bdgwx

I just wanted to say that I learn a lot from Stebo and the other degreed mets on this forum. Actually I can extend that to many other non-degreed posters as well. So thank you all for the wealth of information you provide and stoking my interest in weather.

12Z SHIPS RI probability is 5% for 20 kts in 12 hours. It is essentially 0% for all other time frames.

If history has taught us anything it's that integrated kinetic energy is a better discriminator for storm surge than the maximum wind speed. And Florence has a lot of IKE right now.

Florence has 100 TJ of kinetic energy now.

Yes. All 3 operational cyclone models do this. You'll find the coupled SST products at the following links. HWRF: http://www.emc.ncep.noaa.gov/gc_wmb/vxt/HWRF/ HMON: http://www.emc.ncep.noaa.gov/gc_wmb/vxt/HMON/ COAMPS: https://www.nrlmry.navy.mil/coamps-web/web/tc

Probably splitting hairs, but that looks like a 35" contour on Wilmington.

This kind of goes without saying, but I'll say it anyway. Because the steering flow breaks down and Florence stalls/turns so close to the shore the consequences are magnified a lot. Sure, it injects an element of chance in determining landfall, but it also effects intensity at landfall, precipitation, etc. It would likely weaken under the stall scenario, but it'd also be over water longer so it would likely retain strong tropical characteristics longer as well. There's a lot of give and take with that scenario.

Yep. COAMPS does the same thing. It just makes the turn south further north after stalling longer. Either way the message is loud and clear. The steering flow is going to breakdown as Florence approaches the coast. Various models have been showing it off and on in a variety of different forms.

I guess the NHC could nudge the track south a bit. TVCN is still going to be to the right of the 0Z ECMWF track due to the north turn depicted by the UKMET and COAMPS. I'm not sure if the 18Z model guidance includes the 12Z Euro or not. Anyone know?

I have to be honest. I'm relieved that the GFS is falling more inline with the FV3/ECMWF. I mean given the option of the GFS or FV3 being more right I'd much rather it be the later since that's what NOAA is hanging their hat on for the next generation model.

The green tracks (TABS, TABM, TABD) are the beta-advection models. They use the mean flow of the GFS winds over different layers with a correction made for the beta drift. The different variations loop in different ways depending on how deep of steering flow you want to consider. S is for shallow, M is medium, and D is for deep. They loop largely because the GFS shows a breakdown of the steering flow. It's my understanding that a skilled forecaster can make some interesting inferences about the cyclone environment based on the TABx tracks. As a general rule you'll probably want to ignore them and instead focus on TVCN (or maybe TVCX). It is the consensus of the best track models which as of 2018 are an equal weighting of GFS, ECMWF, UKMET, HWRF, and COAMPS.

I agree. This is not atypical of global models. They often play catch up in regards to rainfall amounts when a tropical system phases with a slow moving front. There's probably going to be a stripe of 4-6" with locally higher amounts somewhere in the midwest when it's all said and done. We just don't know exactly where yet.

The Euro QPF map looks similar to what COAMPS has been showing.

Sahara Air Layer Also, I hadn't heard the phrase "atmosphere depletion" either, but enhanced ocean heat uptake at the expense of less atmospheric heat uptake is the way I understood Vice-Regent's definition. Obviously the harder your compress the spring the more it fights back. In other words, the atmosphere will eventually respond to the ocean heat uptake. It always does.

Using Gough's (1981) solar luminosity formula L(t) = L(t0) / (1 + 0.4 * (1 - t/t0)) we can estimate that solar radiation was still L = 1 / (1 + 0.4 * (1 - 4.55/4.60)) = 99.5% of today's value. This yields a radiative forcing reduction of (1360 / 4) * 0.995 = -1.7 W/m2 relative to today. Using Arrhenius' (1896) original radiative forcing formula ΔF = λ * ln(C/C0) and using 5.35 W/m2 as a more conservative estimate of CO2 sensitivity parameter (the IPCC used 6.3 at one time) we can see that 1000 ppm would produce an effect of ΔF = 5.35 * ln(1000/400) = +4.9 W/m2 relative to today. So yeah, the net CO2 and solar radiative forcing 50 MYA relative to today would be around +3.2 W/m2 whereas just the CO2 forcing today at 1000 ppm would +4.9 W/m2 or about 1.5x times higher. It's obviously just a rough estimate I calculated and it doesn't factor in other climate forcing elements. The point...1000 ppm might be expected to have a bigger effect today all other things being equal because the sun is also brighter. Just food for thought...

Here is the radar screenshot of the Redding, CA firenado.

Saturday might be a player as well in Missouri.

That is a huge powerhouse trough and upper level low showing up on the 12Z EPS. By 18Z on Friday (hour 174) it has 3 fully closed 500mb isohypses and that's just an ensemble mean. The 12Z GEFS also shows big troughing during this period. That's a pretty strong signal for a big weather maker. And it's that time of year so...

We may see some accumulating snow in MO this weekend.

Using 1981-2010 as the baseline GISS comes in at +0.33C for January while the NCEP reanalysis is +0.28C.

No. First, just to clarify, the academic jargon of "ice free" typically means less than 1 million sq km of extent. Second, based on the stuff I've read the consensus seems to be in 2040-2060 timeframe in which the probabilities of "ice free" go likely. At this point though I think we're going to be lucky to make it to 2040.

It's still more than week out so a lot could change. But, the EPS and GEFS means for the QPF swaths are not encouraging for Oklahoma.

The Feb 1st timeframe has been hinted at by the EPS and GEFS for a couple of days now. The weekend of the 27th is a different trough.

St. Louis has been in a snow drought as well. It's been 4 years since we last saw a bona-fide (6"+) winter storm. And as we move into February things get more depressing. St. Louis hasn't had a 6"+ snow in February in over 20 years! So I'm not holding my breath that February will bring anything of interest, but who knows. The trend has break at some point.