As posted by fergie in model forum >> sorry but had to take a peak.. and got out alive!! << which just shows what a bloody mess it is,, and also could somebody explain some of this in english!! would be somewhat helpful
Seeing as it's nice and early in the day, perhaps we can see the remainder of Saturday through without the hysterics expressed on the forum yesterday? Critical points of note are simple: 1. Amplified upper pattern remains favourable for (two) trough disruption(s) early-mid next week 2. Scope of how and where these may occur will NOT be correctly resolved in ANY model at this lead time 3. Ergo, any over-analysis is pointless at this lead time given great uncertainty and variance/volatility in model handling 4. Likely erratic and eventually weakening E'ward progress of occlusion into cold air Tues means uncertainty on areal spread of snow: GFS PPN phase charts to be viewed with due caution. 5. Risk of rain onto frozen surfaces even where no snow. Varied wintry hazards look inevitable but no compelling evidence for a 'nationwide snow event' in strict defined sense. However, threat of disruptive snow for some areas (starting in parts of NI initially under frontal mass ascent; then W Scotland and Wales) is quite obvious, although no regional detail is reliable for now. 6. The potential for some easterly flow later into the week could not be *wholly* discounted yesterday (despite some claiming so); nor again in this morning's output, albeit still considered a lower probability outcome (ca. 40% support for some easterly component in 00z MOGREPS-G) 7. Attempt to resume westerly mobility later in the week (Weds-Thurs, powered by strong jet) may threaten further snow with second trough disruption. Importantly, the transition/timing and evolution of this switch will inevitably be messy and poorly resolved in all models currently. 8. Further swings in output are a given, as models struggle with upstream driving developments in W Atlantic/US. 9. Thus, can we desist from further forum freak-outs today...! :-)