Weather History:
In 1873, a deadly tornado tore through southeastern Iowa, affecting Keokuk, Washington, and Louisa counties before moving into Illinois. The storm produced very large hail (up to 4.5 inches in diameter), killed 8 people, and injured at least a dozen others. This event prompted the first detailed tornado damage survey in Iowa, conducted by the U.S. Army Signal Corps.

7-Day Weather Forecast:
Temperatures are expected to remain cool for the next week. Rain chances increase as the weekend approaches, with the best chance for precipitation Sunday night into Monday. The following week will be less active

Climate Forecast:

• 6–10 Day Outlook (May 27–31): Cooler temperatures expected in the south, near normal in the north, and likely below-average rainfall statewide.

• 8–14 Day Outlook (May 29–June 4): The drier signal is enhanced, and temperatures are expected to be warmer than normal.

• 3–4 Week Outlook (mid-June): The outlook leans warm and wetter, suggesting a shift to a more active weather pattern as summer approaches.

Past Week of Weather:
The past week was notably cooler and wetter than usual, with 3–4 inches of rain along the I-35 corridor and surrounding counties. Des Moines International Airport recorded 4.84 inches, the highest in the state. Temperatures were about 5°F below normal. Overnight lows dipped into the 40s, which is chilly for late May

Other Weather/Climate Discussion Topics:

• Wind and Hail: Northern Iowa experienced strong sustained winds (37–39 mph) and gusts up to 52 mph. Hail up to 2 inches was reported in Grand River (Decatur County) and Osceola.

• Wind Damage: Growers in northern Iowa reported significant losses of plastic mulch beds due to high winds. Wind erosion was also noted in sandy soils in southeastern Iowa.

• Weather Impacts on Crops: High winds caused physical damage to plants (broken leaf petioles, windblown soil particles), and some farms reported unusual leaf spotting, possibly from wind or chemical drift. Drift investigations are ongoing in affected areas.

• Precipitation and Irrigation: The recent rains improved abnormally dry conditions, but growers are reminded to water in new transplants as their roots are not yet established. Weeds are expected to germinate rapidly, so timely cultivation is encouraged.

Specialty Crops Impacts:

• Wind Damage: Growers lost plastic mulch beds and experienced wind erosion, especially in northern and southeastern Iowa.

• Leaf Spotting: Multiple crops (potatoes, radishes, tomatoes, cabbage, Swiss chard, cucumbers) showed inter-veinal necrosis, likely due to wind or desiccation, not herbicide drift.

• Weed Management: Recent rains will trigger weed germination, so growers are advised to cultivate early at the white thread stage.

• Cold Weather Effects: Cool temperatures can increase cat-facing in tomatoes and blossom end rot in susceptible crops. Growers are reminded to monitor for these issues if crops are flowering.

• Irrigation: Irrigation is less necessary after recent rains, but new plantings still require watering.

• Flower Crops: Rain can damage open blooms, but many flowers are harvested in the bud stage. Peony growers are drying blooms before cold storage to prevent moisture issues.

Listener Engagement:
Listeners should share their experiences and the impact of the podcast on their growing decisions, especially if they can quantify the financial benefit of advice received

Summary provided by perplexity.ai

• Historical weather event (May 15, 1968): Major tornado outbreak in Iowa with two F5 tornadoes
  • Caused significant damage in Charles City, Oelwein, Maynard, and other areas
  • 20 total fatalities and over 600 injuries
• Current forecast:
  • Transitioning weather pattern with thunderstorms possible
  • Potential for 2+ inches of rain across Iowa in the coming week
  • Brief cold snap with temperatures dropping to high 40s in central Iowa
  • Moving from "comfortably warm" conditions to more seasonable temperatures

• Moving past the "spring barrier" in forecasting (transition from synoptic to mesoscale/convective weather patterns)
• June outlook: Warmer temperatures expected across the entire U.S.
• June-July outlook: Warmer temperatures with drier conditions possible
• Soil moisture through end of May and early June will be critical for summer conditions

• Recent conditions: Warm with minimal rainfall (only about 0.05" statewide in the past week)
• Importance of irrigation for early plant growth and nutrient uptake
• New irrigation tool mentioned: Sumisensu watering hose from Japan

• Striped cucumber beetles emerging as a major pest issue
  • Overwinter as adults and carry bacterial wilt disease
  • Prefer cucumber family crops, especially cucumbers, cantaloupe, and maxima-type squash
• Control methods:
  • Exclusion (row covers and high tunnel screening with ProtekNet)
  • Parthenocarpic varieties that don't require pollination
  • Kaolin clay applications on young plants
  • Organic pesticide options (azadirachtin, pyrethrins)
  • Soil drenches with beneficial nematodes or entomopathogenic fungi

