April 8, 2024 | Eclipse Weather

[Hiramite]

I might as well post the Blend every morning.   Yesterday's was better for MBY.

[NWOhioChaser]

31 minutes ago, Hiramite said:

I might as well post the Blend every morning.   Yesterday's was better for MBY.

Worse and worse for my area. 

[MaineJay]

Here's yet another sky cover resource folks can use as we approach zero hour.

http://www.cleardarksky.com/csk/index.html

Example image.

[Rush]

Quote

In summary, the outlook for favorable viewing conditions continues to deteriorate as the event approaches. NBM cloud probabilities for clear or mostly clear skies are near zero, with <50% sky cover being a 1 in 4 chance at best along the path of totality. As a Fort Worth native and lifelong eclipsophile, this forecast is soul-crushing. But having battled bad weather on previous eclipse chases, I can assure you there are still incredible things to experience even if the eclipsed sun isn`t visible: - The darkening of the sky during totality is even more pronounced with dense cloud cover, particularly if rain is also falling. - The transition from a daytime sky to seemingly night (and vice versa) occurs in a matter of seconds. - If you have a high vantage point (tall building, hill, etc.), the moon`s shadow can still be apparent as it approaches at more than 1600 mph. While this outlook is incredibly disappointing, all it takes is a well-timed break in the clouds to allow for a magnificent view. For example, rain and storms disrupted the 2017 eclipse in the Kansas City area; but in the midst of the inclement weather, there were some breaks in the clouds during totality.

NWS Dallas is throwing in the towel.

[MaineJay]

ECMWF forecast.

Explanation here.

Quote

These charts are the most recent from the ECMWF's high resolution (HRES) forecast.

Select desired times and parameters using the drop down menu.  Date/time can also be selected using the slider underneath the chart or the play/pause symbols at the bottom left of the chart.

Model clouds are classified into three height categories:

• Low-level Cloud Cover (LCC) is shown as brown and approximately corresponds to levels between 0m and  1800m above the model's earth surface.
• Medium-level Cloud Cover (MCC) is shown as magenta and approximately corresponds to levels between 1800m and 6300m above the model's earth surface.
• High-level Cloud Cover (HCC) is shown as cyan and approximately corresponds to levels higher than 6300m above the model's earth surface.

This display helps with the recognition of clouds of different layers, even when they overlap – click on the middle icon to the bottom right for the scale.   Brighter colouring represents greater cloud cover.  Cloud-free areas appear white while areas of full cloud cover at all levels appear dark grey (e.g. active fronts).  

The plotting algorithm uses an HSL (Hue Saturation Luminance) colour representation for the different clouds. Three basic colours (hues) are used to represent the three cloud layers: brown for low-level clouds, magenta for medium-level clouds and cyan for high-level clouds. These three cloud layers are combined as three vectors in HSL space. The saturation of each layer is proportional to its cloud cover which varies from 0 (no clouds) to 1 (overcast). "Luminance" is associated with the sum of LCC, MCC and HCC: cloud-free areas appear white, and areas of the maximum cloud cover are dark grey. Note that the total cloud cover is not generally equal to the sum of LCC, MCC and HCC because of overlap. To help interpret the charts, the colour legend shows relevant colours (hues) for different level combinations, whilst a more comprehensive representation of the colour scheme is given in the diagram below.

A "Rubik's cube" representation of the colour table used for the different categories of cloud cover (triplets denote cloud cover in each of the low, middle and high layers, respectively).

This display method helps with the recognition of clouds of different layers, even when they overlap. As an example, active fronts in the forecast are easily seen, as dark grey bands.

More information about the colouring algorithm can be found in ECMWF Newsletter No. 101.

 

[clm]

Not sure how accurate this is, but its Forbes, so not totally tossing it out. 

https://www.forbes.com/sites/jamiecartereurope/2024/03/30/why-your-total-solar-eclipse-map-is-suddenly-wrong/?sh=7079a92643d7

https://www.forbes.com/sites/jamiecartereurope/2024/03/31/15-places-in-the-us-that-just-lost-their-total-solar-eclipse---while-texas-gained/?sh=2c4b0afe3f66

 

 

[Hoosier]

4 hours ago, clm said:

Not sure how accurate this is, but its Forbes, so not totally tossing it out. 

https://www.forbes.com/sites/jamiecartereurope/2024/03/30/why-your-total-solar-eclipse-map-is-suddenly-wrong/?sh=7079a92643d7

https://www.forbes.com/sites/jamiecartereurope/2024/03/31/15-places-in-the-us-that-just-lost-their-total-solar-eclipse---while-texas-gained/?sh=2c4b0afe3f66

 

 

It's true, but it's not a problem for 99.9% of people.  Easy answer is to not position yourself near the edge of totality, unless it's done on purpose because you want a longer duration of bailey's beads or some of the other effects that happen on the verge of totality.

[Hoosier]

7 hours ago, MaineJay said:

I've watched the 2017 eclipse GOES loop a few times.  You can see how many of clouds over the Lower Mississippi Valley dissipate as the Moon's shadow moves across.  Not completely clearing, but from like 75% to 25% in some cases. 

