March, 2012

Friday’s Weather

March 29th, 2012 at 9:44 pm by under Chad's WLFI Weather Blog

Wave of rain is passing through the area now, but will depart over the next few hours.

Storms are blossoming to our west & are severe.

I am thinking these will tend to congeal into a broken, not solid, cluster of showers & storms (with some additional scattered showers & t’storms forming in Illinois), then pass through our area Friday morning-afternoon before tapering.  Coverage may peak at 60%, but thinking 45% coverage will be average, so this will not be a solid shield of rain & storms.

Tapering in our area, these will pull away as the warm front lifts northward.  At this point, warm, humid, air will surge in with temperatures rising into the 60s & even 70s in the viewing area.  Given impressive low-level shear with the warm front & a surface low to our northwest aiding in turning of the wind with height, a few isolated severe storms may pop.  The threat would be large hail (1-1.75″ diameter) & isolated tornadoes.

Time frame for the threat of the isolated supercellular-type t’storms would be 2 p.m.-6 p.m.

It still appears the front will slip south of the area Friday night, chilling it down into the 40s with some fog.

Saturday is tricky, but right now it appears the northeast counties may struggle to even get to 60 with 77 in our southwest as the front moves back north & stalls.

 


Wave of Showers This Evening, More Widespread Showers/T’Storms by Early Friday Morning

March 29th, 2012 at 4:44 pm by under Chad's WLFI Weather Blog

Passing, rather compact wave of rain will get into the area this evening (mainly in the southern half of the viewing area) with more substantial rainfall arriving by early Friday morning.

New showers & t’storms in Missouri will tend to congeal into a broken cluster of showers/t’storms, then pass Friday.  These will tend to taper Friday p.m., but a couple isolated severe t’storms may sneak into the viewing area as the warm front lifts northward & baths us in warm, moist, unstable airmass.

The main threat would be an isolated large hailer or two, but you always have to watch the low-level shear along a warm front (when good heat & humidity are present with decent wind fields aloft) for a brief tornado.  Thus, isolated tornado threat needs to be acknowledged, given the moist, warm, unstable, but highly-sheared environment (especially in the lowest 1 miles of the atmosphere near the ground).

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Outlook to the Friday Rainfall

March 28th, 2012 at 9:43 pm by under Chad's WLFI Weather Blog

A dry line brought extremely dry in today & a surface cold front is now bringing in the chilly air.  That same front is beginning to buckle back north (as a warm front) to our west & a robust plume of warm, humid air is surging back northward in Kansas & Missouri.

The lift & shear near this surface warm front is leading to large-hailing, tornadic supercellular t’storms in Kansas tonight.

This warm front will lift northward & turn our skies quickly overcast tomorrow night, preventing absolutely any kind of frost or freeze.  It will bring a round of showers & some t’storms to the area Friday, but these may tend to taper late in the day.

As they taper & the warm front lifts northward, a couple severe storms may sneak in as we begin to warm up nicely (after 50s…………to possibly 60 for most of the day).  You always have to watch any stray storms near/south of a surface warm front in that warm, moist air, as shear parameters support tornadic development.  Forecast guidance suggest a hailer or two, as well, if any stray storm can make its way in here from the south.

 


Strong, Dry Winds Today

March 28th, 2012 at 6:38 pm by under Chad's WLFI Weather Blog

It was a windy day with elevated to high fire danger.  Relative humidity levels were as low as 11% today in the viewing area-amazing for Indiana.  Here at WLFI, the relative humidity dropped to 21%.  It was so incredibly dry that it actually felt several degrees colder than the actual air temperature, especially with the wind.  In such dry air, the moisture on your skin evaporates so much that it acts as a natural air conditioner around you, chilling you.

Gusts were measured as high as 47 mph.


Upper Ridge Building Back, Then Coldest Weather Since Early March

March 28th, 2012 at 4:05 pm by under Chad's WLFI Weather Blog

Upper ridge building back in will bring the 80s Sunday & Monday.

However, the coldest weather since early March will rush in later next week.  Highs may only run 47-52° by Wednesday with a brisk north wind.  Overnight lows may drop to 26-31°.  Some wet snow may fall in Wisconsin, Michigan, northeast Ohio & over the Northeast U.S.

In-between these two “events” severe weather will be possible Monday afternoon-evening.


Few Severe T’Storm Warnings Early This Morning, Now Fire Weather Warning Newton, Jasper, Benton

March 28th, 2012 at 12:58 pm by under Chad's WLFI Weather Blog

We had some Severe T’Storm Warning early this morning with a few reports of pea & marble hail in Newton & Warren counties.  I received a report of 1″ diameter hail near Attica.  However, due to lower coverage, some of you didn’t even receive a drop of rain.  Now, it is sunny, windy, very dry & warming into the 70s.

Very dry, desert/High Plains air has overspread the area behind the dry line with some gusts to 40, even 45 mph.  This will make for an elevated brush fire danger today, especially in our western & northwestern counties.


