The National Weather Service has issued a Winter Weather Advisory for the Western Southern Tier and Northern Pennsylvania. A Winter Storm WARNING is in effect for all counties south of the Twin Tiers.

However, the Twin Tiers need their forecast for the week, and that’s why I’m here. Unlike the last snowstorm that just grazed the area, this one appears to be headed right for us. We have a surface low coming right across the Appalachians, another low sweeping down the plains and looking like it will combine with the Appalachian low, and a high pressure bubble just to the east of these two that will prevent a “type B hop” toward the East Coast. (Type B refers to the direction of a snowstorm like this: A goes around the Appalachians from the south, B goes across the Appalachians by generating a cyclone to the east of the original and causing the original to disappear, and C goes around the Appalachians from the north; C is the one that usually affects us, and that’s what this one’s turning out to be.)

The roles, as it turns out, are going to be a bit reversed from last weekend’s storm: the major city corridors are likely going to get less than the last one (but still nothing to sneeze at) while we brace for the worst. The good news is that with storms coming up across the Appalachians, it forces a lot of the heaviest snow out of the system through orographic lift down in West Virginia and deep in coal territory, well before it reaches us. Reading the NWS discussion, they’re only calling for 2 to 4 inches. That’s a stretch I think, and I think it’s based on the development of a type B situation. I don’t think it will happen. I will be bolder and call for at least 6 inches.

After the storm passes, it will establish a northwesterly flow over the area, bringing colder than average temperatures, but seasonably cold (low-to-mid 20s for highs, as opposed to the average of 29).

Tuesday:
Snowfall begins in the afternoon. Afternoon highs in the upper 20s. Easterly wind becoming stronger as the day progresses. Tuesday night, snow.

Wednesday:
Snow continues. Early morning low in the upper teens. Highs in the mid-20s.

Thursday:
Snow begins to dissipate. Colder. Early morning lows in the mid-teens. Highs in the low 20s. Northwesterly wind.

Friday:
A mix of sun and clouds. Early morning low in the upper single digits. High temperature in the low to mid 20s.

More in the Weekend Outlook.

~JMF

LAKE EFFECT SNOW DEVELOPING OFF LAKE ERIE WILL EXTEND WELL INLAND INTO PORTIONS OF THE ROCHESTER AREA FROM LATE TONIGHT THROUGH THURSDAY. EXPECT ACCUMULATIONS OF 2 TO 5 INCHES…WITH THE GREATEST AMOUNTS ACROSS THE WESTERN AND SOUTHERN PORTIONS OF MONROE COUNTY.

IN ADDITION TO ACCUMULATING SNOWFALL…STRONG WINDS WILL CREATE SIGNIFICANT BLOWING AND DRIFTING SNOW. THIS WILL RESULT IN GREATLY REDUCED VISIBILITY AT TIMES…ESPECIALLY IN OPEN AREAS.

-NWS Buffalo

Winter has finally arrived in WNY. The entire area last night and early this morning was blanketed with a few inches of slushy wet snow. About half of that has melted away in the warmer temperatures and passing showers, but as outlined above, we’re in for more snow on Thursday.

2-5″ of snow is nothing for us, but this snow will be of the fluffy variety on Thursday. Couple that with high winds and we have a recipe for blowing snow creating dangerous whiteout conditions. If you’re doing any driving tomorrow, be prepared for reduced visibilities in any squalls of snow. As is with any kind of lake effect snow, conditions can vary from sunny one minute, to a whiteout the next.

We have prefect conditions out there tonight for prime radiational cooling. Winds at the surface and through much of the lower atmosphere are already calm and/or light, we have clear skies, and the dew point has already dropped below 30 degrees.

Tonight’s record low at the Rochester airport is 27 degrees set way back in 1876. It’s possible we could come very close to that low, maybe not at the airport, but a few backyard thermometers will see readings in the upper 20s.

We will keep the cool weather around for Columbus Day. Our daytime high will only make it into the upper 40s. Well below normal for this time of the season.