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Area Forecast Discussion (AFD)

Issued by Denver/Boulder, CO (BOU)

FXUS65 KBOU 220920

Area Forecast Discussion
National Weather Service Denver/Boulder CO
320 AM MDT Sun Sep 22 2019

.SHORT TERM...(Today and tonight)
Issued at 303 AM MDT Sun Sep 22 2019

An upper level trough was exiting nern CO early this morning, 
with some lingering precip, over the far nern plains. This precip
should end by 12z. Otherwise, dry conditions will be in place the
rest of today and tonight. Highs across nern CO will drop back to
seasonal levels this aftn with readings in the 70's.

.LONG TERM...(Monday through Saturday)
Issued at 303 AM MDT Sun Sep 22 2019

For Monday, the next system will come in the form of an open wave 
that will be in place over western Nevada. Models have it eventually 
deepening and closing off by Tuesday mid-day as it moves into the 
desert SW. For the region, dry conditions will prevail for the start 
of the week with a +1-2 degree increase at 700 mb. This will bring 
mostly sunny conditions in the morning turning to partly cloudy by 
the afternoon with highs in the lower 80s for the plains and 60s in 
the high country. As stated earlier, the closed low will continue to 
spin over the desert SW as it becomes cut-off from upper level flow. 
This will keep Colorado in a slight NW but weak upper level steering 
flow. Dry conditions will continue with highs staying around 
seasonal normals in the lower 80s Upper level pattern changes little 
by Wednesday, however, surface models are hinting at a dry cold 
front moving into the northern plains by Wednesday morning helping 
to cool temperatures into the upper 70s. Mid-level moisture will 
increase slightly behind, however no precipitation is expected. By 
Thursday models show some movement of the closed low as it moves 
into the four corners region late Thursday. Another surge of cooler 
air from the north is possible Thursday night into Friday as the 
surface low  drops SE. Moisture will increase as the upper jet drops 
south and impacts Colorado bringing a chance of precipitation back 
to the region Friday. Temperatures will reflect this surge with 
lower 80s on Thursday dropping into the mid-70s by Friday. 


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 303 AM MDT Sun Sep 22 2019

VFR conditions today thru tonight.  Light south winds this morning 
will transition to a northeast to east direction by early aftn. 
Winds early this evening will become southeast and then drainage by