November 12, 2013 archive

Wednesday Forecast: A Bitterly Cold Start

Updated 11.12.13 @ 8:50p

Zionsville, IN After waking up to half an inch of snow, sunshine engulfed most of the region Tuesday. The vitamin D didn’t help temperatures moderate much as highs were more like mid to late December as opposed to mid November. We discuss a warming trend below, after a frigid start to your Wednesday.

Status-weather-clear-iconWednesday: Mostly sunny; 19/ 39

A strong area of high pressure will move overhead Wednesday and help supply a mostly sunny sky.  Despite the sun, it’ll be another unseasonably cold day.  Many outlying communities will begin the day in the upper teens before rising into the upper 30s to near 40 by afternoon- a solid 15 degrees below normal.

Status-weather-clouds-iconThursday: Partly cloudy; 28/ 49

The same high pressure that will be directly overhead Wednesday will begin to move east Thursday. This will put our region in a southwesterly air flow and allow temperatures to begin moderating. After another cold start, highs will push towards the 50 degree mark Thursday afternoon.

Status-weather-clouds-iconFriday: Partly cloudy; 35/ 52

We’ll wrap the work week up with a few more clouds and temperatures still slightly cooler than normal, though much milder than those we’re dealing with now.

 

Status-weather-showers-day-iconSaturday:  Turning cloudy with PM showers (0.20″); 40/ 59

Model data continues to hint at increasing clouds and the threat of afternoon light rain. We’ll initially have to overcome the dry air mass in place, but by afternoon/ evening we should have scattered showers beginning to impact central portions of the state.

Status-weather-showers-scattered-iconSunday: Cloudy with rain likely (0.45″); 52/ 60

More widespread rain will arrive for the second half of your weekend.  Highs will approach 60 and should we see any sunshine (not looking likely at this point), temperatures could go into the lower to middle 60s. While temperatures will be much warmer we’ll have to contend with rain Sunday.

Status-weather-storm-night-iconMonday: Showers and possibly a thunderstorm (0.50); 34/ 63

A strong cold front will blow through the state Monday evening. Out ahead of the front, an impressive surge of warmer and more humid air will move north and encompass central Indiana during the day. In fact, latest model data suggests dew points reach the lower 60s Monday. The combination between the warmer, more humid air in place and an impressive surge of arctic air behind the front could team up to produce a clap or two of thunder with the moderate to heavy rain threat Monday afternoon as the front moves through. Temperatures will then crash Monday night.

Status-weather-snow-scattered-day-iconTuesday: Scattered snow flurries; 24/ 34

The big story Tuesday will be the much colder air mass rushing into the state on strong and gusty northwest winds. Just enough moisture may linger to create the chance of scattered snow flurries.

Permanent link to this article: https://indywx.com/2013/11/12/wednesday-forecast-a-bitterly-cold-start/

Pattern Showing Signs Of More Sustained Wintry Weather?

As we progress into the second half of November and December, friends and family begin to hit the road for holiday travel.  It’s also at this time where winter weather enthusiasts begin to wonder when that first “true winter storm” will arrive.  As we look towards this period, it becomes more important to note the state of the “big three” teleconnections.  These include the PNA (Pacific North America pattern), NAO (North Atlantic Oscillation), and AO (Arctic Oscillation).  While it’s impossible to predict, with 100% certainty, the weather based solely off these teleconnections, they can be very good indicators of where the pattern may be heading in the next couple three weeks.

In a “perfect world” for those wanting cold and wintry weather here across the Hoosier state you want to see a positive PNA, which promotes western ridging and eastern troughiness (associated with cold weather).  Additionally, you want to see a negative AO and NAO (promotes high latitude blocking and corresponding cold, arctic, air is shunted south into the Lower 48).  What do the teleconnections currently show?

ao.fcst

 

 

 

 

pna.fcst

 

 

 

 

nao.fcst

 

 

 

 

Taken at face value, this suggests a cold and potentially wintry pattern may ensue to close out November and as we go into December.  We’re looking at an AO and NAO trending negative and a PNA trending positive.  *It should be noted that, at times, a negative NAO can be so strong that it supplies the cold air, but can also lead to a suppressed storm track- south of the available cold air…

Each storm provides it’s own set of challenges and must be dealt with as they come. We can look at past storms and patterns (called analog forecasting) to help get an “idea” as to what patterns and storms in front of us may produce, but no storm is identical to the other.  At this early stage in the game, it appears as if a pattern is setting up that could provide “wintry mischief” just at the time when most folks want it- for the Thanksgiving and Christmas season.

Stay tuned…

Permanent link to this article: https://indywx.com/2013/11/12/pattern-showing-signs-of-more-sustained-wintry-weather/

A Closer Look At Tuesday

Hoosiers are awaking to roughly half an inch of snow across the majority of central Indiana. The forecast went as planned overnight and we’ll keep a close eye on the lake effect band of snow hammering the Indiana snow belt.  Short term, high resolution, data (below) suggests snow showers move back into north-central Indiana by late morning/ early afternoon- primarily north of the Indianapolis metro.

hires_ref_indy_14

Otherwise, it’s going to be a cold day with temperatures only rising into the middle 30s. This is much more like December as opposed to mid November and a solid 20 degrees below the average high of 54.

hrrr_t2m_max_indy_13

We have another “fun time” ahead in the mid range and we’ll begin to discuss the next storm potential later tonight.  As you can see, the GFS and ECMWF are in all sorts of disagreement below…

test8

Permanent link to this article: https://indywx.com/2013/11/12/a-closer-look-at-tuesday/

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