Category Archives: JMA

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…

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Thursday Evening Long Range Update: Late Summer And Early Autumn Pattern On The Horizon…

As we traverse the “dog days” of summer and look ahead to early autumn, what does the overall pattern hold? As is typical this time of year, the tropics are on the verge of becoming much more active, as well. Given analogs and other drivers, we suggest those with plans to the Gulf or Carolina beaches pay particularly close attention to the developments in the coming weeks and couple of months ahead.

The short-term is, obviously, highlighted by unseasonably warm-hot conditions but there’s reason to buy into the ‘mean’ ridge position retrograding west prior to month’s end. The large majority of long range data shows this taking place, as well.

Note the way the new European Weeklies, CFSv2 Weeklies, and JMA Weeklies handle this evolution in similar fashion over the coming 2-3 weeks.

European Weeklies: July 26-31
European Weeklies: July 30-Aug 4
European Weeklies: Aug 8-Aug 13
CFSv2 Weeklies: July 21-31
CFSv2 Weeklies: July 26-Aug 5
CFSv2 Weeklies: July 31-Aug 10
JMA Weeklies: July 19-25
JMA Weeklies: July 26-Aug 2

The screaming message is that the period of heat this weekend into early next week will transition west by the 2nd half of next week and into the Week 2 time period. Furthermore, though not saying there can’t be periods of “transient” heat still yet the remainder of the summer, the bulk of the sustained heat should be behind us once to the middle of next week.

Additionally, data is bullish on a wet close to July. This makes sense with the northwest flow aloft.

As the crucial late-summer stretch hits and harvest season is on the horizon, there’s reason to believe a favorable precipitation pattern should persist- if not potentially a bit wetter than normal. The wildcard, of course, as is typically the case has to do with the tropics. It only takes 1 or 2 tropical systems with the “right” inland track to provide heavy rains into the inland regions and there’s many reasons to buy into the fact this will be quite a busy “heart” of the tropical season this year. We’ll have to handle those as they come, as the steering currents can vary in significant fashion and there’s no way to accurately pinpoint inland areas most at risk of late-summer/ early fall heavy rain events from these tropical threats. Certainly, if your plans take you down to the beautiful Gulf Coast or Carolina beaches, it’ll be important to pay close attention to the developments and goings on as the season matures…

Stay tuned as we continue to move forward. In addition to our August Outlook, we’ll have more on where we believe the pattern is heading this fall and winter in the coming weeks…

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