September 2nd, 2014 at 1:04 pm by under Chad's WLFI Weather Blog

Spotty showers are still found over the area after more widespread rains last night & this morning, especially in our south.

Thinking spotty showers & t’storms will continue to be possible through the afternoon with partly to mostly cloudy skies.

Temperatures have been slow to rise with all of the clouds (they are currently in the 70s).  79-84 should do for today.

 


10:34 P.M. Update

September 1st, 2014 at 10:36 pm by under Chad's WLFI Weather Blog

Showers & t’storms continue to expand northeastward along & south of the stalling front. 

Warnings are around St. Louis & southwestern Illinois.  I still do not expect severe threat here (it should stay southwest of our area), but rain & t’storms will be with us overnight-early Tuesday morning.

I just looked at the 00z NAM model & it tends to gell with the thinking of some locally-heavy rains of +2″ occurring south of 28.  This is about a 25-30 mile shift south in looking at the evolution of the rainfall southwest of here this evening & lack of storms forming over our northwestern counties.

125


9:26 P.M. Update

September 1st, 2014 at 9:20 pm by under Chad's WLFI Weather Blog

There is a band/line of agitated cumulus along the cold front over our northwestern counties, but no t’storms have formed.  However, band of heavy t’storms resides from southwest Illinois to Oklahoma & it is moving east-northeastward.

So, have showers & t’storms in the forecast for the overnight-early morning hours.  Took out any mention of isolated severe, but locally heavy rainfall is possible south of Route 28.

101


6 P.M. Update

September 1st, 2014 at 5:52 pm by under Chad's WLFI Weather Blog

Still looks like a line of storms is possible on the front this evening with additional rain/storms training over the front overnight.  Isolated severe gust/hail still in place.

Locally-heavy rainfall is still possible south of U.S. 24.

The best potential of more widespread flash flooding & heavier rainfall will run from central Missouri to the St. Louis area, then south-central Illinois, through south-central Indiana.  Local 4-5″ amounts are possible there.

102103


4 P.M. Update

September 1st, 2014 at 4:09 pm by under Uncategorized

A few scattered showers/t’showers are passing through the viewing area now.

The actual surface cold front is just northwest & west of the viewing area.  Here, a band of towering, agitated cumulus is noted, so we will still watch for potential narrow squall line to form.  Isolated severe threat still seems reasonable.

With it paralelling the flow aloft, it may train some.

Also, a lot of t’storms will likely develop in Missouri to Illinois.  That mass of t’storms will tend to move east & northeastward tonight bringing showers & t’storms to the area.

Locally-heavy rainfall still seems to be a good call south of U.S. 24.

101


2:15 P.M. Update

September 1st, 2014 at 2:27 pm by under Chad's WLFI Weather Blog

Squall line continues to develop & sweep through Michigan with watch & warnings.

Here, agitated cumulus are noted in bands just ahead of the cold front as skies clear some in our western counties with erosion of surface cap (CINH).

Still expected line of storms, but only “isolated severe”  seems reasonable rather than “scattered severe” owing to extended period low clouds have resided in our area.  This has kept temperatures & instability down.

110113


12 P.M. Update

September 1st, 2014 at 11:51 am by under Chad's WLFI Weather Blog

SURFACE COLD FRONT………

Surface cold front runs from Chicago to St. Louis at the moment with lots of low stratus across the area underneath low-level capping (inversion).  Outflow boundary is also progressing through area from the severe weather well west of here last night.  A few showers/t’showers are possible at any point this afternoon as boundary slowly progresses through area.

CINH & LOW STRATUS CLOUDS………

Thinking this capping will wear off & the sun will appear this afternoon.  With already 1000 J/kg of surface CAPE (given current dew points as high as 76!), once the sun appears, this may soar to 2500 J/kg, but it doesn’t look as unstable as it did yesterday (4000 J/kg).

“ISOLATED SEVERE” RATHER THAN “SCATTERED SEVERE”……….

Stronger wind fields aloft will support more organized storms, but I prefer to keep the wording “isolated severe” rather than “scattered severe” due to less instability expected & just so much low cloudiness lingering on into the afternoon.

This said, short, high-resolution models support storm development along cold front.

SOME LOCALLY-HEAVY RAINFALL POSSIBLE (BEST POTENTIAL SOUTH OF U.S. 24)………….

This would tend to occur this evening, followed by considerable t’storm activity north of the front overnight.  This could dump locally-heavy rainfall.  Given wet soils, some localized flash flooding is possible.

