National Weather Service Forecast Discussion

Thornton Weather Forecast   
Today's Forecast Story   
664
FXUS65 KBOU 031200
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
600 AM MDT Fri Jul 3 2026

.KEY MESSAGES...

- Critical fire weather conditions in South Park again today.

- Isolated showers and thunderstorms possible this afternoon for
  portions of the northern plains.

- Near normal temperatures with scattered showers and storms on July
  4th. A few storms could become strong to severe.

&&

.DISCUSSION /Through Thursday/...
Issued at 548 AM MDT Fri Jul 3 2026

Another night of nocturnal convection brought a few late-night
severe storms and heavy rainfall to our northeast counties once
again. The heaviest rain was observed in locations that have seen
multiple rounds of severe weather over the past few days across
Logan and Sedgwick Counties. Between observations and radar totals
showing between 1.5 to 2.5 inches falling along I-76 in these
already saturated areas, a Flash Flood Warning was issued until 6AM
along I-76 from Sterling to Sedgwick, as additional rainfall is
expected for the next hour or so that could bring some flooding to
small creeks, streams, roads, and poor drainage and low-lying areas.

Beyond the overnight convection, the main story for today will be
hot temperatures, and critical fire weather conditions taking hold
across South Park once again, where a Red Flag Warning is in place
from 12PM to 7PM for single-digit relative humidities and winds
gusting to 25 mph. There is potential for some afternoon showers and
storms to develop, mainly for areas along the Wyoming and Nebraska
borders where the SPC has our three northeastern most counties in a
Marginal Risk, with winds and hail being the main threat. We could
also see some gusty outflows move from north to south across the
plains in the evening from storms to the north.

For the Fourth, increased low-level moisture and MLCAPE ranging from
1,000 to 2,500 J/kg+ across the plains, mixed with enough 0-6km
shear to allow for supercells to develop, we are looking at
potential for isolated to scattered strong to severe storms
developing by the afternoon, with the SPC highlighting areas along
the northern I-25 corridor eastward across the plains, where large
hail and severe winds will be the main hazards. Be prepared to
receive weather warnings if you plan to be celebrating outdoors on
Saturday afternoon and evening!

Hot temperatures and afternoon showers/storms will continue each day
through the forecast period, with at least some improvements to fire
weather conditions expected to keep critical fire weather conditions
at bay, as we see a welcomed reprieve from single-digit relative
humidity values after today.

&&

.AVIATION /12Z TAFS through 12Z Saturday/...
Issued at 548 AM MDT Fri Jul 3 2026

Winds have become light and variable this morning, with KDEN
showing easterly to southeasterly winds becoming more predominant
at this time. The webcam at KDEN is also showing smoky skies in
place that are still expected to bring slant range visibility
concerns through the morning. Still expecting a few hours of light
and VRB winds before easterly winds take hold for the afternoon
hours. While confidence is too low to include in the TAF at this
time, there is a nonzero chance that a few virga showers pass over
the TAF sites this afternoon and early evening, with the best
chances for KBJC. If this occurs, the best chances would be
between 23Z-2Z and bring gusty variable winds between 20-25 kts.


&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon today to 7 PM MDT this evening for
COZ214.

&&

$$

DISCUSSION...9
AVIATION...9

NWS BOU Office Area Forecast Discussion