Chad’s WLFI Weather Blog

11:45 P.M. Update

September 27th, 2014 at 11:03 pm by under Chad's WLFI Weather Blog

Highs today varied from 79-84.

Tonight, patchy high/mid clouds will exit & patchy, locally-dense fog will develop with lows of 51-56.

Sunday & Monday look great with brilliant sun & highs from around 80 to as high as 84, with lows in the 50s with some patchy fog.

Again, Tuesday looks a hair cooler at 77-81 with 79-84 Wednesday & 78-83 Thursday.

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It looks like scattered showers & t’storms will come in Thursday & increase Thursday night, followed by a main round Friday.  It is still a bit questionable when exactly the heaviest showers/storms pass (with cold front) Friday & if any rainfall will linger into Saturday morning.

Regardless, storm system looks pretty strong with strong wind fields at all levels & good forcing.  For us, question is instability.  If it can get unstable enough, then severe threat would need to be put in place.  The latest data still suggests an issue of getting unstable enough for severe threat, but it looks plenty unstable enough from Kansas to Iowa to western Illinois to Missouri & Arkansas for severe event late week.

It also still appears that locally-heavy rainfall may occur with widespread 1-2″ amounts.

Much cooler weather still looks to follow with a couple nights in the 30s before the warmth rapidly returns.

We will continue to monitor & tweak forecast as needed as additional data arrives.


Latest Outlook Now-October 10

September 27th, 2014 at 4:12 pm by under Chad's WLFI Weather Blog

Patches of high & mid clouds splotch the sky with warm, nice sunshine.  The deeper 850 mb moisture for fair weather cumulus remains Indy metro & southward & that is where they have formed today, rather than farther north into our area.  This is close to where the 60-degree dew point line is generally located.

Tonight, with patchy high/mid clouds pulling away, patchy dense fog is possible.  Lows will run 51-56.

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Sunday & Monday look great with lots of sun & highs back to 81-84 with lows in the 50s.  It will cool just a hair Tuesday with highs at 77-81.

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Wednesday & Thursday will return back to 81-84 with lows by Wednesday & Thursday nights in the 60s.

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Data continues to show a gusty, windy system with several waves of showers & t’storms Thursday to Friday & perhaps Saturday.

There is a question as to whether the front will pass Friday at some point or as late as Saturday.  This will become much more apparent in the coming days.  With the models wobbling back & forth, I would prefer to let the dust settle before settling on an exact day of frontal passage.

Regardless, it appears scattered showers & t’storms are possible by late Thursday as cold front & first surface low approaches.  These may increase in coverage Thursday night, before a break ensues.  Strong south-southwest winds of 20-30 mph will likely be steady through the afternoon-night.

Although it appears that Hurricane Rachel remnants will not make a right turn toward the U.S. per National Hurricane Center forecasts & long-range data, there is a lot of deep tropical moisture that will likely be pushed northward.  So, I still think locally-heavy rainfall is good wording.

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As for Friday or Saturday, several things can be discerned:

1)  It is likely that a strong upper jet streak (core of very strong winds way up in the troposphere) will swing in from the southwest & cause second surface low to deepen rapidly over northeastern Illinois.

2)  Dynamics are forecast to be strong & shear impressive with fall system that will deepen from 1002 mb to about 992 mb in 10 hours in its track from Missouri to Michigan.

3)  It is likely that severe weather event will unfold with this deepening from Oklahoma to southeastern Iowa, Missouri & western Illinois to Arkansas.

4)  Here, issue is instability.  Today, CAPE forecasts are not impressive here at 200-500 J/kg.  Forecasts have been more impressive in previous days.  This said, it is too unclear how surface instability will evolve to put much forecast on severe outlook for our area.  We will just have to monitor.  My confidence is much higher in severe threat west & southwest of our area, than here.

