Vol4Life

Without a doubt, that will be what MRX uses for their afternoon update. Lol!

Thank you so much Holston! That was a great explanation!

From a storm evolution standpoint, what needs to happen in order for this to be more of a snow event versus zr? Clearly, there’s some warming aloft. Do we need the HP to be stronger or positioned differently? Or is this more of a storm track issue?

What would this do to the temp profile in the Valley?

MRX seems skeptical (and rightfully so after the flip flopping) on the Sat night/Sun morning storm. Here’s the portion of you their disco that pertains to this storm: AREA FORECAST DISCUSSION National Weather Service Morristown TN 400 PM EST Thu Feb 4 2021 .LONG TERM...(Friday Night through Thursday)... Key Messages: 1. Snow chances have increased Sat night and Sun morning, but confidence remains very low with how this system will evolve. 2. Dry with near to slightly below normal temps Sun afternoon warming above normal Mon. 3. Active weather next week with difficult to time precip chances, but milder temps early in the week cool below normal mid/late week. Discussion: Friday Night and Saturday... Fast, progressive upper level flow will remain across the TN Valley during this time at the base of broad troughing covering much of the northern tier of the country. Weak surface high pressure quickly moving across the Midwest and OH Valley will provide dry conditions and temps just below normal. Lows Fri night will dip into the 25-30 degree range with highs Sat in the upper 40`s to near 50. Saturday Night and Sunday... Well, this period has once again become more interesting as the 12Z NAM and deterministic ECMWF have trended toward the deterministic GFS and GEFS ensemble means in phasing northern and southern stream energy which gives the possibility of accumulating snow Sat night into Sun morning. However, the ECMWF ensemble mean, deterministic CMC, and CMC ensemble means still keep this energy separate leading to a drier forecast. Regarding the synoptic details, a fast moving northern stream mid/upper shortwave will progress across the Midwest states Sat night while a southern stream shortwave moves along the Gulf coast states with a surface response near the FL Panhandle. The N stream shortwave further deepens the broader longwave trough and sends a piece of true arctic air across the Midwest and Great Lakes in its wake, but the different solutions among the guidance stem from whether or not the N and S stream shortwaves can phase before all of the energy moves to our E. Consensus is for 850 mb temps to be -3 to -4 deg C Sat night with surface temps several degrees above freezing early in the night as the right entrance region of a 130- 140 kt H3 jet associated with the northern shortwave induces strengthening warm, moist advection and isentropic lift. The strength and duration of moisture advection and overall forcing will be determined by whether or not the features actually phase, so stayed with NBM slight chance PoPs Sat night/Sun morning, but blended WPC QPF with the GFS/ECMWF QPF to take into account some of the higher QPF probabilities. In terms of snowfall amounts, the aforementioned surface temps above freezing at the onset will lead to a rain/snow mix, but expect a quick transition to snow by late evening as the lower levels cool, possibly aided by dynamic cooling and wet bulbing. The temp profile and WPC/GFS/ECMWF blended QPF yields 0.5 to 2 inches of snow, which is a reasonable starting point based on the flip flopping guidance. This system will quickly exit NE Sun afternoon with dry conditions and highs only in the low/mid 40`s behind the associated cold front.

Lock it in!

If you have the whole run, that would be great! Thanks Holston! I’ve never really paid attention to the Para until the last several days.

Does anyone have the accumulation map for Para-GFS? I’m having a hard time getting it to load.

Man, they really are! Wow!

So it is still snowing at that point?!?

Absolutely pouring snow right now in West Knoxville

How does the Euro show snow in Mississippi and then it turns to rain in TN?

Living in West Knox, the thing that worries me about this storm is the sharp cutoff. On the latest 3k NAM, it shows around 4 inches where I live, but 30 minutes west, it’s basically showing a trace.

We may have received the kiss of death when Jeff got fully on board earlier. The forum area seems to do much better with “pessimistic Jeff”. Haha!

Ironic because in their overnight forecast discussion, they seemed to be coming around to the idea that Knox would see some snow.

It appears that the NW expansion of the precipitation shield that we were seeing in runs yesterday and earlier today has ceased. Hoping that trend will start back up so that our friends to the north and west get in on the action.

I know the NAM has a tendency to over amplify systems, but does it handle thermal profiles pretty well?

Remind me...what model are those plumes based off of?

Very good point. Also, a little OT, but I really enjoy your input on VQ

Thank you Tellico!

Wow...Does anyone have a map of the latest NAM? I’m in a spot where I don’t have access to it.

NWS busts again! Should have included Knox in the WWA, but they were too worried about sun angle!

Starting to snow West Knox!

It’s snowing pretty good right now in West Knox!

Daniel, I’ve enjoyed your posts. Please keep posting!