September 2017 Observations and Discussion

[james1976]

I know exactly what your feeling, esp when I flew back from 118F heat in June in AZ and upper 90's with humidity in mid July from the Monsoon. Enjoy it bud!

 

Meantime, 12z Euro advertising record breaking low temps later next week as a major trough amplifies over the GL's region Day 8-10.

Tom, is it showing record cold this way as well?

[james1976]

12 GFS looks to have another big trough around 12th. Long ways out but fits the stuff that Tom has been talking about.

[jaster220]

Here is a nice illustration of the mechanics involved to produce our post Labor Day cold shot; 

 

 

 

 

 

Saw this post from a met and I'm seeing more '67/'76/'11 analogs...

 

They missed a step..

 

1b) North Korea fires missile at Typhoon as it passes Japan  

 

[OKwx2k4]

Here is a nice illustration of the mechanics involved to produce our post Labor Day cold shot;

 

 

 

 

 

Saw this post from a met and I'm seeing more '67/'76/'11 analogs...

Pretty polarized range of winters there for me still. I hated 2011-12

[jaster220]

Pretty polarized range of winters there for me still. I hated 2011-12

 

My thoughts "to a T"

 

Not one of those following seasons were awesome for SMI as a whole, and some were borderline horrid. A repeat of 76-77 would be my best case scenario of the bunch, and more for my work area along the coast, less so for mby in Marshall. A buddy here at work that lives locally remembers snow half way up his door after the big LES bliz in Jan of '77. My sister was living further north along the coast in Ludington and they had 31" on top of an already massive snow pack. I read an old news article that South Bend had 18" and massive drifting, so St. Joseph here where I work would've been somewhere between those two. It was bad enough that S. Bend peeps were writing that it may be generations before they experienced something of that magnitude.  But Ol Man Winter said "you ain't seen nothin" and trumped that exactly one year later with at least double the snow (36" was the official amt, but they conceded it was their best guess) and the MOAB's effects were several orders of magnitude worse than the '77 event. Still boggles my mind that certain areas of W Mich got that treatment (3) winters in a row...what a tri-fecta of a pattern! 

[Tom]

Arctic Hammer time in early September???  Saw this post from a met:

 

[East Dubzz]

Was actually just on my way to post that run of the Euro..

 

[jaster220]

Arctic Hammer time!!

 

 

 

 

 

 

Posted in August!

[Niko]

Early Autumn weather is coming around September 5th-11th time frame? Highs in the 50's and 60's while lows in the 30's and 40's? Fall weather is coming early this year.

 

InternationalFallsMNwxforecast.PNG

 

eauclairewiwxforcast21.PNG

 

Wausauwiforecast3.PNG

 

duluthmnwxforcast5.PNG

 

MarquetteMIwxforecast.PNG

B4 you know it, snows will be flying.

[Niko]

Curious to see how chilly the airmass will be after LDW. As of now, the CF looks pretty potent. Lets see if it holds.

[james1976]

DMX talking the pattern change:

 

It will be warm initially south Monday as well, especially based

on slower GFS timing, before a pattern change takes hold into next

week. ECMWF and GFS deterministic and ensemble solutions both

depict a decent cold frontal passage Monday, but after better

temporal agreement yesterday have again diverged somewhat on

timing with ECMWF about 6-9 hours faster. It would take awhile to

get precip going, but there may be just enough forcing for post-

frontal precip late Monday as the system moves through. Temps

should drop 10-15F from Sunday into Tuesday with the feel of a

much drier, fall-like airmass. Cycles of troughing through the

Great Lakes will keep this pattern in place through next week with

the CPC 6-10 and 8-14 day outlooks strongly weighted toward both

below normal temperatures and precipitation.

[Niko]

With next weeks passage of a strong CF coming through, my temps will be flirting with the 30s for overnight lows.

 

Bonfire indeed!!!!

[Niko]

The tropics are getting active out in the EA. Experts believe that a hurricane will be developing soon out there and heading for the Caribbean Islands and possibly affecting the SE United States. Heads up on that. Tbh, I hope it does not cross the GOM. Ofc, that all depends on how the upper level winds play out.

[Tom]

Frosty nights to begin the Labor Day weekend around the Lakes????

 

 

 

 

 

 

12z GFS...not as chilly...

 

[Niko]

Frosty nights to begin the Labor Day weekend around the Lakes????

 

 

 

 

 

 

12z GFS...not as chilly...

 

Jaster will definitely need a double blanket if the NAM verifies. Temps in the 20s to near 30F will cause him to shiver. Break out the fire wood buddy.

[jaster220]

Frosty nights to begin the Labor Day weekend around the Lakes????

 

 

 

 

 

 

12z GFS...not as chilly...

