Chad’s WLFI Weather Blog

10:36 P.M. Update…………….August 22, 1947: Purdue Airport Microburst

August 22nd, 2014 at 10:28 pm by under Chad's WLFI Weather Blog

Tonight there are four areas of some scattered showers/t’storms outside our viewing area, but in the region.

Two of the areas are along the outflow boundary from our last evening & morning showers/storms (Kentucky to southwest Indiana & southeast Illinois & over west-central Illinois)  The other area in Iowa & northeast Indiana are just north of the stalled, weak surface front.  This front is slowly lifting northward as the heat expands south & southwest of our area.

I am keeping an isolated shower/t’storm in the forecast for tonight-tomorrow morning & a few isolated t’storms in the forecast for tomorrow afternoon-evening.

Areas of locally-dense fog are possible tonight, too.

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On a torrid, boiling hot day on August 22, 1947, a storm blew up & produced an apparent microburst at the Purdue Airport.  Equipment there measured a gust to 78 mph.  6 barracks buildings had roofs blown off.

The temperature fell from 101 to 74 in a matter of minutes as the storm quickly blew up around 3 p.m.

A massive upper ridge engulfed the eastern & central U.S. with extreme heat prior & the day of the storm.  It was one of the worst heat waves on record for northern Michigan just a few days before.

The storms & the few others that popped occurred with a weak front that pushed in from the northeast.

Overall 1947 was a brutally hot, dry summer, but unusually cool nights occurred in late July with near all-time record lows in the 40s.  This was due in part to the extremely dry, desert-like conditions that caused dew point to drop to extremely low levels, which allowed the night-time temperatures to plummet.

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Late Summer-Fall-Winter-Spring-Summer 2014-15 Outlook

August 22nd, 2014 at 6:21 pm by under Chad's WLFI Weather Blog

Weak to moderate El Nino Modiki will set up for the fall, winter & spring before fading next summer.  Modiki El Ninos differs from traditional El Nino in that the main area of abnormally warm surface waters in the Equatorial Pacific is more in the central part than the eastern part.  This results in different effects than what would be expected in a normal weak to moderate El Nino.  The last El Nino Modiki occurred in the winter of 2009-10.

Other aspects of this forecast pertain to anomalously warm & cold areas of ocean around the world expected during the fall-winter-spring in tandem with a sleeping sun with very few sunspots expected.

At first, it looked like an all-out strong, traditional El Nino with a warm winter with little snow, but latest trends don’t necessarily show a warm, relatively snow-free winter like late 2005-06 winter or 2011-12, 1997-98, 1982-83 or 1918-19 winters.

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The years that match the current ocean warming/cooling pattern around the world with number of sunspots & volcanic activity, as well as the past behavior & projected behavior of these factors was researched.  I found years that favored the current regime the most.

To put this to the test, I put plugged these years into NOAA climate data division program & it spit out what all of these years had in common for the winter & summer prior to the El Nino Modoki.  The temperatures matched up very well!  Notice the unusually cold January & February & the warmer-than-normal May & June (this occurred), followed by the cool summer!  This is what occurred this year.

So, we can say that the current pattern around the world & our regime matches well with the years I plugged in to develop this outlook.

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THE OUTLOOK:

Fall Temperature

September, October & November………….& Overall For the Fall

(The more robust the blue or red or orange, the greater the temperature above or below normal…………white is normal).

1.  Highest temperatures of the year will likely occur in September.

2.  Below-normal temperatures overall in October.

3.  Above-normal temperatures in November.

4.  This will average out to a warmer-than-normal fall, then.

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Fall Precipitation

September, October & November………….& Overall For the Fall

(The more robust the blue or orange, the greater the precipitation above or below normal…………white is normal).

1.  September & October will tend to feature normal precipitation.

2.  November shows a tendency for a bit drier-than-normal.

3.  This will average out to normal precipitation this fall.

4.  If there is snowfall, it would tend to be below normal & not amount to much, it appears.  Of the years, a trace was the average.  Only 2004 had 2.1″ of snow in the fall at West Lafayette with higher amounts in the north & northeast.

