Weekend of weather extremes across the country

A weekend of weather extremes is setting up across the country this weekend. Record cold temperatures are possible across the eastern-half of the country. Heavy snow is possible for parts of the Northeast. Heavy rain & flash flooding may occur in Florida. And, abnormally hot temperatures will impact the West.

Eastern Cold

A late-season weather pattern will help send a cold airmass into the eastern-half of the country as the jet stream takes an equatorial dive. This will send abnormally cold temperatures to locations east of the Mississippi River; temperatures will be 15-30 degrees below average in some areas. Morning temperatures in the 30s are possible for areas as far south as northern Mississippi, northern Alabama, northern Georgia and Upstate South Carolina. Make sure you protect the sensitive vegetation and bring the pets inside.

Fig. 1: Saturday morning temperature anomalies

Fig. 2: Sunday morning temperature anomalies

Fig. 3: Saturday morning low temperatures

Fig. 4: Sunday morning low temperatures

Northeast Snow

As the cold airmass advances east, a surface-low will ride northeast along the East Coast. This low is expected to rapidly deepen from late-Friday through Saturday, which will set the stage for a wet snow across parts of the Northeast from late-Friday into Saturday. Some of the snow may be heavy in the higher elevations where 4-8″ may fall. There is the possibility for areas of lake-effect snow on Saturday off of the eastern-shores of Lake Huron, Lake Eerie and Lake Ontario. This is very late in the season for lake-effect snow. This will be a heavy wet snow so be alert for falling branches.

Fig. 5: Snow forecast

Florida Heavy Rain & Flooding

The same cold front will advance into Florida over the weekend and begin to stall. This will help increase shower & thunderstorm activity across the state. Some of the rain may be heavy at times due to the lift from the frontal boundary. A second area of moisture will work into the state from late-weekend into early next week thanks to a tropical disturbance. A tropical disturbance is expected to develop over the western Gulf of Mexico late-Friday/early-Saturday and work its way east. This disturbance should not become the first Tropical Depression of the season but this will continue to be monitored. Regardless, it will pump in heavy rain into the state; the heaviest rain will fall from central Florida, south. 3-7″ of rain will fall across southern Florida and the Keys. Remember, if you come across a road that is covered in water, turn around.

Fig. 6: Rain forecast

West Hot Temperatures

While the eastern-half of the country will deal with the cold temperatures, the West will experience an early-season heat wave. The hot temperatures will be caused by a potent upper-level ridge. This will allow temperatures to soar into the triple-digits across the Desert Southwest from Friday through the weekend. The hot temperatures will creep north over the weekend, even allowing the Pacific Northwest to see anomalously warm temperatures. A few 90s cannot be rule out as far north as Washington over the weekend. Temperatures will be a good 15-30 degrees above average. Make sure you stay hydrated and exercise caution outdoors. Do not leave the pets outside in the heat and do not leave pets or kids in vehicles.

Fig. 7: Upper-level ridge builds

Fig. 8: Friday afternoon temperature anomalies

Fig. 9: Saturday afternoon temperature anomalies

Fig. 10: Sunday afternoon temperature anomalies