Updated Thu 08/31 @ 5:25 PM — The strong upper level ridge (H) centered over New Mexico and Texas this afternoon will continue to expand northward and eastward through at least Monday—
Current Water Vapor Satellite Image with superimposed RAP model windstreams and 500-1000mb thickness (orange contours/orange arrows) will expand eastward and northward, giving us increasingly warm to hot weather by Sunday. (Click on image for a larger view.)
By Labor Day, the NAEFS continues to forecast extraordinarily high temperatures for the beginning of September—
NAEFS forecast high temperature for Monday, Labor Day. (Click on image for a larger view.)
Luckily, dew points won’t be too bad, probably only in the mid 60s at the hottest point in the day.
There will likely be no rain until next Thursday!
Thursday and Weekend Outlook
Updated Wed 08/30 @ 7:55 PM —Beautiful, dry and increasingly warm [hot] weather is in store for us over the next several days.
The high cirrus cloud shield noticeable today will be with us again Thursday morning, which is the outflow moisture from the remnants of Hurricane Idalia. This will move eastward and blue skies are expected Thursday afternoon.
Sunny with increasingly warmer temperatures Friday and Saturday.
A strong upper level ridge of high pressure (another ‘heat dome’) will be developing in the middle of the country and moving eastward. By Sunday, we’ll have above average temperatures approaching 90º.
By Monday, things get seriously hot—
Todays’s 12z NAEFS shows high temperatures by Monday to be more like July than September. (Click on image for a larger view.)
By Tuesday, rather extreme high temperatures for September are possible here—
NAEFS high temperature forecast for next Tuesday! (Click on image for a larger view.)
There’s not likely to be much if any rain over the next 7 days.
Updated Tue 08/29 @ 9:06 PM — A cold front will move through between 4 AM and 7 AM Wednesday morning with showers. The GFS has dialed back the rainfall considerably with this frontal passage. Skies will clear for sunshine about 10 AM.
18zHRDPS 1 hour rainfall at 6 AM Wednesday. (Click on image for a larger view.)
As for Hurricane Idalia, it seems to be speeding up yet still intensifying. Here’s the latest Hurricane HWRF model forecast at 8 AM—
18z HWRF model forecast at 8 AM Wednesday with accumulated rainfall. (Click on image for a larger view.)
Tuesday Forecast Update
Updated Tue 08/29 @ 8:34 AM — I’m updating my Tuesday forecast to be cloudy AND with a chance of a few showers in the afternoon, mostly between 2 and 6 PM. Most areas will not see showers this afternoon.
06z HRDPS forecast showing the total rainfall from showers by 6PM today. Most areas just cloudy. (Click on image for a larger view.)
The main line of showers with the cold front moves through about 4-5 AM Wednesday morning. Clearing with sunshine expected by mid to late morning on Wednesday.
Tuesday Forecast
Updated Mon 08/28 @ 8:21 PM — It looked like it might rain all day today, but the models kept us dry and such was the case.
Tuesday is looking even cloudier and more muggy than today. A few scattered showers before daybreak, but most of the day expected to be very cloudy with little to no rain. There will be a noticeable increase in humidity, some of it directly coming from the outflow of Hurricane Franklin.
An approaching cold front will bring a gradually increasing chance of showers late Tuesday afternoon. Increasing chances by 11 PM to midnight, with showers and thunderstorms expected after midnight into 4 or 5 AM. Clearing Wednesday morning.
All model forecasts keep tropical storm/Hurricane Idalia to our southeast with no direct effects. However tropical systems play havoc with model forecasts. The latest GFS suggests some lingering showers along the Jersey shore on Wednesday.
Today’s 18z GFS forecast for 12 noon Wednesday shows Hurricane Franklin and the tropical storm remnants of Hurricane Idalia. The mid level trough (blue line) will keep the storms from advancing to our area. The storm tracks will likely remain parallel to the 576 thickness line (wavy orange line) (Click on image for a larger view.)
