Some ominous stratocumulus clouds are streaming rapidly from the WSW to ENE across the Wasatch Front this morning, with breezy winds at the surface. A few dusty raindrops out there earlier as well. It feels like something weatherwise will be happening today...
 |
| GOES-19 East True Color imagery - Focused over northern Utah ~1400-1500 MDT 4/22/2026 |
Overnight, conditions were a bit turbulent, with periods of gusty winds and some light blowing dust observed at air monitoring stations. Winds had been southerly through part of the night but shifted out of the WNW over the northern SL Valley during the pre-dawn hours, indicating a potential boundary or front moved over. Coincidentally, temperatures dropped from the mid 60s to mid 50s at KSLC with the WNW wind shift (~0330 MDT).
 |
| KSLC surface observations ~0300-0400 MDT 4/22/2026. Wind shift from WSW to WNW near 0330 MDT, with a 7 degree F drop in temperature. |
So... it looks like we had a cold front move into the SL Valley this morning. Currently, the surface frontal boundary looks to be draped halfway south down the valley (figure below), but often affects from terrain can make identifying the precise location of a surface front difficult. The actual front may be somewhere further east than indicated here.
 |
| Surface observations across the SL Valley 4/22/2026. Blue dashed line represents the approximate location of the cold frontal boundary. |
The Forecast Funnel
Now zooming out and looking at all available information, let's determine what's going on. We will start by taking a quick look at what the upper-level pattern looks like on a hemispheric scale. The chart below shows a number of squiggles (troughs and ridges) in the 300 mb pattern. These squiggles are called Rossby Waves and provide information on the large scale atmospheric pattern and how it can potentially evolve. The more large scale squiggles (> ~3000 km in wavelength) the faster the progression of the 300 mb pattern. From the chart below, the current number of Rossby Waves (wave number) looks to be around 3-4, which is a low wavenumber and means the atmospheric waves likely will move more slowly. The next piece of information we can gather is that there is a large scale closed trough located along the western seaboard of the U.S.
Next we move down the level of non-divergence (500 mb). The 500 mb analysis (heights, winds, and temperature) and satellite imagery below reveals a broad longwave trough slowly progressing east across the western U.S. The 500 mb analysis indicates a cold pocket of air and jet streak - area of increased wind speed (blues) - working its way over Utah. Both of these features are important for creating active weather, with the colder upper-level temperatures creating steep lapse rates/unstable conditions and the jet streak aiding in dynamic lift.
 |
| SPC 1500 Z 500 mb heights, temperature, and wind analysis 4/22/2026 |
 |
| GOES-19 East True Color imagery, with 500 mb heights, winds, and vorticity overlaid 4/22/2026 |
Progressing down the atmospheric column and zooming into Utah a bit, we next check out the 700 mb analysis (heights, winds, temps, and RH). The 700 mb analysis is considered in the mid-levels of the atmosphere and can provide a lot of information on what the winds, temperatures, and precipitation will do at the surface. In the 700 mb analysis chart below, a trough (axis-thick dashed blue) associated with cooler air (thin-dashed blue lines) and moisture (green fill) is moving into northern Utah. Winds are also identified as out of the W at 15-30 kts.
 |
| SPC 1500 Z 700 mb heights, temperature, wind, and RH analysis 4/22/2026 |
Finally, moving down to the surface once again, we look at the surface analysis (MSLP, temp, and wind). I zoom out a bit more from Utah to reveal the complete picture of the surface pressure pattern. In the figure below, the surface low and surface high are identified. Utah sits somewhere right in the middle of these two features, with a westerly surface winds and relatively tight pressure gradient noted over the state. Regions of tight pressure gradients can indicate areas of increased wind speeds.
 |
| SPC 1500 Z surface MSLP and wind analysis 4/22/2026 |
Now that we have developed an understanding of the current state of the atmosphere over Utah, we can move on to determining how the current conditions will evolve through the day and beyond. This is where numerical weather models come into play. The below figure shows the ECMWF 00Z model products across the western U.S. today through tomorrow (4/22-4/23/2026).
 |
| ECMWF 00Z 4/22/2026 four-panel forecast 4/22-4/23/2026: (Top left to bottom right) MSLP, 1000-500 mb thickness, and precipitation type; 300 mb gph and winds; 700 mb gph, RH, temp, and winds |
In short, the progression of the model shows the trough moving over Utah today through tomorrow, with a few embedded shortwave troughs (pieces of energy) impacting the state with cooler and wet weather. The first shortwave trough will bring cooler air and periods of scattered valley rain and high mountain snow showers and maybe a thunderstorm today (4/22/2026). By early Thursday, a trailing shortwave trough will move through, bringing an additional shot of colder air and a period of light valley rain/snow and mountain snow showers. Conditions look to dry out by late Thursday, but it doesn't look like either today or tomorrow to be a washout.
Going Forward
Conditions moderate some going into the weekend, with the warmest day slated on Saturday (highs near 60 F for the northern Utah Valleys). The second half of the weekend into early next workweek looks to turn cooler and wetter once again as multiple troughs merge and slowly spin across the western and central U.S. Best opportunity for precipitation is currently forecasted for Sunday into Monday. As seen from the ensemble ECMWF output below (precip anomaly and temperature anomaly), prepare for a slightly cooler and wetter than normal period over the next 5-7 days. Not expecting significant precipitation of deluges, but there looks to be plenty of opportunities for intervals of showers across the state.
 |
| ECMWF Ens 00 Z 4/22/2026 - Left: 7-day precipitation anomaly (in); Right: temperature anomaly (F) |
Rubbing the crystal ball a little more, we can peer into the long-range forecast, which alludes to additional active cool and wet periods going into early May. This loose forecast has the high likelihood of changing, but it is the pattern the ensemble models have been hinting at for the past few days. We will see...
 |
| ECMWF Ens 00Z 4/22/2026 - Total Precipitation Plume (in) for KSLC 4/22-5/06/2026 |
No comments:
Post a Comment