137 replies to this topic

[wisconsinwx]

Well, with the new Day 1 SWO out, and N Illinois and S Wisconsin in the slight risk, there might be a need for a thread.  We shall see, but at the least convection and much needed rain is possible, even likely.

[Thundersnow12]

the 0z 4km wrf has qutie of bit of convection across northern IL near/after 0z this evening lasting into the overnight hours.

[Alek]

talk about just what the doctor ordered....really need this (rain that is)

[cyclone77]

Unfortunately Thompson at SPC just slashed the probs way down. Unfortunately he's almost always right.

Still should be an interesting day with that MCV feature coming out of KS later. Already lots of sunshine over MO, southern IA, and central IL.

[Thundersnow12]

The sun should come out here within the next few hours, some serious moisture advection taking here and to the southwest.

The HRRR is igniting storms later across IA/MO with that MCV and brings a complex of scattered storms/rain into northern IL after 0z.

[Alek]

DP managed to recover to 63 so far at MDW

[Thundersnow12]

It's a rather small, but vigorous wave we have to work with later with great wind fields in the lowest 3km. Also dew points in the upper 60's to low 70's south and west of here in the heart of the moisture axis.

[Thundersnow12]

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1129 AM CDT SAT JUN 16 2012

VALID 161630Z - 171200Z

..THERE IS A SLGT RISK OF SVR TSTMS FROM SOUTHEAST CO
ACROSS MUCH
OF OK...THE MID/UPPER MS VALLEY...INTO LOWER MI...

..IA/MO/IL/WI/MI

SATELLITE/RADAR IMAGERY SHOW A SERIES OF REMNANT MCVS OVER PARTS OF
NEB/KS/OK. THESE FEATURES HAVE BEEN WEAKENING THROUGH THE
MORNING...BUT ARE LIKELY TO PERSIST IN SUFFICIENT STRENGTH INTO THE
AFTERNOON TO ENHANCE CONVECTIVE RE-DEVELOPMENT OVER PARTS OF IA/MO.
THE AIR MASS OVER THIS REGION HAS BEEN RAPIDLY DESTABILIZING WITH
DEWPOINTS IN THE MID 60S TO LOWER 70S AND MLCAPE VALUES OVER 2000
J/KG NOTED. EFFECTIVE DEEP-LAYER SHEAR IS NOT PARTICULARLY STRONG
ACROSS THIS AREA...BUT THE HBR PROFILER NEAR ICT SHOWED A PRONOUNCED
MID LEVEL REAR-INFLOW JET ASSOCIATED WITH THE MCV A FEW HOURS AGO.
THIS MAY HELP TO ORGANIZE CONVECTION INTO A BOWING SEGMENT LATER
TODAY. PRESENT INDICATIONS ARE THAT STORMS WILL FORM FIRST OVER
NORTHERN MO/SOUTHERN IA AND TRACK EAST-NORTHEASTWARD THROUGH THE
AFTERNOON AND EVENING INTO NORTHERN IL/SOUTHERN WI AND PERHAPS INTO
LOWER MI TONIGHT. DAMAGING WINDS ARE LIKELY TO BE THE MAIN
THREAT...AS WEAK MID LEVEL LAPSE RATES TEND TO WEAKEN UPDRAFTS AND
LIMIT THE LARGE HAIL POTENTIAL.

[cyclone77]

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1129 AM CDT SAT JUN 16 2012

VALID 161630Z - 171200Z

...PRESENT INDICATIONS ARE THAT STORMS WILL FORM FIRST OVER
NORTHERN MO/SOUTHERN IA AND TRACK EAST-NORTHEASTWARD THROUGH THE
AFTERNOON AND EVENING INTO NORTHERN IL/SOUTHERN WI AND PERHAPS INTO
LOWER MI TONIGHT...

HRRR continues to advertise complex as well, much like the 12z NAM4...

[Geos]

Starting to hear some thunder, cooler outflow as well with these cells.

[Alek]

HRRR continues to advertise complex as well, much like the 12z NAM4...

Pulling for that in a big way

[Hoar_Frost]

Just heard a roll of thunder from a storm to my northwest (west of Elgin). Otherwise, it's partly sunny and 88/65.

[Thundersnow12]

the 12z 4km WRF is kinda ehhh, big complex rolls across the southern half of IA then falls apart after crossing the river.

[Thundersnow12]

MESOSCALE DISCUSSION 1186
NWS STORM PREDICTION CENTER NORMAN OK
1140 AM CDT SAT JUN 16 2012

AREAS AFFECTED...EXTREME ERN KS...SRN IA THROUGH NWRN MO

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 161640Z - 161815Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...STORMS ARE EXPECTED TO DEVELOP FROM ERN KS THROUGH WRN MO
AND SRN IA BY EARLY AFTERNOON. PRIMARY THREATS WILL BE ISOLATED
LARGE HAIL AND DAMAGING WIND. A SEVERE THUNDERSTORM WATCH WILL
LIKELY BE NEEDED ONCE INITIATION APPEARS IMMINENT.

DISCUSSION...LATE THIS MORNING A TROUGH EXTENDS FROM A WEAK SFC LOW
IN EXTREME NERN KS SWWD THROUGH ERN AND SRN KS. ANOTHER CONVERGENCE
BOUNDARY EXTENDS EAST FROM THE LOW THROUGH SRN IA. DECAYING OUTFLOW
BOUNDARY OR REMNANT GRAVITY WAVE CONTINUES MOVING RAPIDLY FROM
NCNTRL MO SWWD THROUGH CNTRL OK. THE ATMOSPHERE IS DESTABILIZING IN
WAKE OF THE INITIAL OUTFLOW AND EAST OF TROUGH AXIS FROM ERN KS
THROUGH MUCH OF MO AND SRN IA. OBJECTIVE ANALYSIS SHOWS PLUME OF
STEEPER LAPSE RATES ADVECTING EWD ABOVE MID-UPPER 60S DEWPOINTS.
THIS IN CONJUNCTION WITH DIABATIC WARMING SHOULD BOOST MLCAPE TO
2000-2500 J/KG THIS AFTERNOON. PROFILER DATA FROM HOBART KS INDICATE
A 50 KT WLY MID LEVEL JET BETWEEN 3 AND 5 KM SOUTH OF AN MCV LOCATED
OVER NERN KS.

