Category Archives: Weather Outlook


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Wednesday Evening Update
Tonight’s NAM has joined the GFS in predicting rain for much of Saturday and Saturday night. The GFS continues with some showers continuing on Sunday.
The still unofficial FV3-GFS is more optimistic for Saturday evening and Sunday, as it keeps this precipitation to our south. Too early to tell.

The [relative] warm-up mentioned in my posting last week is on track to arrive late Friday.   Unfortunately, the milder temperatures will be accompanied by low pressure and rain.

The low pressure system arriving late Friday will be interacting with a cut-off air upper low in the southeast.  Much of the heavier rain will be Friday night and it may taper on Saturday.

There’s much uncertainty with the specifics and timing of this rain, because interactions with upper closed lows are difficult to model.

There’s some suggestion that the upper low may spawn another low pressure system for part of Sunday.  Too soon to tell.

Milder temperatures will persist into next week, with a bit of a roller coaster effect as cold air dips in several times.  It will be milder, then a day or so of cold, then milder again.

Real changes back to winter are forecast to occur around Christmas Eve with a large storm and deep cold returning.    


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The coming weekend is going to be unseasonably cold and dry. The coastal storm’s track has consistently been forecast to pass south of the Philadelphia area late Sunday into Monday.

Despite my winter long range climate forecast for a cold winter in Philadelphia posted last weekend, the latest climate models show the balance of December to be somewhat milder than average. This change is predicted to occur later next week. We’ll see if this happens.  



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Weekend Outlook Update Thursday 7 PM
Weekend Update – Like last weekend, it appears that the rain will arrive sometime mid to late Saturday afternoon. High near 49. Heavy rain Saturday night.

Rain ends during the [late] morning on Sunday. High temperatures about 63 Sunday, but some statistical models are suggesting 67! Updates Friday evening.

The overall weather pattern for Philadelphia over the next two weeks is for below average temperatures (average high about 49) with at least one 3 day warmup occurring over the coming weekend.

Low pressure will bring a southwesterly flow of mild air for Saturday and especially Sunday.  The statistical EKDMOS has a high of 60 for Sunday while the NBM shows a high of 58!

Unfortunately, there’s a high probability of rain for Saturday, but Sunday afternoon may be dry. Too soon to be sure. Stay tuned.


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Let me answer the title question up front – I don’t think so.

All models keep the critical thickness levels too warm for snow formation here on Thursday morning.  What we may have is a brief period of sleet or freezing rain before changing to rain early and even that is in doubt.

Basically, there may be some ‘cold air damming’ which results in a cold lower layer, allowing sleet and icy conditions before a change over to rain.

We really won’t have a good handle on the thermal profiles for Thursday until Wednesday night.   But I felt I had to chime in, after hearing a hyped up forecast from the local TV weather people.

As mentioned, the models have been highly inconsistent over the past week.  If there’s any chance of more interesting weather, it might be with the departure of this system late Thursday or Friday morning.  Stay tuned.