Category Archives: Summer

2019 Spring Outlook…

2019 IndyWx.com Spring Outlook

Forecaster: Team; Date Issued: 02.16.19

Last spring was a tale of two seasons in itself. March (featured a foot of snow) and April were significantly colder than normal and then we shifted things to summer in May (the last month of meteorological spring was close to 10 degrees above normal). As a whole, it was a quiet severe weather season.

Despite the wild swings, at the end of the day, things “balanced out” nicely across the central Ohio Valley, including central Indiana.

As we look ahead to what the 2019 version holds, here are a few headlines that have our attention:

I. Weak Nino is behaving more like a Nina (Tropical Northern Hemisphere pattern can be thanked for this).

II. Neutral NAO is expected

III. Neutral PDO (Pacific Decadal Oscillation)

In addition, we’re paying special attention to the SST configuration in the Gulf of Mexico. A warmer than average GOM can most certainly lead to a more “hyper” severe weather season as spring gets going.

The late winter/ early spring drought monitor can give a hint where early warmth may try and get going. However, this year, we can’t rely on this tool as the Plains and East, including the heart of the #AGbelt, have seen copious amounts of moisture over the winter.

Drought Monitor as of 2/14/19
December 2018 Precipitation Anomalies
January 2019 Precipitation Anomalies

Let’s look at what the model guidance is printing out for meteorological spring:

JMA

March
April
May

CFSv2

JAMSTEC

European Seasonal

Summary

We anticipate a slightly warmer than average spring season across not only central Indiana, but the Mid West and Ohio Valley region, as a whole. A weak El Nino is expected to persist into the upcoming summer and the conditions typically associated with such should eventually show themselves (as opposed to more of a Nina-like flavor now) through the spring. We agree with the consensus of model guidance above that March is likely to feature the coldest temperatures, relative to normal, and that’s primarily due to what should be a colder 1st half of the month before more bonafide spring conditions take hold the 2nd half of the month. Precipitation is anticipated to run near average, if not slightly below average, levels through the spring. As for severe weather, we expect a much busier season than last year, especially with the warm SSTs lurking in the Gulf of Mexico.

1 Comment AG Report, CFSv2, Client, El Niño, European Model, Forecast Discussion, Forecast Models, JAMSTEC, JMA, Long Range Discussion, Monthly Outlook, NAO, PDO, Plant '19, Rain, Severe Weather, snow, Spring, SST Discussion, Summer, Unseasonably Cool Weather, Unseasonably Warm

New Month; New Pattern (In Some Aspects) Around The Corner…

October got off to a warm start, but unseasonably chilly conditions have dominated over the past couple of weeks.  In fact, we’re on a stretch of (12) consecutive days below average after the summer-like start.  The other common theme?  Dry, dry, dry.  Officially, IND is running close to 1″ below average through the first few weeks of the month.  Changes loom- at least to some extent.

We notice the ensemble data (both the European and GFS) is painting a more active, wetter regime as we move through early November.  Given the upper air pattern, we would tend to agree.

European data, courtesy of Weathermodels.com, paints a much more active picture early November.

GFS data, courtesy of Tropicaltidbits.com, shows the return of a wetter pattern for early November.

While confident on the return of wet conditions as we traverse the first week or two of November, data is struggling to get a handle on the PNA past the short-term.  The PNA, or Pacific North American Pattern, teleconnection is one of our favorites this time of year to “key in” on the medium range pattern.  While the NAO and AO get a lot of attention the deeper we get into the cold season, the PNA can be a tremendous tool during transition seasons.  We note latest data is trending significantly more towards a positive PNA (compared to previous runs)- which is a colder signal.

To no surprise, data has trended chillier during today’s 12z update.

To close, bank on a return of the wet conditions as we move into the mighty month of November.  From a temperature perspective, the forecast is much tougher for the first half of November.  As things stand now, we continue to favor a relaxation of the anomalous chill overall, but can certainly see where “pops” of cold air can easily sweep in behind what should be an active storm track from the mid-south up into the Mid West and Ohio Valley.  Stay tuned.

No Comments Autumn, Ensemble Discussion, Forecast Discussion, Forecast Models, Harvest'18, Rain, Summer, Unseasonably Cool Weather, Unseasonably Warm

First Frost Of The Season Comes Right On Schedule…

The average date for the first frost and freeze in Indianapolis takes place on October 11th and 14th, respectively.  Right on cue, the first frost of the season will take place for most central Indiana neighborhoods over the weekend.  If you happen to miss out on the frosty conditions this week, reinforcing chilly air will descend on the region early next week.

We forecast (3) of the upcoming (7) nights to fall into the 30s.  This is, obviously, a significant change from the extended summer like conditions we’ve been dealing with as of late.  One primary driver behind the significantly cooler pattern has to do with the change in the PNA.  The shift towards a positive PNA will result in the cooler air remaining in place with more staying power than the fleeting cool shots of a few weeks ago.

A series of cold fronts will sweep through the Ohio Valley over the upcoming couple of weeks and each will likely feature progressively cooler conditions.

With the positive PNA in place, it’s no surprise to see the mean trough setting up shop over the eastern portion of the country.

At the surface, we see the cool pattern taking hold into not only the short-term, but the 10-15 day range, as well.

No Comments Autumn, First Freeze, First frost, Forecast Discussion, Forecast Models, Harvest'18, Long Range Discussion, PNA, Summer, Unseasonably Cool Weather, Unseasonably Warm

One More Summer-Like Day Before A Big Change…

High pressure and warm southwesterly winds will lead to one more summer-like day before significant changes take place.  Plentiful sunshine can be expected Tuesday with temperatures closer to a record high (88° set in 1939) than the average of 68°.

A cold front will sweep through the region Wednesday evening and will lead to a better chance of more concentrated showers and thunderstorms for our hump day.  Precipitable water values (PWATs) will approach 2″ Wednesday afternoon which is almost unheard of by October standards.  As a result, a couple of the storms may be accompanied by locally heavy rainfall.

Winds of change will be blowing in earnest Wednesday night and Thursday morning and a legit fall feel will greet us out the door!  Most of central Indiana can expect temperatures to be falling into the 40s Thursday morning along with a nice northwest breeze.

Longer term, a new storm system (including remnant moisture from Sergio) is expected to impact our weekend weather.  We’ll trend our forecast wetter with reviewing some of the latest data.  Sunday appears to be the wettest day.

An even more impressive push of fall air will follow on the heels of Sergio’s remnants early next week, including the potential of frost for more of the Ohio Valley, including central Indiana.

No Comments Autumn, First frost, Forecast Discussion, Forecast Models, Harvest'18, Heavy Rain, Rain, Summer, T-storms, Tropics, Unseasonably Cool Weather, Unseasonably Warm, Windy