5)  Timing is an issue.  Prior, data suggested Wednesday-Thursday rainfall time frame, which slowed to Thursday-Saturday.  Recently, there has been that Thursday-Friday trend.  This also said, I can tell you that I can pinpoint the rainfall potential down to Thursday late-Thursday night & again Friday.  Whether the actual front & best lift come through Friday morning, Friday afternoon or Saturday morning is in question………………heck it may end up being Saturday afternoon.  It is too hard to say this far out.

To combat this issue, I took a medium road with frontal passage & best lift coming through in the Friday to Saturday morning time frame.  This will remain the wording until early week when I can get a better handle on it.  We may even see temperatures drop from the 60s Saturday morning to 50s in the afternoon.

6)  I still like the mention of locally-heavy rainfall (1-2″) even in the Friday-Saturday time frame, given the lift & tropical moisture.

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On thing is for sure, it will cool off rather quickly & dramatically from 80s for highs to 60s, then 50s behind this system.  A couple to perhaps three nights may see lows in the 30s in the viewing area.  Frost is possible.

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The good news it that trends point to this rather ordinary early-October cool wave being brief.  60s & 70s may return again thereafter with drier weather.


Latest on Outlook Through Next Week & Beyond

September 26th, 2014 at 9:55 pm by under Chad's WLFI Weather Blog

More torrential rainfall & severe t’storms are hitting the Desert Southwest again.  More rain is also overspreading southwest Texas.

Check out the obs for the North Las Vegas, Nevada area:

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Highs today ran 81-85 with mostly sunny skies.  Some fair weather cumulus mixed with cirrus will be with us Saturday with highs in the 80s after 51-57 in the morning.

Highs, with mostly sunny skies, will run in the 80s Sunday & Monday.

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We will likely remain near 80 to the lower 80s Tuesday-Thursday.  We might shave a couple of degrees off, but it will remain mostly sunny.  Lows will run from near 50 to the upper 50s, except around 60 to the mid 60s Wednesday & Thursday nights.

Data still suggests showers/storms late Thursday-Friday to perhaps Saturday with deepening surface low.  Dynamics are ample, but instability is questionable for severe weather.  It still needs to be monitored.

A few days with highs in the 50s & lows in the 30s with frost looks to be followed by a pretty rapid warm-up.


80s Now………..Some Frost Soon………Frost/Freeze Climatology

September 26th, 2014 at 4:45 pm by under Chad's WLFI Weather Blog

It is nice & warm today, but as we get ever closer to October, it is good to into frost/freeze climatology for the area.

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2:40 P.M. Update

September 26th, 2014 at 2:48 pm by under Chad's WLFI Weather Blog

As of 2:40 p.m., temperatures are warm at 79-84!

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Tomorrow looks good, but there will be high cirrus coming in.  Also, fair weather cumulus clouds will develop as more low-level moisture surges in from the Gulf of Mexico.

It will be warm once again with highs of 80-84 after 51-57 tonight with perhaps some patches of fog.

Sunday looks great with 80s & morning lows in the 50s.

It should remain dry until later Thursday when scattered showers & t’storms will arrive.


The Latest Trends Regarding Warmth, Dryness & Eventual T’Storms with Brief Cold Snap

September 25th, 2014 at 11:28 pm by under Chad's WLFI Weather Blog

Surface high, which will control our weather with sun & dry conditions through the weekend & most of next week will act as a wall to our next storm system.

It will take time to move southeastward.

This will do two things:  1) keep any rainfall out of the forecast until late Thursday & 2) keep rainfall in the forecast Friday & into Saturday (periodically).

It looks as if strong upper trough & cold front with impressive height falls will accompany the main surface low perhaps Saturday, October 4.  This could lead to severe weather threat.

Tropical moisture may lead to locally-heavy rainfall.

Highs in the 50s & lows in the 30s with frost will followed the front, followed by a pretty rapid warm-up.

This gives a good idea of the trends based on the latest analysis.

