Winter Wizard

Yes, the issue with this storm is almost entirely in the mid-levels. Surface track does matter to an extent, and it is favorable for us, but the upper-level low tracks right over us - you want it to be south and east. Trough axis as a whole is too far west. We end up getting stronger warm air advection at the 700-850 mb level and that's what changes the cities over to sleet and freezing rain. The stronger warm air advection is also what's helping create lift and why you're seeing the intense FGEN bands depicted on the front end.

This is a sounding near DCA right as it flips to sleet at 14z. Razor thin margin.

Yeah that’s one of the most bizarre looking warm tongues I’ve seen. Can’t say I’d put much weight into it tbh.

Sleet line at 54 runs from Fairfax to Silver Spring to Annapolis to Dover, north of there is heavy snow.

The margin of error between a mauling and a sleetfest on the 3k NAM is less than a degree at 700 mb.

Yeah for sure, NAM has always been the outlier since the winds were much stronger at the mid-levels compared to other guidance. Seems to be falling in line now.

700 mb winds seem to be slightly weaker compared to the 6z run. Should mean slower WAA.

Switched over to sleet in Annapolis. Looking at 0.25-0.30” of ice accretion in the trees.

Annapolis, MD: 1/25: 0.3” 1/31-2/2: 3.5” 2/7: 1.3” 2/11-12: 2.5" TOTAL: 7.6” Bonus - State College PA: 12/16-17: 15.0”

Up to 2.5” in Annapolis from this morning’s snow/graupel. Icing on the cake for a nice event.

Final total from my parents' house in North Wilmington is a little over 3 inches. Looks like a nice little event, that area has been fringed multiple times this winter.

Calling it 2 inches on the dot in Annapolis. Better than expected, so I'm pretty satisfied. Looks gorgeous outside.

Looks like this last band is making up for lost time in Annapolis. Woke up around 2 with basically nothing on the ground after hours of rain and sleet, but now looks like we have more snow than last weekend's fail. Will measure shortly. Congrats Baltimore/Mason Dixon Line folks who cashed in. And sorry DC...again.

Light snow just began in Annapolis

Hour 33 on the NAM: compared to 12z, precip is noticeably slower to arrive and confluence is stronger over Maine.

Annapolis, MD: 1/25: 0.3” 1/31-2/2: 3.5” 2/7: 1.3” TOTAL: 5.1” Bonus - State College PA: 12/16-17: 15.0”

Just wait until you see the reports coming out the eastern Shore and Sussex County, DE

1.3” looks like the final total in Annapolis and you can hear the drip, drip, drip outside melting it away. Such is life when you live close to the Bay.

Annapolis sleeting

Pushing 2” in Annapolis with a nice band coming in.

I’m in Annapolis and generally the farther north and east you are, the better banding you’ll see. Being against the Bay also keeps us a bit warmer though due to the marine layer so we may mix for longer.

Stronger ridge would lead to a more amplified ULL and probably would support the more tucked in solutions. But again, this is purely anecdotal for now.

850 mb winds on the NAM are ripping southeast at over 40 knots 0z Monday which torches the mid-levels I-95 south and east. This is significantly higher than any other guidance has and the SLP track is also farther west. Also, checking out the obs: this is anecdotal, but could support a deeper ULL:

All snow in Annapolis

I think this is just a matter of perception - keep in mind that a negative bust for you usually means a positive bust for someone else. Additionally, there is still a margin of error even in short range, and slight adjustments to a storm's track have significant implications. The January 2015 bust in NYC is a great example of this, same with Boxing Day 2010 for our area. If we think about recent storms like March 2017 and the one this week, it could be that NWP models underestimate mid-level warmth, as evidenced by the sleet line going farther north and west than expected. This storm is also another example of how deceiving snow maps can be in marginal setups, as many of them count sleet as snow and that inflates totals.