Category: Severe Weather

Active Thursday Ahead…

* Your complete 7-Day forecast can be found below this post.

We continue to monitor things closely Thursday as a busy day is on tap.  Thunderstorms will initially blow into the region Thursday morning as a warm front lifts north through central Indiana.  These storms will be capable of producing heavy rain and vivid lightning.

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We’ll then get into a much warmer south wind (gusting up to 30 MPH) and watch radar trends closely to our west.  We’re still very concerned for a squall line plowing east through the region Thursday evening.  Time of greatest concern lies between 5PM and 8PM for this line, but we caution timing may have to be adjusted after looking over evening data.  Damaging straight line winds are of the greatest concern Thursday evening, along with torrential rainfall.

ThrSeverThreatSIMRadarFollowing the squall line, we’re also concerned for strong and potentially damaging northwest winds Thursday night, gusting up to 50 MPH, as low pressure rapidly deepens moving into the Great Lakes.

Bullet Point Thoughts You Need To Know For Thursday

  • Morning round of heavy rain and thunderstorms
  • Severe squall line capable of wind gusts over 60 MPH Thursday evening- targeting 5pm to 11pm
  • Heavy rain totals around 1″
  • Strong northwest winds Thursday night that could gust up to 50 MPH

Permanent link to this article: https://indywx.com/active-thursday-ahead/

Focus On Mid Week Flood/ Storm Threat…

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Accumulating snow?

Forecast Updated: 02.19.14 @ 8:00a

One More Calm Day…A weak front blew through early Wednesday and produced a light shower for southeast parts of the state.  Sunshine will return Wednesday along with a blustery northwest wind.  It’ll be another mild day.

Concern For Flooding And Severe…With continued melting of a deep snow pack, combined with around an inch of rain (most of which falls within a 3 hour time period Thursday) and the stage will certainly be set for flooding.  In fact, we remain very concerned for flooding Thursday. If you live in a flood prone area, please prepare to seek higher ground Thursday as flood waters rise.

The second concern is a severe potential Thursday evening.  While the greatest threat for severe weather will remain south and east of our immediate region, we’ll have to be mindful of the potential of damaging straight line wind gusts Thursday evening.  The greatest threat lies between 5PM and 8PM Thursday as a line of thunderstorms pushes east through the state.  Again, damaging straight line winds, in excess of 60 MPH, is our greatest concern at present time.  Stay tuned.  Drier and much colder air will roar in behind the front Thursday night on strong and gusty northwest winds.

Weak Weekend Disturbances…A couple of fast moving disturbances will pass through the region this weekend and could spark scattered snow showers in the much colder air.

Accumulating Snow Early Next Week…Model data continues to struggle in the mid range handling energy coming east before what continues to look like a big blast of arctic air to wrap up February.  As of now, we’re targeting Tuesday for best chances of accumulating snow, but stress this a low confidence forecast in regards to timing at present.  Stay tuned.

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Permanent link to this article: https://indywx.com/focus-on-mid-week-flood-storm-threat/

Rare And Potentially Crippling Winter Storm Brewing…

Fresh on the heels of a significant winter storm that impacted central Indiana Wednesday night-Thursday, we’re eyeing our next winter storm and, quite frankly, it could be a memorable one.

We continue to keep a close eye on the pending winter storm Sunday and remain impressed with what we see.  A severe winter storm is brewing and may require blizzard watches and warnings before all is said and done as a combination of heavy snow, strong winds, and severe blowing and drifting promises to make travel difficult, if not impossible, for some areas Sunday.

Setting the stage:

A powerful arctic boundary will drift south towards Indiana Saturday night and Sunday morning.  As this takes place, low pressure will track off the lee of the Rockies and move east, northeast.  Model data continues to suggest this area of low pressure taps into some Gulf of Mexico moisture and really begins to deepen (strengthen) as it tracks into the central/ eastern Ohio Valley Sunday.  To the northwest of the low’s track, a deep blanket of fresh snow will fall.  As the winter storm departs, the coldest air since 1994 will pour into the region on a gusty northwest wind.  Temperatures will reach record territory, and downright dangerous levels, by Monday and Tuesday.

