Quick Evening Notes: Warm Pattern Grabs The Headlines In The Longer Range…
As we look over the 12z long range guidance, we see a common theme: warmer (dare I say “hotter”) than average. Additionally, most data paints a drier than normal trend Days 10-20, as well.
The GEFS shows eastern ridging gaining control during the period which favors a warmer than normal pattern. Consensus of other data is similar in the upper levels.
At the surface, all three major global models agree on warmth in the long range period, including the GEFS, EPS, and CFSv2:
Guidance suggests below average precipitation during the period. With broad scale ridging in place, we agree on a drier theme compared to normal. While trying to put our finger on the flip from the prolonged cold to warmer was difficult to nail down from March and April, May always looked like a drier than average month from several weeks out. (One note is the potential of active times across the Great Lakes region as “sudden summer” gains steam to the south and stubborn chill refuses to let go to our north. The gradient would promote heavier than normal precipitation relative to average).
Given the agreement in the data, along with some additional pattern drivers, we continue to believe the medium to longer term period (including mid and late May) will feature an overall warmer than average pattern along with drier than normal conditions.
More on the short-term in the morning, including what will be a summer-like feel by late week.
II. Our next weather maker will arrive midweek and provide a few showers Wednesday (not a huge deal from a precipitation perspective). However, as a deepening surface low tracks into the Great Lakes Thursday morning, a period of heavier rain and even thunder is possible. In general, this looks like a 0.50″ to 1.00″ type event.
III. Somewhat cooler air will whip in behind the low, allowing leftover precipitation to end as a couple wet snowflakes across the northern half of the state Friday morning. The bigger story will be the “bumpy” start to Friday with strong and gusty north winds.
IV. High pressure returns for the weekend and with it will come a return of sunny skies. Though the mornings will be frosty, afternoon temperatures will “warm” to pleasant levels, especially with the increasingly strong early-March sun angle.
V. Looking ahead, let’s keep a close eye on the second week of March. Potential is present for a stormy period to emerge under the block. We note the GEFS and EPS (respective ensembles of the GFS and European models) are in relative agreement on a stormy, cold look during this time frame. While far too early for specifics, the potential is there for a rather widespread wintry event from the Plains into the Northeast.
Embedded thunderstorms may target southern Indiana late tonight and Friday morning before more widespread thunderstorms (a couple could become strong) Saturday. The Storm Prediction Center (SPC) has included the southern half of the state in a “marginal risk” of severe thunderstorms Saturday.
All total, additional rainfall between now and Sunday morning should reach 2″ to 3″ across a widespread portion of the southern half of Indiana with locally heavier amounts.
We’ll finally dry things out as we close the weekend and head into early next week as high pressure settles overhead.
Next week will begin a pattern transition from the unseasonably warm weather we’ve enjoyed as of late to a colder regime for the first half of March. We note models continue to tank the NAO and AO.
Accordingly, the models are seeing the trough and associated colder than average pattern returning to the eastern half of the country as we rumble through the first half of March. With such a strong block in place, this can turn into an active pattern for a couple weeks to go along with the cold. Both the GEFS and EPS agree on the overall look.
While there’s no way to get specific on the individual storm threats that will eventually come with this pattern, the potential is present for a few storms to “bowl” underneath the block through the first 10-15 days of the month. Each storm will have the capability of delivering wintry precipitation, but this can also be a tricky time of year where most, if not all, ingredients need to come together to create significant wintry events. In a winter that’s been frustrating to central Indiana snow lovers (frigid, but dry first half and milder, wetter second half), perhaps it would be fitting to get a couple good snow dumps in March (when most are wanting and ready for spring)…