Category Archives: Weather Forecasts


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The weather forecast for the weekend has improved somewhat since I posted the “outlook” yesterday. Specifically, Sunday looks to be dry for most of the day.

A blocked pattern that has kept a deep ocean low pressure system to our east is now breaking down somewhat.

The ocean low will progress eastward enough to allow sunshine on Saturday before some clouds move in again later in the afternoon.  High 68-70.

It looks like clouds move in 2-4 PM on Saturday.

An upper air disturbance rotating around a system in the Midwest will spawn weak low pressure that will move into our area, now later on Sunday.  The path of the showers is now further east.

Sunday will have a mix  of sun and clouds in the morning and early afternoon.  Considerable cloudiness is expected during the mid afternoon. High 65.

High level cloudiness (cirrostratus) expected with mid and lower level clouds in the afternoon.

The showers previously forecast in yesterday’s outlook is now forecast to occur late in the day or evening and will be very light and widely scattered.  Heavier showers will develop further east and south of Philadelphia during Sunday evening.


High pressure that brought delightful weather on Friday will drift to our east, allowing a return flow of warmer and more humid air to enter our area.

Saturday will be sunny and warm.  High 85-86.  Dew points will still be in the comfortable range.

On Sunday, a weak upper air trough moves through. Temperatures will increase as will humidity, with dew points moving into the more noticeable 60s.  High temperatures near 87-88.

The weak trough may result in some cloudiness in the afternoon Sunday.  Some weak vorticity also present. The models are showing light showers far to our west, with nothing moving in to the immediate PHL area.  I’ll keep an eye on it.

A stronger front moves through Monday night.


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Sat Evening Update: Skies clear early Sunday morning, based on the latest models.

The forecast is little-changed from the forecast “outlook” I posted yesterday.

Friday’s easterly flow will shift to a southeasterly flow ahead of a warm front that attempts to move through Saturday.

Saturday will be quite cloudy; any showers are expected to hold off until Saturday evening and Saturday night.  High 76.

A weak cold front moves through late Saturday night or just before daybreak on Sunday accompanied by light showers.  The front slows as it passes through.

Most models have clearing early Sunday morning, but the latest NAM suggests that some cloudiness may linger into mid or late morning Sunday and longer at the shore.

Sunshine is expected by Sunday afternoon with high temperatures about 82.

Tropical Storm (#09) is expected to intensify off the Georgia/South Carolina coastline.   Most models have it blocked from moving north, up the coastline.  It may become a Category 1 Hurricane.

COAMPS-TC Experimental model Forecast and Track

Tropical storms seem to reduce the accuracy of the model forecasts.  We’ll see how it goes this weekend.