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Fall Palmer Drought Index

1.  You can see even in the years put into this data, the show that abnormally dry area in northeastern Indiana, just like now.

2.  Data tends to point to wetter conditions overall in the western half in September & drier conditions in the east/northeast of our area.

3.  In October, it shows normal conditions over most of the area, except some above-normal soil moisture conditions in our northwestern areas.  This applies to November, as well.

4.  Overall, it appears the higher likelihood of wetter soils as we move into fall will be in our northwestern areas with drier conditions in the east & northeast & normal soil conditions for the time of year elsewhere.

TVWS

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December, January & February…………….& the Overall Winter

Temperatures

1.  There is a tendency for overall above normal temperatures over most of the area except more normal regime perhaps in our southeastern areas for December.

2.  January & February look colder-than-normal with potential of the coldest weather of the winter in early- to mid-February.

3.  Per this analysis, odds favor an overall colder-than-normal winter when the milder December is combined with the colder January & February.

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December, January & February…………….& the Overall Winter

Precipitation

1.  Precipitation in December & January looks normal.

2.  A bit drier-than-normal conditions look more likely in February.

3.  Overall for the winter, data shows an overall trend to slightly drier-than-normal conditions.

4.  In terms of snowfall,  it looks either normal or just a bit above normal for December-February.  I think most of the snow will fall in January with perhaps one larger storm in February & other very minor snows in that month.

Normal snowfall in the area varies from 18″ in the southwest to 32″ in the northeast.  At West Lafayette, I am forecasting 20.9″ for December-February.  Normal for winter is about 20″.

Of the 10 years that matched our current one, 4 had one snow event with over 6″ of snow in their respective winters.  They tended to occur in February (see above for regards to larger storm in February).

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March, April & May………………& Overall Spring

Temperatures

1.  March favors normal temperatures will below-normal temperatures just south of our area.

2.  April tends to show above-normal temperatures.

3.  May look cooler-than-normal over most of the area, except the northwest & west.

4.  Overall spring temperatures look close to normal, but notice the warm anomaly in the Northern Plains & the cool anomaly in Texas, Southwest & Gulf Coast areas, owing to El Nino earmarks showing & continuing.

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March, April & May…………….& Overall Spring

Precipitation

1.  March looks drier-than-normal.

2.  April looks a bit drier-than-normal over the northern half of the area, with normal precipitation elsewhere.

3.  May even favors a bit below-normal precipitation.

4.  In terms of snow, of the 10 years matching this one, every year except 2 had at least 1″ of snow in spring (all in March).

CDEG

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June, July & August……………& Overall Summer

Temperatures

1.  Analog favors normal June temperatures, but above-normal temperature trends in July & August.

2.  This will make for an overall above-normal temperature trend for the summer of 2015.

3.  The average number of +90 days for the year average out to about 21 in the data set.  I am forecasting 20 for West Lafayette & similar numbers for the rest of the viewing area.

4.  Of all of the summers studied, the average highest temperature following the winter was around 94.7.  I am forecasting a maximum of 96 for next summer at West Lafayette.

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Precipitation

June, July & August………….& Overall Summer

1.  June look a bit wetter than normal, overall.

2.  July looks wet with above-normal rainfall area-wide.  It tends to be one of the wetter months of the year, anyway.

3.  This reminds me so much of the 2010 July when it was very wet, but very hot in that several instances had dew points in the upper 70s to around 80 & we were as high as 95.

4.  A sharp drying trend is noting in the data for August.

5.  Overall summer precipitation rounds out to above-normal between a likelihood of a wet July & a dry August.

IJKH

Palmer Drought Index

June, July & August………….& Summer Overall

1.  As a carry-over from the dry spring, analog points to Abormal Dryness in the Palmer Drought Index in our northwestern areas in June.

2.  July’s wetness show a complete elimination of spring dryness & a chunk of the area with quite wet soils.

3.  Again, trends favor rapid development of dry weather in August with Abnormally Dry conditions developing in the area with the potential of Short-Term Moderate Drought, especially toward Illinois.

