Probabilistic Heavy Snow and Icing Discussion
NWS Weather Prediction Center College Park MD
427 AM EDT Sun Mar 17 2024

Valid 12Z Sun Mar 17 2024 - 12Z Wed Mar 20 2024

...Four Corners States...
Day 1...

Cutoff mid/upper over AZ will continue to drive precip over NM/AZ
through Monday. Confluent flow east of the low will provide
sufficient moisture, though the intensity of the precipitation is
expected to wane later today as the energy fills and gradually
weakens through Monday.

Snow levels around 6500 ft are expected with PWPF for >6" high on
the southern Sangre de Cristos on Day 1 with low values for the
White Mtns of AZ on Day 2.

Low pressure lingers over AZ probably through Tuesday, but the
moisture focus shunts farther south as the surface high reaches the
Gulf Coast late Tuesday, leading to only lighter precip over
southern NM/AZ by Monday.


...Great Lakes and New England...
Days 1-3...

Digging shortwave trough advancing through trailing an upper low
shifting east Ontario will shift over the Great Lakes today through
Monday. A surface low ahead of the trough will linger over
northern Maine today as the associated cold front sweeps across New
England this morning. The strong cold air advection in the wake of
the frontal passage and much lower heights with the trough axis
overhead will bring a period of significant LES snow to the
favored N/NW snow belts of the U.P. of Michigan where Day 1 PWPF
for >6" snow are 30-60%.

The LES focus shifts to the eastern Great Lakes late tonight as
another reinforcing shot of colder air arrives with the upper
trough axis. Transient single band activity is likely off Lake
Ontario Monday with Day 2 PWPF for >4" centered on the Tug Hill
Plateau and northern Green Mtns of VT.

A reinforcing impulse on Tuesday renews NWly LES with Day 3 PWPF of
40-70% over the Chautauqua Ridge and the Tug Hill.


The probability of receiving at least 0.1" ice is less than 10%
across the CONUS through Day 3.


Taylor/Jackson