Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS65 KBOU 220239

Area Forecast Discussion
National Weather Service Denver/Boulder CO
839 PM MDT Mon May 21 2018

Issued at 832 PM MDT Mon May 21 2018

At this time pockets of instability and increased moisture have
helped to intensify storms over the eastern plains. Currently, a
severe storm will continue to move North over the next half hour
before it exits into Wyoming. There is a small chance that other
storms could form over this area and intensify over the next few
hours. Conditions will stabilize overnight bringing an end to


.SHORT TERM...(This evening through Tuesday)
Issued at 314 PM MDT Mon May 21 2018

Isolated to scattered afternoon thunderstorm activity over the
mountains is expected to come to an end through the evening with
the loss of daytime heating. Clearing skies will then occur
overnight. Tomorrow should be a repeat of today as the moist
southwest flow aloft continues. An embedded short wave should be
enough to produce another round of thunderstorms through the
afternoon. Once again, most of the activity should be over the
higher terrain. A surface low pressure area over eastern Colorado
tomorrow will produce a bit of a Denver Cyclone over the urban
corridor that will help to keep moisture pooled against the
foothills. Forecast CAPE values further east on the plains
indicate only weak instability, so only isolated probability of
precipitation forecasts will result. With only marginal
instability, strong to severe thunderstorms are not expected.

.LONG TERM...(Tuesday night through Monday)
Issued at 314 PM MDT Mon May 21 2018

...Summer-like weather expected much of this upcoming week...

Weak short wave and associated showers and thunderstorms are
expected to push off to the northeast Tuesday evening. Drier air
works in overnight with gradual clearing expected. Very warm and
drier southwest flow Wednesday will bring warmer temperatures and
probably less thunderstorm coverage by then. The northeastern
plains could still see a couple stronger storms in the afternoon
with better low level moisture holding in place with southeast
winds. CAPE could reach 1500-2000 J/kg, and bulk shear of 30-40
knots would be sufficient for a severe storm threat. However, the
warmer air aloft and lack of short wave will likely keep any storm
coverage limited.

On Thursday and Friday, the flow aloft will turn more westerly and
weaken with flat upper level ridging expected. As a result, we
should see a continuation of warm temperatures but less
thunderstorm coverage. High temperatures should push well into the
mid to upper 80s across the plains.

By Saturday, the upper level ridge will likely amplify over the
state as the next upper level low drops into California. Expect
another very warm and mostly dry day with such sharp upper level
ridging. Would not be surprised if Denver reaches 90F at some
point in the Thursday through Saturday period.

The next upper low is advertised by most medium range models to
open up and lift northeast across the Central Rockies late Sunday
into Monday. Confidence decreases in the timing here, so we`ll go
with a slight chance of thunderstorms and offer a few degrees of
cooling by next Monday.


.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 832 PM MDT Mon May 21 2018

VFR conditions are expected for the period. Winds will decrease
and turn to drainage with speeds from 5 to 10 kts. By tomorrow
morning winds will shift to the SE with some gusting in the
afternoon around 22 to 25 kts.




SHORT TERM...Dankers
LONG TERM...Barjenbruch
AVIATION...Bowen is the U.S. government's official web portal to all federal, state and local government web resources and services.