Category: Long Range Discussion

Saturday Morning: A Look Where We’ve Been And Where We’re Going…

August has been cooler and drier than normal month-to-date.  As we’ll get into below, this cooler, dry trend should continue to wrap up the month.

* Click on any image to enlarge.

August temperature departure- month-to-date.

August temperature departure- month-to-date.

August precipitation departure- month-to-date

August precipitation departure- month-to-date2015 to date has been cool central and east:2015 to date has been cool central and east:

2015 to date has been cool central and east:

4The upcoming winter looks fun and challenging.  It’s a volatile look with the strong Nino and warm northern, eastern Pacific (positive PDO).  Certainly can’t “broad brush” the upcoming winter forecast solely based off similar strong Ninos of the past…

10Positive PDO temperature anomalies favor western Canada ridging and troughiness east.  It’s a pattern that favors a cooler than normal regime across the east and southeast.

11As we go into the weekend, sunshine and comfortable conditions today will give way to increasingly cloudy skies Sunday with a threat of a shower or thunderstorm, especially during the afternoon and evening.  A few of these storms could reach strong levels.  The culprit?  Another strong late August cold front.  Most rainfall totals will be around a quarter inch Sunday, but there will be some locally heavier totals with stronger storms.

5Warmer conditions will build in briefly in between the early week cool spell and stronger push of cool inbound Sunday night that will remain with us through the majority of the upcoming work week.

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7Longer term, we think conditions warm going into next weekend after a very cool, fall-like week, but don’t necessarily agree with the GFS ensemble plot below into early September.

3We expect ridging to build in to close the last couple days of August.

9However, recurving Typhoon Atsani argues for a return of cooler air (briefly) and an associated trough arriving between September 2nd and 4th…

8Images credited to the following:

  • weatherbell.com
  • http://www.usno.navy.mil/JTWC/
  • http://mrcc.isws.illinois.edu/cliwatch/watch.htm#seasonMaps

Permanent link to this article: https://indywx.com/2015/08/22/saturday-morning-a-look-where-weve-been-and-where-were-going/

Thursday Weather Notebook…

Wow, what a difference 24 hours can make! If you haven’t stepped outside yet this morning you’ll certainly notice the cooler, drier, and almost fall feel to the air upon…

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Permanent link to this article: https://indywx.com/2015/08/20/thursday-weather-notebook/

August Outlook

Before we dive into what we expect for the month of August, here’s a look at where we stand so far for July (with 4 days left as of this post).

This was our July forecast upper air pattern, issued 6.29:

July2015UAHere’s a look at temperature anomalies through 7.27:

ncep_cfsr_noram_t2m_anomWhile overnight lows have been running warm with all of the clouds and moisture, daytime highs have been significantly below average:

tmax30dydevWith four days left in the month, it’s already been the wettest month on record at IND.  The Corn Belt, as a whole, has been quite wet month-to-date.

nws_precip_conus2_mtd nws_precip_indy_mtd precip30dydevAs we progress into August (where does time go) we think we continue in an active pattern, locally, biased cooler than normal and wetter than normal.

AugustUA2015While modeling disagrees with the specifics in regards to the timing, most mid to long range modeling does agree on the overall idea of the hot dome (ridge) backing west and setting up shop over the southwest portion of the country early August which will put our region in (you guessed it) the favorable northwest flow for active weather.  Similar to July, disturbances will ride the periphery of the hot dome to our southwest and offer up plenty of chances for showers and thunderstorms.  That’s not to say we’re looking at setting another record for greatest amount of rain within a month, but it is saying precipitation should be above average yet again.

From time to time the ridge will attempt to expand northeast, but we don’t think it’s potentially until the last portion of the month before the ridge has much chance to encompass our region for any staying power more than a few days.  We suggest getting used to this 500mb look:

EarlyAugThe latest NAEFS and CFSv2 highlights the cooler than normal period we should undergo early August (especially after the 5th).

wk1.wk2_20150726.NAsfcT2015072712_054@007_E1_north@america_I_NAEFS@TEMPERATURE_anomaly@probability@combined@week2_186The latest European Weeklies suggest there may be a window for a “calmer” regime after the 25th.  That said, it’s a rather volatile pattern.

Yet another tool we’ve been keeping a close eye on the past few months has been the SOI (Southern Oscillation Index) as it’s been a big help in tipping us off for prolonged wet weather.  Note the consistent negative SOI:

Screen Shot 2015-07-27 at 11.22.11 PM

 

 

 

 

 

 

World

Not to sound like a broken record, but we continue to think the relentless wet weather pattern “keeps on keepin’ on” as we progress through August.  It’s very interesting to note the dynamics at play between the strengthening El Nino and warm northeast PAC waters… More on that, and the implications we feel for fall and winter, in the weeks and months ahead. 🙂

July2015SST

Permanent link to this article: https://indywx.com/2015/07/27/august-outlook-2/

At Odds With Some Of The Modeling In The Mid/ Long Range…

Right off the bat, we tend to lean more in the direction of the 12z GFS and its’ associated cooler look next week, rather than the warm European. It’s a…

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Permanent link to this article: https://indywx.com/2015/07/16/at-odds-with-some-of-the-modeling-in-the-mid-long-range/

Breezy And Much Cooler Today; Beautiful Sunday On Tap…

Flooding is an issue across many central IN communities this morning. Particularly hard hit is the Muncie community.  Zionsville’s Eagle Creek is also above flood stage this morning.    Thankfully, breezy…

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Permanent link to this article: https://indywx.com/2015/06/27/breezy-and-much-cooler-today-beautiful-sunday-on-tap/

