Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 240853

Area Forecast Discussion
National Weather Service Denver/Boulder CO
253 AM MDT Fri Jun 24 2022

.SHORT TERM...(Today and tonight)
Issued at 233 AM MDT Fri Jun 24 2022

There will one more warm afternoon on tap for the urban
corridor and northeast plains.  Showers and thunderstorms however
will increase from west to east, starting late this morning in the
mountain and spreading across the urban corridor and northeast
plains this afternoon and evening.  This is in response to a short
wave trough this will be passing across northern CO late this
morning into early this evening.  RAP/NAM12 forecast sounding
indicate CAPES 500-800 j/kg this afternoon, with precipitable
water values 0.50-.70 in the mountains, 0.80-1.0 inch across the
plains. Heavy rainfall threat will be offset by storm motions of
25-30 mph this afternoon, but there will still be a marginal risk
of flash floods in the burn areas. The other issue associated with
the storms will be strong outflow winds that make their way out
of the foothills and across the northeast plains this afternoon.
DCAPE values around 1000 j/kg will be sufficient enough to
generate a few strong wind gusts, possibly 45-60 mph. Showers and
thunderstorms should exit the northeast plains by late this
evening. A cold front will push southward into CO and into the
Denver area by 12z Saturday morning.

.LONG TERM...(Saturday through Thursday)
Issued at 250 AM MDT Fri Jun 24 2022

Models continue to show a cooler, cloudier and more moist weather
period for the forecast area this weekend.

There is weak to moderate west to southwesterly flow aloft for the
CWA Saturday and Sunday. There will be plenty of mid and upper
level moisture in that flow. The QG Omega fields have weak upward
vertical velocity over the CWA all weekend. In the low levels,
models show a cold front move through early Saturday with decent
upslope behind it. There is a reinforcement of cooler air on
Sunday with more upsloping.

Models continue to show the best CAPE in the mountains Saturday and
Sunday. However, the instability is not very significant.  Over the
plains there is a bit of CAPE on Saturday for the western half, with
little or no CAPE on Sunday. Moisture is pretty good, with
precipitable water values in the 0.50 to 1.00 inch range all
weekend. Will keep the pops high over the mountains and foothills
most of the weekend. For the plains, pops of 30-60%s look good
for most areas, with less over the northeast corner. Temperatures
look to be below seasonal normals both Saturday and Sunday.

For the later days, Monday through Thursday of next week, there will
be northwesterly flow aloft for Monday as upper ridging builds to
the west.  The upper ridge moves eastward and across the CWA Tuesday
into Wednesday.  It warms up and dries out those two days.  There
could be some elevated fire weather conditions over the plains both
those afternoons. At this time, models show the upper ridge to
flatten enough on Thursday to allow a cooler airmass to get into the
CWA. There is also better moisture around on Thursday. We`ll see.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 233 AM MDT Fri Jun 24 2022

Expect an increase in thunderstorm activity this afternoon
afternoon as an upper level trof and jet streak move over the
area. VFR conditions can be expected tonight. Southwest winds will
transition to northwest this afternoon. Strong outflow winds 35-45
kts may develop, strongest 21-01z. The focus should shift to the
northeast plains this evening, with north/northwest winds
developing at the terminals early this evening transitioning to
southwest by late evening. By Saturday, north/northeast winds will
develop with the passage of a cold front. ILS/MVFR clouds
restrictions will be possible after that time.


Issued at 250 AM MDT Fri Jun 24 2022

Subtropical moisture will support just a limited threat
of flash flooding for the burn areas this afternoon and early
evening. Storm motions will be to the east at 25-30 mph this
afternoon. Overall rainfall amounts should be under a quarter inch
from most storms, although an isolated stronger storm would be
capable of producing 0.25-0.50 inch in 30 minutes. The main time
frame will be between noon and 6 pm.

The increased moisture will allow for likely showers and thunderstorms
over the mountains this weekend. As a result, there will be an
increased flash flood threat over the alpine burn scars in the
afternoons and evenings of both Saturday and Sunday.




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