The type of cloud matters.  Cumulus can definitely dissipate as the sun becomes more obstructed, but good luck trying to get rid of low clouds.

[Hoosier]

Good thing that today's/tomorrow's severe outbreak isn't occurring next Monday.  Weather concern aside, would be potentially disastrous having so many roads clogged with traffic.

[Rush]

Latest CMC.  I said this morning there was a trend starting in Texas.  Here we go.

 

[Undertakerson2.0]

AFDBUF mentioning now. 

Generally speaking, this is great news for us - we don't need "perfect", we'd like perfect but don't "need" it. If it's a bit cloudy, no big whoop. I only don't want rain and thick clouds and their forecast suggests neither is likely, 

 

[Hoosier]

Massive difference in cloud output between the GFS and Euro.  Never heard this until a few days ago but supposedly the GFS has a cloudy bias, so let's hope that's the case this time.

 

[MaineJay]

The stimulated IR look from the ECMWF.

[Rush]

13 minutes ago, MaineJay said:

The stimulated IR look from the ECMWF.

Perfection

[Undertakerson2.0]

50 minutes ago, MaineJay said:

The stimulated IR look from the ECMWF.

That looks mostly like a situation where I'll be in clouds right up to about two hours before the event - and then mostly or total clearing in time for the "big show". 🙂

[Undertakerson2.0]

AFDCLE with reference - they mention high clouds possible. This may be also be very unique chance to see some of the partial through that upper thinner veil. I've seen accounts with pics where people had that condition and were able to view the eclipse unassisted by the glasses 😮 If they aren't thick enough for that, it would mean to me that we're still gonna see the main part, perhaps not the really detailed things like Bailey's Beads etc. 

Also the mention of a Lake Breeze - I've also seen that those can keep clouds at bay even if they do try to form - at least close to the shore points. 

[Rush]

Another look at the noon runs.  CMC and Euro very similar vs GFS.

[Wayuphere]

The coming Nor’easter type storm deciding to do the slow craw/stall near Maine until Saturday bodes well for us in the NE.  Once that high pressure arrives later this weekend it will be sticking around for several days.👍

[Undertakerson2.0]

AFDBUF - mentioning the potential cloud structure and what impact, if any. 

[Wayuphere]

This vantage point is only open May to Oct and is not plowed, but what an awesome spot to view the eclipse. I’m hoping the DOT opens the gates and runs a plow through there.  
It looks west toward Mt Katahdin from I95 northbound side, just north of Millinocket at the scenic turnout.
Fellow Mainers would know this spot, especially those from the County.  Its elevated with many miles of unobstructed views to the west. I wonder if spots like this could see the oncoming full shadow?  It’s a 3 minute totality zone.

[Undertakerson2.0]

https://www.space.com/what-if-it-is-cloudy-for-total-solar-eclipse-april-8-2024

 

[Hiramite]

Not liking the trend for upper OV, but not panicking yet. Hoping that being in the bullseye for the heaviest cloud cover 6 days out is a "good" thing.

 

8AM Monday.

Edited April 2 by Hiramite

[Undertakerson2.0]

One thing I dislike about the Blend is that any one model can totally skew the map. In this case, seems like GFS runs are making the Blend more "colorful" than if that were dropped. Let's see what WPC Discussion says whether they are tossing any of the op models. 

[Rush]

The guy who writes the Texas morning forecast discussion would fit right into our winter storm threads.  Yesterday he's throwing the towel and today he's back in.

Quote

This fast moving system may prove beneficial to our much anticipated solar eclipse on Monday as a substantial amount of dry air will spread in behind the departing system on Sunday. A fast moving shortwave ridge will quickly overspread the Plains late Sunday into early Monday but this feature will dampen quickly as yet another upstream trough will approach the Desert Southwest sending a thick plume of Pacific moisture across the Southern Plains on Monday. In addition, there will be a pool of 1.7-1.9" PWs over the western Gulf which will get tapped into by strengthening southerly winds and will likely result in thick low cloud cover racing northward. Some of the latest model guidance shows this occurring after eclipse time which would be optimal...meaning we would potentially only have to contend with high cloud cover. We`ll continue to refine this forecast over the coming days but the latest information for the eclipse is below: * Ensemble guidance is a little more optimistic with respect to total cloud cover with probabilities increasing to around 20-25% for favorable viewing conditions. * Consensus of models currently shows that thick lower clouds may hold off until after eclipse time which would be optimal. * Probabilities remain high (>80%) that high clouds will be in place across much of North and Central Texas during eclipse time.

 

[Undertakerson2.0]

1 minute ago, Undertakerson2.0 said:

One thing I dislike about the Blend is that any one model can totally skew the map. In this case, seems like GFS runs are making the Blend more "colorful" than if that were dropped. Let's see what WPC Discussion says whether they are tossing any of the op models. 

Opted to use a composite of the 18 UTC GEFS and 12 UTC ECMWF ensemble means later Sunday into next Tuesday along with best clustered model guidance of the 12 UTC ECMWF/Canadian to both reduce individual model differences, but maintain some depth of systems. The latest 00 UTC model and ensemble suite remains mainly in line. --- WPC