Feb 18, 2013: Rain Tomorrow, Then Cold/Windy

Forecast Highlights:

Cold temperatures were observed this morning, dropping into the 10s for lows with wind chills approaching zero degrees, with temperatures so far today having warmed up into the upper 20s and 30s with continued breezy conditions. A brief warm up is expected with a minor rain event on Tuesday, followed by another round of cold and windy conditions until the next storm affects the region on Friday night into Saturday.

---

Tonight - Thursday: Rain, Then Cold/Windy

Cloud cover will increase tonight into Tuesday morning as the next rain event approaches, with a low pressure tracking through the Great Lakes region bringing a cold front through the region as a secondary low pressure develops over Maine. Precipitation will spread into the area by the late morning into early afternoon hours; while temperatures at 850mb will be near to below freezing, warmer boundary layer temperatures are expected as highs peak in the low to mid 40s, and rain is expected to fall aside from some snow at the end of the storm for interior north/western areas, where minor accumulations under 1/2 inch are possible. The rain will continue through the early evening hours before ending, with at least 1/4 inch of rain likely.

A cold air mass will return behind the trough with windy conditions expected again, lasting through Wednesday and Thursday. Highs on both days are expected to reach the upper 20s inland and the low 30s across the rest of the area, with WNW/NW winds of 15-25 mph with gusts up to or over 40 mph expected. Cold overnight temperatures are expected for Wednesday night, dropping into the 10s across the area similarly to last night, with wind chills again expected to approach zero degrees.


Friday - Weekend: Next Storm Expected

The next storm will affect the region on Friday night into the weekend; while this storm has its origins well west of the region, tracking towards the Great Lakes, a block-like feature over southern Canada will prevent it from continuing on that path, with the primary low pressure instead weakening as it approaches the region, spreading precipitation eastward on Friday night, while a stronger coastal low pressure develops on Saturday before moving away from the region. After increasing clouds on Friday with highs in the upper 30s to low 40s, scattered light precipitation, either as rain or snow showers, will spread into the area on Friday night, with minor accumulations expected at most.

The main event is expected to affect the region on Saturday into Saturday night with the developing coastal low pressure. The model guidance remains variable with its handling of this system, with some keeping it mostly south of the area, while others show a stronger and further north low pressure with heavier precipitation across the region, including the area. This aspect of the storm remains somewhat uncertain, and additional changes are expected with the model guidance; most of the operational models were further north with the storm with more significant impacts in the region, although the ECMWF remains more suppressed and drier, and there is still a larger spread with the ensemble members between a minor event and a more significant storm.

At this time, at least some impacts are expected from the coastal low on Saturday into Saturday night, with marginal temperatures as the coastal low develops supporting precipitation type more as a rain/snow mix, although the forecast is subject to change. It is a possibility the coastal low may have more significant impacts in the region, in which case a snowstorm would be expected inland, possibly extending into NYC as well, although this is still 5 days out, a range where the model guidance has struggled this year and has either underestimated or overestimated storms, such as the February 8-9 blizzard which this far out was expected to be a 1-3 inch snow event for the northern Northeast, and the January 25 light snow event which was showing up as a moderate snowstorm on the model guidance several days out. Stay tuned over the next few days for more information on the weekend outlook, as well as another storm potential towards early-mid next week and the potential for a colder pattern to continue into early March.