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…

VIDEO: Stage Set For Record Cold Saturday AM; Updated Long Range Thoughts Towards Memorial Day Weekend…

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In Position To Challenge The All-Time Record Low For May Saturday; Discussing Degree Of Moderation Late Month…

We may only be a few weeks away from meteorological summer, but you wouldn’t know it. Instead, we’re talking about the potential of wet snow mixing in with a cold rain to close the work week and threat of lows falling into the 20s Saturday morning!

A strong cold front will settle south across the Ohio Valley Friday morning. In response to the front moving south, surface low pressure will organize along the boundary across the TN Valley Friday morning before roaring northeast and off the New England coast Saturday morning.

Widespread light rain will overspread the southern half of the state during the wee morning hours Friday, continuing into the mid to late morning before pushing off to the east. This will be a cold rain and may even mix with wet snowflakes at times before ending.

This won’t be a huge precipitation producer across central Indiana with most checking in between 0.10″ and 0.25″ (heavier amounts expected across southern Indiana).

Temperatures will slowly fall through the 40s during the daytime Friday. (Yes, we’re talking about May 8th)!

That then sets us up to at least be in position to break the all-time record low for the month of May (28° set in 1966). This will be an airmass with arctic origins and if high pressure can clear us out in time Friday night, overnight lows by Saturday morning are likely to fall into the upper 20s. High resolution guidance takes IND to between 26° and 27° while the European data remains consistent at 28°. Regardless, this will be “rare air” for so late in the season. Those with ag interests should use today to prepare for a hard freeze Friday night into Saturday morning.

Looking ahead, the bulk of the upcoming 7-day period will remain much cooler than average, but there are at least hints of a potential pattern change during the 8-10 day period. The European data is much warmer than the GEFS or new JMA Weeklies that are in-house. Additionally, the teleconnections don’t scream an all-out pattern change. Regardless, a period of moderation would certainly be welcome after this unusually chilly spell. We’ll have much more on this later today with our long range video update. Stay tuned.