Category Archives: Forecast Models

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!

No Comments Arctic Cold, Forecast Discussion, Forecast Models, snow, Unseasonably Cool Weather

Thoughts Shift From Storms To Snow…

Before we discuss the weekend winter storm threat, we still have to get through the overnight period-morning hours Tuesday with embedded heavy rain and storms.  Some of these storms could offer up gusty winds and a few could be strong as they rumble across central Indiana Tuesday morning.

Most of the storms should push through west-central Indiana well before the morning rush hour.

Forecast radar 4am Tuesday.
Forecast radar 6am Tuesday.

Attention will then shift to the winter storm threat this weekend- particularly Friday night through early Sunday morning.  We still have to fine tune the all-important specifics, but confidence is rising on the possibility of a significant wintry event impacting at least portions of the region this weekend.  March snow events provide added headaches of dealing with the impacts of marginal temperatures, higher sun angle/ time of day, etc.  Conversely, the tight thermal gradients noted with most late season, spring snow events can be impressive, as they can quickly feedback, ultimately leading to swaths of thumping wet, heavy snow.  Hoosiers don’t have to think back too terribly far to some impressive and impactful March snow events.  Modeling today is in relatively good and surprising agreement, especially considering the lack of agreement models have dealt us weather ‘folk for the past few months.  🙂

GFS ensemble members are focusing in on a snow event this weekend.

It’s still early in the game and a lot can (and likely will) change with model runs over the next few days.  It’s wise not to make knee-jerk reactions to the operational model solutions, but instead understand the overall pattern driving the potential of this memorable March wintry event.  Anomalously cold air in southern Canada will spill south this weekend and help aid in the “fun and games” ahead.  At the same time, given the time of year, “suppression depression” isn’t likely as their will be resistance from the south-central Plains and southeast ridging in place.  As of now, we think the I-70 corridor could be the “sweet spot” for snow totals, understanding fine-tuning will be required moving forward.  Where a snowpack accumulates this weekend, expect temperatures Sunday night/ Monday morning to fall into the 10s.

Much more later!

No Comments Forecast Discussion, Forecast Models, Rain, snow, T-storms, Unseasonably Cool Weather, Winter Storm

Sunday Afternoon Rambles…

1.)  It’s another unseasonably pleasant afternoon across central Indiana.  Despite a gusty SW breeze (open county is approaching 40 MPH throughout central IN Sunday afternoon), the sunshine and warm temperatures are providing a phenomenal second half of the weekend.

Temperatures are running 20+ degrees above normal this afternoon.

2.)  Clouds will begin to increase tonight and give way to showers as we open the work week.  There will be plenty of dry time Monday morning into the afternoon, but a passing shower will remain in our forecast.  Heavier rain and embedded thunderstorms will arrive on the scene Monday night into the wee morning hours Tuesday.  As a whole, we expect between 0.50-1″ of rain, overall, by Tuesday morning.

Greatest rainfall coverage will arrive overnight Monday night.

3.)  We’ll trend cooler for the mid week stretch, but nothing “cold” for this time of year.  In fact, temperatures will remain above average as high pressure provides dry conditions.

Weak high pressure builds in for mid week.

4.)  Confidence is high on an active period of weather arriving for the weekend into potentially early parts of next week.  That said, despite overall high confidence on a busy time of things, the specifics remain “murky,” at best.  It’ll be important to check back for updates on the weekend forecast as we progress through the upcoming week.  Solutions range anywhere from a period of rain and storms to possibly some wintry “mischief.”  One thing seems certain and that’s for a period of colder air (below normal) arriving in the 8-10 day period.  In fact, the latest European model suggests overnight low in the 10s late next weekend.

The weather turns active next weekend.
No Comments European Model, Forecast Discussion, Forecast Models, Rain, snow, T-storms, Unseasonably Cool Weather, Unseasonably Warm, Weather Rambles, Weekly Outlook, Windy

Looking Ahead To Spring…

Meteorological spring begins in a few days (runs March through May).  We’ve already touched on the expected busy severe weather season and want to dedicate this post towards looking deeper into the weather pattern and the resulting precipitation and temperature impacts.

