In our JMA Weekly recap from last week, we noted the model was transitioning towards a wetter pattern for early and mid June.
It’s encouraging to see the latest ensemble data from the American GFS and European (courtesy of TropicalTidbits.com) support this idea, as well.
In addition to a wetter pattern, we would also want to pay attention to the potential of a gusty storm complex or two riding southeast around the hot dome off to our southwest.
After an unusually dry May (- 3.44″ as of this post), Alberto’s remnant moisture will help us, at the very least, cut into the rainfall deficit tomorrow. Longer term, it sure is nice to see the medium range guidance in agreement on a wetter time of things. As we’re all aware, this is a crucial time to determine the overall long-standing summer pattern. Dry ground and early warmth can easily “feedback” on itself, and it’s easy to understand some of the concern, particularly AG-related over the past few weeks. With that said, it’s certainly not too late to try and at least ease some of the worry a bit.
When we look at the MJO, we note the amplitude and it’s forecast to swing through the wetter phases, at least locally, (4,5,6) through the month of June:
In closing, the JMA Weeklies led the charge in the idea of more active times returning in June, and the combination of GFS and European ensemble data suggests they had merit. With the added bonus of having the MJO on our side, it’ll be hard to avoid a change of the guard towards an overall wetter pattern in the weeks ahead. Perhaps Alberto’s remnant moisture is only the beginning…
Week 2
Weeks 3-4
Back here on the home front, a quiet start to our Monday will turn stormy at times this evening as the front nears. We think best coverage of showers and thunderstorms will come between 5p and 10p. There will be some winners and losers when it comes to rainfall amounts by midnight. Some can expect over an inch in the stronger storms while others may only see a tenth of an inch, or so. Something that must be taken into forecasts moving forward is the tendency of most model data (high resolution and global data alike) to “over forecast” rainfall amounts as of late. Also of note is for the potential of a couple of strong to severe storms to develop this evening. We always have to be wary of fronts draped across central Indiana as they’ve been known to help tornadic activity spin up. We’ve lost count of how many slight risk days with warm fronts nearby that turn busy… If you’re planning to be outdoors this evening, please have a means of receiving the latest watches and potential warnings that may be issued.
High pressure will build in for the midweek period and supply plentiful sunshine along with continued warmer than average conditions. Overnight lows will fall into the upper 50s (couple of degrees above average) with the drier air mass in place, but afternoon highs will continue to climb into the lower and middle 80s (around 10 degrees above average).
Longer term, thoughts are shifting towards the open to meteorological summer (where is this year going?!). The GFS ensemble suggests the overall warm pattern remains intact as we open a new season with widespread warmth expected through the first few days of the June.
2.) Overall, a drier air mass will build into central Indiana today and Thursday (cooler, too) before moisture returns to close the week. Scattered showers and embedded thunder are more likely Friday and again late Sunday into Monday.
3.) Looking ahead, we notice a more active pattern is presented off the overnight GEFS model. The heat ridge backs west and sets up a busy “ring of fire” pattern with a northwest flow aloft across our region. We have a ways to go before developing consistency and overall confidence, but this is at least an encouraging sign. The end result, should this come to fruition, would be a significantly wetter open to June.
At the surface, all three major global models agree on warmth in the long range period, including the GEFS, EPS, and CFSv2:
Guidance suggests below average precipitation during the period. With broad scale ridging in place, we agree on a drier theme compared to normal. While trying to put our finger on the flip from the prolonged cold to warmer was difficult to nail down from March and April, May always looked like a drier than average month from several weeks out. (One note is the potential of active times across the Great Lakes region as “sudden summer” gains steam to the south and stubborn chill refuses to let go to our north. The gradient would promote heavier than normal precipitation relative to average).
Given the agreement in the data, along with some additional pattern drivers, we continue to believe the medium to longer term period (including mid and late May) will feature an overall warmer than average pattern along with drier than normal conditions.