“Clipper” storms originate in Canada and sweep southeastward across the United at high speeds. The storms are generally moisture-starved and often weaken or dissipate when they cross the Appalachian Mountains. Washington, D.C. usually gets light precipitation or nothing at all from these storm systems. Occasionally, the storms will intensify and tap moisture from the Atlantic Ocean, but that does not happen often.
Sunday’s clipper, a Manitoba Mauler, did not tap any Atlantic moisture. The storm dissipated at an astonishing rate as it crossed over the mountains. Its clouds and precipitation vanished in a matter of hours. (Note, there are three different types of Canadian clipper lows: Alberta Clippers, Saskatchewan Screams, and Manitoba Maulers. The name is based on the province in Canada where the storm originates.)
When I left my house pre-dawn, about 6:15 a.m., the sky was mostly overcast. I feared my sunrise shoot would be a bust because of too many clouds. When I arrived in Washington, I found the skies to the east of Washington were mostly clear. The cloud banks remained to the north and west of town.
As the clouds moved east, they seemed to vanish. They seemed to just evaporate overhead. None of the clouds made it to the eastern horizon. I have included the satellite and radar maps above to show the huge dry slot associated with the storm.
What happened with Sunday’s clipper is that it moved to the north of Washington and the westerly, down-sloping winds rapidly dried out the atmosphere. I ended up shooting a perfectly clear sunrise in the middle of the storm’s dry slot. The clear skies, however, gave me the opportunity to shoot the sunrise reflected upon the polished black granite of the Vietnam Veteran’s Memorial. That wasn’t the original plan, but it was a good backup.
Clippers that move to the south of Washington give us the best chance for snow. If the clippers intensify near the coast, they can pull in moisture from the Atlantic Ocean and produce accumulating snow in the area. Most clippers, however, produce a dusting of snow or nothing at all, like with Sunday’s clipper.
Tomorrow’s clipper should move to the south of Washington and should produce widespread, accumulating snow. It is expected to tap the Atlantic for moisture. Most of us love an over-achieving clipper storm. It will still move fast and will not turn into a nor’easter.
Note: My 16 year-old son, Michael, joined me on the photo shoot. He is currently learning photography and one of his photos is included below.