It is a hot and humid day today in Barclay, MD. I walked around my grandfather’s garden, and it was quite warm and muggy already this morning.
The visible satellite imagery shows mostly sunny skies across the state. There are some stratoform clouds over Western Maryland.
The infrared satellite imagery shows that the clouds over western Maryland are not thick. I have excluded this image from this post.
The water vapor satellite imagery shows a shallow shortwave trough moving through the Great Lakes area. For Maryland, this shortwave may increase the vorticity, particularly over the western part of the state.
The 12Z upper air sounding from Washington, DC, shows that there is some energy present, though it is expected to increase through the day. There was 38 J/kg of Convective Available Potential Energy (CAPE) and the forecasted surface CAPE is expected to exceed 1500 J/kg. There is a small capping inversion in place that will limit morning convection, but will likely mix through the day, especially as the shortwave trough approaches.
The shear is low again today, with only 9 kts of low-level shear and 16 kts of deep-layer shear. Any storms that form early in the morning will be poorly ventilated. However, as the shallow trough approaches, shear may increase and lead to stronger storms along the cold front.
The Storm Prediction Center (SPC) Mesoscale surface analysis map shows dewpoints in the low 70s across the state. After spending 10 years in New Mexico, it’s humid, and I am enjoying being indoors. The winds are not very strong, but the wind shift marks the frontal boundary. Also, the surface winds ahead of the front move along the front, promoting a linear storm mode versus discrete storms.
The CAPE map (based on the RAP model) shows that CAPE has increased to over 2500 J/kg just ahead of the cold front.
One interesting feature is found by overlaying the cold front and the RAP pressure model. The line of storms on radar is behind the lower pressure.
It is certainly humid enough for storms today, and given the approaching cold front along the eastern side of the shortwave trough, I expect some storms today. Most storms will quickly move to a linear mode, though an occasional storm may form ahead of the front.
Thank you for reading my forecast.
The upper air soundings and mesoscale analysis plots are from the Storm Prediction Center website.
The forecasted upper air soundings are from TwisterData.com.
The surface observation and upper level charts are from Unisys Weather.
The satellite data is from NASA – MSFC