631
FXUS65 KBOU 081728
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1128 AM MDT Mon Jul 8 2024

.KEY MESSAGES...

- Drier starting today with a prolonged warming trend kicking
  off.

- A heat wave is expected to bring temperatures into the triple
  digits across the urban corridor and plains Friday through
  Sunday. Heat related highlights will likely be needed during
  this stretch.

&&

.UPDATE...
Issued at 919 AM MDT Mon Jul 8 2024

Below discussion remains on track, with any spotty showers/storms
today likely to remain confined to Park County and areas
immediately adjacent. Elsewhere, both mid-level moisture and
instability should be insufficient for any development.

&&

.SHORT TERM /Through tonight/...
Issued at 430 AM MDT Mon Jul 8 2024

Drier and more stable air is moving into the area from the
northwest. With the drying and a little warming aloft, most of the
area should be capped or have such weak instability that we`ll
only have a few cumulus clouds. With a little more moisture
lingering over the central mountains, there`s still a chance of a
few weak showers or storms over the mountains around Park county
in the late afternoon and evening. We`ve further backed off the
PoPs and cloud cover, but left a little in that area. Forecast
temperatures near or a little above guidance look good.

&&

.LONG TERM /Tuesday through Sunday/...
Issued at 430 AM MDT Mon Jul 8 2024

Northwesterly flow aloft will continue to be over Colorado on
Tuesday. There will be a subtle shortwave within this flow which
may provide very weak QG ascent over our forecast area. At the
surface, there will be light northerly flow and the majority of
the moisture that has been in our area for a couple days will be
pushed out. Dew points will be in the 30s which will limit shower
and storm activity to the mountains and foothills. The plains
will be dry as high temperatures return to normal.

500 mb heights will rise on Wednesday as northwest winds persist.
Temperatures will warm to the low 90s across the plains as there
will continue to be limited moisture. A few isolated showers and
storms may form over the mountains and foothills but the lack of
instability across the plains will keep conditions dry there.

The dreaded summer heat wave will then be upon Thursday through
Sunday. A 500 mb ridge that is currently over California creating
all-time record high temperatures in spots will move over Utah on
Thursday. High temperatures will reach the mid to upper 90s across
the plains with plenty of sunshine. By Friday through Sunday, the
ridge will be directly situated over Colorado. Some global models
have 500 mb heights reaching above 600 dm in western Colorado.
The ECMWF ensembles have a mean 500 mb height of 5980 m on Sunday
over KDEN which equals the daily max on the SPC sounding
climatology page. The subsident flow under this ridge will keep
conditions dry and mostly sunny and 700 mb temperatures will
increase to around 22-23 C across the I-25 corridor. Those 700 mb
temperatures would equate to surface temperatures of around 100 F.
Given low to mid level winds will be from the north across the
plains, any convective cloud development will likely stay focused
on the higher terrain. This means sunshine will be maximized on
the plains. At the same time, the northerly winds are not adding a
downslope component to the flow and that aspect of the forecast
may end up keeping Denver from hitting the all-time record high of
105. Nonetheless, highs in the 100s are expected across the urban
corridor and plains Friday through Sunday. It was hard to argue
with the NBM high temperatures that were loaded into the forecast
grids so they were left as is. The high temperature forecast for
Denver is 101 on Friday and 100 on Saturday and Sunday.
Interestingly, all three of those values are the record highs for
the date. Ensemble forecasts show that a high of 103 or 104 is
well within reason in Denver. In fact, if temperatures made a run
on Sunday at the all-time high temperature of 105, it wouldn`t
surprise me. Regardless of the exact temperatures, this period
will have the potential to create significant health impacts if
the proper precautions are not taken. Staying hydrated and
avoiding strenuous activities during the middle of the day will be
important for individuals that will be outside. To our partners
in the emergency management field, now is the time to start making
preparations for opening cooling shelters. Heat related
highlights will likely be needed for the high population areas
Friday through Sunday.

&&

.AVIATION /18Z TAFS through 18Z Tuesday/...
Issued at 1127 AM MDT Mon Jul 8 2024

All terminals VFR through TAF period. Light NE winds this
afternoon will rotate CW to become SW drainage overnight.

&&

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

&&

$$

UPDATE...Rodriguez
SHORT TERM...Gimmestad
LONG TERM...Danielson
AVIATION...Rodriguez