1) So a look at where we stand now I posted this earlier but you can see that over the last 10 runs the GFS has trended the main disturbance W/SW from OH to OK This allows for less confluence over the NE (cold high pressure) and earlier strengthening/amplification of the main s/w
2) The result is that the GFS now take the primary low into Kentucky, not AL/MS and miller B secondary cyclogensis occurs over the NC coastal plain not off the SC coast. The 6z GFS shown This scenario causes a changeover for most east of the mtns Big snow for The apps/interior NE
3) The GEFS (GFS Ensemble) mean has been consistently further south/east (less ampified). The 6z run still is BUT it trended more towards the op GFS. Look at the low placements now vs the 00z run. More members over the NC coastal plain not offshore. I.e trending towards op GFS.
4) Now the GFS/GEFS is just one model family. The ECMWF/UKMET are further south/less amped. The 00z ECMWF shown. It takes the primary into N AL, with miller B secondary cyclogenesis off the SC coast. It still tracks the surface low over the NC coastal plain.
5) This is a snowier/more frozen solution compared to the GFS for our area and also into the MA/NE as is the UKMET which shows the primary tracking along the Gulf coast and re-development off the Ga coast. Still tracks into NC coastal plain. But less amped than GFS
6) The 00z EPS (ECMWF Ensemble) mean though also trended further NW. Here are same images as shown for the GEFS. More tracks over eastern NC as opposed to offshore. Still a big winter storm for many, but ice/changeover issues likely implied.
7) And for the sake of completeness, the same ensemble graphic but for the Canadian Ensemble (GEPS). Again a trend W/NW of the members on the 00z cycle vs the 12z cycle.
8) So where does this leave us? Well, the trend is unmistakable But does it continue and will the end solution be as amped/west as the GFS shows My guess is no it wont be as strong as the GFS shows but I do think we will see the secondary likely over the NC coastal plain or coast
9) This would likely lead to mixing or changeover issues for those at least in central/eastern NC, eastern Va if true depending on how stubborn the CAD wedge is and if it is stronger than modeled, a possibility. For now, we need to watch the model trends today.
10) I still feel confident in a major winter storm affecting the area. Western NC, NW SC, N Ga, E TN, W-C Va stand the best chance at this moment to see the most snow and less if any mixing issues. Central SC, Central NC, E Va, look to have to worry about ice the most.
11) A chageover to rain is possible if the more inland track is true and the CAD wedge breaks down as fast as the global show. Still 4 days out. So things can change. Stay tuned!
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1) I looked at the individual EPS members at 12z. And grouped them into 3 scenarios. Op model idea (close to coast or inland track), ENS mean idea (offshore track), and other which is mostly a really suppressed track. I came up with Group 1: 21 Group 2: 22 Group 3: 7 #snow
2) I think this is a better way to look at the ensemble to see what scenario is favored. For now, it is 50:50 mostly with the outside chance we have a much more suppressed solution. I will try and update this each cycle to see how we trend.
3) Same exercise with the 12z GEFS. The GEFS had more scenarios though. The original 3, but option 4 (Slider) as the surface low move ENE out to sea south of Hatteras. And the 5th a more NW flow event with the northern stream dominant, similar to yesterday. I came up with:
Local Weather Summary 1) Sunny and cool today and Wednesday. High around 41 today, low tonight in the low 20s. High Wed around 51. Some increasing clouds Thursday as a disturbance moves towards the area. High 55, low 28.
2) This disturbance could bring a shower or perhaps even a snowflake mixed in late Thursday night. But it will be dry for many and temps in the upper 30s will likely mean all rain for most. But I cant rule out a stray flake. This disturbance will form a strong low off the coast.
3) It will stay out to sea, but will help the system behind it that will bring our winter storm threat dig towards the Gulf coast. Friday should be Partly Cloudy with a high near 50.
1) So for this weekend storm. Right now, to me it looks to have 3 potential paths. 1. The GFS/CMC path which is that there is enough separation between the storm ahead and disturbance behind that the s/w cuts off and becomes neg titled This leads to the big storm idea GFS/CMC
2) Path 2, favored by the ECMWF/UKMET Is that the shortwave cant become neutral or negatively but is positively tilted This is a weaker, flatter, further south scenario Significant strengthening is slower and off shore. This could still bring wintry weather to the South, but less
3) Path 3 not shown, but still possible is that the northern stream is stronger and we see more of a strong clipper/low pressure type event, like yesterdays models implied. This would still bring some snow, but with less Gulf/Atlantic moisture involved and focused more on NC/VA
Local Weather 1) Decreasing clouds today with temps rising into the mid to upper 40s this afternoon. Cold and dry Tues/Wed. Low 23 High 40, low 23 on Tues. Low 20 High 49 on Wed. As a disturbance move east, it will go negatively tilted Thursday and spawn low pressure development
2) Off the Carolinas coast. I have been watching this all weekend, but for now it looks to stay far enough offshore to only bring some showers to the immediate coastal areas. For now, P. Cloudy for RDU, Thurs: High 54, Low 29. P. Cloudy Friday: High 49, Low 31.
3) Sat looks dry, High 43, Low 26. We will need to watch a system behind the prev storm which could dive further S, thanks to the previous storm blowing up off the NE coast. If it can dig far enough south and tap Gulf moisture we could see wintry weather here Sunday.
Local Weather 1) rain is likely the next couple of days with a general 1-3 inches for many. Some areas of the foothills/NW piedmont and SE NC could see 3-5 inches of rain locally.
2) After the front passes Wed night/Thurs am we see a dry, less humid and cooler weather pattern. Morning lows will be in the 40s in the west and low 50s in the Triangle Friday/Saturday with highs in the mid 70s. Sunday looks nice as well making a wonderful weather weekend.
3) Next week temps warm a bit back into the upper 70s to low 80s. Rain chances remain low but could increase slightly for mid week.
Here are the major 00z global models and their ensembles. #Isaias will likely stay just off the SE FL coast, although a brief landfall of the center still cant be ruled out. I think landfall will likely be between Cape Romain SC and Cape Fear, NC. I have shifted my track (1/4)
a bit west with landfall of #Isaias near the NC/SC border, I am still a bit NE of the model consensus at the moment. With a track up the NC coastal plain, Tidewater/Delmarva/NE Coast. It does looks more likely that the center will stay mostly onshore on its ride NE. (2/4)
As far as intensity. #Isaias has not been a easy storm to forecast intensity wise. I would imagine little strengthening today as it is close to the coast. There could be a window to re-attain cat 1 strength tomorrow over the ocean before landfall Monday night. (3/4)