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…

Unsettled Week Ahead…

After an unseasonably cool and dry week to open the month, much more active times await as we head into the middle of August.

Upper air disturbances will ride southeast into the region to open the work week on the nose of a much more humid airmass trying to invade the area. These ripples of energy will be enough to lead to more organized thunderstorms, including locally heavy rain at times. Unlike what’s typical this time of year, this week will feature times of storms that rumble in during the nighttime and morning hours.

A frontal boundary will settle south into the region during the middle and latter parts of the work week before stalling out. This will serve as a focal point for additional thunderstorm chances for the 2nd half of the week, continuing into the weekend.

While it’ll be a warmer week, it’s more the humidity that will really make a difference. Daytime highs will remain close to average this week, overall, but overnight lows will be muggy- only falling to around 70° most nights.

We have no changes to our weekly rainfall forecast: 1″ to 2″ for most with localized heavier totals where stronger storms track.

  • I’ll be on the road tomorrow and will have our client video posted Monday evening.