'Hurricane’ Schwartz: Memorial Day weekend forecast
Weather forecasters are under pressure every day of the year. The weather on any given day may not be important to you, but it’s surely important to somebody. And that person will be mightily disappointed (to put it mildly) if we get it wrong. Weekends are generally more important.
Weather forecasters are under pressure every day of the year. Weekends are generally more important. And then there are the big holiday weekends. We want to pay special attention to them. So here goes my forecast for Memorial Day weekend.
-Friday:
Mostly sunny and windy with a high of 75.
-Saturday:
This one is a sure thing: A large area of high pressure will be centered right over the region. That means a sure bet for sunshine and next to zero chance of rain. The only real question is at the shore, how soon the sea breeze will come in to keep it cool. Here's one computer model for Saturday morning (the others are similar):
This would suggest:
Phila- sunny and cool. High 68. Chance of rain is near 0%
Shore-sunny and cool. High 68. Chance of rain near 0%
Poconos-sunny and cool. High 59. Chance of rain is near 0%
-Sunday
The high pressure area moves offshore, allowing warmer southwest winds to move in. But there's still no sign of significant moisture, so I'll be even more optimistic about sunshine. Once again, the latest computer model maps are nearly identical to yesterday's.
Phila-mostly sunny. High 78. Chance of rain 5%
Shore-mostly sunny. High 70. Chance of rain 5%
Poconos-sun & clouds. High 68. Chance of rain 10%
-Memorial Day
This is the one day we're seeing a change from the previous day's forecast. The latest map shows the rain keeping much further north, significantly lowering the chances for showers in much of the area. But the chances of showers has diminished. Memorial Day will also be the warmest day of the long weekend.
Phila- partly sunny and very warm. High 88.
Shore-mostly sunny. High 78.
Poconos-mostly cloudy. High 74.
To swim or not to swim
We can pretty much guarantee that the ocean is going to be cold on Memorial Day weekend. The only question is how cold. Here are the current water temperatures, followed by the average for this week, and then the averages for July 4 and Labor Day:
Now, a bit of background on holiday forecasts. The three biggest - Memorial Day, 4th of July, and Labor Day - all present their own challenges.
Memorial Day weekend
This is the one most likely to have bad weather for outdoor activities, such as barbecues and the beach. It's still May and average highs are only in the 70s. Record lows are in the 40s (30s in some suburbs). We have to be concerned about cold fronts coming down from Canada plus "back-door" cold fronts that come in from New England. I've seen Memorial Day weekend forecasts "bust" by more than 20 degrees.
4th of July
This holiday has the best chance to be hot and humid. The average high is 84. Back-door fronts are rare. The biggest problems: extreme heat or thunderstorms. Heat is easiest to predict. But thunderstorms can be unpredictable, sometimes putting boaters in danger. July is historically our wettest month of the year, so there's usually a chance of storms.
Labor Day
The average high is about 80. We're less likely to get extreme heat or heavy thunderstorms than on the 4th of July. But there is potentially an even bigger problem: It's normally peak hurricane season. I've seen some pretty scary close calls in this area.
Labor Day weekend typically has a warmer ocean than 4th of July. Because it takes longer for the ocean to warm than land, the warmest water temperatures come much later. A sea breeze off a 59 degree ocean is a LOT colder than one off a 72 degree ocean. That's why I liked to vacation in August or even September, rather than June or July.
Glenn "Hurricane" Schwartz
Chief Meteorologist