Philly Winter Weather Update

A quick update. Latest GFS model just available  shows a major snowstorm possible late Friday through Saturday.   I first mentioned this possibility last Saturday.

Again, there have been several storms that were incorrectly modeled for our area this season, but this one is looking like you’ll need your snowblower working.  Still too far off in the future to be certain, but all the ingredients seem to be lining up.

I’ll update tomorrow.

Tues 8 AM update:  The snow arrives earlier, about noon on Friday.  May mix with rain in NJ before a change back to snow.  Looking increasingly likely

Philly Winter Storm Outlook

It’s been a mild and easy winter so far, and quite frankly, I’ve enjoyed the lack of snow and the mild temperatures.  (It’s a fallacy that all weather people like ‘bad weather’….maybe just those hyping it on TV.)

As mentioned, the medium and long range models haven’t been too consistent or accurate in the long term this winter, having shown a few big coastal storms for us that disappeared a few model runs later.

HOWEVER, the models (GFS and ECMWF) hare been showing for this weekend, specifically late Friday through Saturday time frame, the development of a deep coastal storm that may give us our first significant snowfall.  Unlike previous predicted storms that turned out to be modeling errors, this storm has shown consistently for the past week and there is relatively good agreeement between different models. .

The big uncertainty is the exact track, which is based on the amount of amplification of the jet stream.  A deamplification  may bring in mixed precipitation to areas– The usual north and west of I95 vs south and east scenario.  The model trends have been showing a deamplification trend after the storm, so this predicted snowstorm could easily turn into a mixed precipitation event.   Stay tuned.

Winter Weather Update

The wave expected to form Monday into Tuesday has developed earlier and is currently moving up the coast,  brushing our southern region with light snow.  The GFS still keeps this away from Philadelphia, but the modeling of this wave of low pressure has been anything but accurate.   I had mentioned that the model trends were closer to the coast, but this wave has formed earlier and much more westward.

The latest NAM has 0.07 inches water  (QPF) falling as light snow at PHL airport this afternoon.   This could be an inch of snow if it verifies.  This needs to be watched, since this wave of low pressure was not captured by the models even yesterday to hit us.

Weather… and Other Things 'Up in the Air'