Quick Fleeting Ice Event

February 5, 2025 7:11am

Ice storm warnings are out, as well as areas with winter weather advisories. See below:

■ Moisture pushes in later today. A view of the Euro and GFS below:

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■ Over the years, while the 3KM Nam is poor on precipitation output(qpf) it often excels in temp/wind setup in these events. I’ll use it in this case.

● Temps. Watch the dam burst with the flood of milder air Thursday morning. That’s why this is a short lived ice event. By late morning, midday Thursday, across the high ground you’ll be saying what ice event as you’ll be enjoying mild winds rapidly melting any ice that occurred. Wind advisories may be issued for that, and if we have any area of drenching rains, small creek rises are possible. So while the focus is obviously on the ice for obvious reasons, it’s not a long duration event.

The highest ice accretion occurs on the highest east facing areas where the east winds aid in freezing things a bit faster and drive the moisture in. (I like .15 to .25 general max ice accretion with higher amounts on those wind driven exposed east facing slopes)

As you work west. Temps are marginal. Ice accretion is slower to form at 31, no wind vs 27 driving east wind along the Allegheny Front, Savage Mt, etc.

■3KM Nam temps below: valleys east of the Alleghenies hold on to the low cold a 2-4 hours longer vs over the eastern ridges. Those driving sw winds are slow to scour out that cold

■ 3km Nam winds. Ok this feature is a staple in these events when we have a over runninh event followed by milder air

watch that period tomorrow morning 7-10am. You see the winds prior to 7am across Garrett, those are ESE winds. Then you notice a lull. You’ll get 1-3 hours of calm. At that moment temps slowly come above freezing. We have lost the essterly flow that drives in the low level cold.

As the calm departs, it’s rapidly replaced by strong gusty SW winds that rapidly

1- melt the ice

2- send temps 45-50

● windy.com app illustrates this a bit better with the Nam . Watch the wind direction. Colors represent gust. You get the calm and rapid increase of SW winds and mild air

So while ice amounts may borderline some down limbs, etc it’s very short lived and rapidly a memory by midday tomorrow. That said, while its in progress overnight. Watch for icy areas driving and sporadic downed limbs and outside shot at power outages.

1- Watching a little more wintry precip Saturday

2- potential snow maker to go in to next week.