23ºF

Metro Detroit weather forecast: Riding the temperature roller coaster

photo


If you’re not a big fan of change, then you’ll find this forecast somewhat unsettling as we’ll bounce around from mild to cool weather and back to mild right into the upcoming weekend.

Yesterday’s cool temperatures are slowly being dislodged by a warmer air mass surging northward. As of mid-afternoon, temperatures ranged from 63 degrees (17 degrees Celsius) in Monroe to 51 degrees (10.5 degrees Celsius) in Sandusky.  To put this (and the rest of the forecast) in better perspective, today’s long-term average high is 55 degrees (13 degrees Celsius).

It’ll remain relatively mild during the first half of the night, as we’ll be in the warm wedge of air ahead of an advancing cold front – which is nothing more than the front edge of the approaching colder air mass.  Once the front passes by, 5 to 10 mph winds will shift from the south to the northwest, and temperatures will start dropping quickly…probably from the mid 50s (12 degrees Celsius) into the mid 40s (7-8 degrees Celsius) in just a few hours.  Rain showers will precede the front, and then end once the front passes by.  The rain should be gone in time for the morning rush hour, although some roads could still be damp.

Friday will start mostly cloudy as we’ll still be close to the front, but skies should become partly to mostly sunny as the day progresses.  Temperatures will only rise into the low to mid 50s (11-12 degrees Celsius) as increasing sunshine fights a losing battle against the colder air moving in.  North-northwest wind at 5 to 10 mph.

Friday’s sunrise is at 8:09 a.m., and Friday’s sunset is at 6:24 p.m.  

Increasing cloudiness Friday night, with lows in the upper 30s (4 degrees Celsius).

Mostly cloudy on Saturday with rain showers possible (best chance is in the afternoon).  An approaching upper level disturbance still isn’t being handled necessarily well by the computer models, which is not surprising since the disturbance is still well out in the data-poor Pacific Ocean.  Once it crosses the west coast and can be studied by our continental weather balloon network, the models should get a much better handle on it.  Highs in the low to mid 50s (11-12 degrees Celsius).

Rain showers may diminish late Saturday night, with steady temperatures in the low to mid 50s (11-12 degrees Celsius) as another surge of warm air overspreads the area.

Showers redevelop on Sunday, with highs in the low to mid 60s (17-18 degrees Celsius).

Showers and possibly some thunderstorms are possible Sunday night ahead of the next cold front. There has been some talk nationally about severe storm chances Sunday night and, with a strong cold front barreling into a relatively warmer, moist air mass, one does have to examine this scenario more closely.  However, there are some big things working against severe possibilities. To keep this simple, in the summer when the air is hotter and more humid, it’s lighter and, thus, easier to lift. The more violently we get those updrafts to rise, the better our chances for severe storms…so lighter air is better. Think about it this way: if I gave you a pillow to carry up a set of stairs, you get up there much quicker than if you were carrying a one hundred pound weight. By late fall, the air is much cooler than in the summer, so it’s heavier and, thus, not as easy to get that violent upward motion started. That’s why we need what are called dynamics to mechanically help force that air aloft.  While the cold front is a nice trigger to get that process started, it’s important to remember that we need to sustain those updrafts so the developing storms get taller.  In the case of thisSunday night, a chunk of stronger jet stream winds will cross the Upper Peninsula. We meteorologists watch these carefully, because the left front and right rear quadrants of these jet streaks are areas where the associated dynamics enhance lift.  But with that jet streak so far north, we’ll be rather far from the supporting dynamics. Without this dynamical forcing, it’s tougher to get severe storms…especially with them crossing our area in the middle of the night, when it’s cooler than the afternoon highs. So, we’ll watch the scenario carefully and update you if there are any changes but, at this point, our concern is much lower here than it is for areas to our south and west (western Ohio, Indiana, and Illinois).

Once the Sunday night cold front moves through, temperatures head back to highs in the mid to upper 40s (7-9 degrees Celsius) for most of the coming week.  Although there are some uncertainties in the long range computer models, it appears that most of the week will be dry.


About the Author: