Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 151037

Area Forecast Discussion
National Weather Service Denver/Boulder CO
437 AM MDT Sun Sep 15 2019

.SHORT TERM...(Today and tonight)
Issued at 437 AM MDT Sun Sep 15 2019

Satellite pictures are showing a batch of upper level cloudiness
over the CWA right now associated with an upper closed low over
Arizona. Models have this feature over the four corners by 00Z
this afternoon, then over west central Colorado by 12Z Monday
morning, albeit weaker. There is weak upward synoptic scale energy
over the forecast area today and tonight on the QG Omega fields.
Weak southwesterly flow aloft is progged both today and tonight.
The low level winds will be southeasterly and easterly today, with
normal drainage patterns tonight. For moisture, there will be
some, mostly in the upper levels, streaming across the CWA from
the south and southwest today and tonight. There could be a bit of
mid level moisture over the mountains late this afternoon and
tonight. Precipitable water values are in the the 0.50 to 0.75
inch range tonight. There is limited CAPE progged today, mainly
over the far eastern CWA. There is some over the mountains this
evening. Again, nothing significant. The QPf fields show a tad of
rain over mountains this evening, but only from the ECMWF model.
Will leave pops out today, and go with some 10%s in the mountains
tonight. For temperatures, today`s highs are 0-1.5 C warmer than
yesterday`s highs.

.LONG TERM...(Monday through Saturday)
Issued at 419 AM MDT Sun Sep 15 2019

A weak shortwave will pass over in southwesterly flow on Monday,
followed by a stronger one on Tuesday. This pattern continues
later in the week with some minor model differences on additional
shortwaves and the eastward drift of the larger scale trough
around Friday or Saturday. For the most part, this will be a dry
and warm period, with a little moisture ahead and with the
shortwaves bringing small chances of thunderstorms at those times.
There will also be a little cooling and drying behind the troughs.
It will become windy over the mountains by Tuesday, and this will
continue. It does look like the windiest periods will be with the
trough passages when there will be a bit more moisture, which may
restrain the fire danger, but there will be an elevated threat
mainly behind the troughs in the drier air on Wednesday and again
about Friday or Saturday. With the warm and dry conditions, fuels
will be drying again after last week`s rains.

The model blends were generally appropriate, but I did cool
temperatures on Tuesday a bit as there should be plenty of cloud
cover. PoPs are limited as the clouds will cut into any
instability, the moisture is mostly at mid levels and there` not
much cooling aloft. The timing of the trough also appears to be a
bit early, if it were well timed, there could be scattered storms
in the afternoon that would deserve some increase in the PoPs. It
looks like any forcing for lift later in the week will be working
on a similar environment, with most of the moisture and cooling
aloft passing north of Colorado.


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 437 AM MDT Sun Sep 15 2019

Normal drainage winds will continue at DIA through sunrise, then
east and southeasterlies winds will blow from late this morning
into the early evening hours. There will nor be any ceiling
issues today nor tonight at DIA.




LONG TERM...Gimmestad
AVIATION...RJK is the U.S. government's official web portal to all federal, state and local government web resources and services.