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.
Let’s look at what the model guidance is printing out for meteorological spring:
JMA
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.
The early “baseline” of our ideas focuses on the likelihood of El Nino returning for the upcoming winter season. As we’ve stated many times in the past, each Nino event is different from one another and other ingredients (highlighted above) can play a significant role in ultimately determining the eventual outcome.
That sea surface temperature configuration in the northern Pacific argues for western Canada ridging and downstream troughiness such as the JAMSTEC, European, and CanSIPS would imply.
In addition to the central PAC anomalies, we also are keying in on some other items of interest in the overall SST configuration:
The SST CA model is quickly becoming one of our more trusted seasonal forecast models. We note how it becomes increasingly bullish on a central and eastern trough as winter wears on (by the way, this is likely to go deep into spring this year, too).
Cold overwhelms the pattern and when you combine it with the active storm track (noted by the green hues, suggesting above normal precipitation through our neck of the woods), confidence is continuing to grow for an above normal snow season.
The SST configuration on the JAMSTEC would suggest a cold, stormy set-up, locally. That said, while it sees the above average precipitation, it’s awfully warm at the surface.
The NMME (to no surprise…) would suggest a very warm, wet winter.
As a reminder, our complete and final annual winter outlook will be posted here during the second half of October. That will include additional model data, along with several other points behind our reasoning for our winter forecast. As we always do, we’ll put “pen to paper” when it comes to our winter forecast, including our expected temperature and snowfall anomalies. Given the data above, including the warm JAMSTEC and NMME, it’s going to be very, very hard to see a warm winter here. In fact, our idea is for the exact opposite, given the SST configuration, and lines up more closely with the SST CA idea at this point. We’re also in the camp of a very, very active storm track through the Ohio Valley. “Big-hitter” potential is present from a winter storm perspective, especially given that we are likely to see resistance from the SE ridge.