4.  Overall pattern shows bit below-normal rainfall in our north half & it average out to normal rainfall in the south half.

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Wettest Augusts

August 22nd, 2014 at 3:41 pm by under Chad's WLFI Weather Blog

As of today, 2014 is the 14th wettest in the Purdue University/Purdue Ag Farm data set 1887-present.

Taking our 6.18″ at WLFI & plugging it into the data set, it would be the 12th wettest August since 1887.

This makes sense, as you move move northeastward & eastward in Tippecanoe County, the August rainfall totals increase rapidly.  Some parts of the county have had just 1.70″!

Totals still vary viewing area-wide, but the areas that were very dry a few days ago have picked up 1.5-5.25″ of rain since then.

I also have the top 5 driest Augusts since 1887 at West Lafayette.

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1:30 P.M. Update

August 22nd, 2014 at 1:09 pm by under Chad's WLFI Weather Blog

Additional rainfall fell late overnight & early this morning along & north of the front & outflow boundary in the northeastern 2/3 of the area.  Some of it was locally-heavy with flash flooding reported on roads, streets & in fields & lawns.  Coverage ended up peaking about 60%.

The rainfall has exited & even the rainfall in Illinois is diminishing.

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Since yesterday, rainfall has varied WIDELY in our viewing area.  Our southwest 1/4 to 1/3 has had NOTHING to 0.20″, but parts of Jasper & Pulaski County picked up 4.80″ of rainfall over the past 36 hours.  The highest total seen was 5.25″ southeast of Rensselaer.

Mary Anne in Remington reported 1.49″, but in northwest Pulaski County, I received a report of 4.63″!

Chuck 4.5 miles northeast of Frankfort received 3.74″ in 24 hours.

O No Moe, who only had 1.75″ since July 17 in northern Miami County reported 2.88″……….finally a good rain for northern Miami County!

This map is from the National Weather Service Indianapolis showing rainfall yesterday morning to this morning.

Notice the SHARP cut-off in our southwestern counties!

In the past few days I saw where 10.63″ has been measured at Hartford City, Indiana (Blackford County)!

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DMA Map IIDMA Map III

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Low-level jet has weakened & veered, so I think the rainfall in Illinois will completely fade away & areas that are currently cloudy in the viewing area should begin to see at least a bit of dim sun appear in the coming few hours.  There is already sun in our northern & northeastern counties.

In our northern & northeastern counties (where there is more sun), surface CAPE (instability is pushing 2000 J/kg).  For everyone else, there is strengthening capping & about 1000 J/kg of CAPE.

All this said, I still like a 30% POP (t’storms) in the forecast for the evening (though this is contingent upon how much cap or EML continues to strengthen & expand).

I have notice decent cumulus development in our northeastern counties as of 1:30 p.m. through the thin veil/film cirrostratus where there is no capping.  Kept “isolated severe” mention in the forecast, despite no good forcing, for if the surface CAPE really increases & cap can erode.  There is quite a reservoir of it to our west & southwest with up to 5000 J/kg, so 30% POP & iso severe seems to be a good call at the moment.

We will monitor.


Updates

August 21st, 2014 at 6:24 pm by under Chad's WLFI Weather Blog

10:08 p.m.

Some storm pics:

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Storms are exiting area, but I cannot rule out another storm or two popping on the outflow boundary surging into hot, untapped air in Fountain/Montgomery counties over the next hour.  After that, we are in the clear for any severe storms.

However, I cannot rule out a few showers/t’showers overnight.  I will keep 30% coverage with the outflow boundary in the south, migrating north & the weak stationary front in the area.

Otherwise, some patchy, locally-dense fog is possible late tonight-early Friday morning.

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STORM REPORTS:

1.75-2.25″ Diameter Hail (Golfball to Walnut) County Road 800 & U.S. 52 Near Clark’s Hill

1.75″  Diameter Hail Northwest of Colfax

1-1.5″ Diameter Hail  2 Miles North of West Lafayette.