VISIBLE IMAGERY INDICATES A RAPID INCREASE IN MID LEVEL CLOUDS OVER
ERN KS...LIKELY INDICATIVE OF MESOSCALE ASCENT ASSOCIATED WITH THE
MCV. AS THIS ZONE OF DEEPER ASCENT CONTINUES EWD THROUGH THE
DESTABILIZING ATMOSPHERE...STORMS ARE EXPECTED TO DEVELOP FROM
EXTREME ERN KS INTO WRN MO AND SWRN IA. VERTICAL SHEAR IS GENERALLY
MODEST SUPPORTING MOSTLY MULTICELLS. HOWEVER...A SMALL ZONE OF 35-40
KT SHEAR EXISTS WITHIN BELT OF STRONGER MID LEVEL FLOW SOUTH OF THE
MCV...SUGGESTING A FEW STORMS COULD BECOME BETTER ORGANIZED AND
DEVELOP UPDRAFT ROTATION AND BOWING SEGMENTS.

[Geos]

I'm just going to miss the main part of this first round by a few miles!

Did get the outflow though - down to 78°.

[Chicago Storm]

the 12z 4km WRF is kinda ehhh, big complex rolls across the southern half of IA then falls apart after crossing the river.

Other short term guidance is in agreement.

If that's the case i'll pass.

Dry soil for max heating potential Mon-Wed>lame weaking MCS.

[Alek]

I was pretty confident in the action falling apart before it got this far east but dewpoints have come up nicely...I think it's killing it off a little premature but i'm not exactly high confidence on that call

[cyclone77]

Big cell blowing up in far southeast NE. Could be the kickoff.

[cyclone77]

Dews seem to be pooling nicely along some sort of boundary that lies from Dekalb, back through the QC and down towards Ottumwa. Most locations near that boundary have dews hovering around 70.

[Geos]

Dewpoint up to 68° here. Highest it's been since last summer/late fall.

[Alek]

Dews seem to be pooling nicely along some sort of boundary that lies from Dekalb, back through the QC and down towards Ottumwa. Most locations near that boundary have dews hovering around 70.

Dewpoint up to 68° here. Highest it's been since last summer/late fall.

IIRC there was a lot of concern over at LOT regarding the models potentially overdoing dews, hence the low pops...I think they've come up tot he point where we should see better than isolated action.

[Hoar_Frost]

Heavy rain just started here in Geneva. First rain since 31 May. Some thunder and lightning.

[Alek]

Decent cell over northern Cook with more trying to get going back to the west.

[cyclone77]

Nice towers going up right overhead here.

[Alek]

Nice towers going up right overhead here.

yep, new MD for western Illinois as well...I think we'll see some decent coverage over the area this evening/overnight...trying to maintain hope.

For the first time this year, it actually feels hot/humid/stormy out.

[Chicago Storm]

Decent cell over northern Cook with more trying to get going back to the west.

Boring.

Horrible way to end the dry spell.

[cyclone77]

Decent cell over northern Cook with more trying to get going back to the west.

The cell just northwest of ORD is up to 48kft now.

[Alek]

Boring.

Horrible way to end the dry spell.

meh, i'd take a brief downpour over no brief downpour any day

[Geos]

More small cells popping up all over N IL, NW IN, and up by Madison now. Definitely feels unstable outside.

New cell over South Elgin.

[cyclone77]

Cells in southeast Iowa pushing 50kft now.

Going to be interesting to see how the complex organizing in southwest Iowa interacts with the storms east of there later today.

[Geos]

Cells in southeast Iowa pushing 50kft now.

Going to be interesting to see how the complex organizing in southwest Iowa interacts with the storms east of there later today.

17z RAP has your location in a near 2" bulls eye! Tower here just produced an actual shower - first since the early AM hours of June 1st.

Couple storm reports:

..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..

0116 PM HAIL SCHAUMBURG 42.03N 88.08W
06/16/2012 E0.25 INCH COOK IL PUBLIC

0115 PM HEAVY RAIN 1 SW ARLINGTON HEIGHTS 42.08N 88.00W
06/16/2012 M0.75 INCH COOK IL COCORAHS

RAIN FELL IN THE PAST 15 MINUTES

[69 A Porcupine]

Other short term guidance is in agreement.

If that's the case i'll pass.

Dry soil for max heating potential Mon-Wed>lame weaking MCS.

Lame weakening MCS> Lame AZ like soil and dry air from hell...

[69 A Porcupine]

meh, i'd take a brief downpour over no brief downpour any day

Absolutely agreed!
Besides even if an inch or two falls it shouldn't effect heating potential that much for this week for the people pulling for that..

[SchaumburgStormer]

For the first time this year, it actually feels hot/humid/stormy out.

Yeah the quick dumping that I got earlier sure makes it feel soupy right now... Granted, it feels a lot worse as compared to what we have experienced thus far this year but still not too bad.

[Thundersnow12]

OFB from the storm that rolled across the nrn metro area stalling north of 88 for now and doesn't look like it will sink south.

Some serious instability sitting along the IA/MO border into MO slowly pushing NE.