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!

If you’re interested in becoming a partner of IndyWx.com and sponsoring various snowfall forecasts, forecast discussions (video and print), be sure to send us an e-mail at bill@indywx.com.

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

Tuesday Evening Video Update…

You must be logged in to view this content. Click Here to become a member of IndyWX.com for full access.  Already a member of IndyWx.com All-Access?  Log-in here.

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