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Wintry Feb 17-19 Smastsmasher Snow/Ice

The 6Z NAM keeps surface temps around 31 at GSO all day Thursday.

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6z NWS Blend of Models FRAM. Concerning to see >0.25" of ice being spit out 3 days in advance. I'm hoping this event's higher precip rates will be a saving grace here & cut back on ZR totals more than the models are leading on. The blue ridge escarpment in northern NC & southern VA is probably screwed, that 0.5-0.6" you're seeing just north of Mt Airy.

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RAH has changed their tune:

Unfortunately, the wedge of colder air will likely result in another
round of frozen precipitation for parts of the region as another low
pressure system develops in the Gulf of Mexico and moves northeast
towards the Carolinas. The setup is definitely similar to what
happened over the weekend, although once again there is some
uncertainty with how cold surface temperatures will be. Have trended
the temperatures in the direction of the (colder) NAM which
typically handles CAD situations the best. Temperatures aloft will
be warm enough that snow will not be a threat anywhere, and the
surface cold layer will be thin enough to prevent refreezing above
the surface, leaving rain and freezing rain as the only expected
precipitation types.The high pressure to the north will be well
situated to provide reinforcing cold air, but this system appears to
produce higher precipitation amounts than the last one. Between the
higher amounts of precipitation that are forecast (which could
translate into higher freezing rain amounts) and lasting impacts
from the last round of ice, have decided to issue a Winter Storm
Watch for some northern counties. However, a much larger area is
under the threat for receiving at least a glaze of ice, reaching all
the way down to Asheboro and Raleigh. Precipitation is likely to
move in after midnight Thursday and persist for at least 24 hours
before winding down by Friday morning. There is quite a bit of
uncertainty in just how wide a range high temperatures will be on
Thursday between varying model solutions. The Triad may barely rise
above freezing while Sampson County will likely reach 60 degrees.
Similarly, there will be a decent spread in temperatures Thursday
night, ranging from the freezing mark to the mid 40s.
 
HRRR and RAP bringing big snows across all of North Miss, Tennessee, North Alabama, with it still snowing by the end of each of their runs. Heavy sleet across NW. Georgia on both models with some snow down on the RAP in the Dade/Walker and maybe Catoosa county areas.
Map?
 
Many areas of northern NC & southern VA are still without power from last week's ice storm. The lingering effects from this ice storm combined w/ saturated soils from recent persistent, heavy rainfall are pretty worrisome imo, because it will lower the amount of ice required to bring down trees & power lines.
 
Canadian Models continue To advertise freezing rain throughout:

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6z Nam12k
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3k only goes out to hr 60 and it would advertise More as precip is still on going
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Many areas of northern NC & southern VA are still without power from last week's ice storm. The lingering effects from this ice storm combined w/ saturated soils from recent persistent, heavy rainfall are pretty worrisome imo, because it will lower the amount of ice required to bring down trees & power lines.

You got a better surface wind map than this?
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This is begining Precip me/packfan on RGEM
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Nam Begining Precip; Trended colder 6z, but Not to Regem levels yet. splitting hairs, probably meet in middle.
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This is getting interesting. A few things to track today; of course the models (high setup --> if more Classic than in-situ CAD), the amount of dry air being and forecasted to filter in before the event (there are model dew point differences of upper teens to mid 20s), and of analysis from our on board mets (Webber,Delta) and NWS discussions.
 
Wsw out for my area. I've never seen one issued here less than a day after another one.
It may have happened but I certainly don't remember it.
 
6zNam is 1031 HP, 12zEuro 1033, 6zRGEM 1034. That will be important to watch. Its placement and how long it stays anchored as well. They have the location same spot
 
ICON held on to its solution .. i don’t like how FRAM is already at the point it is .. that happened day of last storm but now it’s happening a day or so out so the more time we have the worse this could trend
 
NAM trended well south with the freezing rain at 6z. We are just now in its wheelhouse with another 24 hours of potential south or north trends before it really locks on a solution. For the upstate it’s the ICON/NAM/CMC/RGEM vs the GFS and Euro. So basically the models that handle CAD better vs the ones that don’t but are still borderline.
 
