Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 260937
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
337 AM MDT Wed Jun 26 2019

.SHORT TERM...(Today and tonight)
Issued at 335 AM MDT Wed Jun 26 2019

Main concern for today is the threat of severe storms across the
far northeast plains of Colorado and the approach of 90 degree
temperatures across lower elevations.

The ridge axis will be shifting east of Colorado today while
transitioning to a moderate southwest flow pattern. This will
continue to bring in drier and warmer air to much of the area. Water
vapor does show some higher level moisture in the flow across the
southern Great Basin and some of this moisture will move into our
county warning area during the morning hours. Overall precipitable
water values continue to dry out with readings now across the
Front Range around a third of an inch but higher out east. Any
convection that does develop today will mainly produce gusty winds
but little if any rainfall. Temperatures will continue to warm
today and readings from the upper 80s to lower 90s as 700mb
temperatures warm another 2 to 3 degrees Celsius.

The exception will be across the far northeast plains where there is
deeper moisture to work with. Surface dewpoints are in the upper 40s
and 50s there and forecast models expect a dry line to develop over
the far plains, mainly east and northeast of a line from Sterling to
Akron. This appears where the threat of severe storms is highest
with surface based CAPE values in excess of 2000j/kg along with
marginal shear profile. Large hail and damaging winds would be
the main threats with the storms today. SPC also has highlighted
this area in a marginal risk and this looks fine. Storms will exit
rather quickly during the evening hours leading to clearing skies
towards midnight and mild conditions overnight.

As for fire weather issues today, there will be elevated fire
danger this afternoon as humidity levels drop to below 15 percent
across the plains. However, sustainable and gusty winds will be
marginal and mainly occur during brief times with the showers.
Given the abundant precipitation during the past week and current
fuel status no fire hilites are planned.


.LONG TERM...(Thursday through Tuesday)
Issued at 335 AM MDT Wed Jun 26 2019

The upper ridge over New Mexico will build northeast into Kansas
Thursday, then Nebraska and the Great Plains Friday. With
continued southwesterly flow aloft, expect warmer temperatures
each day, with readings in the 90s across the plains. Minimal
moisture moving up from the south will allow for isolated showers
and thunderstorms, mainly staying south of I70 in the mountains
and plains on Thursday, then remaining mainly over the higher
terrain for Friday. Humidity will be low enough and winds breezy
enough to bring fire weather concerns to South Park and southern
Lincoln County, however fuels are still very green, the fire
threat is low.

On Saturday, some moisture from the current Tropical Depression
One-E off the Pacific coast of Mexico will make its way north and
push into the state from the southwest. This will increase
thunderstorm coverage across the mountains, as well as into the
urban corridor and eastern plains. With such a warm and dry
environment, the main hazards would be strong outflow winds and
lightning. Temperatures will likely stay similar to Friday with an
increase in cloud cover.

The moisture really increases for Sunday and spreads across the
area. At the same time, the upper trough over the PacNW starts
heading east to push a front down into the northeastern plains to
start a cool down for Sunday and Monday. PWATS are expected to be
in the 1.0-1.5 inch range over the plains both days, allowing for
wetter storms, and an increase in shear may allow for some
stronger storms.

Models begin to differ more on how the PacNW upper low will kick
out to the northeast for Tuesday and into the week. But overall
should see it increase winds across the area and allow for one
more stormy day across the area before drier and slightly warmer
weather moves in for Wednesday.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 335 AM MDT Wed Jun 26 2019

Could see some weak convection again today developing south of the
terminals and then moving northeast in the southwest flow aloft.
Low levels will remain dry so any impact will be strong and gusty
outflow winds from the showers. Hard to pinpoint the areal extent
of windy conditions, but APA and DEN would have the best shot.
Will likely add a tempo group at DEN for these gusty winds in the
20-24z time frame.

&&

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

$$

SHORT TERM...Entrekin
LONG TERM...Kriederman
AVIATION...Entrekin



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