Yesterday was mostly sunny, warm and pleasant. I did some walking south of Moab, and did not need a jacket, though I was happy for it after sundown.
This morning in Moab, it has been sunny, cold and still.
National Weather Service (NWS) in Grand Junction, CO, forecasts (for Moab) a sunny day, with a high temperature of 58 F. The winds will be from the northwest at 5-10 mph. This evening will be clear, with a low temperature of 30 F. Winds will be from the north at 5-10 mph, becoming light and variable after midnight.
The NWS in Salt Lake City, UT, forecasts (for Salt Lake City) a mostly sunny day, with a 30% chance of snow in the morning, but then a high temperature of 50 F. The winds will be from the northwest at 5-7 mph. This evening will be clear, with a low temperature of 35 F. Winds will be from the northwest at 5-8 mph, becoming east southeast after midnight.
The NWS in Salt Lake City, UT, forecasts (for St. George) a sunny day, with a high temperature of 73 F. The winds will be from the north northeast at 5-7 mph in the afternoon. This evening will be clear, with a low temperature of 39 F. Winds will be from the north northeast at 6-11 mph, increasing to 15-20 mph after midnight.
The NWS in Grand Junction has issued a Freeze Warning for a few areas in southeastern Utah, including Moab for this evening and into tomorrow morning, as shown on the Watches and Warnings graphic below:
The visible satellite imagery shows no clouds over the state so far this morning. This image has been excluded from today’s post.
The infrared satellite imagery shows no thick clouds over the state this morning. This image has been excluded from today’s post.
The water vapor imagery shows dry air over most of the state today.
The 12Z sounding from Salt Lake City shows a nearly saturated atmosphere below 500 mb. There was 0.35 inches of precipitable water present in the column this morning. There was 4 J/kg of Convective Available Potential Energy (CAPE) and -12 J/kg of Convective Inhibition (CINH) present. There was no thermal inversions near the surface, and the 0-3 km average lapse rate was 7.4 C/km.
The hodograph shows that there was 15 kt of low-level shear (mostly due to directional changes) and 103 kts of deep-layer shear (mostly due to speed changes).
The surface observations (from the SPC Mesoscale Analysis Map) show cold temperatures and low humidity, (based on the surface dewpoint depressions). The winds are light, and the skies are clear over most of the state.
The surface pressure chart shows a strong high pressure system over the northwestern part of the state this morning. Ahead of it is a sharp pressure gradient that will increase throughout the day, according to the RAP. While the winds will not increase much, the pressure gradient is marking the edge of a strong c0ld front.
Synoptically speaking, the 300 mb NAM chart (from Unisys) shows strong northwesterly to zonal flow as the trough moves east towards the Great Plains.
The 500 mb NAM chart shows strong Positive Vorticity Advection (PVA) into the western part of the state by 00 Z.
The 700 mb NAM chart is unavailable at this time.
The 850 mb NAM chart shows strong Cold Air Advection (CAA) moving into the southern part of the state as this cold front pushes south.
The Precipitation chart shows very little chance of precipitation over the state today. This chart has been excluded from today’s post.
Today is already much cooler than yesterday, and will remain so throughout the day. This evening will be unpleasantly cold, and I am not looking forward to taking a shower tomorrow morning in the bathhouse.
Thank you for reading my post.
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 College of DuPage – SATRAD