Some Scattered Storms Possible In the 11 p.m.-6 a.m. Time Frame

March 27th, 2012 at 9:35 pm by under Chad's WLFI Weather Blog

Updated radar image from 10:13 p.m.:

Scattered storms are overcoming capping & initiating in north-central Illinois.

These are occurring in a plume of mid to upper 50s dew points (with decent instability on heels of strong low-level jet [or core of winds at 5,000' transporting juicier air in from the Gulf]) on the southern end of a strong 500 mb jet streak (or core of strong winds at +15,000′ up).  Marginal instability combined with decent deep layer directional & speed shear are conducive to some multi & single cell, splitting storms with mainly large hail (isolated damaging gust) in a northeast-southwest band.  Relatively low dew points & high LCLs (cloud bases) will prove hostile to any tornadoes.

So, as for us, some scattered storms with a peak of 40% coverage will pass between 11 p.m. & 6 a.m.  A few severe storms are possible with mainly large hail of a few 1″ diameter stones (mixed with pea & marble stones in a storm).  An isolated damaging wind gust is possible.  This all would occur in the western half of the viewing area.

Given the 40% criteria, there will actually be a few places that see very little, if any rain fall at all.


Few Severe Storms Possible Tonight-Early Wednesday Morning

March 27th, 2012 at 2:35 pm by under Chad's WLFI Weather Blog

It still looks like a few severe storms will be possible tonight.

Very potent dynamics (associated us being on the southeastern edge of a core of very strong winds at 20,000′) will cross dryline tonight.  Plume of 55-60 dew points will also rush northward & tongue edge of these will move up into the area.  This will result in modest instability at the surface, but good elevated instability for some storms to feed upon.

Storm mode will be multi-& single-cellular with a tendency for storms to split.  Coverage will run 40%.  Given this coverage it is conceivable that there will be locations in the viewing that see not a single drop of rain tonight.

A few large hailers are possible with an isolated damaging wind gust.  Timing would be in the 11 p.m. -6 a.m. frame for the viewing area.


Low Temperatures This Morning

March 27th, 2012 at 1:47 pm by under Chad's WLFI Weather Blog

A light freeze occurred in our eastern counties this morning, but the rest of the area had 33-38 with a patch or two of frost.  The wind kept the lower atmosphere near the ground mixey, which prevented a really cold air from sinking & straddling the ground, leading to much colder readings in some areas.  The calm nights where the cold air sinks to the ground oozes & sits like molasses (lid or inversion near the ground helps this process) creates the coldest nights.

Vegetation should fare just fine.  Also, when you have a heavy frost with temperatures at or below 28, you start to run into issues.

This cool morning likely just slowed the metabolism of our blooming & foliating vegetation (mainly warm-season vegetation).


Detailed Tuesday, March 27-April 5 Outlook

March 26th, 2012 at 6:46 pm by under Chad's WLFI Weather Blog

TUESDAY…….

The cold front that went through today, bleeding in that cold, dry air from the northeast & east will move back north as a warm front tomorrow morning.  This will bring a nice, warm, windy day with highs generally at 65-70° with south wind gusts as high as 35 mph.

 TUESDAY NIGHT-WEDNESDAY…….

Bathed in the warm air, a surge of very dry, hot air originating in the Plains & the deserts of the U.S. southwest will roar in on strong southwest & west winds up to 45 mph Wednesday afternoon.

However, on the leading edge of this push will exist shear & good wind fields in the atmosphere.  This boundary, a dry line, will pop severe storms to our west & we will get some of these storms Tuesday night-Wednesday morning.  With scattered, 40% coverage, a couple of the storms may produce large hail or an isolated damaging wind gust or two.  However, given this coverage there will be a few locations that get NO RAINFALL at all.

After this, that dry, warm air will bring sunny skies Wednesday afternoon with highs of 75-80° with dew points of 30-37° bringing an elevated fire danger.  In fact, the relative humidity may drop as low as 20%  during the late afternoon with those strong winds.

WEDNESDAY NIGHT-FRIDAY…….

The actual surface cold front will pass dry Wednesday night with a rapid drop in temperature to 36-42° by Thursday morning.  High Thursday will only run 54-59°, followed by frost & freezing Thursday night-Friday morning.

That front that passed will move back north as a warm front & will bring showers & some t’storms Friday with a stiff east to southeast wind & high of only 55-60° Friday.

SATURDAY-SUNDAY…….

Once the warm front moves back north, it will turn mostly sunny with a brisk south wind Saturday &  highs of 70-75°.  Sunday looks mostly sunny & windy with highs of 75-80°.

MONDAY…….

Strong storm system with lots of wind & warmth may bring severe t’storms to the area Monday P.M.  Given the strength of the system & where the dynamics & instability currently line up, a severe weather event is possible in or near the area.

Interestingly, this storm system may bring early-April accumulating snowfall to Nebraska & South & North Dakota.

MID-NEXT WEEK…….

More frost & freezing temperatures are possible mid-next week.