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Three Things Noted In Longer-Range Data Tonight

September 25th, 2014 at 9:54 pm by under Chad's WLFI Weather Blog

Today was cool in the morning, but warm in the afternoon!

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Three things noted in the longer-range data tonight.

1.  It appears as if surface high to our east will hold any rain off until Thursday p.m.  This means rainfall Friday, too.  In fact, there are indications that additional showers & t’storms may actually hang on into Saturday as front stalls over the area.
The rainfall looks periodic & confined to several waves, not solid rainy conditions all the time with warm conditions.

2.  Strong upper level winds & CAPE of up to 1500 J/kg with the dynamics may produce severe weather, specifically next Saturday as the main, strong cold front passes.  Height falls with passage of the front would tend to up severe potential.  Course, this far out, exact details are nebulous at best, but such data supports a QLCS squall line.

3.  It still looks like a cold burst of air behind this with highs in the 50s & lows in the 30s with some frost for the entire viewing area.  GFS model has a low of 34 for Lafayette area around October 5.


Did Anyone Spot “Fireball In the Sky” Last Night (Around 10-10:30 P.M.?)

September 25th, 2014 at 5:29 pm by under Chad's WLFI Weather Blog

There were reports of four “fireballs in the sky” last night in the eastern U.S., including one in our area.  It was reportedly around 2 a.m. UTC or 10 p.m.

I did see a couple of reports from Peru, but that is it in our viewing area.

http://www.huffingtonpost.com/2014/09/25/fireballs-sky-east-us_n_5882472.html?ncid=txtlnkusaolp00000592

http://amsmeteors.org/fireball_event/2014/2306


Some Areas 80° As of 3 P.M.

September 25th, 2014 at 2:56 pm by under Chad's WLFI Weather Blog

It is another nice day with patchy high & mid clouds in the viewing area.

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Yesterday Tropical Depression 18E was a jumbled mess of 2-3 clusters of convection, much of it well away from the center.  It was hard to discern the center with winds barely to 30 mph.  Today, we have a 50 mph, well-formed, strengthening tropical storm that has greatly organized into a nice, circular system that lacks the haphazard cluster of t’storms well away from the center.

It has gone from sad-looking to an increasing threat for Baja.

The experts at the National Hurricane Center do not have Rachel reaching hurricane strength.

Model do bring Rachel’s remnant moisture into the Southwest & Plains by mid-next week.

This may enhance rainfall even here next Thursday.  The potential exists for locally-heavy rainfall, but this is still a week out, so tweaks to this forecast as likely.

It still looks like some scattered showers & t’storms Wednesday late afternoon-early night, then break, followed by more widespread showers/t’storms Thursday.

At the moment, there is no strong signal of a severe threat at the moment in our area.  I will continue to monitor, as given the influx of 65-70 dew points, it will actually turn a bit muggy late next week.

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Whether the showers/storms had on periodically longer beyond Thursday will be governed by surface high on southeast coast.  Regardless, colder air will followed this with some frost.

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Frost & Freeze Climatology for West Lafayette

September 25th, 2014 at 1:08 pm by under Chad's WLFI Weather Blog

Below are the dates of first 36 or less, 32 or less, 28 or less & less than 20 1879-1965 at West Lafayette.

1966-2014 will be coming later today.

These are all weather records from the official government (NOAA) station at Purdue & the Purdue Ag Farm.  Federal government established an official weather station at Purdue in late 1879.  Eventually, this was moved to the Purdue Ag Farm.

I also plan on plotting the dates on a graph to plot any sort of trend in the data set.

In the data 1879-1965, the earliest occurrence of teens was October 25, 1887.

The earliest occurrence of at least 36 was August 29, 1965.

The earliest occurrence of 32 or less was September 20, 1956

The earliest occurrence of 28 or less was September 30, 1888 & 1899.

The earliest occurrence of 25 or less was October 7, 1889.

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