Sara's Tropical Moisture Plus Cold Front Equals Heavy Rain Potential

I love what our local National Weather Service Office is doing with the threat for heavy rains overnight. They give us the MOST LIKELY scenario and the WORST CASE scenario regarding rain totals, making sure to point out the chance for the worst case is only 10%.  They show you the options and then give you THEIR opinion.  Their thinking is the heaviest will be south of Lake P. eastward to the AL/FL line.

I always tried to show you the model guidance and then tell you what did Bob think?  Let's explain the setup that MIGHT lead to some heavy rain totals.  Remember yesterday's water vapor with all the dry air over the Gulf.

The dry air has raced to the east over Florida with the surge in Tropical moisture coming up from Sara's remains.  Her surface circulation dissipated over night, but you can follow her mid-level swirl (yellow circle) over the southern Gulf.

That moisture is being drawn northward as a surface & upper low over Kansas lifts to the NE.  One thing missing from this storm is really cold air.

As I mentioned yesterday, the cold will come in waves.  The black dashed line on the satellite view is the dry line.  Note how the dew points are 20-30 degrees lower behind the front.  IF everything keeps moving, we should get into the drier air by midday Tuesday.  The change in the upper pattern will bring down colder air later this week.

The top view is today with the middle valid for Thursday and the bottom valid for Saturday. You can see how our upper winds go from the SW around to the NW, but that upper low over the Great Lakes does not dive southward.  Instead, it moves over New England keeping the cold of the cold air well to our north. Here's the radar indicating several lines of showers & T-Storms approaching.  It's the "training effect" where the lines slow down allowing storms to move along the same track.  That could lead to some street flooding.

The only Tornado Watch is to our north & west and that, if extended, should stay well to our north as the upper energy lifts away. Until the SE winds shift to the W-NW tomorrow, a Coastal Flood Advisory is in effect for minor flooding outside the levee protection system.

A Flood Watch will stay up through midday Tuesday followed by a nice cooldown.  I don't see any freezes coming for the North Shore with this front.  Let's have your FOX 8 Weather App updated and pay attention as these lines of showers pass through overnight.  I have a 9:15 AM tee time tomorrow so I'm thinking most of the rains will be gone shortly after daybreak.  We'll see.  Stay tuned!