[su_box title=”Sunday Update ” box_color=”#defcdc” title_color=”#000000″]The forecast posted below on Friday evening remains on target. Rain will taper off and end between 2-4 PM from west to east. The cold front has already moved through about 11 AM this morning.
Temperatures for the Phillies game tonight will start near 50º and fall to near 40º by the end of the game. Winds NW 15 mph with gusts over 30. [/su_box]
[su_box title=”Saturday Morning Update ” box_color=”#defcdc” title_color=”#000000″]Forecast remains on track. High and middle clouds through the day. Winds become a bit gusty in the afternoon.
from Friday evening…
A diffuse warm front that gave us the [unpredicted] light showers today will slowly move north by Saturday afternoon. (The models didn’t pick up on this until just a few hours before the showers started.)
[su_note note_color=”#d9f2da”]Update -Tonight’s NAM shows high temperatures 73-77 degrees for Saturday. [/su_note]
For Saturday- A southeasterly flow of warm air will bring unseasonably warm temperatures, along with enough mid and high level moisture aloft to create high and mid-level cloudiness. High temperatures are forecast in the 70-73º F range for the Philadelphia area, despite this cloud cover layer which may at times be significant during the day. Winds light from the southeast in the morning, shifting to the south and increasing somewhat after the warm front passes in the early afternoon.
[A cold front approaches later on Saturday night into Sunday morning. The cold front is expected to bring showers to our area between 9 AM and 3 PM on Sunday as it moves through. It will be cloudy for much of the day, possibly clearing late in the afternoon. There is some uncertainty about the timing of the showers ending, as low pressure developing along the front may cause the light showers to linger. Total rainfall is currently expected to be less than 0.20 inches water.
High temperatures will be early in the day Sunday, before the frontal passage and will fall through the 50s during the afternoon, reaching the 40s by evening and near freezing by Monday morning.
The statistical models are still showing a high in the low to mid 70s on Saturday! However, it doesn’t look like it will be all that sunny, as the GFS is showing considerable mid and high level cloudiness for Saturday.
On Sunday, a cold front moves through during the morning. The actual front moves through about 7-9 AM accompanied by showers. There is considerable spread with how quickly (or slowly as the case appears) that showers and clouds will move out after the frontal passage.
Some of the models are showing low pressure developing along the front to our south, keeping considerable clouds in our area and maintaining the chance of showers, especially in NJ on Sunday. Temperatures drop into the 50s behind the front.
It’s a few days away and I’ll have a better handle with my regular Friday evening forecast.
[su_box title=”Forecast Update Sun AM” box_color=”#defcdc” title_color=”#000000″]The forecast from Friday remains on track. High temperature 57-59. Clouds move in during the afternoon.
Winds 5-10 mph W->WSW, increasing later in the afternoon::
HRRR forecast -Fort Washington gridpoint
[su_box title=”Forecast Update Sat AM” box_color=”#defcdc” title_color=”#000000″]Very windy, as expected, today. NBM model wind forecast for our area Saturday (in red box)
The deep low pressure system that brought us heavy rain Thursday into early Friday will move away while it deepens. A cyclonic flow of colder air will move in for Saturday.
Saturday will be mostly sunny, windy and somewhat chilly. High 48. The models don’t show any instability cloudiness, although I’m curious to see if any develops in the cyclonic flow.
Sunday will start sunny. A low pressure system approaching from the Midwest will bring some cloudiness in during the afternoon hours. High 56-58.
The low pressure system and another cold front moves through late Monday with rain. Temperatures drop later Monday night. While there was some thought that there might be some snowflakes mixing in as the precipitation ends, the models, including the FV3-GFS, don’t seem to support that scenario now.