Category: Forecast Discussion

Saturday Snow…

There’s just something special about seeing the first flakes of the season.  While this initial wintry event won’t be a big deal accumulation-wise for central IN, a few inches of snow will be likely across northern portions of the state Saturday.  Here’s our initial snowfall forecast, brought to you by the IndySportsReport.com.112115SnowForecast1stLookThe next two days will be easy and rather “boring” as far as the weather goes.  Look for more in the way of sunshine today before clouds begin increasing as Friday progresses into evening.  The initial push of moisture should reach central IN Friday night (as rain).  Rain will then transition to snow showers before ending across central IN Saturday morning into the early afternoon.  Farther north, look for a quicker transition to snow where we forecast a 2″-4″ type accumulation event for places along and north of a Newton County to De Kalb County line.  This is an early call and may require some fine tuning as we go through the next 24 hours.  We’re about as confident as we can be with the forecast at this juncture, but do note a couple differences with the track of the low between the various models we use.

Here’s the track set-up:

A wave of low pressure will “scoot” east, northeast Friday into Saturday as highlighted here by the fine folks at Weatherbell.com.

FriEvening

FriNight

SaturdayMorningEnough of a south wind will keep us just warm enough to provide mainly a rain event for central and southern portions of the state.  Colder air will be deeper and more entrenched across northern IN where this should be a mainly snow event.  As the winds quickly whip around to the NW Saturday morning, temperatures will plummet and lingering moisture will quickly transition to snow for all of the state.

Behind the rain-to-snow event Saturday morning, the coldest air of the season will plunge into the state.  Lows Sunday morning will fall into the teens for many of central IN, especially if we can lay down a snow cover up north.  Throw in a gusty NW wind and wind chill values in the single digits are a good bet.

Can things still change with the track of this storm?  Absolutely.  While we feel as confident as we can be at this stage in the game, we do note a couple differences with the track of this area of low pressure (as mentioned above) between the various computer models we use.  We’ll continue to keep a close eye on things.  One other item of note is the relatively warm surface temperatures and that will cut back on accumulations across not only central, but northern parts of the state, as well.  Much more later!

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Permanent link to this article: https://indywx.com/2015/11/19/saturday-snow/

Tuesday Evening Video Update…

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Permanent link to this article: https://indywx.com/2015/11/17/tuesday-evening-video-update-4/

El Nino Update; Updated Winter Thoughts…

As we rumble closer to the start of meteorological winter, we wanted to provide some updated thinking around what lies ahead.  Before we dig into some of the latest data and dissect the updated SST profile, here’s a recap of our winter outlook posted 10.17.15.  You can read the complete outlook here.

  • Worst of winter, from a cold and snow perspective, is during the back half of the season.
  • Colder than average winter ahead by 1 deg. (F) on average.
  • Slightly less snow than normal at 20″ (first flake to last flake).

At first glance upon looking at the latest SST profile, there aren’t many huge changes from (6) weeks ago.  However, there are some interesting trends, mostly pertaining to El Nino region 1+2 versus 3.4.

SSTUpdate1114151.) In the most recent El Nino monthly recap, Region 1+2 cooled .09 degrees (F) from September to October.  Meanwhile, Region 3.4 warmed .32 degrees (F) during the same period.  This trend is interesting and something we think continues looking over the data.  Central-based, Modoki El Nino events argue for a colder east across a more widespread basis.

2.) The warm, or positive PDO, continues.  This argues for eastern cold.  Remember the past two winters that ran colder than normal across our region?  The positive PDO played a big role in powering those.

3.) Though admittedly much more of a wild card, the current SST configuration in the northern Atlantic continues to argue for a developing negative NAO as mid and late winter arrives.  Personally we feel the NAO impact, locally, is felt more in the later winter period.  A negative NAO would also argue for colder than normal.

The latest Sea Surface Temperature Constructed Analog (SSTCA) model is in and remains firm on the idea of a cold east and south.

The warm PDO continues through winter and the warm PAC anomalies continue "spreading" west.

The warm PDO continues through winter and the warm PAC anomalies continue “spreading” west.

The central and eastern regions are favored for colder than normal temperatures through meteorological winter.

The central and eastern regions are favored for colder than normal temperatures through meteorological winter.

The predominant upper air pattern shows central and western Canada ridging with southern and eastern troughiness- also a sign of an active southern stream (storm track).

The predominant upper air pattern shows central and western Canada ridging with southern and eastern troughiness- also a sign of an active southern stream (storm track).

