Category: Forecast Models

Entering A Stormy Period…

We’re enjoying quiet times across Indiana this evening, but times are quickly changing to put us into a stormy position between Wednesday morning and wrapping up the work week.

While the overall pattern is an easy one to label from a broad scale perspective as “stormy,” the precise details are incredibly difficult to pin point much more than 12-24 hours in advance.  With that said, most of the state is very much in fair game for periods of storms (generally tracking in a NW to SE fashion) between now and the end of the work week.  Eventually, drier air will set us up for a very pleasant weekend, including lots of sunshine and cooler temperatures.  In fact, latest data still suggests we can expect to wake up to the 50s Sunday and/ or Monday morning(s).

Before we enjoy the pleasant weekend weather, the first of a series of storm complexes will approach Wednesday morning.  Mesoscale Convective Complexes (MCCs) can be a true pain for short-term modeling to handle, but the overall idea this evening is for the first of (2) complexes to impact parts of the region Wednesday morning.

This is an idea what the radar may look like around 9a.  This would be the same complex that will deal quite the blow to portions of the eastern Plains and upper Mid West tonight (localized damaging straight line winds will be an issue to our NW).  Thankfully, we expect weakening of this complex as it dives off to the SE, in our general direction.

hrrr_ref_indy_16We’ll go through a quiet period during the afternoon hours before a second surge of storms takes aim on the region tomorrow night into Thursday morning (again, understanding we’ll have to “sure up” timing as we go).

hires_ref_indy_40Additional storm complexes will follow Thursday into Friday before that drier air gets here.  Some of these could be strong to severe.

While rainfall amounts won’t be uniform, there’s the potential for some neighborhoods to get 2″-3″ of rain between now and week’s end (where storms train).

cmc_total_precip_indy_17Looking ahead, after a dry weekend and open to next week, indications point towards a return of wet and active times as we approach Day 10.  Long range ensemble data backs up the wet, stormy look nicely, and there’s really no end in sight…

MidJuly

Permanent link to this article: https://indywx.com/2016/07/05/entering-a-stormy-period/

Unseasonably Cool; The Calm Before The Storm…

The morning is off to a dry and unseasonably cool start, including filtered sunshine.  Temperatures are running 15-20 degrees below normal across the state, with many central IN neighborhoods currently in the lower to middle 50s.

t0Mid and high level clouds will spread over the region today, but we’ll stay dry.  We’ll notice a lowering and thickening cloud deck by evening and this is a hint at things to come Sunday.

Screen Shot 2016-07-02 at 7.44.09 AMRain will overspread the region Sunday morning, increasing in coverage and intensity as we progress into Sunday evening.

hires_ref_indy_31Rain will turn locally heavy at times and we expect a widespread swath of 2″-3″ totals through the heart of the state, with localized heavier amounts.  Precipitable water values exceed 2″ across central and southern IN Sunday evening and will likely promote a flash flood threat.
1Most of the rain falls Sunday morning-Monday morning before drier air begins to try and work in here as Monday afternoon arrives.  As of now, we think Monday evening firework shows should be a go!

Sunday will also be a chilly day for the time of the year as temperatures north of I-70 likely remain in the 60s most of the day.

We’ll have a video update posted later this evening with fresh thoughts from the 12z model suite.

Permanent link to this article: https://indywx.com/2016/07/02/unseasonably-cool-the-calm-before-the-storm/

Friday Morning Video Update: Pleasant Open To The Holiday Weekend Before Wet Times Build In…

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Permanent link to this article: https://indywx.com/2016/07/01/friday-morning-video-update-pleasant-open-to-the-holiday-weekend-before-wet-times-build-in/

Long Independence Day Weekend Taking A Wet Turn…

A cold front will slide through central IN Friday, but heavy rain and widespread storms aren’t expected as the front slides through the region. Instead, we’ll keep mention of scattered showers before drier air returns Saturday (with lots of sunshine).

For the purpose of this post, we’re more focused on the all-important Sunday-Monday forecast. Sunday will likely dawn dry, but trends are for wetter times late Sunday into Monday.  A slow moving area of low pressure is forecast to track out of the central Plains Sunday into the Ohio Valley Monday. Copious moisture will be affiliated with this area of low pressure, including a severe threat to the south of the storm track.  Heavy rainfall will fall along and north of the track of the low.  While we still have a couple days to fine tune things, it’s becoming increasingly likely that portions of the forecast area (especially southern and central areas) are impacted by heavy rain later Sunday into Monday.

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6We note ensemble support, as well.

3Rain totals will likely be hefty for some, including widespread 2″+ totals where the axis of heaviest rain falls.

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2Stay tuned as we continue to look over data and update the important Independence Day weekend forecast.

Permanent link to this article: https://indywx.com/2016/06/29/long-independence-day-weekend-taking-a-wet-turn/

Catching Up On Tuesday Night…

June to date is running warmer (+3.6°) and wetter (+0.71″) than normal in Indianapolis.


