Update Thu @ 7:31 PM — The latest HRRR model forecasts a narrow line of thunderstorms moving through between 5 AM and 6 AM Friday morning. The HRRR continues to predict wind gusts over 50 mph after midnight.

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Update Thu @ 9:27 AM — The latest model trend is for the rain to arrive later in the evening Thursday and for the front to move through about 5 AM Friday.

• Some sun to break out around noon into early afternoon, especially from the city and eastward.
• NBM high temps Blue Bell 59.2º ± 5.1º (unusually high uncertainty-spread)
• Continued and increasingly windy especially nighttime.
• Rain arrives in our area a bit later, between 9-11 PM
• Highest wind gusts about 4 AM. Gusts 50-60 mph possible.

Looking ahead to the weekend, colder, windy weather on Saturday with some cloudiness mid-day and chance of some snow flurries. My Weekend Weather Forecast late Friday afternoon.

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Update Wed @ 10:58 PM — Rain starts early evening Thursday. About 0.6 inches of rain, according to tonight’s NBM. The big issue here will be the high wind gusts around and after midnight. Gusts approaching 55-60mph. Rain tapers and ends Friday morning.

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Update Tue @ 11:38 AM — Temperatures on Thursday will be over 60º in much of our area. The NBM has 62º ± 2º for Philadelphia and 59.3º ± 2.3º for Blue Bell. Clouds will be a factor; with a thinner cloud deck, we’ll be even warmer.

The storm late Thursday and Thursday night will head to our north. The heavy rain previously forecast will go to our far north and the rain in our area will be nothing special (~ 0.5 inches)

What will be “interesting” will be the winds and wind gusts. The GFS has been forecasting gusts approaching 60mph after midnight Thursday into Friday morning.

Saturday is looking windy, chilly with some cloudiness as a weak front moves through. Sunday milder. Monday mild with high clouds.

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Previously Posted Mon 5:19 PM —

The extended range models are suggesting a changing weather pattern over the next two weeks with a big warm up this Thursday, rain late Thursday into Friday, followed by colder weather again for coming weekend. The week following looks to be milder again.

The “interesting weather” this week will be the deep low pressure system expected to move up through the Great Lakes Thursday into Friday. We’ll be on the warm, eastern side of this storm.

Thursday looks to be in the 60s, but it will be increasingly cloudy and very WINDY. Heavy rain Thursday evening and night into Friday. Windy after the storm departs.

The weekend looks dry and colder.

Update Tue @ 10:35 PM — Tonight’s major models, whose forecasts extend into the Sunday timeframe, don’t become available until midnight and afterwards. The afternoon GEFS became available earlier this evening continues with light snow (1-2 inches) on Sunday. I’ll update tomorrow morning.

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Update Tue @ 5:48 PM — This afternoon’s models are leaning towards a more off-shore coastal storm with a reduced chance of snow here. Still something that still needs to be watched as there’s high forecast uncertainty in northwest quadrant of the storm.

The latest GFS model, just available—

On a different note, Saturday temperatures are forecast to be 57º ± 3º!

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Update Tue @ 12:39 PM —A quick update. Mild weather expected through Saturday. A cold front moves through Saturday night and stalls. Low pressure develops in the southeast coastal area. Track appears offshore, but several models have some moisture over-running the stalled frontal boundary with some snow possible here on Sunday.

Stay tuned.

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Update Mon @ 10:22 PM —We had the light freezing rain as predicted and the NAM-NEST along with the other models did pretty well with this forecast.

I had mentioned at the end of the previous post that a warm-up around Saturday was expected. It looks like it’s coming sooner, as soon as Wednesday.

The NBM model is predicting high temperatures to be 51º Wednesday, Thursday and Friday for Philadelphia (with Blue Bell predicted high temps about 3º lower). Average season high temperatures are around 44º. So this may finally be our January Thaw.

A question mark for Thursday, as the ECMWF shows some shower activity while the GFS keeps us dry.

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Previously Posted Sun 7:56 PM —

The week will start with coastal low pressure that is expected to move to our east Monday night. However, a weak flow ahead of the main center will result in very light freezing rain tomorrow morning, before daybreak. Total precipitation falling as freezing rain will be as little as 0.04-0.09 inches before changing to plain light spotty rain in the Philadelphia area after 9 AM or so.

This afternoon’s NAM-NEST is the most aggressive with the freezing rain amounts—

The rest of the week will continue a generally cold pattern as a broad upper air trough remains over our area—

A possible warmup around next Saturday before another cold front moves through.