1″  Diameter Hail  1 Mile North of Thorntown

0.88″ Diameter Hail 3 Miles East of Thorntown

0.75″  Diameter Hail 3 Miles Northeast of Wolcott

0.25″ Diameter Hail 1 Mile Northeast of Lafayette

Several Trees & Large Limbs Down in Thorntown

E58 mph  Radnor

M57 mph  Burlington

E55 mph 5 Miles North of Radnor

M53 mph  Cass County Airport AWOS

M51 mph  Winamac

M50 mph  Frankfort

M48 mph  4.5 Miles Northeast of Frankfort

M47 mph  Winamac High School

M45 mph  I-65 & Route 28 West of Frankfort

E45 mph Delphi

M43 mph  Clinton Prairie High School

M40 mph  Grissom Air Reserve Base ASOS

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9:51 p.m.

Severe T’Storm Warning for northeastern Montgomery until 10:30 p.m., southern Clinton until 10 p.m., Boone until 10:30 p.m. & far southern Tipton until 10 p.m.

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Hail core still evident in storm near Colfax 1-2″ max stone size possible.

Notice the curly hook signature near Bowers, south of Clark’s Hill.  This feature on the tail end of this storm actually originated near Kirkpatrick.  It has a pretty tightly-wound rotation signature on it for a bit!

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9:33 p.m.

Large hail being detected in storm near Monroe.  Hail could reach 1.5-2″ diameter (mixed with smaller stones).  Storm Vision shows max diameter of 2.25″ (walnut).

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Other storms are torrential, but not severe like they were earlier.  Notice max gusts estimated at up to 41 mph.

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Watch for flash flooding!  Rainfall rates are +3″ an hour in the most intense t’storm cores.

STORM REPORTS:

1-1.5″ Diameter Hail  2 Miles North of West Lafayette.

E58 mph  Radnor

M57 mph  Burlington

E55 mph 5 Miles North of Radnor

M53 mph  Cass County Airport AWOS

M51 mph  Winamac

M50 mph  Frankfort

M48 mph  4.5 Miles Northeast of Frankfort

M47 mph  Winamac High School

M45 mph  I-65 & Route 28 West of Frankfort

E45 mph Delphi

M43 mph  Clinton Prairie High School

M40 mph  Grissom Air Reserve Base ASOS

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9:15 p.m.

Southeast Howard County has warning until 10 p.m.  Tippecanoe warning goes until 9:45 p.m.  Clinton & Tipton Warning are until 10 p.m.

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9:04 p.m.

Severe T’Storm Warning for Tippecanoe until 9:45 p.m.  Gust to 50 mph possible on east side of Lafayette with potential of 1-1.75″ hail on north to northeast to east sides of town.

Damaging winds continue to race through eastern Clinton County to far southwest Howard.

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8:50 p.m.

Hail is becoming possible with storm on the northeast side of Lafayette.  It may reach 1-1.5″ diameter soon & require warning for Tippecanoe.  Be aware that large hail could fall with this storm soon south of Battle Ground to Birmingham.

Carroll/Clinton warning goes until 9:30 p.m.

Damaging winds of up to 70 mph are working from southern Carroll to northern Clinton County.

Gusts to 45 mph are possible in southern Miami County & 50-55 mph in southern Cass as wind cores strengthen.

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8:42 p.m.

Severe t’storm with gusts to 64 mph is blasting through the southern half of Carroll County.

Be aware northern Clinton & all areas southeast of Flora, Camden & Owasco.

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8:33 p.m.

Severe t’storm with gusts to 62 mph with pea hail is working through Carroll County.

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8:23 p.m.

Gusts to 60 mph possible between Yeoman & Rockfield.

NWS has issued Severe T”Storm Warning for Carroll County until 9 p.m.

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8:14 p.m.

Still nice wind core evident in storm sliding southeast of Monticello, into northwestern Carroll County.  Wouldn’t be surprised to see gust to 60 mph in spot near Yeoman.

Pea to marble hail possible with it, too.

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7:57 p.m.