As we move into the Thanksgiving and Christmas seasons, rest assured we’ll continue to keep close tabs on the “sensible” weather the evolving pattern will deal the region.  As a whole, we feel confident we remain on the right track and think plenty of wintry “fun and games” lie ahead this year.

Here’s a photo from Christmas 2007 out in Breckenridge, CO with my brother.  Could this be the scene for Christmas this year here?  “I’m dreaming of a white Christmas…”

BreckChristmas

Permanent link to this article: https://indywx.com/2015/11/16/el-nino-update-updated-winter-thoughts/

Nice Today Before Our Next Storm Arrives…

Screen Shot 2015-11-15 at 8.55.18 AMHighlights:

  • Beautiful Sunday
  • Clouds and rain return
  • Colder late week
  • Eyeing a potentially wintry end to November

Our next storm system is coming ashore along the West Coast this morning.  That storm will impact our weather this week, but today we’ll focus on the sunshine and beautiful conditions.  Temperatures will climb into the lower to middle 60s.  With what lies ahead, we’d highly suggest taking advantage of the nice weather today and finish up any of that outdoor work you may have.

Clouds will increase Monday and the initial surge of moisture will provide showers and light rain by afternoon and evening.  A strong southerly flow continues Tuesday into Wednesday with periods of rain.  It won’t rain the entire time, but more times than not.  A push of heavy rain still appears likely Tuesday night into Wednesday.

The image below is a look at forecast PWATs, thanks to Weatherbell.com, for Tuesday night.  When these values reach 1.5″-2″ that’s a good indication for very heavy rains.  We’ll continue to forecast widespread 2″+ type rainfall with this storm system.

gfs_pwat_conus2_14Once this next storm moves out, we’ll get back to drier and colder times to end the work week.  Attention will then shift to a colder, potentially wintry, end to the month, including the Thanksgiving holiday. It’s too early for specifics on storminess, but model data does hint at a storm of “interest” around Thanksgiving.  With colder air making a return, it’s certainly possible this next storm has a wintry component to it…

The latest GFS ensemble temperature anomaly chart shows the colder than average pattern setting in to wrap up November.

KIND_2015111500_nxa_384

Permanent link to this article: https://indywx.com/2015/11/15/nice-today-before-our-next-storm-arrives/

Big, Wet Storm System Sitting On Deck…

Enjoy the weekend, my friends, as a big and wet storm system awaits on deck to impact early to mid week across the region.

November, so far, has followed suit of the past few months in a much drier than normal regime.  Over the past (7) days heaviest rains fell across SE portions of the state.  On the month so far, IND sits around 1″ below normal.

Past 7 day precipitation anomalies, courtesy of the MidWest Climate Watch.

Past 7 day precipitation anomalies, courtesy of the MidWest Climate Watch.

That rainfall deficit may be eaten up over the course of a couple days as our next storm system rolls off the Rockies and into the Plains.  (Track sound familiar)?

Monday

Tuesday

WednesdayThe storm will tap into the Gulf of Mexico and include a deep southerly flow plenty capable of producing a heavy rain event across the region.  Note PWATs (precipitable water) nearly 300% of normal.PWAT

gfs_pwat_anom_conus2_18

We target Tuesday night-Wednesday as the focal point for heaviest rain potential and model data remains firm on general consensus of 2″-3″ falling with this next storm system, including locally heavier totals.

soflow

raintotalsAfter this next storm, attention will begin to shift towards a colder pattern setting up for late November, including Thanksgiving…

Permanent link to this article: https://indywx.com/2015/11/14/big-wet-storm-system-sitting-on-deck/

Looking Ahead Towards Our Next Storm…

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Permanent link to this article: https://indywx.com/2015/11/12/looking-ahead-towards-our-next-storm/

Big Time Wind Event; Active Pattern…

Screen Shot 2015-11-11 at 7.17.55 AMHighlights:

  • Nighttime storms
  • Prolonged wind event
  • Eyeing our next storm

The morning has dawned with mid and high level clouds painting the back drop as the sun rises.  We’ve shared several photos on our Twitter page (@IndyWx) of the beautiful sun rise.  Thank you and keep ’em coming!

Low pressure is moving off the Rockies this morning (where another hefty snow dump took place overnight) and into the Plains.  The low will then track into the Great Lakes Thursday.  As the low moves northeast, it’ll swing a cold front through our neck of the woods Thursday morning.  We still bracket tonight into the wee morning hours Thursday for thunderstorm potential.  See the simulated radar valid at 10p this evening, courtesy of Weatherbell.com.

