Category: Forecast Models

Jackets Required: Cool And Increasingly Wet Close To The Week…

We’ll wrap the work week up with filtered morning sunshine, but clouds will quickly lower and thicken as the day progresses and give way to showers later tonight.

It’ll be a much cooler day today (temperatures are running close to 20° cooler than this time Thursday morning) with highs only topping out around 60 for the city, itself, and only into the mid to upper 50s across north-central Indiana.

More widespread rain showers will move in overnight into Saturday.  Heaviest rain will fall across the southern half of the state (1″-2″ possible).  Factor in a strong and gusty easterly wind, temperatures only in the 40s for much of the day, and periods of rain and you have the makings for a downright “raw” Saturday.

The good news here is that we still think things dry out for the second half of the weekend.  The last round of showers should pull off to the east Saturday night and pave way for a dry Sunday, including increasing sunshine as morning gives way to afternoon.

With the increasing sunshine Sunday, temperatures will respond closer to average highs in the middle 60s.  After we spend most of Saturday in the 40s that sure will feel nice!

Permanent link to this article: https://indywx.com/2017/04/21/jackets-required-cool-and-increasingly-wet-close-to-the-week/

Major Temperature Swings: Summer-Like Mid-Week; Sweater Weather This Weekend…

Central Indiana will undergo significant temperatures swings over the upcoming week.  A southerly and southwesterly flow will push an unseasonably warm and moist airmass north to encompass all of the region as we progress through Wednesday and Thursday.

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…

Permanent link to this article: https://indywx.com/2017/04/17/major-temperature-swings-summer-like-mid-week-sweater-weather-this-weekend/

Looking At The Week Ahead…

The second half of the weekend will feature beautiful weather, albeit breezy conditions at times.  Strong southwesterly winds will gust upwards of 40 MPH this afternoon, but also aid in pushing mid to upper 70s northward into central Indiana.  Despite the strong winds, we still recommend finding a way to get outside and enjoy this weather!

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.

Permanent link to this article: https://indywx.com/2017/04/09/looking-at-the-week-ahead/

Word On The Weeklies…

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…

Permanent link to this article: https://indywx.com/2017/04/06/word-on-the-weeklies/

Ugly Close To The Work Week Gives Way To A Gorgeous Weekend…

Today certainly won’t be a “chamber of commerce” like day across central Indiana as we deal with numerous mixed rain and snow showers.  Already this morning, reports of wet snow are coming in to the forecast office from Whitestown, Lebanon, and Crawfordsville.

We’ll also add wind into the mix late morning through early evening, including gusts around 50 MPH.  Factor in the much colder temperatures with gusty northerly winds and you have the makings for a truly “raw” day across the region.  The National Weather Service has issued a Wind Advisory until 8pm.

We should finally get rid of the precipitation later tonight and after a chilly Friday, weekend improvements are coming.  Lows both Friday and Saturday morning will be around freezing for most central Indiana neighborhoods.  After a cloudy start Friday, sunshine should return Friday afternoon as drier air works into the region.  With high pressure arriving this weekend, sunny conditions can be expected and with a southwest wind developing by Saturday afternoon, moderating temperatures are on deck as well.

In fact, after that cold start Saturday, highs should climb into the lower 60s Saturday afternoon and all the way into the lower to middle 70s Sunday afternoon!

Our next storm system will push into the Ohio Valley early next week with scattered showers and thunderstorms Monday into Tuesday.

Permanent link to this article: https://indywx.com/2017/04/06/ugly-close-to-the-work-week-gives-way-to-a-gorgeous-weekend/

Monday Morning Rambles…

1.)  Showers moved through the region early this morning and we’ll go through several dry hours before dealing with our next round of rain and thunderstorms by evening.  Most widespread coverage of showers and thunderstorms appears to come in the 5p-7p range.

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.

Permanent link to this article: https://indywx.com/2017/04/03/monday-morning-rambles-3/

Thursday Morning Rambles…

1.)  Morning showers and thunderstorms continue to impact north-central Indiana this morning and given the look to downstream trends on radar and satellite, it would seem like it’s going to be tough to get into any sort of significant sunshine this afternoon. This is great news as it’ll limit severe potential.  That said, we still can’t rule out a severe thunderstorm this evening with large hail and damaging straight line winds of greatest concern.  The updated (9a eastern) outlook from the Storm Prediction Center continues the “enhanced risk” for the southern half of Indiana.

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.

Permanent link to this article: https://indywx.com/2017/03/30/thursday-morning-rambles-2/

Looking Ahead Into Early April…

Month-to-date, Indianapolis is running near seasonal norms from a temperature standpoint (0.50° above normal).  Chill has dominated the northern tier and eastern third of the country.

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.

By Wednesday night/ Thursday morning, shower chances will begin to increase and that will set the stage for a wet close to the work week as numerous showers and embedded thunder move across the region Thursday into Friday.  This is courtesy of a storm system “bowling” through to our south.  This won’t be a severe weather maker for our neck of the woods, but will serve to create a rather damp and gloomy regime during the aforementioned period.

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.

Permanent link to this article: https://indywx.com/2017/03/27/looking-ahead-into-early-april/

Thursday Morning Weather Rambles…

1.)  All of a sudden what was a warm March has revered big time.  Officially, Indianapolis is running close to 1° below normal on the month and will continue to fall further once today’s data is factored in.  Always fun to see Mother Nature “balance” things out.

2.)  It’s another cold start to the day with many central Indiana neighborhoods in the teens and hard freezes extending south into Florida this morning.

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.

Permanent link to this article: https://indywx.com/2017/03/16/thursday-morning-weather-rambles-4/

Extended Period Of Unseasonably Cold Air…

Today will begin a rather extended period of unseasonably chilly air that will grip the region.  It’s not until the latter portions of next week that we should begin to see slowly moderating temperatures.

The reason for this is a persistent trough setting up over the Great Lakes and eastern portions of the country.  From time to time, individual disturbances will come racing along in the fast northwest flow aloft and help to reinforce the cold and also create snow potential.

Forecast models continue to show an eastern trough into the middle parts of next week.

 

This is an impressively cold pattern for so late in the season.

This is the type pattern that will promote multiple nights in the teens over the upcoming week.  We forecast coldest nights to be Saturday night, Sunday night, Wednesday night, and Thursday night.  Each has the potential to send neighborhoods into the middle-upper teens.

As far as snow goes, we still are keeping an eye on the early stages of the work week.  We’ll fine tune things this weekend, but models continue to show energy diving southeast Monday that would help snow overspread the region during the day, continuing into Tuesday morning.  This time of year, snowfall rates and time of day means a world of difference between snow flying in the air, versus accumulating.  The potential is there for light accumulation Monday night as reinforcing cold air pours in.

Stay tuned!  Much more later!

Permanent link to this article: https://indywx.com/2017/03/10/extended-period-of-unseasonably-cold-air/

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