That said, drastic changes have taken place over the past 24 hours for the cooler and drier. In fact, as we write this, many central IN neighborhoods are enjoying temperatures in the lower 60s already at the 10 o’clock hour. An unseasonably cool night is in store with widespread low-mid 50s come Wednesday morning. (Anyone else craving fall)?!🍂


Highs Wednesday afternoon will only reach the upper 70s for most.


Our next chance of rain will arrive on scene to close the work week, however, moisture return still doesn’t look terribly impressive. We’ll continue advertising widely scattered coverage Friday. 


The plot thickens as we roll into the crucial Independence Day weekend. Latest data suggests a hefty rain storm will be in our general vicinity, but we caution many details have to be ironed out. Our forecast, locally, Sunday-Monday may differ drastically over a relatively short piece. Fine tuning on track, timing, and amounts will have to be adjusted.


GFS ensemble members also show the challenging times ahead.


Stay tuned! In the meantime, get those window opens and enjoy the weather! 

Permanent link to this article: https://indywx.com/2016/06/28/catching-up-on-tuesday-night/

Monday Evening Video Update…

Cooler, more refreshing times are building in.  Temperatures come mid week will have you asking “Is this late June?!”

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Permanent link to this article: https://indywx.com/2016/06/27/monday-evening-video-update-8/

PM Strong Storms…

The morning is off to a sunny, muggy, and warm start.  Temperatures will rise into the lower 90s this afternoon, but when we look at heat indices, it’ll feel like around 100 degrees across many central IN neighborhoods.

The visible satellite shows the sunny skies in place right now, but we note the cloud deck off to the northwest.  That’s in association with a frontal boundary that will press through our region tonight.

VisA line of thunderstorms will develop later this afternoon and a few of these could be strong to severe as they push to the south.  Large hail and damaging straight line winds are of greatest concern.  We think best chances of thunderstorms across central IN will come during the mid to late afternoon hours into the early evening.

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6p

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11pThe air mass is loaded with moisture today.  In fact, precipitable water values will zoom to 2″+ this afternoon and suggest the threat of torrential rainfall with any storm that develops.

2Once to Tuesday, a MUCH cooler, drier air mass will arrive on the scene and help set up an unseasonably cool close to the month.

Permanent link to this article: https://indywx.com/2016/06/26/pm-strong-storms/

Video Update On Tonight’s Severe Weather Event…

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Permanent link to this article: https://indywx.com/2016/06/22/video-update-on-tonights-severe-weather-event/

Latest Thinking On What Will Be A Busy Wednesday…

The SPC (Storm Prediction Center) maintains a significant severe weather risk across Indiana Wednesday.  A Slight risk encompasses the southern portions of the state, while an Enhanced risk takes up residence across central Indiana.  Finally, a Moderate risk is located across the northern third of the state.  Given the latest data, we wouldn’t be surprised if a portion of the Enhanced/ Moderate risk areas are upgraded to a rare High risk during the early Wednesday morning SPC update.  Regardless, we want to be very clear that Wednesday is a potentially dangerous weather day across Indiana.

2We won’t bore you with the meteorological ingredients/ lingo that are coming together to lead to an active Wednesday with this post, but please know that nearly all severe weather parameters point to the threat, and even likelihood, of an active day.

That said, there are unknowns.  How does morning convection impact our ability to heat/ destabilize things during the afternoon?  Are models underestimating the cold pool that will likely develop with the storms during the afternoon/ evening?  If so, a further southeast track and more robust situation could unfold (when compared to what forecast radar products suggest as of this post Tuesday evening).

While all modes of severe weather are certainly possible, for our immediate region, we’re particularly concerned for the threat of widespread damaging winds and flash flooding.  It wouldn’t surprise us if localized 3″+ amounts fall across portions of central and northern IN Wednesday.  Precipitable water values (PWATs) surging to 2″+ give increased confidence on localized flash flooding, especially considering the recent wet times.

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FlashFloodThreatThe first of multiple storm clusters will likely be moving into central IN Wednesday morning.  Here’s an idea of what the radar may look like around 7a.

1We think we undergo a “lull” in the action Wednesday afternoon before a potentially more serious complex of storms blows into town during the evening hours.  We caution that we’re not as confident on specific timing with the evening round of storms.

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4Current data would imply a tornado threat for areas from northern IL into northwestern IN with the afternoon/ evening convection before “morphing” into a more widespread damaging wind threat as the line propels southeast into the nighttime hours.  Timing will have to be fine tuned as Wednesday morning arrives.

To close, if you take anything from this post, please understand the importance of knowing your family’s severe weather safety plan.  Have a means of getting the latest watch and warning information from the National Weather Service and take any and all bulletins seriously.

Much more later!

Permanent link to this article: https://indywx.com/2016/06/21/latest-thinking-on-what-will-be-a-busy-wednesday/

Video Update: Monday Morning Thoughts On A Busy Week Ahead…

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Permanent link to this article: https://indywx.com/2016/06/20/video-update-monday-morning-thoughts-on-a-busy-week-ahead/

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