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July 2019 archive
Permanent link to this article: https://indywx.com/2019/07/24/video-dry-pattern-through-the-weekend-timing-out-when-storms-return/
Jul 23
EPO In Control?
As we look ahead to the August pattern, it’s becoming increasingly apparent that the EPO, or East Pacific Oscillation, is trying to take control.
During positive phases of the EPO, warmer anomalies are usually noted across the eastern United States, whereas negative phases tend to promote cooler anomalies through the central into the eastern portion of the country. While the correlation is greatest in the fall and winter, the EPO phase can also have a say in the summer pattern.
As we look ahead at the forecast EPO and upper level pattern, note the similarities:
First, here’s what a negative and positive EPO would typically yield from the perspective of temperature anomalies:
Here’s the forecast EPO into the first week of August.
Note how closely the modeled upper air pattern (and associated surface temperatures) follow suit:
Present (negative EPO)
July 27th – Aug 1st (positive EPO)
Aug 3rd – Aug 8th (negative EPO)
(While we can’t show it here, it’s interesting to see the latest European Weeklies keep the EPO predominantly negative to significantly so through the bulk of August and into September).
So what’s the moral of the story? We believe after a period of transitional heat this weekend into early next week that temperatures will return to seasonal levels in early August, along with an increase in rain/ storm threats as the northwest upper air flow sets up shop. Our official August forecast will be issued early next week.
Permanent link to this article: https://indywx.com/2019/07/23/epo-in-control/
Jul 22
Dinnertime Rambles: Quiet Through The Short-Term And Longer Range Musings…
I. Drier air continues to surge south and with it will come much cooler temperatures overnight into Tuesday morning. We still believe most central Indiana reporting sites will fall into the middle 50s Tuesday morning. Turn off that A/C and open up those windows!
II. Weak upper level energy will push south and lead to isolated to widely scattered instability-driven showers across northern parts of the state tomorrow afternoon. A couple of these quick-moving showers could scoot into central Indiana, but we continue to believe most will remain free of any precipitation tomorrow.
III. Overall, we’re looking at a very quiet weather pattern through the weekend with an extended period of dry weather, thanks to high pressure. Temperatures will slowly warm from the unseasonably cool and refreshing levels into mid week to more of a seasonal feel this weekend.
IV. As we look ahead, the upper air pattern should transition to more of a classic summer-like regime to open August. However, data shows the ridge continuing to “retrograde” west with time, resulting in a period of wetter conditions with a northwest flow aloft Days 10-15 (roughly Aug 2nd- Aug 7th). It’s always good to see agreement between the European and GFS ensemble products below.
V. Research continues on the upcoming fall and winter and it’s becoming increasingly difficult to ignore the warm sea-surface temperatures across the northeastern Pacific. Interestingly, most seasonal model data maintains this warm “blob” into the late fall and early winter. Note where we are currently (center photo) vs. where the projection off the UKMET (top left) for Oct-Dec and European (bottom left) for Nov-Jan.
While only 1 of several ingredients used in building our seasonal outlooks, this can promote the tendency for more persistent western ridging and downstream trough (associated colder pattern) across the East…
Permanent link to this article: https://indywx.com/2019/07/22/dinnertime-rambles-quiet-through-the-short-term-and-longer-range-musings/
Jul 22
VIDEO: Relief Is Here; Quiet Pattern Into The Weekend…
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Permanent link to this article: https://indywx.com/2019/07/22/video-relief-is-here-quiet-pattern-into-the-weekend/
Jul 21
Early August Ideas…
The year continues to fly by! We’re now finalizing our forecast for the last month of meteorological summer and will include a look-ahead to our early fall ideas with the official August Outlook that hits the site later next week. With that said, here are some of our early August ideas:
I. Sea surface temperatures remain well above average through the western Atlantic basin as well as the northeastern Pacific. This should promote warmer than normal conditions, overall, along the coastal areas. Additionally, we’ll need to continue to keep a close eye on the potential of additional “home grown” (Gulf of Mexico and off the southeast US coast) tropical development as we move closer to the peak of the hurricane season.
II. The MJO isn’t nearly as hyper as months past. While we’ll continue to keep a close eye on things, we currently don’t anticipate being able to lean on this tool as a good indicator for what may transpire through the month of August (at least early on).
III. We need to keep a very close eye on the EPO over the upcoming week to see if modeling continues to project a significantly negative phase into August. This can “up the ante” for a cooler than normal central US during August if so.
IV. Lack of widespread drought/ dryness. The wet spring and early summer really can help make an impact longer term and that has been seen as early as this week (added humidity with the heat wave), but also helps overall when it comes to late summer and the respect to the staying power, or longevity, of heat waves.
