Category Archives: Severe Weather

6-10 Day Outlook: Significant Winter Event Looms…

The 6-10 day period will likely be dominated by an air mass of arctic origin, and the potential is present for the period to begin with a rather significant winter event.  Models have occasionally “teased” the idea of dropping the PV (Polar Vortex) over the Great Lakes during this period, and that’s not something that’s off the table given the pattern here.  Suffice it to say, we expect this period to run much colder than average.

While there will be some specifics we’ll have to sort through as time gets closer, this is remarkable model agreement when looking at the GFS and European ensemble sets in the medium term.

We’ve been discussing the opportunity where we see the flow slow enough to allow one or two of these clipper systems in the medium to longer range to deepen into a stronger storm system.  That may be the case late weekend into early parts of next week and it’s something we’re keeping a close eye on.  In addition to measurable snow, the potential is on the table for notable cold in the 6-10 day period, including multiple days below zero.  In the extreme, this is the type pattern that could lead to double digit below zero  cold across central Indiana- not including the wind chill.

Stay tuned.

No Comments 10-day, Arctic Cold, Forecast Discussion, Forecast Models, Long Range Discussion, Severe Weather, snow, Unseasonably Cool Weather

Blizzard-Like Conditions Develop This Afternoon Into Tonight…

While warm air advection (WAA) created an added challenge this morning (freezing rain north of the city, itself, and rain south of I-70), colder air is working south late this morning and will result in a changeover from freezing rain/ rain to snow over the next couple hours from north to south.

We expect the transition to snow to take place in and around Indianapolis between 1p and 2p.

As upper level energy tracks northeast this evening, strong frontogenesis will help a “deformation band” expand in coverage and intensify across the state.  This will lead to elevated snowfall intensity as the afternoon gives way to evening.  In fact, snowfall rates will likely approach 1″/ hour across central and eastern portions of the state at times during the mid-to-late afternoon and into the evening hours.

8p forecast radar.

As this is taking shape, winds will also begin to crank this afternoon and evening.  Gusts in excess of 50 MPH are expected across central and eastern regions- including Indianapolis.

Obviously this will create concerns for power outages, but the other major worry is for developing blizzard-like conditions and whiteouts through the late afternoon into tonight.

As for snowfall totals, the consensus of latest 12z data continues to support our updated snowfall forecast from this morning.

We’ll have additional updates later this afternoon here on IndyWx.com and on our social media accounts.

To close, we highly encourage not traveling this afternoon.  Conditions are expected to rapidly deteriorate as we move through the next several hours. For many across central and east-central Indiana, roads will likely become impassable by evening with the combination of severe wind gusts and increasing snowfall rates.  Major problems from blowing and drifting snow are expected.

More here in a bit!  Stay safe!

No Comments Blizzard, Blowing/ Drifting, Forecast Discussion, Forecast Models, Freezing Fog, Rain, Severe Weather, snow, Unseasonably Cool Weather, Windy, Winter Storm

Wet Close To 2018…

IND has already recorded over half an inch in the rain gauge this morning and there’s more where that came from between now and tonight. Steady rain will be replaced with scattered downpours late morning to around the lunchtime hour before widespread rain and embedded thunder returns early to mid afternoon.  Most can expect to tack on an additional half inch to inch of rain today and the latest HRRR sees this as well.

We’re also still monitoring the potential of strong to severe thunderstorms across southern portions of the state.  The Storm Prediction Center now includes far southern Indiana in a Slight Risk for severe weather today.  The primary concerns remain strong, damaging winds with a line of thunderstorms that may develop between 2p and 4p.  If your travels take you south towards Louisville today remain weather-aware.

Temperatures will run 25° to 30° colder New Year’s Day and a couple of scattered snow showers may fly- especially across the favored snowbelt areas to our north.

Have a happy and safe New Year’s Eve, friends!

No Comments Forecast Discussion, Forecast Models, Heavy Rain, New Year's Eve/ Day, Severe Weather, snow, T-storms, Unseasonably Warm

Heavy Rain (And Thunder Downstate) Arrives For New Year’s Eve…

We’re enjoying pleasant conditions this afternoon with filtered sunshine and temperatures that should top out in the upper 30s to lower 40s later on.  Enjoy it, as a big rain event gets underway for New Year’s Eve.

This afternoon’s visible satellite shows sunshine dominating across the northern half of #INwx.

Clouds will increase tonight and rain won’t be too far behind.  We think wet weather builds into central Indiana before sunrise Monday (likely between 4a to 6a) and periods of heavy rain are still expected late morning into the afternoon and evening hours.

Rain will arrive into the city itself between 4a and 5a Monday. 

We continue to monitor the prospects of a skinny line of strong thunderstorms that may impact southern Indiana Monday afternoon and evening.  If your travels take you south to Louisville for NYE plans, this is something to monitor.  Widespread severe weather isn’t expected, but strong winds are possible if this line materializes.

Timing out prospects for a skinny line of storms to impact southern #INwx Monday afternoon. Best idea as of now will come between 2p and 4p.

This storm system will have a true tropical connection.  Precipitable water values will be quite “juicy” for late December and plenty capable of producing locally heavy totals.  Widespread 1″ to 1.5″ can be expected, but a few area rain gauges will likely see higher amounts.

Colder air will whip in here late tomorrow night and help lingering moisture fall as scattered snow showers New Year’s Day.  More later on the potential of wintry “mischief” later in the week…

No Comments Forecast Discussion, Forecast Models, Heavy Rain, New Year's Eve/ Day, Severe Weather, snow, T-storms