Category: Forecast

Nov 21

Rain Changes To Snow Today; Busy Pattern Into Early December…

Screen Shot 2015-11-21 at 7.47.29 AMHighlights:

  • Rain changes to snow
  • Early season arctic air settles in
  • Next storm arrives for Thanksgiving
  • Eyeing a cold open to December

Our storm system is arriving on schedule this morning as rain is overspreading central IN.  Just north of the city, snow flurries are falling as we type this (Boone County).  Further north it’s mainly a snow event.  Elsewhere, rain will continue to overspread the region before transitioning to snow from late morning into the early afternoon from northwest to southeast.

Here’s what the radar may look like as we progress from morning into the afternoon

8aSat

Forecast radar 8a, courtesy of Weatherbell.com

10a forecast radar, courtesy of Weatherbell.com

10a forecast radar, courtesy of Weatherbell.com

Forecast radar at 1p, courtesy of Weatherbell.com

Forecast radar at 1p, courtesy of Weatherbell.com

 

Forecast radar 2p, courtesy of Weatherbell.com

Forecast radar 2p, courtesy of Weatherbell.com

We think rain will transition to snow for Indianapolis, itself, just after lunch and may come down heavily for a time from early afternoon into the mid afternoon hours before tapering off as evening arrives.  While it may be falling “fast and furious” for a time, warm surface temperatures will limit accumulations from what they would be otherwise.  Here’s our updated snowfall map.

112115SnowMap3The big concern this evening will be flash freezing as a gusty NW flows travels over a fresh snowpack just to our north and helps temperatures plummet into the teens tonight.  Wind chills in the single digits can be expected followed by highs tomorrow only in the 20s.

Moderation will occur as we move through Thanksgiving week before our next storm system arrives late Thanksgiving Day.  Rain and breezy conditions will move in late Thursday into Friday before a much colder air mass oozes into the state late in the period.  This may set the stage for a rather “interesting” open for December as a storm system tries to “attack” the cold…

Permanent link to this article: https://indywx.com/2015/11/21/rain-changes-to-snow-today-busy-pattern-into-early-december/

Nov 20

Potent System; Friday Evening Thinking…

This evening’s radar shows our potent weather maker providing a plethora of weather elements to our west.  Anything from heavy snow (numerous 12″ + reports coming in across IA) to thunderstorms across MO have made for an active Friday evening.

9pRadarThinking hasn’t changed much from the get go with this storm system, but we wanted to “freshen” things up a bit before bed.

Rain will overspread central IN through the morning hours before transitioning to snow from late morning into the early afternoon.  This transition will occur in a northwest to southeast fashion as colder air wraps into the region.

Here’s a timeline (thanks to Weatherbell.com) of what the radar may look like as Saturday morning progresses into Saturday afternoon.

8aSat

12pSatAs rain transitions to snow, it’ll likely come down rather “fast and furious” for a time before ending.  Despite what may be moderate to heavy snow for a time (especially along and north of the I-70 corridor- there’s the “magic” dividing line again :-)), warm surface temperatures will really limit what snow will actually accumulate.  As things stand now, we still forecast a widespread 2″-4″ snowfall across the northern portions of the state, with 4″-6″ amounts in favored lake effect areas.  Farther south to include central IN, a dusting to less than 1″ is a good bet before precipitation ends.

The growing concern Saturday night will be a stiff northwest wind driving MUCH colder air into the region.  This will help power a brief lake effect event across NE areas of the state before shutting down quickly by the wee morning hours Sunday.

LakeEffectAny lingering moisture on area roadways will freeze up quickly tomorrow night.  With a deep snowpack just to our north, the NW flow will keep things very cold around these parts into early next week.  Note widespread teens Sunday morning across north-central IN and even this might not be cold enough.  If we lay the expected snowfall down, don’t be surprised by some single digit temperatures (not counting wind chill values) across north-central IN Sunday morning.  Highs Sunday will remain below freezing for most.

