Unsettled weather to continue
While weather continues to bring us light rain through the weekend and early next week, there will still be occasional opportunities for fieldwork.
Jet stream flow across North America is expected to transition from the active western trough, eastern ridging pattern of the past few weeks to a highly latitudinal, “blocky” type of pattern during the next week with several high and low pressure systems cutoff from the general flow. The general theme in forecasts for the next several days and weeks is for a continuation of unsettled, cooler and wetter-than-normal weather. While I personally do not see a major extended “break” in the pattern that would finally end the recent string of weather-related delays, I think there will be at least some occasional opportunities for fieldwork.
In the short term, a cool front will pass through the state overnight Thursday (May 5) and early Friday, and bring widespread light rain to Michigan. In contrast to some of the events of the past couple of weeks, rainfall totals are expected to remain on the light side, with general 0.10 to 0.20 totals or less. After a brief period of mostly cloudy, dry conditions late Friday and early Saturday, a second weather system will move across the Ohio Valley, bringing the threat of showers. Current indications are that rainfall with this system will be very light (less than 0.10 inches) and confined to southern sections of the state, with mostly cloudy and dry weather continuing over northern sections.
Yet another weather system will bring the possibility of more rain on an almost daily basis Monday through Wednesday of next week. High temperatures during the next several days will slowly moderate from the low 50’s north to near 60 south Friday to the upper 50’s north to low or mid-70’s south by Monday. Low temperatures will generally war from the upper 30’s north to the mid-low 40’s south Saturday to the low 40’s north to low 50’s south by early next week.
Medium range forecast guidance currently suggests a continuation of the recent pattern, with both 6 to 10 day and 8 to 14 day outlooks (covering May 10-14 and May 12th-18) calling cooler and wetter-than-normal weather statewide. It is important to note, however, that the blocky upper air pattern mentioned above is very difficult to forecast accurately very far in advance – some meteorologists would use the phrase “notoriously difficult.” As a result, forecaster confidence in these outlooks should be considered lower than normal.
For the record books – 178 plus tornadoes
The massive tornado outbreak across the southern and eastern United States last week (on April 27 and 28) will go into the record books as the largest on record for the country as a whole. Tragically, more than 300 people lost their lives as a result of the storms. So far, a total of 178 tornadoes have been confirmed by the National Weather Service for this event, including several violent category EF-4 and EF-5 tornadoes with winds ranging from 160 to more than 200 mph. The National Weather Service is still surveying damage from the outbreak and estimates that the final number of tornadoes for this event may ultimately exceed 300, which as noted earlier, is historically unprecedented. For some climatological perspective, the old record from the April 3-4, 1974, “superoutbreak” was 148 tornadoes, while the average total for the month of April across the country is 185. The event will likely, also collectively, become the most expensive tornado-related weather event on record in economic terms, with several billion dollars in estimated losses.