637
FXUS65 KBOU 041207
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
607 AM MDT Sat Jul 4 2026

.KEY MESSAGES...

- Considerable improvements to fire weather conditions today, but
  dry thunderstorms will be possible for the higher elevations
  that will keep elevated concerns in place today.

- Scattered strong to severe storms expected this afternoon and
  evening, with large hail and gusty winds the main hazards.

- A few storms expected each day of the coming week, with the
  highest probabilities shaping up for Tuesday and Wednesday from
  the Front Range eastward.

&&

.DISCUSSION /Through Friday/...
Issued at 143 AM MDT Sat Jul 4 2026

Another night of nocturnal convection has brought heavy rainfall
and flash flooding to areas across the eastern plains, once
again. Areas of southeastern Washington County and northeastern
Lincoln County received up to 5 inches of rainfall as very slow
moving storms passed over. Storms have now moved out of the area
and the Severe Thunderstorm Watch has been cancelled. All flash
flood concerns have now diminished and all warnings have been
allowed to expire.

Today will bring another threat of severe weather across much of
the forecast area, where the SPC has a Slight Risk (2/5 threat
level) for all areas along and east of I-25, and a Marginal Risk
(1/5 threat level) for the Front Range Foothills. Tonight`s
nocturnal storms have done a good job of keeping low level
moisture in place, with dewpoints remaining in the mid to upper
50s all the way west to the I-25 corridor as of 330AM. With
temperatures expected to warm efficiently through the morning, and
MLCAPE increasing to upwards of 2,000 J/kg through the afternoon
mixed with enough 0-6km bulk shear for supercell formation, storms
will likely develop along the foothills by 2PM, and move eastward
across the plains through 9PM. While strong to severe storms will
be possible along the I-25 corridor, it looks like the more robust
environment will be farther east on the plains where the better
moisture is anticipated to coincide with the higher MLCAPE values.
Expect hail up to two inches in diameter and winds around 60 mph
with the stronger storms. With the better moisture expected across
the plains, there will be an elevated threat for dry lightning
across the higher elevations today that will keep elevated fire
weather concerns in place in these areas, but fire weather
concerns for low relative humidity and gusty winds will see
significant improvements.

Ridging is expected to start rebuilding over the Rockies on Sunday
that will warm temperatures up by a few degrees over today`s
upper 80s to low 90s. Winds are expected to be lighter under the
ridging for at least the first half of the week while 500mb winds
are fairly laxed. This will keep critical fire weather concerns
minimal, with only localized elevated conditions expected through
midweek. Temperatures are expected to reach the 90s across the
plains each day this week, with potential to see temperatures
climb into the triple digits by next weekend.

Afternoon convection will be possible on Sunday and Monday, with
only light precipitation expected, mainly for areas along the
Palmer Divide. By Tuesday, ensembles show an increase in PWAT
values that will bring a return to scattered to numerous
afternoon showers. 500 mb flow starts to increase again on
Wednesday that will increase bulk shear to around 25 to 35kts,
allowing for potential of a few stronger to severe storms
developing in the afternoon. It will also bring increased fire
weather concerns back to the higher elevations by the second half
of the week.

&&

.AVIATION /12Z TAFS through 12Z Sunday/...
Issued at 546 AM MDT Sat Jul 4 2026

Southerly winds have settled in at KDEN/KAPA early this morning,
with light and VRB winds in place at KBJC. Expecting one of two
scenarios to play out through the morning, with the first having
slightly more confidence in therefore it is in the current TAF.
1. Southerly winds will increase by 14Z at KDEN/KAPA before
turning to the east via a southeasterly route through the morning.
2. Light and variable winds develop across all TAF sites before
becoming easterly by the early afternoon.

Convection will still be the main concern for today, with PROB30s
still in place beginning by 20Z for KAPA/KBJC and 21Z for KDEN.
Variable winds gusting between 35 to 40 kts will be possible,
with about a 15% chance a stronger to severe storm passes across
the TAF sites as all are in a Slight Risk for severe weather
today. If this occurs, one to two inch hail and wind gusts to 60
mph will be possible, though the more robust storms are expected
east of the TAF sites.

Expecting winds to eventually turn to drainage for the overnight,
but there could be a delay as outflows may keep winds more NE to
E depending on where storms end up forming.

While smoke is not currently impacting vis at the airports this
morning, guidance continues to show its potential to increase
through the day today that could be a nuisance to slant range vis,
so will continue to keep FU in the TAF while numerous fires
continue to burn across the region.


&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...9
AVIATION...9

NWS BOU Office Area Forecast Discussion