textproduct: Grand Junction

KEY MESSAGES

- Very isolated showers/storms are possible this afternoon, favoring NE UT and along the WY/CO border. Gusty outflow winds will be the main concern with any convection.

- Red Flag Warnings remain in effect through 10PM for all fire weather zones except far NE UT for gusty winds, low humidities, and critical fuels.

- By Sunday, critical fire weather conditions will become more localized, with a return of hot and dry conditions into early next week.

DISCUSSION

Issued at 1042 AM MDT Sat Jun 20 2026

A shortwave trough continues to approach from the west today which will cause the surface pressure gradient to tighten. Winds will start increasing shortly and with dry conditions still in place, widespread critical fire weather conditions will develop this afternoon and evening. Red Flag Warnings remain in effect for almost the entire CWA. As far as winds are concerned, gusts of 25 to 35 mph will be common, occasionally higher at times. The passing wave will force the driest air to remain south of the I-70 corridor with some very meager amounts north. However, an upper level jet streak will move across the northern valleys and NE Utah and may provide enough lift and instability to allow a few showers/storms to fire along the WY/CO border. Chances are low (20 to 30%) but if any convection does fire, dry low levels will favor virga, erratic outflow winds, and some dry lightning. Isolated coverage is expected.

The trough will cause highs to drop a couple of degrees compared to yesterday but they'll still remain above normal by about 5 degrees, give or take. Similar temps are expected Sunday thanks to more northwesterly flow on the backside of the shortwave trough.

NEXT WEEK:

High pressure starts building in from the south next week keeping above normal temperatures in the forecast. Highs will generally run about 10 degrees above seasonal norms.

Towards the end of next week, models are hinting that a shortwave trough may erode the ridge, causing an uptick in moisture across the region. The end result could be some showers and storms though this being so far out, confidence is low with this solution. Stay tuned...

AVIATION /12Z TAFS THROUGH 12Z SUNDAY/

Issued at 525 AM MDT Sat Jun 20 2026

Gusty winds will be the concern today as TAF sites will see gusts of 20 to 25kts through the afternoon and early evening hours. Winds will subside around 02Z. Outside of winds, VFR conditions will remain in place for the next 24 hours.

FIRE WEATHER

Issued at 1042 AM MDT Sat Jun 20 2026

A shortwave trough is moving across the area today resulting in windier conditions in combination with single digit relative humidities. This will lead to widespread critical fire weather conditions so Red Flag Warnings will remain in effect through 10pm MDT this evening for all fire weather zones except UTZ485. Terrain based, mostly dry thunderstorms are possible this afternoon though chances are in the 20 to 30% range. Gusts will fall in the 30-40 mph range during this time, with locally higher gusts possible. Tomorrow, critical fire weather conditions will be more localized as triple digit heat returns and minimum relative humidities hang within the 10-15% range.

GJT WATCHES/WARNINGS/ADVISORIES

CO...Red Flag Warning until 10 PM MDT this evening for COZ200>203- 205-207-290>295. UT...Red Flag Warning until 10 PM MDT this evening for UTZ486-487- 490-491.