Podcast summary generated by Claude.ai

• Current conditions feature stable, pleasant weather
• A localized rain event occurred the previous night (May 7th) across central Iowa, with amounts around 0.21 inches in some areas
• Weather pattern is currently dictated by an "Omega block" high pressure system creating stable air
• Forecast shows temperatures warming into the 80s with relatively dry conditions
• 6-10 and 8-14 day outlooks indicate:
  • Above normal temperatures for Iowa, though this pattern is moving eastward
  • Above normal precipitation chances in the coming weeks
  • Western US expected to have below normal temperatures

• On May 8, 1964, Iowa experienced very strong winds (60-75 mph, up to 85 mph in Des Moines)
• This created widespread dust storms described as the worst since the 1930s

• A temperature gradient between western and eastern US suggests potential for a more active storm track
• Possible thunderstorm conditions developing May 15-21
• Recent precipitation has been below normal over the past week
• Temperature gradient with southern Iowa cooler than normal and northern Iowa warmer than normal

• Dan discussed preparing cut flowers for Mother's Day sales
• Highlighted benefits of overwintering certain flowers in low tunnels:
  • Earlier blooming than spring-planted flowers
  • Longer stems on cool-weather flowers
  • Currently blooming: Iceland poppy, bachelor's button
  • Nearly ready: foxglove
  • Other successful overwintered varieties: dianthus, campanula, larkspur, delphinium, Nigella, bupleurum, bells of Ireland
• Shared an alternative low tunnel design using carabiners, hose clamps, and bungee cords
• Addressed a flower disease issue: blue mold affecting tulips
  • Disease infects bulbs during harvest
  • Shows variety-specific impacts
  • Management includes identifying infected bulbs before planting

Episode Summary generated by Claude.ai

• In 1911, unseasonably cold air brought rain mixed with snow across northwestern Iowa. Most snow melted on contact, but some locations reported accumulations: 1 inch at Denison, 1.5 inches at Alta and Lamars, 2 inches at Algona, Mason City, New Hampton, Onawa, and Rockwell City, 2.5 inches at Rock Rapids, and 4 inches at Elma in Howard County.

• Showers and thunderstorms are possible today, but the weekend will bring pleasant, San Diego-like weather: sunny skies and highs in the 70s. A quieter weather pattern is expected to settle in.

• 8–14 Days (May 8–14): Strong likelihood of above-normal temperatures. The eastern half of Iowa leans slightly below normal for precipitation, while the western half is near normal-overall, a little dry and definitely warm.

• 3–4 Weeks (May 10–23): The outlook leans warm with equal chances for precipitation. Precipitation remains difficult to forecast due to the spring transition.

• May Monthly Outlook: Most of Iowa is likely to be warmer than normal. Precipitation is split: the northeast leans slightly drier, while the southwest has equal chances for above, below, or normal precipitation.

• On Monday, Iowa experienced very windy conditions (gusts up to 70 mph in Ames) but no tornadoes. The severe weather event was well forecasted in terms of risk areas, but many Iowans did not experience significant storms, leading to a perception of overhype.

• The lack of severe storms in Iowa was attributed to a strong atmospheric cap, cloud cover, dust, and wind alignment that prevented updrafts, despite all other ingredients for severe weather being present.

• Winter Rye: Beginning to flower across Iowa. Growers can terminate rye reliably by mowing and tilling at anthesis (pollen shed). One grower plans to mow and bale rye for weed-free straw mulch.

• Overwintered Flowers: Iceland poppies are starting to open; dianthus are looking good. More flower updates are expected next week, ahead of Mother’s Day.

• Greenhouse Tomatoes: Ripe tomatoes are being harvested in greenhouses in Grinnell and likely at some auction houses.

• Garlic & Aster Yellows: Growers are on watch for aster yellows phytoplasma, which devastated garlic crops last year, especially in northeast Iowa and neighboring states. Recent lab tests found rotted garlic cloves infected with pythium and rhizoctonia, not aster yellows. The likely cause was winterkill due to low snow cover, not disease. Spring-planted garlic had much higher survival.

• Management Advice: Rogue out yellow, weak garlic plants now to prevent potential spread of aster yellows by leafhoppers. Mulch and snow cover help protect overwintered garlic.

• Soil Testing: New online and spreadsheet tools are available for interpreting soil test results and generating fertilizer recommendations.

• MASC Payments: A new round of Market Assistance for Specialty Crops (MASC) payments has been announced. Growers should check with their FSA office for eligibility.

Podcast summary generated using Perplexity.ai

• This Day in Iowa Weather History:
  In 1900, a resident of Creston was struck by lightning twice during the same storm and survived, though he was partially paralyzed, singed, and blackened by the strikes.

• 7-Day Weather Forecast:
  The coming weekend looks pleasant, but thunderstorms are expected to return Sunday night into Monday, with a potential severe weather outbreak (all modes possible, including strong tornadoes) on Monday. Afterward, the storm track quiets down, but temperatures remain above average.

• Climate Outlook:
  The 6–10 and 8–14 day forecasts show a warm signal for most of Iowa, especially the west, with near-normal to slightly below-normal precipitation in the north. The 3–4 week outlook (early to mid-May) is more uncertain but hints at equal chances for temperature and a slightly wetter trend.

