Category: Weekly Outlook

Aug 13

Long Range Update: Closing Out August…

With a little over 2 weeks to go in meteorological summer, model data disagrees in the way the month- and season ends. That is, after the upcoming week where the consensus is cooler and drier than normal (we agree, as well). Let’s take a look at the data:

European Weeklies

Week 1

CFSv2

Week 1

GEFS

Week 1

EPS

Week 1

JMA

Week 1

The American data and JMA Weeklies are coolest (compared to the European), but compared to Weeks 2 and 3, there’s better consensus. The initial week is also looking drier than normal- especially after a “smattering” of storms tomorrow and Saturday.

Week 1 Precipitation anomalies- JMA Weeklies
Week 1 Precipitation anomalies- European ensemble

Let’s now take a look at Week 2:

European Weeklies

Week 2

CFSv2

Week 2

GEFS

Week 2

EPS

Week 2

JMA

Week 2

This is where our idea begins to pivot more towards the JMA Weeklies and European data (warmer look). The reason primarily has to do with the MJO moving back into Phase 8 during this time period.

This is a warm phase in August.

Furthermore, the PNA ‘mean’ is forecast to trend off the positive “mountain” (that will help drive the cooler pattern for the upcoming week) and more towards neutral.

Phase 1 is also a warmer look for our part of the country and that’s the way we’re leaning for the last week of the month (despite the very cool CFSv2).

While not overly warm, we think the JMA has the best handle on the temperature pattern in the Week 3 timeframe, locally (seasonable to slightly above normal).

The pattern should also begin to trend wetter during this time period:

This matches up with Phase 1 of the Madden Julian oscillation:

So, to summarize, after a cool and dry period next week, we anticipate the pattern to trend warmer (more seasonable) and wetter to close the month and head into early September. One other item of note is that the tropics should really begin to heat back up during this period, as well. Of course, as is the case from time to time, that can be a wild card from a precipitation perspective. The Gulf of Mexico (GOM) looks particularly busy late August through late September, but there’s simply no way to get more specific from this distance, including potential inland impacts. It’s worth keeping a close eye though.

Before we leave, the latest JAMSTEC seasonal data updated this morning and features a “torch” of a fall, along with a warm, wet winter, locally. That southeast ridge will have to be dealt with this winter. While still early, the early lean is for a warm start to winter (including holiday season). While there are some ingredients that may keep things more interesting than what they could be otherwise, from at least this point, this doesn’t appear as if it’ll be an “exciting” winter for lovers of snow and cold. Much more later- and again, we still have a long way to go…

Permanent link to this article: https://indywx.com/long-range-update-closing-out-august/

Jun 15

VIDEO: Timing Out When Rain/ Storm Chances Return…

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Permanent link to this article: https://indywx.com/video-timing-out-when-rain-storm-chances-return/

May 13

Off To The Races; Warmth Met With Periodic Storms…

A band of light showers is falling across southern Indiana this morning, but these are expected to diminish before pushing into central Indiana. Most of the remainder of our Wednesday should be rain-free.

The quiet times will give way to a couple of rounds of storms during the overnight and into Friday. Most notably for central Indiana, we think storm chances will increase significantly after midnight and through the predawn hours Thursday. Locally heavy rain and vivid lightning is expected with the stronger storms.

These storms are in association with a warm front lifting north through the state. Speaking of warm, we’ll certainly notice a difference in air masses between today (still relatively cool and dry) and tomorrow (much warmer and more humid). In fact, highs Thursday will flirt with 80° across most of central Indiana.


Once we get rid of the early morning storms, most of the remainder of our Thursday will be dry and feature a return of the sun.

Another round of storms is expected Thursday night into Friday, but most of these will remain well north of our area. A few of these could become severe across northwestern Indiana during this period.

Rain and storm chances will increase once again during the day Friday across central Indiana. A few strong storms will be possible.

