Winter Storms Forecast for 2/16 (East Coast) and 2/20 (Plains)

[Jason Persoff]

Looks like two big setups unfolding over the next week.

Potent storm system forming over Nova Scotia over the next couple of days following a very similar track to the last major snowstorm with between 6-12" anticipated throughout New England.

Meanwhile, back west, GFS and ECWMF bullish on a cutoff low to form over AZ by early week with a potent low pressure system setting up over Central to SE CO. Fairly intense moisture surge antecedent to this should result in a large snow system for somewhere on the eastern Colorado/I-25 corridor.

Personally very pleased for us out here in the west where snowpack remains <90%. We need a good evapotranspiration forecast for great storms .

 

[samuel stone]

an interesting note on the plains storm, its coming quickly on the heels of another trough in the jet stream which is goingt set an unusual amount of cold air in place for this storm to work with. if the tempertures the gfs is throwing out verify were going to see significant snowfall to the ENE of the the surface low, an area where typically you get mostly rain with these types of storms, im speaking mostly for NE KS and SE NE for the current GFS prog, but really its gonna depend on where the low tracks. Also, with pretty strong 850mb southerly flw in this region of the storm, there could also be some freezing rain if this comes to fruition. These late winter storms usually generate the most snow when they follow a quickly behind a NW flw cold punch, sending moisture over the top of pre-existing cold surface temps without Alowing for much return flw at the surface. such as GFS is portraying.

EDIT- just noticed on the latest nam 06z run that from 72 to 84 hrs its bringing a small peaice of the storm system, best viewed in 500mb vorticity, through the plains earlier than the main low, during the day wednesday. this "arm" of energy if you will originates over the pacific off the coast of baja CA over much warmer waters than where the main trough comes from, on the precip graphic its really throwing out some heavy snowfall rates in KS! well ahead of the main low. man we need any precip we can get in a baaad way.

 

[Paul Knightley]

ECMWF has 20+cms over Nebraska and some parts of KS, with a 30 knot easterly wind! Thursday looks like a very interesting weather day!

 

[Jason Persoff]

Everything has come together for Central KS over the past day, and some estimates from the NWS indicate up to 18" of snow in Central KS by the time the storm pushes east. Massive ice storm in MO bringing up to 2" of ice (that sounds just awful).

Timing of the upper low was just far enough behind the sfc low for the Denver area--we dodged most of the energy of this system her in CO. Sadly that also meant the mountains did not benefit nearly as much from this potent spring system. We're seeing beautiful "champagne" mega-snowflakes falling in the wrap around flow, though--it looks like a Christmas movie set outside my window.

The GOM was open for business on this storm leading to intense convection. The coldest cold air aloft has led to intense lapse rates and thundersnow is still ongoing pre-dawn southeast of Wichita (!).