Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 291758

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1158 AM MDT Mon May 29 2023

Issued at 938 AM MDT Mon May 29 2023

Satellite imagery showing sunny skies through out the area at
this time. Highs are still on track for the lower 80s this
afternoon. Would be the first 80 plus day for Denver since the
first half of April. Moisture is a little less than yesterday,
mainly west of I-25 and south of I-70. Only expect isolated
showers and storms this afternoon west of I-25. The 10-20 PoPs
look on track that are currently in the forecast here. Better
moisture and instability will reside over the eastern plains where
there will be more and stronger storms this afternoon and early
evening. MLCAPE looks to be 1000- 1500 J/kg, so a few of the
storms could be strong to severe. Going forecast on track with no
changes planned.


.SHORT TERM...(Today and tonight)
Issued at 358 AM MDT Mon May 29 2023

Sct showers and a few storms continue over portions of the ern
plains early this morning.  Thus activity should end in the next few
hours.  For the rest of the day, the flow aloft will be westerly
with weak southerly flow in the lower levels.  MLCAPE is fcst to be
similar to yesterday, over the plains, with values in the
1000-1500 j/kg range. Mid level flow is a bit weaker today,
however, still have enough shear for an isold svr storm or two.
Once again, best area for development will be over the Cheyenne
Ridge with activity moving mainly east across the nrn tier of
counties. Elsewhere expect isold to widely sct storms. Highs this
aftn will be warmer as readings reach the upper 70s to mid 80s
across nern CO.

For tonight, there is an axis of stronger mid level winds moving
across overnight.  Not sure if this feature, combined with nocturnal
cooling aloft and increasing low level jet, will lead to another
episode of convection over parts of the plains or not overnight.
Thus later shifts may need to add some mention of convection for
late tonight.

.LONG TERM...(Tuesday through Sunday)
Issued at 358 AM MDT Mon May 29 2023

Our region will continue underneath the ridge from the blocking
pattern through midweek. Starting Tuesday, 500mb levels remain moist
with relative humidity ranging from 60-75 percent. Weak
southwesterly flow aloft, weak shear, and lack of forcing will
hinder scattered thunderstorms development in the mountains
Tuesday afternoon. CAMs focus storm placement mainly in the
foothills where favorable conditions of MLCAPE values reach
600-700 J/kg. If these storms are able to push eastward into the
urban corridor and plains, we could see a few severe storms due to
MLCAPE values increasing near 1000 J/kg and mid-level lapse rates
near 7-8 C/km by late Tuesday afternoon. The CSU-MLP Day 2 hail
probability product highlights the far the northeastern plains
along the Kansas/Colorado border and the NAM hints at a small
narrow low level jet forming near the border as well. Keeping
these favorable conditions in mind, wouldn`t be surprised if
storms persist through midnight. PWATs remain near 0.80 inches
thus expecting these storms to produce brief heavy rainfall.

Similar conditions will also carry into Wednesday as scattered
storms are expected in the afternoon as the upper level low pushes
northeast closer to our state. By Wednesday late evening, scattered
showers and storms will likely exit the region. Afternoon highs on
Wednesday are near normal with the plains reaching the mid to upper
70s; mountains and valleys will trend near the low to mid 60s. Once
again, like clockwork, all areas will experience scattered to
numerous thunderstorms and showers Thursday afternoon. With the
upper level low arriving to our western mountains, expecting
widespread storm coverage and increasing surface winds with gusts up
to 30-35 mph. Most ensembles favor a cool and wet pattern Friday
through the weekend. Southerly flow should allow additional
moisture increasing the chances of afternoon thunderstorms
through Saturday.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1158 AM MDT Mon May 29 2023

Chance for thunderstorms this afternoon is very low. However, the
few showers and storms that form will likely produce outflow winds
which could move through the Denver airports and bring a wind
shift or two through early evening. Models show a weak wind shift
05-06Z out of the north-northwest. Winds eventually settle a
southerly direction late tonight around 09Z. For Tuesday, there
will be a better chance for thunderstorms and added a tempo into
the TAF for this.


Issued at 358 AM MDT Mon May 29 2023

There will be a limited risk of flash flooding mainly in the
Cameron Peak burn scar this afternoon. Storms will move along
rather quickly so this should limit heavier rainfall. Scattered
thunderstorms are possible Tuesday and Wednesday. These storms
will develop in the mountains each afternoon bringing a limited
threat of flooding over the burn areas. PWATs increase Wednesday
and with additional moisture arriving late this week, there is
increasing confidence in a limited flood threat continuing for
all burn areas through Thursday.




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