textproduct: Salt Lake City

KEY MESSAGES

- Critical fire weather conditions will persist across much of central and southern Utah through Wednesday. Northwestern Utah will also experience wind and low relative humidity this afternoon.

- Blowing dust is possible once again this afternoon across much of UT and southwest WY given preceding dry and gusty conditions. - Strong to severe thunderstorms may form across northern UT Tuesday afternoon. Gusty outflow winds and potentially severe hail appear to be the primary threats.

- A warming and drying trend takes hold Thursday into the weekend with high temperatures climbing above climatological averages.

DISCUSSION

Yet another day of dry, southwesterly flow is in store for today, as Utah and southwest Wyoming remain upstream of a broad trough over the western US. This may sound like a broken record at this point, but these southwesterly winds coupled with low relative humidity will result in critical fire weather conditions developing across much of the state, wherever fuels are critical. Expect wind gusts of largely 25-40 mph this afternoon and early evening (see Fire Weather section for more details).

Late tonight, a shortwave trough will swing across northern Utah, bringing a cold front, brief period of gusty northwesterly winds, and scattered showers and isolated thunderstorms entering the northwest corner after midnight. This threat of isolated thunderstorms will last into the afternoon, with daytime heating providing better instability and some more development with any storms. Despite some low- level dry air, the dry microburst threat may be more limited given lower cloud bases. However, with some shear and steeper lapse rates associated with the shortwave, there could be an elevated hail/wind threat with any stronger storms. Chances for these storms will be best along the UT-ID border. South of the aforementioned cold front, southwesterly to westerly winds will still remain elevated, primarily across central and southern Utah.

By Wednesday, flow will turn more westerly, and while winds will be lighter, there still remains critical fire weather conditions likely across portions of central/southern Utah, particularly further east. Mid- to upper-level flow will be more zonal overall through the rest of the week, though a trailing shortwave early Thursday will reinforce colder air and northerly winds across the north.

On Thursday, a secondary cold front will push through much of the area, followed by more stable conditions statewide. While the air mass will remain dry across most of the area, some moisture could be drawn up into far southern Utah this weekend as the Desert Southwest is on the far western periphery of a broad ridge across the southern CONUS. Plenty of uncertainty still remains, with a 25th-75th percentile spread of 0.50-0.85" of precipitable water in St. George on Saturday and Sunday.

REST OF UTAH AND SOUTHWEST WYOMING

VFR conditions prevail for all regional terminals under increasing mid-to-high level cloud cover. Gusty south-southwest winds with widespread gusts 25-30 kts are expected for most terminals especially across central and southern Utah through this afternoon. Winds shift out of the northwest behind a cold front late tonight into Monday morning across northern Utah. Showers along this front will bring decreasing CIGS across the northern airspace and potential for thunderstorms mainly from KSLC north early in the afternoon.

FIRE WEATHER

Gusty southwesterly winds and critical RH will persist through at least Wednesday, primarily across central and southern Utah. Gusts across western Utah will be highest today, reaching 30-40 mph across areas south of I-80. This area of highest winds will shift east by Tuesday, with the highest gusts across southern and eastern Utah. Winds are still likely to remain elevated on Wednesday across a similar area, though confidence is a bit lower depending on the location of a stalled cold front over central Utah. The Fire Weather Watch has been upgraded to a Red Flag Warning accordingly.

This cold front, crossing northern Utah late tonight then stalling, will result in a brief period of gusty northwest winds as well as the development of scattered showers and isolated thunderstorms lingering into Tuesday afternoon. Overnight RH recoveries will briefly improve Tuesday night across northern Utah.

Conditions will remain very dry after Wednesday, likely resulting in pockets of critical fire weather conditions later in the week where winds are locally stronger. A secondary cold front will push through the area on Thursday, after which more stable conditions are expected.

SLC WATCHES/WARNINGS/ADVISORIES

UT...Red Flag Warning until 10 PM MDT this evening for UTZ478.

Red Flag Warning until 10 PM MDT Tuesday for UTZ492-495-497.

Red Flag Warning until 10 PM MDT Wednesday for UTZ484-489-493- 494-496-498.

WY...None.