The new JMA Weeklies paint a wet and active picture for Week 1, but begin to suggest we get into a milder, drier pattern as we push into the middle and latter portions of May…
Week 1:
The “mean” upper air pattern places coastal ridges with a cool trough settling into the central. The end result will be a wet and active regime, locally, this weekend into next week. Though we’ll see a “spike” in temperatures Sunday, the overall theme is a chilly one as we open the month of May. In fact, temperatures will trend significantly cooler than average as we push into next week.
Week 2:
While it still looks chilly (compared to average), the JMA Weeklies suggest a “calmer” weather pattern moving in. Wet anomalies are noted through the Rockies and Central, but a drier trend across the east, including the Ohio Valley.
Weeks 3-4:
Wet times remain across the Central and spread into more of the southern tier, as well. Slightly cooler than normal temperatures are also forecast across the Southeast. Budding warmth seems to develop over the West.
An area of high pressure will be located off the Mid Atlantic coast while surface low pressure develops in the southern Plains and tracks north over the weekend. The combination of these two ingredients will help pull abundant Gulf of Mexico moisture northward into the Ohio Valley. With a true Gulf connection, moisture-rich air will overspread the region this weekend. In addition to feeling truly muggy for the first time this year, this will also aid in periods of heavy rain this weekend.
From this distance, it appears like widespread 2″ to 3″ of rain will fall over the weekend, but localized heavier totals are expected where thunderstorms “train” over the same areas. While it won’t rain the entire weekend, times of wet weather will outnumber dry hours and if you live near a creek or stream, keep abreast of this developing weather situation as significant water rise is expected over the weekend.
Finally, after Saturday morning thunder, we think the majority of next weekend is dry before a cold front brings a return to widespread showers and thunderstorms late Sunday.
As a cold front slices into the summer-like warmth (highs will approach 80° Wednesday afternoon), scattered showers and thunderstorms will develop late Wednesday into Thursday.
We then will shift gears rather abruptly as we move through the latter portions of the work week and on into the weekend with well below normal chill. In fact, if current data comes to fruition, most of the weekend will be spent in the 40s.
Factor in a stiff northeast wind and periods of rain, we have the makings for a downright “raw” weekend. We suggest having indoor activities planned this weekend as an extended period of damp, blustery, and unseasonably cool weather awaits.
We still have a few days to continue watching the data, but early indications suggest locally heavy rainfall is possible (1″-2″) across the region…
Highs will run close to 15° above average this afternoon.
Stormy weather returns Monday as a frontal boundary slips into the state. A couple storms may become strong or severe Monday afternoon and the Storm Prediction Center highlights northwestern portions of the state for a Slight Risk. Damaging straight line winds are of greatest concern with any severe storm that may develop.
High pressure returns for midweek and supplies a dry regime, along with increasing sunshine and temperatures that will run slightly above average (mid-40s at night and 65°-70° during the day).
There are questions once to the end of the period as the GFS and European handle the evolution of our late-week storm differently. The GFS brings energy out into the Ohio Valley and results in unsettled weather returning Friday, continuing into Easter weekend, while the European is slower. We’ll keep an eye on things over the next few days and update accordingly. The GFS suggests some localized heavier downpours would be possible in the Friday-Sunday period as the majority of the 7-day precipitation snapshot below falls within the timeframe.
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…
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.
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.