‘Tis the season!  More in the AM, and happy snow dreams to all!

teens

Permanent link to this article: https://indywx.com/2015/11/20/potent-system-friday-evening-thinking/

Nov 18

Wet Today; Colder Air Coming…

Screen Shot 2015-11-18 at 7.15.50 AMHighlights:

  • Rain today
  • Breezy and turning cooler
  • Secondary push of early season arctic air

Our big autumn storm system is swirling through the central Plains this morning.  It’ll begin to pick up forward momentum and head northeast over the next 24 hours.

We’re dealing with an impressive fetch of moisture (w/ a Gulf of Mexico connection) this morning and that’ll help feed embedded heavy downpours this morning into the early afternoon.  Here’s a time stamp of forecast radar images, courtesy of Weatherbell.com.

7aSimRadar

11aSimRadar

3pSimRadarAs mentioned above, with a GOM connection, embedded heavy rain will dampen your Wednesday activities.  On average, we’ll add an additional half inch to inch of rain today (that’s on top of what we saw Monday and Tuesday).

RaintotalsOnce to tomorrow all eyes will be on our next storm system that will eventually help pull down the season’s first blast of arctic air.  Ahead of the cold surge, expect light rain to end as light snow across central IN Saturday.  This won’t be a big deal from an accumulation perspective, but it’s always exciting seeing the first snow flakes of the season.  Further north, across our northern tier of counties, a couple inches of snow will be possible.

SatPMStormTrackWe’re also keeping a close eye on Thanksgiving’s weather.  While still a bit early to be specific, initial thoughts suggest we’re dealing with a storm on, or just on either side of Thanksgiving, that will provide rain to begin, but we caution that another surge of early season arctic air looks to pour in behind that storm system and potentially set the stage for a more impactful winter event to open December.  More on that in the days ahead…

Permanent link to this article: https://indywx.com/2015/11/18/wet-today-colder-air-coming/

Nov 17

Couple Storms To Watch And Much Colder Air…

Screen Shot 2015-11-17 at 7.30.17 AMHighlights:

  • Periods of rain
  • Turning cooler
  • Next storm offers up wintry precipitation for parts of the state
  • Early arctic blast

Periods of rain will continue into the mid to late afternoon across central IN as “wave 2” of our current storm system moves through.  We’ve added a couple simulated radar images below, courtesy of Weatherbell.com.

9aFuture

2pFutureThis is all in association with a significant autumn storm system that’s been responsible for delivering hefty snows across the Rockies, blizzard conditions across the High Plains, and severe weather across the central and southern Plains.  This storm will lift northeast over the next 24-36 hours.

TuePM

WedPMA third, and final, wave of moisture will push through the state Wednesday, in a weakened state from what our friends to the west will experience (where another round of severe is expected today and tonight).  This is what the radar may look like mid-morning-ish Wednesday.

10aWedFutureWhen all is totaled up from rain that began Monday afternoon and ends Wednesday afternoon, many locales will pick up 1.5″-2″ of needed rainfall.  While significant, those numbers are lower than what originally model data implied, but we’ll take what we can get to push closer to average for November rainfall.

All eyes will then shift to our second storm system that will arrive over the weekend.  There are still more questions than answers in regards to track of this next “wave” of low pressure, but with much colder air in place and pouring in behind the system, snow will fly across northern IN.  As of now we forecast the majority of this event to fall in a liquid form across central IN, but even here precipitation may end as light snow showers the way things stand now.  Stay tuned as we continue to fine tune the track. Regardless, much colder air will be with us to end the period.

Permanent link to this article: https://indywx.com/2015/11/17/couple-storms-to-watch-and-much-colder-air/

Nov 15

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/

Nov 13

Cold Night Coming; Next Big Storm Slated For Next Week…

Screen Shot 2015-11-13 at 4.04.40 PMHighlights:

  • Moderating temperatures after a hard freeze
  • Next big storm arrives early next week
  • Wintry fun and games around Thanksgiving

Today has featured wall-to-wall sunshine and while it’s looked great from the inside looking out, that wind is still whipping!  Gusts have reached 40 MPH in spots across central and northern parts of the state.