It looks like the best potential of this is south of U.S. 24 where some +2″ rainfall amounts are possible.

108


A Wet August! Hot & Humid with More T’Storms In the Forecast

August 31st, 2014 at 11:05 pm by under Chad's WLFI Weather Blog

LABOR DAY WEATHER HISTORY:

115

_____________________________________________________________________________

It was one wet August over much of the viewing area.  There were a few local exceptions, but by & large totals were above to much-above normal for the month.

Parts of Newton, Jasper, White, Pulaski & Tippecanoe had one of, if not, the wettest August since 1895.

At West Lafayette, August 2014 will go down as the 4th wettest since 1887 in the Purdue/Purdue Ag Farm data set (in process of archiving the records back to 1879):

109111

The heaviest totals, per Doppler radar, ran across northeastern Jasper to Pulaski County & then in a couple of bands from southeastern Jasper, across White County.  Yet two other areas of very heavy rainfall appear to have occurred in north-central Benton & northeastern Tippecanoe counties.  These areas appear to have picked up over 10″ of rainfall for the month.

Below are measured rainfall totals for the month per NWS COOP, AWOS/ASOS, Mesonet, CoCoRaHs & WLFI stations.

DMA Map IIII

______________________________________________________________________________

A few showers/storms may pop at any point during Monday as outflow boundary from tonight severe event to our west passes, but coverage will tend to run 20-30%.

103

However, a squall line may affect us in the evening.  It may train some & with some lingering rain/thunder behind it into the overnight-early Tuesday morning, it is possible that a few locations may see +2″ of rainfall.  As usual, rainfall amounts will vary in the area, however, from 0.60″ to +2″.

Friday-Sunday morning 4.40″ of rainfall fell in Kentland & 5.00″ fell in parts of Benton County.

This said, given the wet August anyway & the t’storms on the way, the potential exists for some flash flooding Monday evening-night.

Scattered severe wind gusts are also possible with it & perhaps a bit of large hail.

With better wind fields aloft, these storms look more organized & longer-lived than the pulsey storms with isolated severe weather as of late.

106107

 


Perfect Summer Day!

August 31st, 2014 at 5:09 pm by under Chad's WLFI Weather Blog

It is a perfect summer day with cumulus, sun, nice breeze & dry weather.

It is humid, but typical of an Indiana summers day.

DMA Map III

 


1:43 P.M. Update

August 31st, 2014 at 1:31 pm by under Chad's WLFI Weather Blog

2-day rainfall totals:

DMA Map II

_______________________________________________________________________________

Only 0.30″ of rainfall fell last night at the Purdue Airport, but the Ag Farm received over 1″.

Kentland was the highest total reported from any spotter with

After highs yesterday of 81 to 88, today will will rise to 82-87 with skies becoming partly cloudy.

It will still be humid, despite passage of weak cold front.

Front will move back northward tonight with clouds (kept it dry) with lows near 70.

Tomorrow will heat up with highs of 85-90 with high humidity.

_______________________________________________________________________________

Storms are likely Labor Day with the best potential in the evening.  There will be a lot of dry hours & it will be hot & humid & rather breezy, but data favors a squall line late in the day.

So, thinking squall line will blow up Minnesota to Kansas this evening with severe weather there, then weaken.  The outflow boundary may pop a few storms at any point tomorrow in our area with 20-30% coverage as it passes.

However, the squall line would tend to pop in Illinois in the mid to late afternoon & move eastward, tending to affect us in the evening.

This situation is different compared to recent rounds of storms.

The stronger mid & upper flow will actual move farther southward & overspread 4000 J/kg of surface CAPE Monday afternoon-evening.  The past several rounds have had the wind fields north of our area with generally pulse-type storms with isolated severe wind/hail threat.

The instability in tandem with the better wind fields points to an organized line of storms with scattered severe wind & hail along the line, not just pulsey, isolated threat.

Locally-heavy rainfall is possible given the high dew points.  Local flash flooding is possible, given recent heavy rainfall & the inability for soils absorb high rainfall rates (due to all of the rainfall fall over the past few days to couple of weeks).

For afternoon lower atmospheric profile, I selected the Lafayette grid point, but it is a good representation of the entire viewing area.

105

_______________________________________________________________________________

It still looks hot September 5 to around the 9 with the potential of 90 or more.

After the hot, humid weather, a more early-fall regime will set up after September 10 with some low temperatures in the 40s with a few days of highs only near 72.