More On The Rain Situation, Or Lack Thereof…

Things are growing a bit dry around these parts.  Officially we’re down 3.25″ for the month and close to 5″ on the year.  (Climate information for IND: http://w2.weather.gov/climate/index.php?wfo=ind)

Rains the past (14) days have favored the central region, falling apart as the systems push east and northeast.  Texas and Oklahoma continue to make news headlines from severe flooding.  – Too much of a good thing all at once.

nws_precip_conus2_14Officially we’re not even listed in the “abnormally dry” shading, but that very well may change with the Thursday update.  Courtesy of the Regional Drought Monitor:

20150519_midwest_noneAnytime you go through May with a significant rainfall deficit it raises a concern for continued dry times going through summer.  Dry typically breeds dry this time of year, and eventually heat.  That said, a strengthening El Nino will fight the recent trend.  Around these parts weak to moderate summer El Ninos tend to yield average (to slightly above) precipitation and average (to slightly below normal) temperatures.  Recent trends, combined with longer term forecasts certainly prove to lead to a battle in the coming weeks and months…

Shorter term as we progress through the coming days, here’s how we currently assess rainfall coverage:

  • Wednesday: Scattered- favoring eastern and southern portions of the state
  • Thursday: Mostly dry
  • Friday: Widely scattered
  • Saturday: Scattered to widespread showers and thunderstorms, but many dry hours, as well.
  • Sunday: Scattered coverage

* Rainfall potential through the weekend: 0.50″-1″ for most, with locally heavier totals under stronger storms.

Permanent link to this article: https://indywx.com/2015/05/26/more-on-the-rain-situation-or-lack-thereof/

Spring Fling!

A true taste of spring weather is on the way for the middle of the week as highs zoom to around 60° (give or take a few degrees) for many.…

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Permanent link to this article: https://indywx.com/2015/03/09/spring-fling/

Where We Are And Where We’re Going…

It’s another frigid start to the day and this seems to be the story of the winter of 2024-2015. The weather roundup of 7am temperatures and March 6th snow cover…

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Permanent link to this article: https://indywx.com/2015/03/06/where-we-are-and-where-were-going/

Warm Up Coming…

After a long and cold winter, many are excited about hearing of the prospects of a warm up and first true taste of spring.

While the European data has totally bought in to the impressive “spring fling” next week, the GFS isn’t as excited of the potentially warmer times.  Case in point, the GFS and European couldn’t be in more different camps for mid and late next week.  Where the GFS has low/ mid 40s for highs the European has low/ mid 60s for highs.  What’s 20 degrees amongst friends?!

Wild model swings and disagreements are common when pattern changes are taking place.   While we might not get as warm as the Euro. would imply, it’s a safe bet we’ll be considerably warmer than the chilly GFS readings.

Note the AO and NAO strongly positive through the next 10-15 days.  This is the time of the year when these teleconnections can impact our region’s weather in the most significant way.  Both of these are warm signals taken at face value.

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Note the pattern flip to a “flat” ridge by Day 10, indicative of the milder times ahead.

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However, by Day 15 we notice the Alaskan ridge redeveloping.  This is NOT a signal for warm weather across our part of the region, as the steering currents would tap available cold air and direct it south into the Mid West and Ohio Valley.

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So, what do we take from this?  We’re going to warm next week without question.  While the extent of the warming is up for debate, the overall milder times for a 5-7 period is a good call at this point.  On the flip side, we’re not ready to buy into the idea that spring is here for good just yet.  The building Alaskan ridge by the end of Week 2 would imply a cold close to March, and potentially continuing into early April.

Another item to keep a close eye on the upcoming 4-6 weeks?  Those NAO and AO signals.  Should they remain predominately positive this time of year then it’ll be exceptionally challenging to get any sort of cold pattern to lock in for more than a day or two.

Permanent link to this article: https://indywx.com/2015/03/04/warm-up-coming/

Looking Ahead…

January is off to a colder than average start across a large portion of the country, including the Hoosier state:

ncep_cfsr_noram_t2m_anomThe snow and ice pack has expanded over the past couple of weeks in rather significant fashion:

nsm_depth_2015011205_National

Two storm systems have offered up busy times over the Ohio Valley the past week. Note liquid equivalent numbers the past (7) days- most significant over central Indiana.  Most of this has been in the form of wintry precipitation (snow and ice).

nws_precip_indy_7

A weak weather system may offer up light snow chances mid week.  The high resolution NAM and European print off light snow while other models “see” us mainly dry mid week.

hires_ref_indy_52

The other big story in the short term will be more bitterly cold arctic air (single digits tonight and close to zero Wednesday morning).

While we’ll certainly “warm” compared to the freezer we’ve been in the first two weeks of January, sneaky arctic highs remain on the field and will put a dent in the air masses from reaching unseasonably mild levels for any length of time this weekend and Week 2.  See Friday’s GFS output and the sneaky arctic high north:

gfs_ptype_slp_east_18

The next significant storm system brews around the 20th (give or take a day, or two) and could offer up rain or a more wintry option.  Keep a close eye on the period 01.20 – 01.23.

Thereafter, the arctic hounds likely come calling again as the period quickly returns to “lock and load” cold late January into February.  The European and GFS ensembles both show a rebuilding blocking AK ridge and suggest arctic air floods the country yet again as cross-polar flow gets involved:

GFSensembleslateJan

It’s all part of a package that should be the beginning of a colder than average and stormy mid and late winter stretch.  Sea surface temperature anomalies are a textbook setup for a very wintry time of things for our neck of the woods.  Note the Modoki El Nino and warm waters sitting off the PAC NW- both cold/ stormy indicators here:

SSTLateWinterSetUp

Permanent link to this article: https://indywx.com/2015/01/12/looking-ahead/

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