Winds will finally die down tonight and with clear skies in place a hard freeze awaits for central IN.  The latest high resolution data, courtesy of Weatherbell.com, suggests mid to upper 20s tonight and we agree.

hires_t2m_indy_19

Our next big autumn storm awaits for the early and middle portions of next week.  Questions remain concerning severe weather across our area, but as of now it appears the dynamics needed for severe weather, locally, will remain too far to our west.  We’ll continue to monitor.  Latest forecast models (Euro top and GFS bottom) have some differences with the track of our next storm- both centered on Tuesday night.

ECTueNt

GFSTueNtThe differences with timing and track are significant and we’ll continue to keep a close eye on things.

We remain very confident on heavy rainfall potential as a prolonged southerly fetch off the GOM (Gulf of Mexico) will transport copious moisture northbound.  Widespread 2″-3″ type rainfall totals are a good bet with this set up.

Longer term, we remain confident on a pattern change towards colder than normal conditions to wrap up November.  Additionally, a storm system will likely cross the country Thanksgiving week and could offer up the season’s first widespread wintry “fun.”

Permanent link to this article: https://indywx.com/2015/11/13/cold-night-coming-next-big-storm-slated-for-next-week/

Nov 12

Very Windy Today; Next Big Storm Next Week…

Screen Shot 2015-11-12 at 7.17.23 AMHighlights:

  • Very strong winds
  • Dry times return
  • Big storm next week

A cold front swept through the state during the predawn hours.  While a few breaks of sunshine may be seen early this morning, low clouds will quickly spread back over the region.

Wind will be the big story today as we still think gusts over 50 MPH are a good bet throughout central parts of the state.  Note the tight pressure gradient that remains in place across the region today into Friday.  Friday won’t be AS windy as today, but still quite blustery.

gfs_ptype_slp_conus2_3

gfs_ptype_slp_conus2_7Our next big weather maker will arrive during the early to middle portions of next week.  Model consensus continues to highlight a hefty rain event and thunderstorms.  Early numbers would suggest 2″-3″ potential.  More details on our next storm tomorrow and on Twitter (@IndyWx).

Before we close this morning, we wanted to post the updated JAMSTEC seasonal outlook for the upcoming winter.  As a whole there aren’t a lot of changes from previous runs.  (We like to see consistency :-)).

JAMSST

JAMTemp

JAMPrecipOverall, it agrees with our forecast and strongly disagrees with any of those warm winter forecasts out there for the south and east.  One note, just because the drier anomalies show up over the Ohio Valley (what you would typically expect during a moderate to strong El Nino event) doesn’t necessarily mean it’ll be a lower than normal snow season.  Keep in mind, moisture content in snow is much less than rain.

After taking a look at things, I like where we stand with our Winter Outlook.  One thing’s for sure, time will tell!

Permanent link to this article: https://indywx.com/2015/11/12/very-windy-today-next-big-storm-next-week/

Nov 11

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/

Nov 10

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/

Nov 08

Changes On The Horizon…

Screen Shot 2015-11-08 at 9.39.59 AMHighlights:

  • Beautiful Sunday
  • Rain arrives Monday afternoon/ evening
  • Stormy Wednesday night-Thursday morning
  • Much colder late next week

High pressure will supply a beauty of a second half of the weekend.  After the frosty start to the day, we’ll “warm” into the lower 50s this afternoon.  It’ll be a perfect crisp November day.

Changes arrive Monday as clouds increase and give way to rain as early as the afternoon as moisture rides north out of the Deep South.  A wave of low pressure will ride up the western slopes of the western Appalachians and enhance early week rain to our east.

The next big ticket item is the storm that will arrive Wednesday night.  We continue to keep a very close eye on this as a severe weather outbreak appears likely.  Specifics still have to be ironed out and we go through the next couple days, but keep abreast of the latest weather information during the Wednesday night-Thursday morning time period.

MUCH colder air will pour into the region behind the big low as it wraps up over the Great Lakes.  A hard freeze appears likely come Saturday morning.

Upcoming 7-Day Rainfall Forecast:  0.50″ – 1″

Permanent link to this article: https://indywx.com/2015/11/08/changes-on-the-horizon/

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