TRENDS for the week of 1 to 7 Feb 2021
-- Temperatures will average 1 to 2 deg below normal, starting somewhat above normal today and Tuesday, then gradually falling into the 3 to 5 below normal range by next weekend.
-- Rainfalls will average about 75% of normal, most of which will come between today and Thursday; a drier interval will follow.
-- Sunshine will improve to near normal values with a rather cloudy start.
FORECASTS
TODAY will be overcast in the north with occasional light rain, turning a bit heavier by afternoon and evening. Partly cloudy and mild further south with outbreaks of light rain developing later. Highs 9 to 12 C.
TONIGHT and TUESDAY will see an interval of moderate to heavy rainfalls, 20 to 40 mm, heaviest north-central counties. It will be quite mild with overnight lows near 8 C and afternoon highs near 10 or 11 C.
By WEDNESDAY it will have become partly cloudy with some persistent fog in north central counties slowly lifting, isolated showers, and slightly cooler, lows near 4 C and highs near 9 C.
THURSDAY and FRIDAY will also be partly cloudy with isolated showers, lows near 3 C each day and highs 7 to 9 C.
By SATURDAY colder air is likely to arrive from the east. At first it will be a dry cold with considerable sunshine, perhaps some isolated wintry showers in east coast counties. Highs would be 2-4 C and overnight lows into the -4 C range with chances of -6 C or lower further west.
By early next week this colder air will come under attack from the Atlantic and there will be an increasing risk of snow or sleet with rain pushing into the south if the Atlantic air wins this battle relatively fast, some guidance shows the cold well entrenched through all of next week so that the only precipitation that could occur would be wintry, and there would be higher chances of the northern counties remaining dry. So that is the new range of model uncertainty as cold seems to be on the ascendant in this projected battle through early to mid February.
Peter O'Donnell for Iwo