Fort Collins, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

803
FXUS65 KBOU 052338
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
538 PM MDT Sat Jul 5 2025

.KEY MESSAGES...

- A chance of afternoon and evening thunderstorms and above normal
  temperatures are expected for the weekend into early next week.

- Some strong to severe storms are possible with large hail and
  damaging wind gusts across the eastern plains this weekend and
  Monday.

- Hot temperatures expected Wednesday with the upper 90s expected
  across the plains. It is possible the hot temperatures extend
  into Thursday.

&&

.DISCUSSION /Through Saturday/...
Issued at 222 PM MDT Sat Jul 5 2025

Scattered storms have formed across our CWA this afternoon and
have been sub-severe so far. Instability is modest with surface-
based CAPE values around 1,000 j/kg. Deep layer shear is rather
low with values generally around 25 knots. The main concern with
storms that form this afternoon and evening will be strong wind
gusts due to steep lapse rates and large dew point depressions in
the boundary layer. However, DCAPE values are around 1,400 j/kg
which suggests most downdrafts will be capable of gusts up to 50
mph and not necessarily severe gusts of 60 mph. We have
collaborated with SPC and we are in agreement that no Severe
Thunderstorm Watch will be needed at the time of this writing. If
a more organized MCS were to form, then a watch may be needed.

On Sunday, there is a decent chance that an outflow boundary from
overnight convection in Nebraska will keep easterly winds over
northeast Colorado for much of the morning and afternoon. This
would advect much better dew points into our area which would
lead to higher instability. In addition, the low level easterly
winds would increase deep layer shear. All factors seem to be
pointing towards Sunday having a much better severe weather threat
than Saturday with large hail and damaging wind gusts expected out
of strong storms over the I-25 corridor and eastern plains.

On Monday, conditions will be very similar to Sunday. Healthy dew
points should stay in our area across northeast Colorado. If that
is the case, another day of strong to severe storms with large
hail and damaging wind gusts will occur.

We break the pattern of daily strong to severe storms on Tuesday
as ridging strengthens aloft with more capped conditions. We will
then begin talking about heat on Wednesday as a 597dm 500 mb high
will form over our forecast area. With strong subsidence and
little cloud cover, temperatures will have the chance to get to
the upper 90s and around 100 degrees across the plains. GFS MOS
has 101 for Denver and the ECMWF ensembles have roughly half the
members at 100 or above. If these warmer solutions appear more and
more likely in the coming days, a Heat Advisory may be needed.

There is a good deal of uncertainty with Thursday`s forecast as a
trough will be quickly approaching from the west. If the trough is
quicker to move through, cooler temperatures near seasonal normals
can be expected with scattered storms. However, if the trough is
slow to move through, another very hot day with temperatures near
100 degrees across the plains is possible.

&&

.AVIATION /00Z TAFS through 00Z Monday/...
Issued at 518 PM MDT Sat Jul 5 2025

One wave of thunderstorms producing gusty winds between 40 and
45kts has moved east and away from the TAF sites. With more
storms still present upstream, have extended the PROB30 for
another hour until 1Z. The main hazard will continue to be gusty
outflow winds, though dewpoint depressions have lowered after the
previous storms, so the next round of outflows will potentially be
slightly lower in magnitude. Once storms move out, expecting winds
to have an easterly component before returning to their typical
diurnal pattern (SE to S for KDEN/KAPA, WSW TO SW for KBJC).

Tomorrow will be similar to today, with light and variable winds
in the morning as they make their way to the NE to E by early
afternoon. More convection is expected to bring gusty outflows
with VRB winds gusting between 35 to 40kts beginning between
19-21Z across all TAF sites.

&&

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

&&

$$

DISCUSSION...Danielson
AVIATION...Bonner