The latest longer-range data continues to be in very good agreement on the upper air pattern.  In short, the balance of the spring season looks to offer up a continued theme of warmer than average temperatures for our region.  (Not saying we won’t have to deal with a wintry “trick or two” over the first couple weeks of March).  When we look at spring, as a whole, we believe it’ll be one known more for the warmth and active, stormy times.

CFSv2 March Temperature Anomalies
CFSv2 April Temperature Anomalies
CFSv2 May Temperature Anomalies
JAMSTEC March through May Temperature Anomalies

The latest JMA monthly idea is one that has to raise an eye brow as it would paint an early summer across the Ohio Valley and Great Lakes.  Anomalous warmth (true summer-like air) would develop with a strong ridge over the Great Lakes and northeast.  This is something we’ll have to keep an eye on.  A big caveat here is how strong and quickly the coming El Nino develops.  It should be noted, El Nino years can feature some of the hottest air early, not late, in the summer season (relative to averages), and the JMA would, indeed, yield an early summer with such a look.

JMA May Forecast 500mb Pattern

It should also be noted modeling is suggesting a wet look, locally, especially during the early portions of spring.  The JAMSTEC and JMA are particularly bullish on a wet pattern.

JAMSTEC March through May Precipitation Anomalies
JMA March through May Precipitation Anomalies

The CFSv2 hits the wet March hard before a drier regime mid and late spring.

March Precipitation Anomalies
April Precipitation Anomalies
May Precipitation Anomalies

In closing, we seem to have a bit of a bumpy ride in front of us as meteorological spring begins.  While Old Man Winter hasn’t been seen much as of late, don’t be shocked if he makes his presence felt a few more times through the first half of March- both from a cold and snow perspective.  That said, data really points towards more of an overall warm regime developing the second half of the month, and continuing through the majority of spring, for that matter.  We’re keeping a close eye on May for an early summer-like feel to take hold, locally.  Subsequent JMA updates will be monitored closely.  We also remain confident of an active severe weather season.  Note the tendency of model data (above) to pull the mean trough position to the northwest March into April.  The clash of late-season wintry conditions west, combined with unseasonably warm temperatures across the east (not to mention the warmer than average Gulf of Mexico) likely will equal busy times as we progress through the spring severe weather season.

No Comments AG Report, CFSv2, Forecast Discussion, Forecast Models, Long Range Discussion, Plant'17, Severe Weather, Spring, Summer, T-storms, Unseasonably Cool Weather, Unseasonably Warm

Don’t Get Lulled To Sleep…

Overall, as mild as this winter has been (particularly on the snow front), it’s easy to think we’re done with wintry precipitation- especially after this stretch of 60°+ weather.  That said, we still have to get through March, and as long-time Midwesterners know, the third month of the year can yield some wild swings, including late season wintry events.  Yes, including even the mild winters of the past…

Modeling is beginning to show at least a shift towards unseasonably cold conditions as we progress through the first couple of weeks of March.  In the face of the prolonged stretch of April-like warmth of late, this will be a shock in and of itself.


Longer-term indications would suggest the period of chilly, wintry-like, air has a window to take over, but the window is small.  Trends would seem to yield warmer solutions once past mid-month, with perhaps a “stick and hold” spring regime taking over.

Before that, we have a couple of weeks in front of us to open March that won’t only provide out-of-season cold, but we must also pay close attention to the potential of northwest flow clipper systems.  There’s no reason to get detailed and specific from this distance, but the pattern suggests we need to be on the look-out for the potential of one or two snow makers as we move through the first couple weeks of the month.  March clippers can be a headache as the March warmth south of the track of the system can help add energy and turn a weak event into an impactful snow event to the north of the low’s track.  Hoosiers don’t have to be reminded how significant March clippers can be at times.  Is this the year we have to deal with one or two of these stronger clippers?  Wouldn’t it be ironic after such a mild winter thus far?  Don’t let Mother Nature “lull” you to sleep…

No Comments Forecast Discussion, Forecast Models, snow, Spring, Unseasonably Cool Weather, Unseasonably Warm, Weather Rambles