July 2019 Observations and Discussion

[Stormy]

Congrats to you CR folks on your nice rain storm! When I saw it blow up over CR I guessed Hawkeye, etc got at least an inch. Only a trace here so far as a nice cell crapped out just before it got here.

[CentralNebWeather]

I have a cousin from Miami that was visiting here on the 4th of July when it was quite warm and sultry. I told her this is about like their weather, but she said this is nothing and it's worse there. I would say it's just as bad in Iowa at times though, in the summer!

We are not a usually as humid here as eastern Nebraska. However, when irrigation is in full swing and the corn is putting off moisture, we can get sultry. No irrigation yet this year but our large amount of rain recently is probably contributing some imo.

[Stormy]

Saw one report of 2.45" somewhere near CR. That notification disappeared before I saw the location.

[Stormy]

We are not a usually as humid here as eastern Nebraska. However, when irrigation is in full swing and the corn is putting off moisture, we can get sultry. No irrigation yet this year but our large amount of rain recently is probably contributing some imo.

I agree with that.

[Andie]

My husband just got back from a business trip to Chicago and he said the humidity is far worse there than our Gulf humidity.

Those Great Lakes can really pump. Out the moisture.

He said he was sweating buckets.

[Stormy]

Wow, most of Iowa is in a slight risk area for today. The SPC probably is expecting that bowing cluster of storms in se. SD. to continue moving southeast across Ia. or something. Didn't take time to read their discussion. Areas along and north of hwy 30 even have a flash flood watch for tonight. We're really needing rain here. During the daytime the corn resembles pineapple.(Leaves are rolling up from moisture stress.

https://www.spc.noaa.gov/products/

 

PS. I got a whopping 0.03" of rain last eve.

[Stormy]

DVN AFD: http://mesonet.agron.iastate.edu/wx/afos/p.php?pil=AFDDVN&e=201907170847

[Niko]

Heatwave on its way as temps starting tomorrow will approach the 90s and possibly near 100F on Friday. Saturday remains quite hot as well as temps flirt between 95-100F. Pair of CF's on Sunday will finally end this heatwave, especially for early next week as temps remain in the low 80s for highs and lows in the upper 50s to around 60F w tons of sun.

 

Note: Warnings will most likely be posted today for Friday n Saturday for this upcoming heat.

[Niko]

Currently, after some rainfall last night, are hovering at 72F w a dew nof 72F as well which gives me a RH of 100%. It is darn right humid out there. Looks like Barry will be finally exiting my area as the day wears on. Ba bye Barry. Nice see ya!

 

Note: Areas to my south last night got some really hvy rainfall (Detroit Metro Area included). Not as hvy in my neck of the woods.

[Hawkeye]

The CAMs are totally whiffing on the severe MCS plowing through Siouxland this morning.

[Niko]

Have to eat crow. Barry remnants striking pretty hard here after all..

Barry was not joking. I was thinking he just might brush our areas, but instead, he provided some extra water. I even had a few wind gusts yesterday, 25 to 30mph from him.

[St Paul Storm]

The CAMs are totally whiffing on the severe MCS plowing through Siouxland this morning.

Yep, and it will have major implications on how things play out later today. To say the models have struggled lately is an understatement.

[james1976]

That's a very colorful hazard map this morning. Totally surprised I'm in a flash flood watch tonight. Would love to get some storms!

[East Dubzz]

Had no idea there was a chance of rain tonight. Hopefully that happens. 

[St Paul Storm]

The complex moving in from the Dakotas is starting to split into two pieces near Fergus Falls, MN. Most of the models showed that, so let’s see if we can get this thing to die off and provide the basis for redevelopment later today. SPC has shifted the slight risk just south of here with the morning update. Way too many variables in play to be confident in any solution right now.

[Hawkeye]

Mesoscale Discussion 1499
NWS Storm Prediction Center Norman OK
0909 AM CDT Wed Jul 17 2019

Areas affected...southeast SD...far southern MN...northeastern NE
and much of IA

Concerning...Severe Thunderstorm Watch 514...

Valid 171409Z - 171545Z

The severe weather threat for Severe Thunderstorm Watch 514
continues.

SUMMARY...Strong to severe storms may continue east/southeast across
IA through late morning. Storms could re-intensify this afternoon,
with an accompanying damaging wind threat spreading across much of
IA and a downstream watch may be needed.

DISCUSSION...An intense bow echo overnight has continued to produce
sporadic strong gusts of around 35-50 kt from FSD into northwest IA
over the least 60-90 minutes. Some weakening has been noted in radar
and lightning trends on the north end of the bowing segment along
the IA/MN border. Further south near the IA/NE border some periodic
intensification has been noted with isolated cells trying to develop
along the southern flank/outflow boundary across far eastern NE.
These storms remain in a weakly unstable environment above a capping
inversion, noted in regional 12z RAOBs. As strong heating occurs
ahead of the bow (temperatures already in the low 80s across
south-central IA), strong destabilization will occur, with forecast
MLCAPE values ranging from around 3000 J/kg across central IA to
around 1500 J/kg toward the MS River near eastern IA/western IL.
Strong effective shear will remain oriented along this instability
gradient as a shortwave impulse crests the Upper Midwest/northern
Plains upper ridge. Furthermore, thermodynamic profiles indicate
favorable conditions for a continuation and re-invigoration of
convection heading into the afternoon with very steep lapse rates
above a weak EML.