As we look ahead to the weekend, it appears we’ll be able to enjoy a mostly dry day Saturday (widely scattered storm possible) before more widespread storms return Sunday. Warm and humid conditions will prevail. A cold front will move through the area early next week which will allow for briefly cooler, drier air to move in during the 1st half of next week. Before that takes place, rainfall amounts between tonight and Sunday are expected to range from 1.5” – 2” with locally heavier totals across central Indiana. Heavier rainfall amounts can be expected across northern Indiana (widespread 3” to 4” amounts during the same period).

Permanent link to this article: https://indywx.com/off-to-the-races-warmth-met-with-periodic-storms/

Apr 25

Weekly #AGwx And #Severe Outlook…

Weekly Highlights:

I. Potent area of low pressure will track along the Ohio River, spreading rain across the Ohio Valley and into the Northeast, including higher elevation wet snow.

II. A surface low and associated cold front will sweep into Plains Tuesday and to the eastern seaboard by Thursday. This system will have to be monitored for not only the potentially of locally heavy rain, but the threat of strong to severe thunderstorms on the journey southeast.

Wettest anomalies will extend from the Ohio Valley and Mid-Atlantic into the Northeast over the upcoming 7-days. Widespread dry conditions can be expected across the central Plains into the Rockies.
Immediate central-Indiana can expect 2″ to 2.5″ of rain between now and next Saturday morning, with locally heavier amounts.
Summer-like heat will bake the West while the eastern 1/3 of the country remains cooler than normal.
We will have to keep close tabs on the midweek cold front as it may ignite strong to severe storms from the Plains to the East Coast in the Tuesday-Thursday time period. The SPC is already highlighting a Day 4 (Tuesday) risk.

Forecast Period: 04.25.20 through 05.02.20

Central Indiana and the Ohio Valley, as a whole, will have to deal with both storm systems highlighted above. While we still believe dry conditions will prevail through a good portion of our Saturday, rain will become more widespread this evening into Sunday morning in response to a surface low moving northeast along the Ohio River. A couple heavier bands of rain may develop across the region tonight into Sunday morning and by the time all is said and done, the southern half of the state (along and south of the I-70 corridor) can expect 0.50″ to 1″ of rain by Sunday afternoon. Further north, amounts between 0.25″ and 0.50″ will be more common. Drier air will build in late Sunday afternoon, along with a cooler northeasterly and northerly flow behind our departing storm system.

Monday morning will open dry, but a weak weather maker will scoot through the state during the afternoon, resulting in scattered showers making a return Monday PM. These will be quick-moving showers and rainfall totals are expected to remain light for those that do see rain.

A much more organized storm system will push southeast Tuesday evening and Wednesday leading to more widespread shower and thunderstorm activity during this time frame. Stronger storms and locally heavy rain will be a good bet with this particular system. Drier, cooler air returns behind this system as we get set to wrap up the work week.

Permanent link to this article: https://indywx.com/weekly-agwx-and-severe-outlook-4/

Apr 24

Looking Ahead Into May: Extended Cooler Than Normal Regime; What About Precipitation?

The 2 big teleconnections (at least that we lean heavily on this time of year) both favor our cooler than normal regime lasting into the early to middle part of May. That’s not to say, there won’t be periods of warmth getting into the region ahead of cold fronts, just that in the overall sense, temperatures should continue to run below normal into the 1st half of May.

We can thank the positive PNA and negative NAO.

After data aligned in handling the MJO movement into early May, disagreement has returned, and we’ll need to keep a close eye on this. Hopefully, by the time we release our official May Outlook (next week), agreement will return.

If, indeed, we do get things into Phase 4 (such as the GEFS shows), a warmer pattern should emerge towards the end of the 1st week of the month. Again, we’ll monitor these trends closely.

The latest European Weeklies remain cool into mid-May.

Apr 23-30
May 1-7
May 8-14

After the recent dry stretch through the majority of the month, the pattern should transition towards a more active/ wetter than normal time of things over the next 2-3 weeks.

Permanent link to this article: https://indywx.com/looking-ahead-into-may-extended-cooler-than-normal-regime-what-about-precipitation/