Previously Posted Sun 7:58 PM —
A few days ago, it looked like our weather might be affected, at least indirectly, by two hurricanes. Both systems are now forecast to move far off to our east and south by Wednesday.
Latest GFS forecast (18z) showing both tropical systems at 1 PM Wednesday. (Click on image for a larger view.)
While we will escape most of the direct effects of this storms, an easterly flow will keep things cool and cloudy on Monday and the outflow moisture from Franklin in combination with an upper air trough will bring a chance of rain on Tuesday.
Updated Sun 08/27 @ 7:41 PM —It didn’t look like it would happen, but some showers have been popping up, just as several models had predicted earlier this morning, occurring a just a bit later later than forecast.
MRMS radar image at 7:35 PM. Showers are expected to slowly drift around and will dissipate later tonight. Many areas won’t see a drop of rain. (Click on image for a larger view.)MRMS radar at 7:57 PM (Click on image for a larger view.)
Sun 10:05 AM Forecast Review — There were plenty of clouds on Saturday, the result of the short wave that moved through, affecting South Jersey with some showers.
Did anyone hear the TV or radio weather people talk about the cloudiness that occurred?
Radar at 3 PM Saturday showed some localized showers in South Jersey. The wind convergence line is visible on radar as well. Not as much activity as predicted by the HRDPS, but still reasonably accurate.
Today, Sunday, the HRDPS is predicting a similar shortwave to move through, this time affecting areas closer to Philadelphia. Will it happen?
HRDPS forecast for today, Sunday, at 6:30 PM. A period of clouds and some showers. Will it happen?
Saturday Forecast Update
Updated Sat 08/26 @ 9:23 AM — Sunshine is expected by late morning. The HRDPS has been consistently predicting a mid level wave to form during the afternoon over South Jersey. Combined with low level wind convergence and high dew points, showers and some thunderstorms are expected to form between 2 PM and 6 PM this afternoon in South Jersey.
Todays’ 06z HRDPZS shows showers and thunderstorms in South Jersey this afternoon. (Click on image for a larger view.)
The NCEP models weren’t emphatic about this possibility, but the latest HRRR suggests the same.
Update
Update Fri 8/25 10:55 PM — A review of tonight’s models still suggests that Sunday will have a period of cloudiness and even some light sprinkles during the mid to late afternoon, mostly southern areas. Still a low confidence forecast regarding this possibility..
Previously Posted Fri 5:14 PM —
A cold front will move through Friday night into early Saturday. A few widely scattered showers possible tonight, but most areas will be dry. High pressure will build in for much of Saturday. A secondary cold front moves through Saturday evening.
The current water vapor image shows the weak low with the secondary cold front and the possible area of low pressure development on Sunday—
Water Vapor image with superimposed RAP model jet windstreams (white)_and 500-1000 mb contours (orange) Secondary Cold Front (blue). Disturbances will track south of us over the weekend, with some uncertainty for Sunday in southern areas of Chester County and Delaware/ South Jersey. (Click on image for a larger view.)
For Sunday, there’s been a question about low pressure developing along the coast to our south, possibly with clouds and light showers for southern areas, especially South Jersey. Latest models have begun to downplay this possibility.
Saturday
Cloudy in the morning, becoming sunny by afternoon. Very warm and still somewhat humid. Breezy.
High temperature 86º ( NBM model— location Blue Bell, PA) High temperature 89º ( NBM model— location Philadelphia, PA)
Sunday
Sunny with periods of considerable cloudiness. (There’s lower then average confidence in cloud cover forecast at this time.) More cloudiness likely in areas of southern Chester and Delaware counties as well as southern NJ.
High temperature 81º ( NBM model— location Blue Bell, PA) High temperature 84º ( NBM model— location Philadelphia, PA)
Winds
18z NBM model wind Meteogram for Blue Bell, PA. (Click on image for a larger view.)