While there may be a relative lull in convective intensity this
morning due to weak capping, as heating and further destabilization
erode the cap, additional development by midday/early afternoon
could pose a more widespread threat across central into eastern IA.
Damaging wind gusts and hail are the most likely threat, however,
forecast hodographs do indicate sufficient SRH with backed low level
winds through 1km to support some tornado threat. This threat could
manifest through either mesovortex spin-ups if the bowing line
segment convective mode persists, or through supercell mesocyclone
processes if any discrete cells can form. Trends are being monitored
closely and a new watch downstream WW 514 may be needed in the next
1-2 hours.

Additional storms are developing in southern SD, likely atop the
cold pool with increased ascent due to the eastward migrating
shortwave impulse. This convection could post an isolated severe
threat through the morning but longevity of this activity is more
uncertain.

[Iowawx]

The heat is a bit more manageable now because of all of the rain we got yesterday. Before yesterday my lawn  was turning yellow and was really dry. Today, it is much greener and looks much better than it did yesterday. 

 

I am still watching that line out in Central Iowa. I sure hope it makes it here. Looks like it would get here in maybe 3 hours or so. 

[Stormhunter87]

Quite the line of storms pushing into Iowa. Just missed the severe storm.

[james1976]

It's not losing any steam. Looks like I'm gonna get something. I'm more interested to see what happens later into tonight.

[East Dubzz]

Looks like that complex will slide south of here. I have no issue with that, as I really need to cut the grass today and the rain would ruin that.

 

My bigger worry is whether or not this could impact tonight's potential. Anyone know if it could?

[snowstorm83]

Today looks to be the first day of the heat wave over here. Already 87 with a heat index of 93 at the 10 am obs. Should make a run for 100 by the afternoon. 

[St Paul Storm]

12z runs all over the place with where convection fires later today and tonight. Some even have MSP missing the action as it’s too far north.

[Iowawx]

Severe Thunderstorm Watch just issued for eastern Iowa until 7:00PM. I am surprised it's until that late, those storms will be out of here well before 7:00pm. 

[bud2380]

Dang, we have a work outing outside this afternoon.  Hope these storms come and go by 3pm.  

[Niko]

It feels very tropical outside. Temps are only in the upper 70s, but, RF makes it feel a very uncomfortable 85F

[Hawkeye]

It appears the southern half of the line will be the strongest, where the best instability is.

[Iowawx]

It appears the southern half of the line will be the strongest, where the best instability is.

So Cedar Rapids probably won’t see the best of this line, right?

[Hawkeye]

So Cedar Rapids probably won’t see the best of this line, right?

 

Radar shows the heavier stuff sagging southeast through the Des Moines area while the northward extension is thinning and weakening.

[james1976]

Redevelopment on the backside in NW IA

[Stormy]

Radar shows the heavier stuff sagging southeast through the Des Moines area while the northward extension is thinning and weakening.

Yeah I noticed. When I saw it surging southeast already in SD this morning I was afraid the best part of the line may end up going even south of me.

[Stormy]

Looks like that complex will slide south of here. I have no issue with that, as I really need to cut the grass today and the rain would ruin that.

 

My bigger worry is whether or not this could impact tonight's potential. Anyone know if it could?

Don’t remember where I saw it, but it was mentioned it definitely could affect the trajectory of the future storms. Like James mentioned, there is redevelopment in nw. Iowa.

[St Paul Storm]

SPC with a major change in the slight risk region. Everyone from the Canadian border to St Louis is in the mix. That broad of an area tells me they have no idea what’s going to happen. Latest HRRR says no one sees anything except N MN due to the unexpected IA storms.

[Stormy]

The radar slightly reminds of 6-30-14, just not as severe yet.

 

[Stormy]

[St Paul Storm]

[quote name="St Paul Storm" post="477464" timestamp="1563383466

Lol..HRRR is on drugs.

 

I honestly don’t remember the HRRR being so bad with storms. It’s not even fully taking into account what’s already happening when the new runs initialize. It’s whacked out.

[East Dubzz]

Don't know if I've ever seen a Slight Risk area like that before. Almost covers the entire state of Minnesota haha

[Stormy]

The south end could see some training per radar trends. Also currently some training in nw. Ia.

[Stormy]

Looking like Ottumwa area could get rocked.

[james1976]

Nice steady rain here with some rumbles of thunder. Man that feels good!

[james1976]

I can actually smell the fresh air from the rain. Smells like fall haha.

The Excessive Heat Watch start time has been pushed back til tomorrow PM for my area. Was supposed to be today.