Update Thu 10/27 @ 5:38 PM — The Friday through Sunday period is looking very nice. Sunday isn’t forecast to be as cloudy as previously thought.
Even the system expected to affect us on Monday (Halloween) doesn’t appear to be as wet as previously forecast. With the exception of the ECMWF model (which still forecasts some heavier showers), it may be relatively dry for Trick or Treaters Monday evening.
Update Wed 10/26 @ 5:17 PM — High pressure will build in for Thursday through Saturday. Very nice autumnal weather expected.
(The only thing to watch: the high will move off to our northeast. An easterly flow around the high may bring in some cloudiness on Saturday, but not currently forecast by the models.)
Low pressure in the Southwest will move towards us on Sunday with an increase in clouds. Rain associated with this system is currently forecast to move in during Sunday evening and linger into Halloween.
Wednesday afternoon’s Water Vapor image showing upper air disturbance that will spawn low pressure in Colorado and move towards us on Sunday. (Click on image for a larger view.)GEFS forecast for Thursday. Large, sprawling high pressure moves in. Low pressure (white circle) will move towards us Sunday. (Click on image for a larger view.) and move
Updated Tue 10/25 10:46 PM — Several of tonight’s high resolution models show some scattered showers between 1 and 4 PM Wednesday afternoon with a weak frontal passage.
Update Tue 10/25 @ 11:09 AM — Today’s models continue forecasting the low clouds to hang tight through today (Tuesday). We are sandwiched between two low pressure systems that will move off to the northeast on Wednesday. We may get some break in the clouds for a time on Wednesday afternoon.
Tuesday’s 06z GEFS forecast for Wednesday at 2 PM. The current trough over us (1) will be swept away by the approaching cold front (2) as the systems shear off to our northwest. (clouds are black/grey) Click on image for a larger view.)
Thursday is looking good as are Friday and Saturday. There’s some question about another coastal low affecting us on Sunday. (high uncertainty.)
A low pressure system will shear off to the northwest of us on Wednesday with most of the rain with its associated cold front also moving off to the north and west.
Update Mon 10/24 @ 8:14 PM — This afternoon’s models suggest the low clouds may hang in tight through most of Tuesday afternoon, except in NJ.
Previously Posted Mon 4:41 PM —
A weak upper level trough and a high pressure system to our north have given us a damp easterly wind flow and light rain/drizzle.
NAESF shows strong trough over Colorado and weak trough over the eastern seaboard on Monday. These troughs will lift out by late Wednesday-Thursday.
The damp easterly flow will persist through much of Tuesday, but skies may brighten by mid to late Tuesday afternoon.
A weak front moves through Wednesday, with most of the energy to our far north. High pressure builds in for Thursday and Friday. Very nice weather expected Thursday and Friday and likely Saturday.
Update Fri 10/21 @ 9:56 AM — As is often the case with coastal low pressure systems, the forecast speed and track varies from model to model. The general trend has been for a slower progression (except for the GFS) keeping any rain at bay until very late afternoon.
The latest GFS is an outlier with the system moving faster but further east. (still missing us!) A known bias of the current version 16 of the GFS is too fast movement of coastal systems.
Current GFS forecast for 2 PM Sunday—
GFS has the rain missing us and moving east. (Click on image for a larger view.)
The latest ECMWF has the rain moving in late in the afternoon and very light in the city—
Friday’s 06z ECMWF forecast for 5 PM Suunday (Click on image for a larger view.)
Interestingly, the GEFS based on the GFS still has rain moving in during the afternoon, although quite light—
So..what’s going to happen? I’m going with the ECMWF-GEFS blended forecast right now. This is very similar to the NBM (model Blend). Very light rain moves in during the mid to late afternoon Sunday. It will be cloudy and somewhat windy. Not an ideal baseball weather backdrop, but it won’t affect the Phillies!
Updated Thu 10/20 10:50 PM — Tonight’s NAM is slower with the rain moving in on Sunday. The rain moves in late afternoon to early evening. The NBM has some very light rain earlier.
Update Thu 10/20 @ 5:38 PM — Many of this afternoon’s models have trended towards a slower northward movement of the coastal system on Sunday and things are looking somewhat more optimistic for a relatively dry (or much less wet) Sunday afternoon.
The latest NAM shows most of the rain still to our south at 1 PM—
Thursday’s 18z NAM shows rain still to our south at 1 PM Sunday. (Click on image for a larger view.)
The model blend (NBM) which incorporates many models but tends to lag 6-12 hours with changes, still shows some light rain here in the afternoon—
Thursday’s 19z NBM model shows very light rain here at 1 PM. The NBM tends to lag and may not be showing the slowing system. (Click on image for a larger view.)
The afternoon GFS will be available shortly I’ll do a quick update later after 10:45 PM when this evening’s NAM becomes available.
Update Thu 10/20 @ 9:49 AM —Increasingly nice weather through Saturday as high pressure builds in over us. Warming temperatures and sunny skies.
Unfortunately, the Phillies may have to play in the rain on Sunday, as all models have joined in the forecast of rain developing Sunday from a coastal low. The ECMWF has joined the NAEFS from yesterday with an upper low and sharp trough along the coast—
Thursday’s 06z ECMWF with upper air low and 250 mb jet stream winds and contours. This upper low will draw the coastal low closer to the coast and affect us on Sunday. (Click on image for a larger view.)
ECMWF accumuated rain forecast —
Today’s 06z ECMWF forecast for Sunday at 2 PM. (accumulated rain) (Click on image for a larger view.)
Update Wed 10/19 @ 9:32 PM — The latest GFS continues with rain for Sunday, as does several other models. (The hold-out is the German ICON model which has a slower system that stays to our east.)
The latest GFS—
Today’s 18z GFS shows a coastal system with rain by late morning. The above is the 2 PM forecast. (Click on image for a larger view.)
Possible change in Sunday’s weather forecast
The weekend forecast had been looking dandy. But the latest NAEFS shows a coastal low affecting our are with rain on Sunday. I’ll look closer at this later today.
Latest NAEFS forecast for Sunday 2 PM. Coastal low may bring some rain. (Click on image for a larger view.)
Updated Wed 10/19 8:16 AM —The Washington Post has a good article today on long range winter forecasts.
Update Tue 10/18 @ 5:07 PM — Continued chilly weather at night. Here’s the latest NBM minimum temperatures for Tuesday night into daybreak Wednesday—
Today’s 19z NBM model minimum temps for Tuesday night. The ± refers to one standard deviation. Fairly high spread for this evening’s temp forecast. (Click on image for a larger view.)
Milder temperatures for the weekend. The weekend looks real good!
Previously Posted Mon 5:53 PM —
It’s been well-advertised that a strong cold front is moving through today and considerably colder weather will be with us for the next few days.
A strong upper air low is over Canada and is gradually moving eastward, allowing colder air to move in tonight through Thursday.
Water Vapor showing upper air flow (with superimposed RAP model jet level streamlines) (Click on image for a larger view.)
Here’s the ECMWF model showing the current situation in the jet flow—
ECMWF forecast for the current upper air flow. Strong jet streaks will bring cold air down into the Northeast (Click on image for a larger view.)
We’ll fall into the 30’s Tuesday night into Wednesday mornng. There’s a wide range of uncertainty (high standard deviation) regarding exact low temperatures—
Latest NBM model with low temperatures expected early Wednesday morning. High standard deviation of almost ±3º. (Click on image for a larger view.)
It will be windy, especially Wednesday and Thursday—
Following the showers and thunderstorms moving through this evening (Monday), no storms on the horizon through the weekend.