As usual, the RGEM is too cold this morning over areas w/ snow cover in Texas & Oklahoma. If you're entrusting this model to try & forecast sfc temps over NC tomorrow night & Thursday morning, good luck to you...

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RGEM forecast vs 12z obs:

KOKC (Will Rogers World Airport): 6z RGEM: -15°F vs 12z obs: -6°F; RGEM bias: -9°F

KMFE (McAllen Miller Int'l Airport): 6z RGEM: 19°F vs 12z Obs: 27°F; RGEM bias: -8°F

KDFW (Dallas-Ft Worth Int'l Airport): 6z RGEM: -6°F vs 12z Obs: 1°F; RGEM bias: -7°F

KIAH (Bush Intercontinental/Houston Airport): 6z RGEM: 7°F vs 12z obs: 13°F; RGEM bias: -6°F

KAUS (Austin-Bergstrom Int'l Airport): 6z RGEM: 2°F vs 12z obs: 8°F; RGEM bias: -6°F

KSPS (Wichita Falls Regional Airport): 6z RGEM: -8°F vs 12z obs: -3°F; RGEM bias: -5°F

KACT (Waco Regional Airport): 6z RGEM: -3°F vs 12z obs: 2°F; RGEM bias: -5°F

KTXK (Texarkana Regional Airport): 6z RGEM: -4°F vs 12z obs: 1°F; RGEM bias: -5°F
 
As usual, the RGEM is too cold this morning over areas w/ snow cover in Texas & Oklahoma. If you're entrusting this model to try & forecast sfc temps over NC tomorrow night & Thursday morning, good luck to you...

View attachment 75443


RGEM forecast vs 12z obs:

KOKC (Will Rogers World Airport): 6z RGEM: -15°F vs 12z obs: -6°F; RGEM bias: -9°F

KMFE (McAllen Miller Int'l Airport): 6z RGEM: 19°F vs 12z Obs: 27°F; RGEM bias: -8°F

KDFW (Dallas-Ft Worth Int'l Airport): 6z RGEM: -6°F vs 12z Obs: 1°F; RGEM bias: -7°F

KIAH (Bush Intercontinental/Houston Airport): 6z RGEM: 7°F vs 12z obs: 13°F; RGEM bias: -6°F

KAUS (Austin-Bergstrom Int'l Airport): 6z RGEM: 2°F vs 12z obs: 8°F; RGEM bias: -6°F

KSPS (Wichita Falls Regional Airport): 6z RGEM: -8°F vs 12z obs: -3°F; RGEM bias: -5°F

KACT (Waco Regional Airport): 6z RGEM: -3°F vs 12z obs: 2°F; RGEM bias: -5°F

KTXK (Texarkana Regional Airport): 6z RGEM: -4°F vs 12z obs: 1°F; RGEM bias: -5°F
Seems like it's actually colder in some areas than the RGEM says. -19 in Northwest Arkansas and -13 in Tulsa.
 
NAM trended well south with the freezing rain at 6z. We are just now in its wheelhouse with another 24 hours of potential south or north trends before it really locks on a solution. For the upstate it’s the ICON/NAM/CMC/RGEM vs the GFS and Euro. So basically the models that handle CAD better vs the ones that don’t but are still borderline.

Even for the models that handle CAD better you're still talking about temps ~33-34F in/around GSP. Need to see them drop another 4F to have any serious issues in the upstate, and even if ice occurs it's likely going to be on elevated sfcs, the ground temps are warm and will likely keep many of the area roads just wet, not to mention the rates will be higher for this storm. It's much easier to get temp changes in a CAD setup in the short-range when you're well above freezing, but changes usually asymptote once you get to 32F as the offsetting effect from latent heat release makes it really hard to get significantly under the freezing mark in reality and on the models without more substantial changes to the setup.

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