The snow/sleet/rain line has reached Ithaca. Thus ends the frozen precipitation portion of the storm. Surface temperatures are just above freezing so freezing rain will not be an issue.
Summary
It is going to snow late tonight into early tomorrow morning before changing to sleet and then finally to a cold rain. Lows will be near 30 tonight and highs tomorrow (Thursday) will only reach around 45 in the late afternoon. Around 0.25-0.5 inches of rain is expected and little frozen precipitation accumulation is expected. Precipitation could end as snow showers as the storm moves out Thursday night into early Friday morning.
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| 12z (8AM) Wednesday 4km resolution NAM model forecast from hr 10 (6PM Thursday) to hr 36 (4PM Friday) This is a projected radar reflectivity. Precip will arrive later than the radar suggests. |
Precipitation
Snow should begin to move in between 12AM and 3AM Thursday. Precipitation will start out light before becoming moderate around 5 AM. As winds from the south higher up in the atmosphere erode the cold air away, the snow will turn to sleet. The transition to sleet should begin between 6 and 8AM before changing to rain about 30 minutes to an hour after the sleet begins. Moderate to heavy rain will continue until the early afternoon. Light to moderate rain will continue through Thursday night.
Temperatures
Temperatures should start around 32 when the snow starts, dropping a degree or two through evaporative cooling. Then they will hold steady until the southerly breeze starts to bring in warmer air. Temperatures will slowly climb into the mid 40s by the afternoon.
Rain:
The main precipitation type of the storm is expected to be rain. A quarter to a half an inch is expected so nothing too extreme like last week. Rain will be the heaviest after the transition as the warm front moves through and in the late afternoon as the cold front swings around.
Snow:
Little to no accumulation is expected. Air temperatures are expected to be near freezing but ground temperatures are well above freezing, so any accumulation will be confined to slowed melting on elevated surfaces.
Sleet:
Little sleet accumulation is expected. A coating at most is expected before the changeover to rain.
Freezing rain:
At the moment, it seems that temperatures will be just warm enough to keep freezing rain away. In order to get freezing rain, surface temperatures need to be below freezing but temperatures should rise as the changeover from snow to rain occurs. It is something to watch to see if cold air remains more entrenched than expected.
Updates will come as we get closer to precipitation onset. Nowcasting of precipitation changeovers will be done unless I happen to be in class.
Thanks for reading!
Alex
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