Monthly Archives: February 2019

Winter Weather

Winter Weather Update

It’s interesting how much model predictions can change. The Sunday system had been predicted to be a weak, disorganized low with light rain, possibly mixed with snow on the onset.

Tonight’s model runs continue with today’s trend of a more developed low with increased QPF. The NAM predicted QPF has gone from 0.15 inches water yesterday to 0.76 inches water tonight. Some dynamic cooling will allow areas north and west of the city to have some sleet and perhaps freezing rain before changing to all rain. The GFS is somewhat warmer and has some sleet even further north and west, also changing to rain. GFS QPF is about 0.50, also greatly increased from the day before.

Clouds move in mid to late afternoon. The mixed precip starts between 7 and 9 Sunday evening and the rain ends about daybreak Monday and clouds linger.

Winter Weather

WINTER WEATHER UPDATE

This morning and this afternoon’s NAM has the Sunday night precipitation coming in later in the evening–  about 9 PM.  Temperatures just north of the city will be near freezing and temperatures of the lower critical levels of the atmosphere are coming in below freezing.

Sleet and Freezing rain graphic
Areas of Sleet and Freezing rain 7-10 PM Sunday

Middle levels of the atmosphere are too warm for snow, but freezing rain and sleet is possible before a changeover to all rain later Sunday night.   Stay tuned.

Philadelphia Area Weather Forecasts

WEEKEND WEATHER FORECAST – EARLY EDITION

[su_box title=”Saturday Weather Update ” box_color=”#defcdc” title_color=”#000000″]No major change in the forecast. Sunday will be mostly sunny until the late afternoon. Rain Sunday evening will be light. Some flakes may mix in at the start in north of Trenton, but all rain otherwise.

Watching a more interesting system for Wednesday, with snow likely mixing and changing to freezing rain/sleet, then rain. Some snow accumulation likely Wednesday morning. Stay tuned. [/su_box]

[su_box title=”Weekend Weather Update ” box_color=”#defcdc” title_color=”#000000″]Saturday will be sunny and chilly. (Cancel the windy conditions.) High temperatures 42-43.

Sunday now looks to have some cloudiness in the morning, then sunny until later in the afternoon, when clouds move in. High 40. Rain, possibly starting with a few flakes of snow, in the evening/night (GFS).

There are differences between the NAM and GFS regarding QPF, but when it rains, nobody really cares if we get 0.10inches of rain or 0.30 inches. [/su_box]

Details from earlier today…

Let me preface this by noting that today was supposed to be cloudy. The models didn’t do too well yesterday.  Let’s see how they do for the weekend.

A frontal system will move through early evening tonight. Only some cloudiness and a low chance of a sprinkle will accompany the front.

Colder air moves in for Saturday. It will be mostly sunny and windy. High 41.

On Sunday, a weak and poorly organized low pressure system moves in later in the day. Sunday starts with some sun, but expect clouds to move in during the late morning.    There are some timing differences with the models with the NAM having some light precip in the afternoon, while the GFS is later, into the evening.

Both the GFS and NAM are similar with QPF values of about 0.12 inches water.   The precipitation will likely fall as rain or possibly rain mixed with snow, as high temperatures are expected to be about 39 and critical temperatures in the upper atmosphere are borderline too warm for snow.

There are enough model differences with this system, that I expect the forecast to change.  Stay tuned.