Kasim Awan

Given the low 500mb temps & heights I would be surprised if something does not develop during this time period (weekend etc).

K8, whilst I agree >300m is favored, we need to keep an eye on the dynamics of the cold air undercut..

ICON looking interesting today > tentative increases in southerly jet component & cold air block to North.

Possibly a few cm for Buxton and definitely the Snake Pass Charlie. Difficult to make an early forecast for low lying areas. Keep an eye on posts.

> Scott will be here soon, to liven up some model discussion
> Back edge heavy wet snow looking increasingly possible I’d say down to 150m

Kasim experimental Model

I am currently developing a 100 metre resolution extrapolation of the WRF model with detailed snow parameters such as accumulation, chance of accumulation, freezing level, 1hr evap cooling temperature, dew point. If you have recently joined this forum drop me a message with your location and I will create a specific page of the model for you.

WRF

Southwards correction now favoured – Euro4 18z will be of interest

Good morning. Watching Wed night / Thu closely here at 400m, those at lower levels should keep an eye on the frontal undercut, the pivot and occlusion >> read my post on the snow thread :).

Good morning all. A positive set of 00z hi res runs I would say. A cluster of output (ec, icon, wrf) have the main occlusion & evap cooling over NE England / S Scotland, however the cold undercutting (into a separate front) still occurs at a reasonable speed across “central” Northern England.

Granted this solution does produce much stronger…[Read more]

The pivot on Wednesday night’s system is interesting too.
I’ve seen similar pivots with winds under 15mph produce 4-6″ at 300ft. Wind speed is working against us here, so the evap cooling thermodynamic gradient will be shallower (will take longer to develop conducive conditions at low levels). This however does not discount possible evap cooling…[Read more]

GFS is too widespread with the precip >> occulled front more localized.

About pinpointing the low level 1-3cm area, Pennines almost nailed on now. Arpege goes for Yorks & Lincs.

Interested in weekend too

ICON indicating risk of temporary low level wet snow > localized accumulations with base snow line of 300m producing risk of significant accumulations here in the Pennines Wed/Thu before > showery PM feed into Fri

@smith54, there is a risk of back edge snowfall late Wednesday / Thursday. Upper air temps of -4C, a surface pressure of 950mb means the effective adiabatic 100m snow line 850hpa temp is -4.5C. So, conducive conditions are possible however the condition of intensity is still required at and around this snow line to secure accumulations. Need to…[Read more]