Posted Saturday 03/01/25 @ 9:10 AM — The cold front is just entering western suburbs at 9 AM—
12zHRRR 3 hour pressure change at 9 AM along with airport TAF observations (Click on image for a larger view.)
The RTMA at 8:45 captures the wind gusts behind the front. Currently not that impressive—
RTMA at 8:45 AM Wind and wind gusts (Click on image for a larger view.)
Previously Posted Fri @ 5:17 PM — —March will “come in like a lion” tomorrow, as a strong cold front moves through the area between 8 and 10 AM. The wind meteogram below shows the wind shift associated with the frontal passage—
Today’s 18z HRRR wind forecast meteogram for Blue Bell, PA. Wind shift with the front 8-10 AM. Gusty winds early evening! (Click on image for a larger view.)
Cold high pressure builds in behind the front, as shown by the latest ECMWF-AI Single model—
Today’s 12z ECMWF-AIFS-SINGLE forecast for Saturday 7 AM. Cold high pressure builds in from Canada. (Click on image for a larger view.)
Saturday Forecast
Some clouds after sunrise, then mostly sunny and increasingly windy in the late afternoon and evening. Some models show a period of cloudiness for an hour or so during the afternoon. Highest temperatures around noon, then temperatures drop during the afternoon.
NBM high temperatures: Blue Bell, PA 55º Philadelphia, PA 58º High uncertainty (based on standard deviation): ± 2.3º
Sunday Forecast
Sunny, windy and cold. Decreasing winds by mid to late afternoon.
NBM high temperatures: Blue Bell, PA 34º Philadelphia, PA 36º Average to Low uncertainty (based on standard deviation): ± 1.3º
A simple forecast for this weekend. High pressure generally in control with moderating temperatures. A few disturbances in the upper atmosphere will pass through both Saturday and Sunday afternoons with some increased cloudiness.
Here’s the water vapor image from this afternoon—
Current satellite water vapor image with superimposed RAP model), Mean Sea Level Pressure isobars (black contours) potential vorticity (NAM and GFS) (fine violet/yellow contours) with superimposed MRMS RADAR. (Click on image for a larger view.)
Saturday Forecast
Sunny in the morning with sunshine through high level clouds in the afternoon. Still somewhat windy/breezy.
NBM high temperatures: Blue Bell, PA 40º Philadelphia, PA 41º Low uncertainty (based on standard deviation): ± 1.1º
Sunday Forecast
Similar forecast to Saturday. Sunny in the morning, sunshine through high cloudiness in the afternoon.
NBM high temperatures: Blue Bell, PA 44º Philadelphia, PA 46º Low uncertainty (based on standard deviation): ± 1.0º
The ECMWF has released a new AI model, called the AIFS -Single. I’ll be adding this to the multitude of models I use to create my forecasts in the coming days.