Localized gusts 50-55 mph possible in the Monticello area with pea to marble hail & torrential rainfall in next 5 minutes.  Flash flooding is possible with this storm with +3.50″ per hour rates at its height.

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STORM REPORTS:

M51 mph  Winamac

M47 mph  Winamac High School

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7:36 p.m.

Near continuous lightning is occurring with these storms.

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Storm Vision is projected a nickel hail swath to move into northwestern White County.  Current data shows 100% chance of hail with the storm near Wolcott, but only 10% chance of 1″ hail.  It is likely marble to as large as nickel.

You can also see with the Dual Pol radar data that it indicates hail in that core.

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Gusts of 50-60 mph are possible in a core of the storms near Wolcott.  Gusts to 45 mph southern Pulaski & to 50 mph Winamac.

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7:10 p.m.

Southern Jasper & eastern Newton now under warning until 7:45 p.m.

Hail of pea to penny size is evident in the more intense portions of this storm cluster.

There are three cores of microburst-type gusts evident at the moment.  Velocity suggests gusts of 50-60 mph in this cores that are fanning outward randomly.

This is not widespread damaging wind, but small, localized cores of intense gusts.  It is a situation where one place has a gust to 25 mph & a few miles down the road there is a 55 mph gust over a 1-2 mile area.

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7:05 p.m.

Pulaski County Warning in effect until 7:45 p.m.

Two wind cores seen.

The core that is most-likely severe is northeast of Clarks to northwest of North Judson, moving toward Denham.

Gust 50-60 mph possible.

The Jasper County core is the second one with gust to 45 mph possible.

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6:47 p.m.

Up to 5000 J/kg surface CAPE in Illinois & 4000 J/kg surface CAPE in parts of the viewing area is making for an extremely unstable airmass.

This will make for a bit more widespread severe threat with  scattered severe gusts & perhaps some hail in the area as storms are organizing into a cluster.

Severe T’Storm Watch is in effect until 12 a.m. for all counties of the viewing area EXCEPT, Benton, Warren, Fountain, Montgomery & Boone.

Thinking storms will continue to elongate some southwestward.

Futurecast has them just in Clinton, Boone, Tipton counties by 11 p.m. & completely out of the viewing area by 11:30 p.m.

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6:37 p.m.

Two cores of winds of 50-60 are seen in Porter County.

Looks like gusts of 35-45 mph near Demotte, but that may increase shortly.

The Demotte velocity is indicative of developing microburst with a stronger maturing microburst northwest Kouts.

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6:18 p.m.

Two cores of winds to 52 mph are evident in Porter County with warning for Porter, southeast Lake.  Chicago NWS has gone ahead & included the northern sliver of Jasper County in the Severe T’Storm Warning until 7 p.m.  Severe gusts may still intrude into northern Jasper.

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5:32 P.M. Update

August 21st, 2014 at 5:36 pm by under Chad's WLFI Weather Blog

It is currently 87 at the station with a dew point of 75, making it feel like 97.

At Mary Anne’s weather station in Remington, it is 87 with a dew point 77, making it feel like 99.

The hottest location in the viewing area at the moment (heat index-wise) is Kentland.  Current temperature is 88 with a dew point of 78, making it feel like 101.

A few storms continue to pop on the outflow boundary from earlier MCS.  THe boundary has been shifting north with the building heat.

I am also continuing to monitor Illinois for the potential of new t’storms development as MCV moves into the state.

SPC Mesoanalysis shows a core of 4500 J/kg of surface CAPE now migrating into Fountain County with 4000 J/kg as far north as Benton & Tippecanoe counties.

Should storms get go, a few could go severe with wind/hail given this extremely unstable airmass, though the dynamics will not particularly strong (despite forcing my MCV).

Any storm, with these high dew points, could dump torrential rainfall with rates of +3″ per hour.

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3:45 P.M. Update

August 21st, 2014 at 3:42 pm by under Chad's WLFI Weather Blog

Tail end of morning MCS (its outflow boundary) has migrated back northeastward as heat has engulfed area from the southwest.

The tail (outflow boundary) has popped scattered showers & t’storms from Peru to Winamac.

