New JMA Weeklies stream in on Thursday mornings and we send out a Thursday morning report, in detail, to our clients dissecting the latest data, but want to try and start making public comments on the model here, as well.
The overall idea after looking at the JMA Weeklies is wet and warm over the upcoming (4) weeks relative to average. That said, there will be periods of drier times, especially Week 1, and late season chill- as can be expected every April.
Week 1:
Week 2:
Weeks 3-4:
The big picture is one that shows a drier pattern developing across the East during Week 1, but we caution that this drier regime doesn’t look to “lock” in. Data suggests we get back to an active pattern between Week’s 2-4, biased wetter than normal in the Mid West and Plains. The other screaming message is that a busy severe season should continue through the period. Cold sets up across the Pacific Northwest, associated with the “mean” trough position, while spring-like warmth continues to build across our region in overall terms. We know what that means as storms eject off the Rockies and track east…
Highlights:
2.) We’ll get a breather on Tuesday, but our next storm system will move in quickly and begin impacting central Indiana during the day Wednesday. A couple strong to severe thunderstorms are possible Wednesday and will require our attention over the next day, or so. We’ll have more details with our updated 7-day later today.
3.) We’ll get into the colder side of the storm to close the work week and thoughts will shift from storms to snow. Wind-whipped snow showers will be a good bet in the unseasonably cold air Thursday into Friday morning.
4.) Timing will once again be our friend as we push into the weekend. Weak high pressure will arrive on the scene and help ensure dry conditions. After a cold start Saturday, a moderating trend will develop.
Highlights:
2.) We bracket the hours of 2p-8p (couple hours earlier from yesterday’s thinking) as the period of potential most widespread strong to severe thunderstorms across central Indiana, and the HRRR forecast radar shows what the radar may look like this evening. Have a means of getting the latest warnings.
3.) Scattered showers will continue into Friday morning before drier air arrives during the evening hours.
4.) This drier trend Friday PM is one that will continue into the weekend. High pressure will supply mostly dry weather through the entire weekend (small shower chances return Sunday evening), including sunshine.
5.) Another active period of weather awaits next week, including multiple rain chances early and late week. The latter storm looks to be the bigger event with heavy rain and thunderstorm potential Wednesday into Thursday. 7-day rain numbers check in between 1.5″-2″ with locally heavier amounts.
6.) The story becomes a chilly one next weekend, and models suggest central Indiana may be dealing with frost and freeze conditions by next Saturday or Sunday morning.
Multiple rounds of showers and thunderstorms will likely impact central Indiana through the mid and late morning hours Thursday.
As we press into the early afternoon hours, model data suggests we see a “lull” in the stormy weather and potentially even a few breaks in the cloud cover. This would serve to “up the ante” in regards to the prospects of severe weather potential Thursday afternoon, particularly mid and late afternoon through the evening hours. Accordingly, the Storm Prediction Center continues to highlight central Indiana for the risk of severe weather Thursday.
In fact, given a look at the most recent data, I wouldn’t be surprised to see the “enhanced” risk area expand further north in future updates. This would also include all modes of severe weather (large hail, damaging straight line winds, and potentially a tornado). As things stand this evening, we bracket the hours of 4p and 10p Thursday for the greatest potential of severe weather.
As we push into the overnight hours Thursday into Friday, unsettled weather will continue, but we’ll get rid of the severe potential. “Nuisance” type showers will continue into the first half of Friday before drier air arrives Friday afternoon and evening. This drier theme will settle in for the weekend and provide a very pleasant open to April.
Precipitation is running above normal, locally, to the tune of nearly 1″ month-to-date. Heaviest rains have fallen across southeastern Indiana over the past (30) days.
A look at precipitation anomalies across the mid west, month-to-date:
As we progress through the upcoming (10) days, a transient weather pattern will persist. This will keep forecasters busy, but it should also be stressed it’s not all a “doom and gloom” type pattern, either. There will be plenty of dry time over the upcoming period, including drier conditions building in tomorrow (Tuesday) into a good chunk of Wednesday.
However, timing is our friend this go around as upper ridging develops over the upcoming weekend. Not only will we dry out, but we’ll also enjoy increasing sunshine as the weekend progresses.
That said, looking further down the pipe line, another (potentially more significant) storm system looms during the 8-10 day period. This would fall in the April 3rd-4th time frame. From this distance, models are bullish on hefty rainfall totals with this storm system and we’ll keep a close eye on things as time draws closer.
Speaking of April, our overall thoughts for the fourth month of the year (where does time go?) would imply a warmer than average month and active (wetter than average). Relative to average, we feel we still may have some chill to traverse early month, but there’s also some indication we could bust into an early summer-like feel mid and late month. With the mean trough position west and ridging east, we’ll have to also be mindful for the potential of an active severe weather month- especially mid and late month. Overall, the CanSIPS idea below is one we would agree with from a mean 500mb perspective.
3.) Sunshine can be expected today and after the frigid beginning, a moderating trend will begin this afternoon that will send temperatures into the lower to middle 40s. That’s still close to 10° below average for daytime highs, but will feel much better than what we’ve been dealing with over the past several days. Add in that high March sun angle and it’ll actually be a very pleasant afternoon.
4.) Unfortunately, we won’t hang on to the sunshine for St. Patrick’s Day. A warm front will lift northeast through the region during the overnight and lead to an increase in clouds by evening. A wintry mix of sleet and freezing rain will impact central IN predawn Friday morning before transitioning to showers mid-to-late morning. “Light” is the key word here with models suggesting less than 0.20″ total. By Friday afternoon we’re back to dry times.
5.) We’ll turn a touch cooler Saturday and it’ll be a blustery day, as well. A couple of early snow showers are possible across east and northeast portions of the state before afternoon sunshine returns. High pressure settles in overhead Saturday evening and will set up a nice second half of the weekend- lots of sunshine and milder temperatures by Sunday (lower 50s).
6.) Looking ahead, the quiet times will be hard to come by as we progress through the latter portions of the month. Both the new JMA Weeklies (shown below) and other ensemble guidance is bullish on a wetter than average close to the month, and also one that features wild temperature swings. Thoughts shift back to severe prospects, especially for our friends to our south and the potential of backlash wet snow showers in the colder air. From a temperature perspective, it’s a pattern that will be very “transient” with no true long-lasting periods of significant warmth, or cold- relative to average.
This morning’s showers and thunderstorms were the first of (3) rounds of storms expected today. Ironically, most of the daytime hours should be rain and storm-free. We’ll note scattered showers and thunderstorms across northern portions of the state this afternoon, as a warm front continues to lift north.
Finally, our severe weather threat will come to an end with the passage of a squall line during the pre-dawn hours Wednesday morning. The biggest threat with this line of storms will be damaging wind, but a quick spin-up tornado can’t be ruled out either.
With the majority of this event occurring when most are sleeping, please have a way to get the latest information on watches and warnings that are sure to come tonight. We highly encourage everyone to have a weather radio, and be sure to set the alert mode to “on” before bedtime tonight.