 

 

How's the NAM been on temps? I remember that it's 84-72hr range surface map(s) has to be taken with a grain of salt in the winter. Quite the little debate over at Amwx about the Euro going way extreme on d8 cold plunge as it apparently likes to do that early in the season. GFS on the other hand seems warm biased. Regardless, here's a d3 call on temps (easiest thing to get correct if you ask me), and it's showing some chilly morning lows for LDW in Marshall. Might have to close the bedroom window and stay complete under covers...brrr

[Niko]

Irma poses a threat. Caribbean and SE United States should be on guard. GOM residents, hopefully,, you are outta the woods.

[james1976]

DMX talking about summer's last gasp and watching closely for record low highs!

 

Bottom line up front...

What perhaps may be Summer`s last gasp will impact us Sunday into

Monday as high temperatures may make it into the upper 80s and

perhaps even low 90s in some locations. By Tuesday and the rest of

the week, highs will struggle to reach 70 degrees (no typo), with

low temperatures making it into the 40s...with upper 30s possible

in northern Iowa.

 

 

Friday through Monday...

With a very broad area of high pressure located over the Four

Corners region, a thermal ridge has been building over the

intermountain west and pushing well into Canada. Meanwhile, a deep

upper low has been spinning off the Alaska shoreline. Several

impulses are expected to eject off the low between today and

Monday. With the Four Corners high amplifying and drifting north,

these impulses will all remain in Canada, keeping us dry through

this weekend.

 

In perhaps what will be the final show of warm weather for this

summer, the thermal ridge will come crashing down over Iowa Sunday

into Monday. 850mb temps should be somewhere near +20C to +25C for

Sunday afternoon, which will yield temperatures well into the 80s

for Sunday. Models then diverge very wildly on the curtain call for

thermal ridge over Iowa. A deep, broad upper low has been well-

advertised for the past several days, with the accompanying

longwave trough digging all the way down to the Gulf of Mexico. At

some point on Monday, the lad cold front will be passing through

Iowa. The 12z GFS is much slower with the fropa and, resultingly,

has another day with the thermal ridge and +25C temps over

Iowa...meaning temperatures could be in the 90s. The 12z ECMWF,

however, pushes the front through during the morning hours on

Monday, leading to strong CAA throughout peak heating and

confining temperatures in the 70s and 80s. At this point, the GFS

solution seems to be the outlier, so have leaned strongly towards

the ECMWF, keeping temperatures in the 80s... this is subject to

change.

 

 

Tuesday and beyond...

Confidence continues to be high in well-below normal temperatures

and dry conditions across Iowa. The trends have been slowly

downward, with 850mb temps perhaps making it down to +5C by

Wednesday night. For the first week in September, record daily low

maximum temperatures are in the 50s, and record low minimum

temperatures are in the 30s. At this time, it appears we should be

5 to 10 degrees to warm to break those records, but we will be

watching closely.

[james1976]

DMX appears to be leaning toward the Euro...

[Tom]

Both NAM models still suggest a pretty chilly morning on Sat across the Midwest/Lakes...3km has a colder bias but both have nailed the cooler trend a couple days for the weather today/tomorrow.

 

 

[Minny_Weather]

Look at our low and rub it in Tom At least our turn is next week.

[Tom]

Look at our low and rub it in Tom At least our turn is next week.

...pretty soon you'll be enjoying these cooler nights/days...today, we have a stiff wind out of N/NE and a pleasant 66F/56F.

 

Saw this graphic which is new and depicts cooler temps across much of our subforum for the month of Sept...

 

 

 

[Tom]

These guys are pretty good at their forecasting skills and here is their final outlook for September...

 

 

 

 

Day 16-30 analog temp anomaly based off the EPS...

 

 

[Niko]

Looking forward to a nice, refreshing cool airmass arriving tonight and especially, after LDW.

[jaster220]

These guys are pretty good at their forecasting skills and here is their final outlook for September...

 

 

 

 

Day 16-30 analog temp anomaly based off the EPS...

 

 

 

Okwx will do fine if this theme can continue into the winter months. That BAM wx map keeps the way above stuff less in the SW, more in the NW states. I'm confident he'll make out well with these trends.

[Thunder98]

It's going to be 94F on Sunday in Dickinson, ND, meanwhile at the same exactly latitude, Duluth, MN has only a high of 76F on Sunday.

 

http://www.city-data.com/forum/attachments/weather/189685d1504193679-autumn-fall-2017-thread-sept-oct-dickinsonndwxforecast.png

 

http://www.city-data.com/forum/attachments/weather/189687d1504193730-autumn-fall-2017-thread-sept-oct-duluthmnwxforcast6.png

[Niko]

It's going to be 94F on Sunday in Dickinson, ND, meanwhile at the same exactly latitude, Duluth, MN has only a high of 76F on Sunday.