Here’s our early thinking with respect to August temperatures and precipitation. Again, our final, more detailed, outlook will be issued next week!
Permanent link to this article: https://indywx.com/2019/07/21/early-august-ideas/
Jul 20
VIDEO: Big Changes On Deck; Looking Into August…
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Permanent link to this article: https://indywx.com/2019/07/20/video-big-changes-on-deck-looking-into-august/
Jul 20
Weekly #AGwx And Severe Weather Outlook…
Forecast period: 07.21.19 through 07.28.19
7-Day Precipitation: Rainfall is expected to run near average through the period.
7-Day Temperature Outlook: Temperatures are expected to run below average through the forecast period.
Severe Outlook: A strong cold front will slice into the unusually hot and humid air tomorrow afternoon and likely spark an increase in overall thunderstorm coverage. A few storms may become severe with large hail and damaging winds. Otherwise, after Sunday, severe weather isn’t expected through the remainder of the forecast period.
Summary: Hang in there, friends. Today will be the last ridiculously hot and humid day before we start to note relief. Sunday will still be hot and plenty humid, but will be the start of a cooler regime that will take hold in earnest by early parts of the work week. Before that, a cold front will spark scattered to numerous thunderstorms Sunday afternoon and evening and a few of these could become strong to severe. Linger upper level energy will keep shower chances in our forecast Tuesday with the much cooler temperatures. As we look forward, the next organized chance of rain and thunderstorms will come next weekend as another cold front sweeps through the Ohio Valley along with reinforcing pleasantly cool air behind the boundary.
Permanent link to this article: https://indywx.com/2019/07/20/weekly-agwx-and-severe-weather-outlook-7/
Jul 19
Dangerously Hot Now, But We’re Talking About An Entirely Different Weather Pattern To Close July And Open August…
Over the weekend we’ll bake in some of the hottest and most humid air we’ve dealt with around these parts since 2012, however big relief is on the horizon.
We’ll get rid of the expansive upper level ridge responsible for the heat this weekend and replace it with a significant trough (at least by late summer standards).
A strong cold front will sweep through the Ohio Valley Sunday and Monday with increasing coverage of showers and thunderstorms (a few may be strong). It’s this front that will help usher in the refreshing changes for next week. We’ll go from heat indices between 104-108 this weekend to overnight lows in the upper 50s to lower 60s at times next week. Ahhhhhh….
As we look ahead to early August, there’s certain to be additional warm-hot days, however, the mean pattern doesn’t look to promote any sort of sustained significant heat through the early portion of the month. Perhaps the most interesting item showing up on the longer range guidance (EPS and GEFS) is a return of a northwesterly flow aloft and the potential of a wetter regime building in as we traverse the early August period.
Hang in there, the reward on the other side of the weekend will be worth it with cool, Canadian air flowing south.
Permanent link to this article: https://indywx.com/2019/07/19/dangerously-hot-now-but-were-talking-about-an-entirely-different-weather-pattern-to-close-july-and-open-august/
Jul 18
VIDEO: Keeping An Eye On Storms To Our Northwest This Morning; Pattern Change On Deck Next Week…
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Permanent link to this article: https://indywx.com/2019/07/18/video-keeping-an-eye-on-storms-to-our-northwest-this-morning-pattern-change-on-deck-next-week/
Jul 17
“Sneaky” Storms Precede Dangerous Heat…
As we prepare for the hottest air of the summer, we’ll have to remain on guard for the potential of thunderstorms impacting at least a part of the state Thursday morning.
Upper level energy will track southeast into the state late tonight and early Thursday and combine with just enough energy to allow thunderstorms that should develop during the overnight (across southern WI and northern IL) to track into western Indiana during the predawn hours. (It should be pointed out this is separate from the convection that is currently resulting in warnings across MO and IL- as of 6:20p eastern time). Thereafter, these storms are expected to rumble into central Indiana in a weakening format around the morning rush Thursday.
Thereafter, the big story will be the high heat and humidity that will lead to truly dangerous conditions across central Indiana beginning tomorrow afternoon into Sunday. Heat indices will top out between 100-105 each afternoon and in some cases a few degrees higher. It’ll be important to build in frequent breaks inside and drink plenty of water. Most, if not all, neighborhoods can expect to remain rain-free through the first half of the weekend (after we deal with our Thursday morning storms).
Thankfully, we still are forecasting a “game changer” of a cold front to plow through the region late Sunday and early Monday with storms (a few could be severe) followed by a much cooler and more refreshing air mass next week.
This is likely the first of a couple of cold fronts that will pass through the region between now and the end of the month, ensuring we wrap up July seasonal to cooler than average.
Permanent link to this article: https://indywx.com/2019/07/17/sneaky-storms-precede-dangerous-heat/