Mountain West Discussion

[snowmax]

[Scott]

[Front Ranger]

21 with moderate snow and about 2" so far.

[Anti Marine Layer]

The do translate. The 32 is just to compensate the difference for the 32 vs 0 for the freezing point of water.

9 farenheit units is equal to 5 celcius units.

If the temperature drops by 9 farenheit, it drops 5 degrees Celcius.

F = 1.8C +32

[Front Ranger]

DEN will score their second earliest sub-freezing high on record today. Earliest is 9/29/85, and next was 10/11/09.

[Kayla]

Never cleared out here overnight so only dropped down to 11F with about 8" of settled snow on the ground.

 

Clouds are finally breaking here now so we should easily drop into the single digits or lower tonight. Currently 21F.

[snowmax]

The do translate. The 32 is just to compensate the difference for the 32 vs 0 for the freezing point of water.

 

9 farenheit units is equal to 5 celcius units.

 

If the temperature drops by 9 farenheit, it drops 5 degrees Celcius.

If the temp drops 51, that is not 10C. That’s my point.

[Front Ranger]

Ended up with 3". Still some flurries now, but should clear up tonight and yield record cold tomorrow morning.

[Front Ranger]

DEN hit 9 this morning, breaking the record of 16 from 2009. This is the earliest single digits on record. Only 3 other years have ever hit single digits in October.

[Scott]

If the temp drops 51, that is not 10C. That’s my point.

 

Yes, that's what I was pointing out.   When you do are calculating only change in temperature, you disregard the 32.

 

Change F = 1.8 C, NOT change F = 1.8C+32 (which seems to be what you are doing?)

 

Or you can use Change F = 9/5 C

 

You have to disregard the 32 degrees if you are just calculating change.

 

If the temperature drops by 51 degrees F, the drop in C is 51/1.8 = 28.3 C (or 51*5/9).

 

Don't use the 32 in the equation if you are calculating change directly.  

 

The 32 in F = 1.8C +32 is only to compensate for the freezing point of water between the two scales.   It is what you use to convert one temperature to the other, not to calculate change.   If you calculate change, you either have to disregard the 32 (easiest) or convert both beginning and end temperatures first and then calculate.

 

An easy way to convert it in your head is that for every 9 F in change, C changes 5 units.  

 

For example: 

 

-20 C = -4 F 

-15 C = 5 F

-10 C = 14 F

-5 C  = 23F

0 C = 32 F

5 C = 41 F

10 C = 50 F

15C = 59 F

20 C = 68 F

25 C = 77 F

30 C = 86 F

35 C = 95 F

40 C = 104 F

 

Notice that for every change of 5 C, there is a 9 F change.

 

If the temperature drops from let's say 77 F to 41 F, the F changes 36.  To get the change in C you take 36 and divide it by 9/5 (or divide by 1.8, or you could even multiply by 5/9; it's all the same).

 

So if F changed by 36, C changed by 20.   

 

change 36 F X 1.8 = 20

 

If you don't do this, you have to convert the starting and ending numbers first.   Does this make sense?

[Front Ranger]

2019 has been quite the year for Colorado weather record extremes.

• Lowest pressure record for the state with the "Bomb Cyclone" storm in March
• Largest hail stone on record fell in August
• New state record hottest temp of 115 just confirmed for Lamar, CO in July
• Latest 100 on record for DEN in September
• Earliest single digits on record for DEN on 10/11

And the crazy temperature drop with the October cold front was not only the largest on record for October, the 70 degree drop in less than 2 days was among the biggest ever for Denver: https://denver.cbslocal.com/2019/10/11/denver-weather-among-largest-day-changes-on-record/

[Black Hole]

All quiet in AZ. Mid to upper 90s the next couple of days, then upper 80s. Always cools off at night so it's not too terrible.

[Front Ranger]

All quiet in AZ. Mid to upper 90s the next couple of days, then upper 80s. Always cools off at night so it's not too terrible.

Are you writing discussions yet?

[Front Ranger]

GFS shows a significant snowstorm here next Thursday.

[Kayla]

Expecting some snow here tonight, maybe 1-4" with more in the mountains. More snow expected Monday morning and yet again on Wednesday morning so a very active pattern continues.

 

Models are trending colder by next weekend with another Arctic front and snow now slated to move in. Starting to think that we're going to start building our snowpack in October this year.

[gardenmom]

It was a crazy day here today. Sunshine this morning, rain moved in then a severe thunderstorm that brought really heavy winds which apparently drew cold air down because it then started snowing (only lasted a half hour). A bit later in the day another round of thunderstorm that brought hail. So pretty much hit all the spectrums of weather!!

[Anti Marine Layer]

It was a crazy day here today. Sunshine this morning, rain moved in then a severe thunderstorm that brought really heavy winds which apparently drew cold air down because it then started snowing (only lasted a half hour). A bit later in the day another round of thunderstorm that brought hail. So pretty much hit all the spectrums of weather!!

At least it was not 83 degrees before the storm like in Denver a few weeks ago.

[Kayla]

Ended up with 3" of snow last night. Been getting some off and on snow showers throughout the day. Looks like another inch or two tonight.