 

http://www.city-data.com/forum/attachments/weather/189685d1504193679-autumn-fall-2017-thread-sept-oct-dickinsonndwxforecast.png

 

http://www.city-data.com/forum/attachments/weather/189687d1504193730-autumn-fall-2017-thread-sept-oct-duluthmnwxforcast6.png

Dang, that is a hot forecast. Not too shabby for ND.

[jaster220]

k, totally a just for fun post here, but I knew something like this would happen sooner or later, just figured it'd be with a winter system. Since the upgrade, I've noticed the GFS mid-long range often projects the absolute "if everything under the sun aligns perfectly" scenario and runs with it

 

Soooooo, this would ofc be horrible news if another major, let alone a MEGA hurricane came to the US coast after Harvey's devastation in TX. Thankfully, it's just the GFS being the GFS.. (we hope-gulp)

 

 

[james1976]

[Niko]

People in the Carribean, GOM (even westward from there, need I say Texas and Lousiana), and SE coast of the US need to really be on alert. Hurricane Irma now a CAT2. Expected to become a major Hurricane.

[Niko]

k, totally a just for fun post here, but I knew something like this would happen sooner or later, just figured it'd be with a winter system. Since the upgrade, I've noticed the GFS mid-long range often projects the absolute "if everything under the sun aligns perfectly" scenario and runs with it

 

Soooooo, this would ofc be horrible news if another major, let alone a MEGA hurricane came to the US coast after Harvey's devastation in TX. Thankfully, it's just the GFS being the GFS.. (we hope-gulp)

 

GFS Super-cane 2017.png

[Tom]

12z Euro back to seeing a stronger frontal wave crossing the northern Plains and tracking towards the Upper GL's on Labor Day.  Remember the last time models trended stronger with this type of situation??  Might be doing the same exact thing this go around which also drives a deeper trough over the region.

 

 

 

Spins up to a monster Canadian storm south of Hudson Bay....

 

 

 

[Tom]

In as many days during met Summer, the U.P. will open met Autumn with another Frost Advisory.  This time, sharing some real estate with its second half of the state in N MI.

 

 

 

Frost is expected tonight as temperatures drop into the mid 20s
to lower 30s. The coldest temperatures are expected across the
interior west half of Upper Michigan and in low-lying areas.
Temperatures near the Great Lakes should not drop below 40.

 

 

 

 

[jaster220]

In as many days during met Summer, the U.P. will open met Autumn with another Frost Advisory.  This time, sharing some real estate with its second half of the state in N MI.

 

The blue on that map could be confused with at WSWatch - haha. Seriously though, that 984mb placement is a great sign for a couple months down the pike. Nov 15th '89 was just west of that @ 964mb and bliz conditions raging across much of Mich! The morning began with 50's in Detroit and a pool of ZERO degree air just north of Superior. That was the gasoline thrown on the fire. What an early season bomb - 2nd windiest storm of my life next to Jan '78 

[Tom]

Latest CPC thinking for the month of Sept....cool & dry is the theme atleast for around here...

 

http://www.cpc.ncep.noaa.gov/products/predictions/long_range/lead14/off15_temp.gif

 

 

 

http://www.cpc.ncep.noaa.gov/products/predictions/long_range/lead14/off15_prcp.gif

[Tom]

Insanity, if it even comes close...EPS is suggesting some members of 170+ mph winds for current major Cat 3 #Irma

 

[Minny_Weather]

Insanity, if it even comes close...EPS is suggesting some members of 170+ mph winds for current major Cat 3 #Irma

 

Either 00z or 06z GFS (forget which) advertised a minimum pressure of 885mb. That'd be nearly historic.

[jaster220]

Insanity, if it even comes close...EPS is suggesting some members of 170+ mph winds for current major Cat 3 #Irma

 

Table says 170 knots!! Was it Gilbert that had 185 sustained & 200+ gusts in the gulf? Katrina was up there too over open waters. Sure don't need this anywhere near those platforms or we will be paying 10$ a gal for gas! Would kill me with my extended commute..

[jaster220]

Either 00z or 06z GFS (forget which) advertised a minimum pressure of 885mb. That'd be nearly historic.

Wilma was deepest in Atlantic @ 882, After 17 yrs, Gilbert got bumped to 2nd place @ 888. Camille was thought to be strongest but reanalysis downgraded her pressure and winds from 190 mph to 175 mph sustained. Labor Day of '35 over the Keys remains lowest baro over land and most intense landfall @ 892 followed by Gilbert @ 900 mb. So yeah, getting into "rare air" if some of these models are close!

[Niko]

With a trough being poised ova the midwest, that might trigger Irma  up the EC, if not more inland. Something to keep in mind.