Last night we mentioned a couple of things going “for” and “against” a major winter storm here in central Indiana.  While there’s no doubt going to be a sharp “cut off” of heavy snow with this storm, this “cut off zone” is most likely well north and west of central Indiana.  Additionally, the impressive thermal gradient between the brutal arctic air mass to the north and the warmer air (relatively speaking) to the south and east will only add fuel to a deepening storm moving northeast into the Ohio Valley.  Finally, with arctic air pouring into the region, the “fluff effect” will be in full-go mode, meaning the northwest flank of the heavy precipitation is likely to have snow ratios of 15:1 as compared to the “normal” 10:1 ratio.  This will be very important to watch as the system develops and will most likely be the spot (far too early to pinpoint at this juncture) where snowfall amounts in excess of one foot will fall.

All of our medium range model data is in agreement on central Indiana receiving quite the blow from Old Man Winter Sunday.  Here’s a look at the latest GFS, European, and Canadian forecast models, valid Sunday afternoon:

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As you can see, there’s excellent agreement and this leads to a rather high confidence idea on a high-impact and rather rare severe winter storm set to impact Indiana.  Can we tell you with certainty exactly where the 12″+ band of snow will lie across the state?  Not at this time.  That said, we suggest preparing now for a rare and potentially crippling winter storm Sunday.  The combination of heavy snow, strong winds, historic cold, and severe blowing and drifting will make for an extremely dangerous situation Sunday, continuing into early next week.  Temperatures by Tuesday morning will approach 20 degrees below zero, with wind chill values plummeting to 40-50 degrees below zero Monday into Tuesday…

Permanent link to this article: https://indywx.com/rare-and-potentially-crippling-winter-storm-brewing/

Extremely Dangerous Severe Weather Outbreak Ahead…

Good morning!  We’re waking up to sunshine this morning after a round of rain and thunderstorms overnight.  Over 1″ of rain fell for many during the overnight period (1.53″ to be exact here at IndyWx.com HQ).

Unfortunately, skies now are clearing and this is only going to aid in the severe weather potential today, including some dangerous long-lived and strong tornadoes.

ECWVThis is a very rare November high severe weather risk day and must be taken seriously by all.

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The thinking here hasn’t changed in that we feel discrete super cells develop during the late morning and early afternoon before morphing into a squall line capable of producing damaging straight line wind. With the dynamics and energy in play here, any of these super cells could spawn a tornado. Additionally, it’s possible that a few of these tornadoes could be long tracked and very strong tornadoes.  The latest high-resolution simulated radar data shows this well.

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We still target a cold front passing through the region around, or just after, sunset and with this frontal passage the severe weather will come to an abrupt end.  The latest HRRR data shows this well as dew points begin to crash behind the cold front, indicative a much drier, cooler, and more stable air mass arriving tonight.

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Permanent link to this article: https://indywx.com/extremely-dangerous-severe-weather-outbreak-ahead/

Late Saturday Night: Thunderstorms Develop Overnight; Update On Sunday

Good evening, Hoosiers!  Showers are developing now, and these will increase in coverage and intensity as we progress through the overnight. As we move into the wee morning hours, don’t be surprised if you’re awoken with loud claps of thunder, gusty winds, brief heavy rain, and small hail.  That said, we think overnight thunderstorms remain below what would officially be considered “severe.”

Here’s a look at the simulated radar later tonight, valid at 2am local time, courtesy of the HRRR model.

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As for Sunday, we continue to look over the latest data and our thoughts haven’t changed. It still appears the two biggest threats will be from damaging straight line winds and the possibility of quick spin-up tornadoes associated both within the squall line, itself, but also with any individual severe cells that develop before “morphing” into the squall line.  It should also be pointed out that even outside thunderstorms, southwest winds will howl across central Indiana, periodically gusting upwards of 40-45 MPH even outside of thunderstorms. Hunker down…

The latest high-resolution NAM suggests the possibility of super cells entering western Indiana early Sunday afternoon before organizing into a squall line as it moves through central and western Indiana. This line will mean business as it moves east across the state, and latest data suggests the most significant severe threat for central Indiana will be from 12 noon through 6p, moving west to east.  By sunset Sunday, most of central Indiana will see a much needed (and much colder) wind shift to the northwest, ending any threat of severe weather.

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Permanent link to this article: https://indywx.com/late-saturday-night-thunderstorms-develop-overnight-update-on-sunday/