A reservoir of 5000 J/kg of surface CAPE continues to boil & expand in Missouri, southern Illinois & Indiana with intense heat & humidity (some dew points pushing 80!).

As MCV pivots through eastern Iowa & encounters the expansion of boiling surface instability storm development needs to be watched.  Storm development will need to be monitored on that outflow boundary, too.

Isolated severe wind/hail will exist, but with that +4000 J/kg CAPE expanding, the potential continues to exist for more widespread severe development.

We will continue to monitor.

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2:25 P.M. Update

August 21st, 2014 at 2:32 pm by under Chad's WLFI Weather Blog

OVERNIGHT-AM RAIN & OPPRESSIVE DAY WITH CLEARING……….
Overnight-morning complex of storms has exited (with up to 2″ of rainfall in our northeastern counties!)

Now it is heating up rapidly & getting very unstable.  Some dew points are pushing 80!  Wow that is oppressive! (Kentland currently 86 with a dew point of 79, giving them a heat index of 100!)
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THE TRIGGERS FOR SOME NEW STORMS………...
This said, thinking some new storm development will take place via two triggers:

1.  Tail end of overnight complex of storms’ outflow boundary in area.
2.  Disturbance in Iowa (MCV or old vortex from severe storm complex there overnight).
Storms would tend to ride down into our area like cars on a highway via our weak front laid up across the area .
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COVERAGE…………..SEVERE?

This said, will keep 40% coverage of storms in the forecast for late afternoon, through evening.

With it being so hot & unstable, I still like isolated severe wind/hail threat in the forecast if the storms can really get going.  If it can get extremely, boiling unstable like it is in southern Illinois & southwest Indiana right now, then severe threat might actually become more widespread.

We will monitor.


Some Heat Indices at 100……..Monitoring Storm Re-Development

August 21st, 2014 at 2:14 pm by under Chad's WLFI Weather Blog

With the sun coming out & it heating up rapidly (& destablilizing), scattered t’storms may re-develop late this afternoon-this evening.

They may form in two ways:

1.  Tail end of a.m. MCS outflow boundary may trigger a few.

2.  MCV pivoting through Iowa may be trigger for additional storms.

Thinking that the potential exists for these to organize into a cluster due to that MCV apparent (old vortex from overnight MCS [complex of storms] over the Upper Midwest & Northwest Corn Belt) pivoting through Iowa.

With surface CAPE to 2500 J/kg in the area now & 4500 J/kg in southwest Indiana, it is certainly unstable enough for storms to go.

As of 2:15 p.m., it is 84 with a steamy dew point of 74 at the station.  Petit Mesonet station has 85 with a tropical dew point of 75, while Prophet’s Ridge private unit is 84 with a dew point of 75.

At Grissom, it is 77 with a dew point of 77 with 100% humidity!  Now that is oppressive!  I just saw that Kentland is 86 with a dew point of 79!  That gives them a heat index of 100.

That said, will still go for 40% coverage of storms with isolated severe wind gusts/hail.

If we can get the surface CAPE to 5000 J/kg, then more widespread severe threat may develop.  We will monitor.

 


MCS Exiting………….Much-Needed Rainfall In Part of the Area

August 21st, 2014 at 12:37 pm by under Chad's WLFI Weather Blog

MCS is exiting area.  It brought much-needed rainfall late last night & this morning to our east & northeast, while other places picked up more rainfall they did not necessarily need.

Grissom Air Reserve Base measured 1.81″ of soaking rainfall!

1.66″ fell at the Kokomo Airport with 1.16″ at the Logansport Airport.

Fulton County Airport measured 0.90″.

The heaviest rains were definitely in the north & northeast.

At WLFI, I measured just 0.15″.  Frankfort measured 0.13″, while Michigantown reported 0.21″.

Parts of our southwestern & southern areas had nothing.

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With sun & heating this afternoon-evening, a few more storms are possible.  As of 1 p.m., at WLFI, we now have sun!  Temperature has shot up to 82 with a dew point of 73!  It is muggy!