The cold front moved through pretty much on schedule today. Tomorrow, our weather will be influenced by the deep low pressure system over eastern Canada and its associated cyclonic flow.
Friday will be unseasonably cool. It will continue to be windy with occasional gusts. While there will be considerable sun, the cold air aloft will result in considerable instability cloudiness in the afternoon with some upper vorticities moving through. (Areas south of Philadelphia will have more sun.) High 49-50º.
The weekend will feature gradual moderation of temperatures and the models are showing temperatures approaching 69º by Sunday.
Another system moves through on Monday.
Low pressure in the Great Lakes will spawn a very intense coastal low near Maine. The associated warm front moves through early morning and then a sharp cold front moves through about noontime Thursday. The models agree with the cold frontal timing, but disagree with the precipitation regarding the warm front.
The NAM and associated models have showers and perhaps some thunderstorms breaking out with the warm front, as early as 8AM in our area. The GFS waits for the actual cold front passage timing for the showers, about noontime.
It will become windy at daybreak and increasingly windy with the frontal passage— gusts near 40-50 mph. It will remain very windy in the afternoon. The winds are due to an intense pressure gradient between the intensifying low and the large high pressure system moving in.
This front ushers in a short-term upper air pattern change with an upper air cold cyclonic flow. Look for unseasonably cold weather, windy conditions and changeable skies, again with another frontal passage on Monday.
Revised Wed 07:29 AM — Last night’s models show a very low chance of more showers/thunderstorms between 2 and 5 PM Wednesday. If they occur, they will be very widely scattered. Sun breaks out mid-morning…The EKDMOS is still showing high temps of 78º today.
Today’s weather was much nicer than predicted by last night’s models. This morning’s models had significantly backed off from the previous night’s poor pessimistic forecast and moved the heavier precipitation from this evening to early Wednesday morning.
The current models runs are all showing showers and thunderstorms moving through here 3-5 AM Wednesday morning. Some may be heavy.
Wednesday will have a mix of sun and clouds and a southerly flow will bring temperatures into the 70s. The EKDMOS is showing 78º, but other models are in the low to mid 70s.
There’s another chance of showers and thunderstorms about 2-3PM Wednesday afternoon.
Interesting weather for Thursday with a cold front. I’ll tackle that tomorrow.
Updated 11:30 PM — Several of tonight’s models have eliminated the noontime sprinkles and predict the bulk of the rain later in the day and evening will pass by to our south. One HIRESW model version has light sprinkles as early as 2PM.
Today was likely the nicest day of the week.
The first of several impulses moving in from the west will approach on Tuesday.
Clouds move in during the morning hours Tuesday.
While the main impulse is expected to move in Tuesday night, the high resolution models show an initial slug of moisture and dynamics causing light sprinkles about 2PM Tuesday. Total QPF 0.03 inches water.
That passes through leaving just clouds until evening, when somewhat heavier showers will arrive. High temp about 64º.
Best time to get out and exercise is before noon, and possibly again in the mid-afternoon.
(Wednesday looks to have temperatures in the low to mid 70s.)
With Daylight Saving Time, the new models’ 24 hour forecast data become available between 10 PM and 10:35 PM. I’ll update later if necessary.
As mentioned in this morning’s post, we’re transitioning into a several day colder pattern starting this weekend. Temps early next week may have highs in the 40s!