 

Pretty incredible that I'm already at 17 inches of snowfall for the season with more on the way and it's only October 20th. 

[Kayla]

Ensemble just keep getting colder in the extended as well. 12z EPS is showing mid winter temps beginning next weekend and into the first week of November.

 

Kind of scary to think what actual mid winter will bring this year.

 

[Front Ranger]

I'm flying out to Atlanta today, just ahead of a snowstorm that all of the sudden looks like it could drop at least a few inches tonight. Bummer timing. I'll be back on Sunday for another possible storm, though.

[snowmax]

I'm flying out to Atlanta today, just ahead of a snowstorm that all of the sudden looks like it could drop at least a few inches tonight. Bummer timing. I'll be back on Sunday for another possible storm, though.

5.5 inches here in Highlands Ranch.

[Front Ranger]

5.5 inches here in Highlands Ranch.

Nice. Looks like we got around 3".

[Front Ranger]

Looks like Sun-Wed has a chance to be below freezing here. I'll have to check the records... very unusual if not unprecedented to have 4 sub-freezing days in a row here this early.

[Kayla]

After being the warmest model over the past week the 18z GFS is now the coldest model with Monday's front. Looks like highs around the mid teens with lows dropping below zero on Tuesday. 

 

Expecting 2-5" of snowfall with tomorrow morning's front and then probably another 2-4" on Monday. Likely just enough to get the most out of radiational cooling early next week! 

[Scott]

I don't know how reliable these phone forecasts are, but if they are even close, next week is going to have the coldest October temperature here in history.

[Kayla]

Been dumping snow here all morning. Down to 25F with strong north winds.

 

Already 4-5" of snow on the ground so its been an over performing front. 

[Anti Marine Layer]

Looks like plenty of snow will be falling over the next few days over the Rockies. Denver should go from 69 for the high today to only 29 tomorrow with snow lasting through Wednesday.

[Scott]

NOAA is also predicting the coldest October

temperature here. The old record is -1 in 1991.

[Front Ranger]

Pretty incredible to have two historic air masses for the Rockies this month.

[Kayla]

Still snowing and 25 degrees... Way over performing front. I'm not home but it looks like 8-10" is on the ground now.

[Kayla]

Saw that the NWS is fully on board for the cold going with a high of 9F and a low of -5F on Tuesday. I assume they are going well under guidance now with the significant snowpack. Both the forecasted high and low would of course be new daily records. 

 

If the forecast verifies it would be the earliest single digit high on record at Bozeman MSU besting October 30th 1935.

[Front Ranger]

Going to be another epic crash over the next 8 hours here. Currently low 70s...will be near freezing or colder by midnight.

[Kayla]

Going to be another epic crash over the next 8 hours here. Currently low 70s...will be near freezing or colder by midnight.

 

It was impressive here. Went from 53F at 3:30am down to 24F by 7am this morning. 29 degree drop in 3.5 hours and a 40 degree 24 hour temp change from this time yesterday. Have fun!

[Scott]

If forecasts are correct this is going to be a historic cold snap for a lot of the west. Grand Junction Colorado (which has one of the mildest climates in the state) has a forecasted low of 8 on Wednesday. If it really pans out, this will shatter the old October record of 16. Records go back to 1894.

 

One of the most interesting readings forecasted is the 9 to 15 in Salt Lake City. This would be interesting since all monthly record lows in Salt Lake City are at least 48 years old. This will be the first monthly low record since 1971.

[Front Ranger]

If forecasts are correct this is going to be a historic cold snap for a lot of the west. Grand Junction Colorado (which has one of the mildest climates in the state) has a forecasted low of 8 on Wednesday. If it really pans out, this will shatter the old October record of 16. Records go back to 1894.

 

One of the most interesting readings forecasted is the 9 to 15 in Salt Lake City. This would be interesting since all monthly record lows in Salt Lake City are at least 48 years old. This will be the first monthly low record since 1971.

Yeah, part of that is the well documented increase in UHI at that airport in SLC.

[Scott]

Yeah, part of that is the well documented increase in UHI at that airport in SLC.

That will make the record especially impressive if it pans out.

[Jesse]

That will make the record especially impressive if it pans out.

 

Similar to some of PDX's records lately.

[Kayla]

Ended up with 12" of snow yesterday. (had my neighbor measure!) Up to 24" of snowfall for the month of October. Currently 10F.

 

Temps should struggle to reach 20 degrees today out ahead of the next Arctic front. This one looks quite a bit drier but we should still see 2-4" of fairy dust. 

[TT-SEA]

Ended up with 12" of snow yesterday. (had my neighbor measure!) Up to 24" of snowfall for the month of October. Currently 10F.

 

Temps should struggle to reach 20 degrees today out ahead of the next Arctic front. This one looks quite a bit drier but we should still see 2-4" of fairy dust. 

 

 

That is just nuts... the seasons are so screwed up there.   Its basically arctic circle for 9 months with a brief thaw for 3 months.

[Front Ranger]

That is just nuts... the seasons are so screwed up there. Its basically arctic circle for 9 months with a brief thaw for 3 months.

It hasn't been normal since she moved there.