Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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450
FXUS65 KBOU 302239
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
439 PM MDT Sun Apr 30 2017

.SHORT TERM...(This evening through Monday)
Issued at 342 PM MDT Sun Apr 30 3427

Clouds and strong winds are lingering over the eastern plains this
afternoon as the plains storm creeps eastward. Winds should drop
off significantly once the mixing decreases early this evening as
the low level forcing for the winds is getting out of the state.
Meanwhile a weak shortwave is bringing in moisture across the
Great Basin today. This is several hours slower than shown in the
morning model runs, but it should bring some light showers to the
mountains tonight. With the mountaintop winds still fairly strong,
the moisture should create a few inches of orographic snow on the
ridges. The moisture and instability will move across the plains
on Monday. Instability is fairly shallow, but there seem to be
enough ingredients to mention a slight chance of rain showers
over the plains in the afternoon. Winds will be lighter on Monday
as both the surface gradient and flow aloft relax.

.LONG TERM...(Monday night through Sunday)
Issued at 342 PM MDT Sun Apr 30 3427

A strong northwesterly flow aloft will be over the region Monday
night with enough moisture in the mid levels to produce some snow
showers in the mountains but with limited accumulations. If any
rain showers spread into the plains it will be primarily along the
northern border. Still some weak mid level subsidence around
through 06z Monday night, then weak ascent ahead of the next
approaching trough. The next system over the Northern Rockies 12z
Tuesday, will drop southeast into central WY by 00z Wednesday,
then into NE/KS by 12z Wednesday. Best chc of pcpn with this
system will be Tuesday aftn through Wednesday night. Mdls showing
weak qg ascent with this system with the left exit region on of a
120Kt jet max translating west to east across the cwa at this
time. Mdls not generating a lot of snowfall with this system but
some orographically favored areas could amounts in the 3-6 inch
range. Across the northeast plains, maybe some enhanced bands of
rain showers associated with the jet stream overhead. Conditions
are progged to improve by Wednesday aftn with the showers winding
down. A ridge of high pressure will bring dry and warmer
conditions to the cwa for the rest of the period. The ridge axis
is progged to move into the Great Plains by Sunday with a
southwesterly flow over CO at that time. Some mid level moisture
as well coupled with daytime heating for a chc of aftn/early
evening showers/tstms over the weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 439 PM MDT Sun Apr 30 2017

VFR through Monday. Strong north winds should decrease
significantly between 00z and 02z. Leftover snowcover over the
southwestern suburbs and Palmer Divide is limiting mixing,
resulting in lighter westerly winds over there - affecting APA
winds. Westerly to drainage winds expected overnight, with some
stronger westerlies at BJC. North-northwesterly winds expected
Monday with speeds 12 knots or less.

&&

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

$$

SHORT TERM...Gimmestad
LONG TERM...Cooper
AVIATION...Kriederman



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