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Area Forecast Discussion (AFD)

Issued by Denver/Boulder, CO (BOU)

FXUS65 KBOU 252047

Area Forecast Discussion
National Weather Service Denver/Boulder CO
247 PM MDT Fri May 25 2018

.SHORT TERM...(This evening through Saturday)
Issued at 245 PM MDT Fri May 25 2018

There is limited convective cloudiness over the CWA this
afternoon. There are a couple radar echoes over the far northeast
corner right now. Winds are pretty much adhering to  normal 
diurnal trends, and a bit weaker in speed than normal. Models keep
an upper ridge over the CWA overnight and Saturday. ls 18Z 
Saturday the axis pushes east out of Colorado. Weak westerly flow 
aloft tonight gives was to slighting increasing southwesterly flow
aloft by 00Z Saturday afternoon late. There is benign synoptic 
scale energy over the forecast area tonight and Saturday morning. 
Weak upward vertical velocity moves in Saturday afternoon. The 
boundary layer winds should follow normal patterns tonight and 
Saturday. For moisture is is dry overnight and much of Saturday, 
with a bit of upper level cloudiness increasing from the west 
Saturday afternoon. There is no measurable precipitation for the 
CWA on the QPF fields tonight or Saturday. For pops, will put some
"isolated"s over Zones 50 and 51. For temperatures, Saturday 
highs will be 1-3 C warmer than today's highs. We could get close 
to setting some record high readings for the date.

.LONG TERM...(Saturday night through Friday)
Issued at 245 PM MDT Fri May 25 2018

Saturday night and Sunday, a dry southerly flow aloft will
increase over CO as the ridge axis shifts into the Great Plains. A
closed low centered over eastern NV/western UT at 12z Sunday, will
slowly shift eastward inot central UT by 00z Sunday. No relief
from the heat on Sunday with another day in the low 90s for
Denver. 700 mb temperatures 16-18C Sunday afternoon. Fire danger
will be elevated mainly over South Park and the southern Front
Range Foothills. Too dry aloft over the mountains on Sunday for
more than isolated tstms in the afternoon and evening. Some
potential over the northeast plains, with surface based computed
CAPES 600-1200 j/kg in the afternoon and evening, highest near the
NE/KS borders. On Monday, the closed upper low will be over
northern UT/western WY with weakening mid level winds and slightly
cooler mid level temperatures in the afternoon. Weak QG ascent
with a better chance of thunderstorms across the cwa, highest
along the northern border. Weak QG ascent present Sunday night and
Monday. Better low level moisture will be over the northeast 
plains Monday with surface based CAPES of 500-1000 j/kg along the
I-25 corridor with values around 2500 j/kg along the eastern 
border. Cooler with 700 mb temperatures 9-11C on Monday afternoon,
even cooler Tuesday with temperatures 7-9C. On Tuesday, weak mid 
level subsidence with a westerly flow aloft over CO. ECMWF 
continues to generate sfc based computed CAPES 300-700 j/kg along 
the I-25 corridor to 1000-1500 j/kg along the eastern border. Not 
as much with the GFS, especially over the CO mountains. In any 
event the best chc of pcpn across the cwa will occur Sunday night 
through Tuesday. For the rest of the week, drier and warmer with 
another upper level ridge over the region Wednesday through 

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 245 PM MDT Fri May 25 2018

The winds are still weak and variable in direction at DIA. Models
say they should be weak northeasterly this afternoon/early 
evening, with normal drainage patterns overnight. There will be no
ceiling issues and no pops.


Issued at 245 PM MDT Fri May 25 2018

For Saturday, the relative humidities will be pretty low over the
southern half of the CWA by Saturday afternoon; with South and 
Middle Parks included. Winds gust speeds will be marginal for a 
Red Flag warning. Will let the watch going Saturday afternoon in 
South Park where the fuels are quite dry.

No change for Sunday as hot and dry conditions continue for one
more day. Will go ahead an included a Fire Weather Watch for 214
for Sunday as well. Could see slightly stronger winds on Sunday
as the flow aloft strengthens a bit.


Fire Weather Watch from Saturday morning through Saturday 
evening for COZ214.

Fire Weather Watch from Sunday morning through Sunday evening 
for COZ214.



LONG TERM......Coop