain in just 3 weeks time. Below are the 30 day rainfall totals but this graphic does not include some 1-3" amounts that fell during the day Monday. There's a lot of pink in northeast Iowa indicating 10 or more inches. These are the 30

MORE STORMS MONDAY....

Thunderstorms rolled through the area during the day Saturday. Some storms were strong and produced hail and gusty winds. Now more storms will roll through into Monday. An area of strong storms will move out of Nebraska and move through Iowa into Monday morning. Storms will likely be in a weakening state, but some strong ones may survive into the early morning hours. There will then be additional rounds of storms through the day... The Storm Prediction Center has lowered the risk for severe weather for Monday, but there's still the potential for some strong storms. High pressure will then move in and Tuesday through Thursday will be mostly dry. Temperatures will drop some behind this system,

SUMMER 'OFFICIALLY' BEGINS

The Summer solstice occurred at 4:44 pm on Saturday, marking the longest day of the year (in terms of daylight). We do start to now slowly lose daylight (just by a few seconds at first) from now on. Meteorological summer began on June first -- marking the warmest time of year, on average. Regardless, it felt like summer outside. It was warm, it was muggy, and there were periodic showers and thunderstorms. Sunday will be another warm day: Most of the day will be dry in the Upper Midwest with thunderstorms breaking out in SD/Nebraska and western Iowa in the late afternoon/early evening: That's where the severe weather risk mainly lies for strong winds and large hail -- As the storm system move

COVID VIRUS IMPACTING WEATHER FORECASTING...

Before I get to the impact of COVID 19 on forecasting, I wanted to show this image I took Friday evening of what's known as an orphan anvil north of my place in Portland, Maine. You can clearly see the anvil top of what was once a thunderstorm. However, the updraft that caused it was shut down and so was the warm moist air that was driving the storm. The base is gone but the anvil aloft still retains its shape. Choked off from its life support, the anvil is in a decaying state and will soon dissipate as its pulse fades away and the storm perishes. A beautiful but harsh reality of what it takes to sustain a thunderstorm. The COVID virus has impacted just about everything you can imagine and t

TERRY ASKS FOR A MULLIGAN...

At the beginning of the week I showed the temperature departures for the month of June (they currently look like this). I asked the question, is this the prototype for summer temperatures ahead? I then showed the EURO weekly 46 day temperature projections through the end of July that looked like this. They are very warm and focused on the central U.S. I said at the time that if the weeklies were right it would no doubt be a warmer than normal summer. However, I followed that up by noting the MJO was not in phases that would support consistent heat until early July at the earliest. I also indicated there was doubt about how strong a summer ridge would be and how far into the Midwest any warm

DOROTHY, I'M NOT IN IOWA ANYMORE...

The weather has been a a bit slow around the Midwest the last week so today I start you off with something unique to my area. For those of you unaware, I now make my home in Portland, Maine. Two things to know about the area from a weather standpoint. Number one, I'm only about 4 hours from Canada. As the crow flies less than 300 miles from the border. This is a northern latitude and winters can be feisty. Number two, the Gulf of Maine (part of the Atlantic Ocean) is two blocks away. That means I'm in a location with rich moisture that can produce vicious nor'easters as well as hurricanes. I see these sights commonly around town, evacuation routes for potential tropical systems and hydrant m

A TWO HEADED JUNE...

So far June has been two headed here in the central Midwest. Temperatures got off to a sizzling start with the average high the first 8 days in Cedar Rapids at 87 degrees (including two 90 degree days. The following 8 days were much cooler with the average high down to 78 degrees. Thanks to the Iowa Mesonet for the graphic. The same was true in the Quad Cities where the average high the first 8 days of June averaged 88 degrees compared to 80 the second 8 days. All the measurable precipitation has fallen in the first 10 days of the month, much of it associated with the remnants of tropical storm Christobal. Below you can see the daily rainfall numbers for Cedar Rapids and the Quad Cities. Inc

A SUMMER OF DISCONTENT...

The official start of summer is just days away. There's always speculation about the amount of heat that will come with it. Are we headed for a summer of discontent? One thing I've noticed recently is the trend away from the cool temperatures that dominated April and May. You can see the departures were significant in both of those months. April 2020: May 2020: Then came the reversal. Here's what we've seen in June so far. Is this the prototype for temperatures going forward? If the EURO weeklies are correct most definitely. This is the 46 day temperature departures that the control shows. This ends the last day of July. A very toasty look for most of the nation. The EURO sees a persistent r

TEMPERATURES ON THE WAY UP....

It's been a REALLY pleasant weekend around eastern Iowa. Crisp mornings, comfortable afternoons and plenty of sunshine. Not much more you can ask for in the middle of June. And it was a much needed break for a lot of us from the rain. Now warmth is going to build back in with a big area of high pressure in the upper levels of the atmosphere: This will send temperatures back up, but humidity won't climb all that much. So it won't be terribly uncomfortable, but it will be warmer. If you look in the image above you can see an area of blue in the Pacific NW, that is a trough which is expected to move our way later in the week (and will mean storminess). So first and foremost the week will start

A FALL-LIKE WEEKEND....

It feels beautiful across much of the Upper Midwest and it's because of a "backdoor cold front" that came through early Saturday. Temperatures are sitting below normal and humidity is very low for June standards. The humidity is the big factor in making it feel nice and comfortable outside -- low dew points. Here's a look at the 40 and 50 degree dew points Saturday evening: The cool, comfortable air is due to a stout east wind. That is due to the cold front, which came in from the east, where as most cold fronts come in from the west/northwest -- hence the name "backdoor cold front." The east wind off Lake Michigan is a cool wind still this time of year. Check out the water temperatures on t

TORNADO SEASON DOA, THE WEEKEND SEES A COOLING TREND....

May through mid June is the peak of the tornado season here in the Midwest and so far this year we have breezed through the period with twisters being weak, few, and far between. Following a big start to the season over the southeast U.S. during early spring. the action has slowed all across the nation ever since. After 73 deaths through April, only one fatality was reported in May and so far none during June. During May only 139 twisters were reported compared to 506 last year and the 3 year average of 322! Notice how after being close to the maximum count in late April we have now fallen below the 50th percentile. You can see how 2020 ranks with all other years since 2005. Again, the count

CONTROVERSY ON THE RAINS RETURNING...

It goes without saying that much of my area and the central Midwest has been living on the wet side much of the last month. These are the rainfall departures for the past 30 days around the heart of the corn belt. The greatest surplus of 3-6 inches extends from NE and EC Iowa across northern Illinois. Chicago is up 6 inches over that 30 day period. These figures represent the actual totals which are in the range of 7-10 inches in a number of locations. Despite the overall wet period soil moisture levels long and short term are about where they should be as of Thursday. The metric below known as the arridity index, based on temperature, precipitation, and evaporation show both Cedar Rapids an

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