10pWed

CAPE (Convective Available Potential Energy) is lacking with this storm and moisture return isn’t impressive.  This is good news as it will reduce the amount of severe weather we’ll see.  However, it should be noted that it won’t take much to bring down a severe wind report or two and that is our primary concern tonight with any storm.

CAPE- courtesy of Weatherbell.com

CAPE- courtesy of Weatherbell.com

Surface Dew Points- courtesy of Weatherbell.com

Surface Dew Points- courtesy of Weatherbell.com

Precipitable Water- courtesy of Weatherbell.com

Precipitable Water- courtesy of Weatherbell.com

Because of the lack of moisture return and the overall speed of the system, rainfall tonight won’t be impressive for most (0.25″-0.50″ on average) with the exception of localized stronger storms.

What will be impressive is the wind, even without storms.  A Wind Advisory has been issued for late tonight and Thursday, via the National Weather Service out of Indianapolis, and rightfully so.  We wouldn’t be surprised if a portion of this is upgraded to a High Wind Warning later today or tonight as gusts of 50 MPH+ will be a concern through the day Thursday as our low occludes over the Lakes.

A period of drier air will return to wrap up the week and head into early next week, but we eye another big storm system for the middle of next week.  Forecast models differ on precise details, as you’d expect at this juncture.

WedStormTrack

ThrStormTrack

The GFS (above) isn’t shying away from another significant impact event.  The European isn’t as bullish early on.  All mid range models do produce moderate to heavy rains over the region.  Stay tuned as we continue to monitor.

Permanent link to this article: https://indywx.com/2015/11/11/big-time-wind-event-active-pattern/

Still Eyeing Mid Week Storms; Windy And Colder To Close The Week…

Screen Shot 2015-11-10 at 7.07.33 AMHighlights:

  • Wednesday night storms
  • Very windy to close the week
  • Colder Friday

The overall set-up over the next couple days will feature a strong autumn storm coming off the Rockies (today), crossing the Plains (Wednesday), and heading northeast into the Great Lakes to offer up some “fresh water fury!” (Thursday).

Here’s the track of our storm, courtesy of Weatherbell.com.

TueEvening

WedEvening

ThrEveningWe still need to monitor things closely for the potential of severe weather Wednesday evening, but latest data would suggest a lower chance of severe, overall.  Certainly not worth letting your guard down, but the lack of moisture return and timing are both on our sides in this particular event.  Localized damaging straight line winds are still of greatest concern of any of the severe elements across central IN and this would be for Wednesday night.

Here’s a look at the latest simulated radar for 10p Wednesday.  As we always say, don’t pay particularly close attention to the precise time.  This should be used as guidance as what the radar may look like Wednesday evening.

10pradarWedAs mentioned above, the speed, timing, and lack of moisture return strongly argue against significant rainfall with this storm.  We’ll forecast around 0.25″ with locally heavier totals in storms.  Not a big deal from a precipitation perspective.

What is a big deal is the wind on the backside of the low as northwest gusts really crank in the Thursday-Friday time frame (30-40 MPH).  Needless to say, Thursday isn’t a day to wear a hat. 🙂

Longer term, data continues to argue against any sort of sustained chill through the rest of November.  We note the SOI is actually positive right now.  This is certainly unusual with the ongoing El Nino and well above the base state (a warm sign).

Screen Shot 2015-11-10 at 6.55.51 AM

 

 

 

The MJO is also projected to rumble through the warm Phases of 2 and 3 over the next few weeks.  Note these are overall warmer than normal phases in November.

Screen Shot 2015-11-10 at 6.59.42 AM

 

 

 

 

 

 

 

 

 

 

 

 

Screen Shot 2015-11-10 at 6.57.56 AM

Permanent link to this article: https://indywx.com/2015/11/10/still-eyeing-mid-week-storms-windy-and-colder-to-close-the-week/

Monday Morning Video Update…

We continue to eye Wednesday night for severe weather potential.  Due to timing, as of now the greatest concern is thunderstorms that contain damaging straight line winds.  If traveling west…

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Permanent link to this article: https://indywx.com/2015/11/09/monday-morning-video-update/

Video Update: Chilly Weekend; Severe Potential Next Week…

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Permanent link to this article: https://indywx.com/2015/11/06/video-update-chilly-weekend-severe-potential-next-week/

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