In Casper this morning, the weather heated up quickly. It is quite warm, breezy and mostly sunny, with a few mid-level cumulus clouds present.
The National Weather Service (NWS) in Riverton, WY, forecasts a mostly sunny and breezy day today, with a high temperature of 89-93 F and southwest winds of 15-20 mph. This evening will be mostly clear, with a low temperature of 57 F and southwest winds of 15 mph. The NWS has issued a Hazardous Weather Outlook and a Red Flag Warning concerning the Critical Fire weather over the state today ahead of an approaching cold front. Breezy, dry conditions and the possibility of a few lightning strikes make this a dangerous situation.
The visible satellite imagery and the enhanced infrared satellite imagery show no cloud cover over the state today. These images have been excluded from today’s post.
The water vapor satellite imagery shows no major moisture boundaries over the state today. This image has been excluded from today’s post.
The 12Z upper air sounding from Riverton, WY, shows a relatively dry sounding this morning, with only 0.52 inches of precipitable water present in the column. There was no Convective Available Potential Energy (CAPE) and a large thermal inversion. The 0-3 km average lapse rate was 5.8 C/km.
The deep-layer shear was 41 kts (speed shear), and the low-level shear was 20 kts (directional shear).
The surface observations (from the SPC Mesoscale Analysis Map) show the dry, sunny conditions and warm temperatures. There are no strong boundaries present over the state at this time.
The surface pressure map shows no strong pressure gradient, even though conditions are quite breezy. The RAP shows no strong pressure gradients developing over the next six hours, but perhaps some will by this evening.
Synoptically speaking, the 300 mb NAM chart (from Unisys) shows that the trough has dug farther south along the Pacific Northwest coastline, leaving Wyoming in nearly-zonal flow aloft.
The 500 mb NAM chart shows no strong vorticity advection over the state today. This chart has been excluded from today’s post.
The 700 mb NAM chart shows rapidly-rising air over the northeastern corner of the state by 0Z this evening.
The 850 mb NAM chart shows no strong thermal advection over the state today. A cold front will move through soon, but not by 0Z. This chart has been excluded from today’s post.
Overall, I expect a hot, dry, breezy day today. Tomorrow will be interesting, as the approaching cold front may drum up a storm or two. Also, there is some mid-level instability, so I will be watching the skies, even today.
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