• Recent Weather Events:
  Last week saw 19 tornado reports in southwest Iowa, large hail (up to 4 inches), and straight-line wind damage. Higher dew points in the southwest contributed to more instability and severe weather. Data gaps from missing weather balloon soundings affected forecast accuracy.

• Precipitation:
  Eastern Iowa received 2–4 inches of rain, improving drought conditions. Central Iowa saw around 0.6 inches; some western locations reported up to 2 inches.

• Specialty Crop Impacts:
  Discussion focused on potting media trials for seedling production. Vermont Compost Fort Light had high nutrients but poor germination uniformity; Pro-Mix had good germination but less vigor. Growers might start seeds in low-salt media and pot up to nutrient-rich mixes.

• Grower Tips:
  For early melon planting, some risk of frost is accepted for the chance at early harvest and higher profits. Strawberry growers should watch for blossom pests.

Podcast summary generated using Perplexity.ai

• The hosts recall a historic severe weather event: an F3 tornado in Van Buren County on April 16th, 1967.

• For the current day (April 17, 2025), the main severe weather threat is large hail (1–2+ inches), especially from Omaha through Des Moines and Ames; tornado risk is low due to low dew points.

• Forecast: Severe storms possible overnight. Friday and Saturday expected to be pleasant, with more rain chances from Saturday night into Sunday. Rainfall of 0.75–1.25 inches possible across the state.

• Eastern Iowa, especially between Waterloo and Cedar Rapids (D1 drought area), is currently receiving needed rain.

• The 6–10 and 8–14 day forecasts show a warm and wet signal, especially in southwestern Iowa. The month-ahead and seasonal outlooks are less certain, with possible slightly increased warmth and dryness moving into early summer.

• Despite a strong signal for above-normal temperatures, the last frost of the season may not have occurred yet, especially in central and northern Iowa.

• Widespread frost is unlikely, but localized events could still occur, especially in valleys or low-lying, dry areas.

• Soil temperatures are fluctuating widely due to dry soils, with values expected mostly in the low/mid 60s to mid 40s over coming weeks. Some forecasts show soil temps as low as 42°F in northern Iowa by early May.

• Growers are advised not to rush warm-season crops like tomatoes and peppers into the field before mid-May or early June, due to risk of cold soil and air temperatures.

• It’s been windier than usual, which is notable particularly in northwest Iowa.

• Cloud cover and cooler temps have persisted in eastern Iowa, verified by grower feedback.

• Accumulation of growing degree days is ahead of normal, prompting early alfalfa weevil egg hatch in southern Iowa.

• Some growers are experimenting with blackening cover crops to encourage warmer soils for earlier sweet corn, but cloudy weather has limited the benefits.

• Problems with bean germination in greenhouse trays may be linked to seed maggots and/or sensitive response to high nutrient salt levels in potting media. Microclimate and possible ammonia burn are additional considerations.

• Growers are advised to bioassay suspect potting media using sensitive crops like beans and peas.

• The host corrects a previous statement: Strawberry flower buds are hardy to 20°F; open blossoms are damaged in the high 20s.

• With wetter weather on the horizon, growers are encouraged to finish field prep and tillage now, before rain delays field access and results in transplants outgrowing their cells.

*Podcast transcript and summary provided using AI

• On this day in 1936: Severe blizzard in northern and northwestern Iowa

• Forecast for the coming week:

  • Above average warmth

  • Chance of a widespread system early next week

• Discussion on Chicago Low vs. St. Louis Low weather systems

• 8-14 day outlook: Leaning warmer, near normal precipitation

• 3-4 week outlook: Warmer signal, equal chances for precipitation

• March outlook: Equal chances for temperature, slightly above normal precipitation for eastern Iowa

• Current La Niña conditions expected to transition to ENSO neutral in spring

• Warmer than normal temperatures (10-20 degrees above average)

• Frost depth measurements: Omaha at 0 inches, Des Moines at 24 inches (as of Feb 24)

• Recent precipitation events

• Earliest tornado on record in South Dakota (February)

• 4th least amount of snow on record for Iowa

• 14 inches below normal snowfall statewide

• Near normal temperatures overall

• Below average precipitation

• Recruitment drive for new observers in March

• Importance of citizen science in weather data collection

• High tunnel plastic degradation issue at Yellow Table Farm

• Slowed greens harvest due to recent cold spell

• Low tunnel crop performance update

• Heated high tunnel observations at Phelps Farm:

  • Celery pest infestation (russet mites)

  • Early emergence of spotted cucumber beetles

  • Dandelions flowering

• Avatar: Large variety grown by Amish growers

• Cleopatra: Medium-sized, 70 days to maturity

• Afterglow: Medium-sized, half Tuscan, 78 days to maturity

• Orange Sherbet: Large variety for direct market

Summary provided by perlexity.ai