Hail and Damaging Winds in Colorado, August 19, 2016

Area Forecast Discussion
National Weather Service Denver/Boulder CO
939 AM MDT FRI AUG 19 2016

.UPDATE...
Issued at 920 AM MDT Fri Aug 19 2016

Main concern today will be thunderstorm impacts with approaching
cold front and upper trof this afternoon and evening. Varying
amounts of low level moisture and stratus deck across the plains
this am but given latest satellite imagery and observations, deck
appears to be thinning so should see some heating from late am
through mid afternoon. This should result in temperatures in the
mid/upper 70s and support CAPE values around 1000j/kg. Big player
today will be cold front located in Central Wyoming and just
through Casper as of 15z. This timing will push the front into
the Denver area between 21-22z and should be the focus for
thunderstorms. Given strong mid level low of 35-40kt could be a
few severe storms with strong winds to 60 mph and marginal hail up
to 1 inch in diameter. Expect storms to rapidly diminish this
evening behind the front and as strong subsidence moves in behind
the upper trof.

&&

.SHORT TERM...(Today and tonight)
Issued at 448 AM MDT Fri Aug 19 2016

Summer will take a break for the next couple days as a cool
airmass has moved in from the north and an upper level trough will
be overhead through tonight. Mostly cloudy skies and winds out of
the north will keep temperatures some 15 degrees cooler than
normal this afternoon. Model soundings show that the airmass will
be quite moist through the day. GPS integrated precipitable water
values this morning are just short of one inch this morning and
may drop to 0.75 inches by midday. Regardless, enough moisture is
going to be present for the dynamic forcing from the upper level
trough to produce shower activity through the day. Embedded
thunderstorms are going to be possible through the afternoon
hours. QG diagnostic fields show mid-level subsidence developing
tonight, but cross sections show low levels of will remain nearly
saturated. This may produce a conditionally unstable airmass that
is able to produce showers if the low level upslope remains strong
enough. Will bring down the Pops a little bit tonight, but still
hold onto a slight chance of showers.

.LONG TERM...(Saturday through Thursday)
Issued at 448 AM MDT Fri Aug 19 2016

Models have weak west-northwesterly flow aloft for the CWA
Saturday well into Sunday, then it is weak southwesterly into the
later days. There is very weak downward motion progged on the QG
Omega fields Saturday through Sunday night. The boundary layer
flow looks to be dominated by normal diurnal patterns Saturday
through Sunday night. Moisture is pretty sparse Saturday and
Saturday night, then increases Sunday and Sunday night.
Precipitable water values are in the 0.25 to 0.50 inch range
Saturday into Saturday night, then they increase into the 0.50 to
1.0 inch range by late day Sunday. There is a tad of CAPE over the
southwestern and south central CWA Saturday late day. There is
plenty of CAPE progged on Sunday and Sunday evening for all but
the northwestern and north central CWA. There is a tad of
measurable rainfall over the southwestern CWA late day Saturday,
with a bit more coverage for late day Sunday. For pops will go
with 0-30%s both late day periods, with the highest pops for the
the higher CWA areas. Saturday's high temperatures will be close
to today's readings. Sunday's highs will be 2-5 C warmer than
Saturday's. For the later days, Monday through Thursday, models
have weak upper troughiness around for Colorado Monday night well
into Thursday. Will have the best pops in the mountians.

&&

.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 920 AM MDT Fri Aug 19 2016

Stratus deck appears to be thinning so should see clearing out of
the lower decks between 16-17z. Surface cold front to move through
terminals between 21-22z and looks like active showers/thunderstorms
along the front through late afternoon. Expect strong winds...heavy
rain and hail with the thunderstorms as possible ILS/MVFR
conditions.

&&

.BOU Watches/Warnings/Advisories...
None.
&&

UPDATE...Entrekin
SHORT TERM...Dankers
LONG TERM...RJK
AVIATION...Entrekin

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
948 AM MDT FRI AUG 19 2016

COZ030>051-201600-
JACKSON COUNTY BELOW 9000 FEET-
WEST JACKSON AND WEST GRAND COUNTIES ABOVE 9000 FEET-
GRAND AND SUMMIT COUNTIES BELOW 9000 FEET-
SOUTH AND EAST JACKSON/LARIMER/NORTH AND NORTHEAST GRAND/
NORTHWEST BOULDER COUNTIES ABOVE 9000 FEET-
SOUTH AND SOUTHEAST GRAND/WEST CENTRAL AND SOUTHWEST BOULDER/
GILPIN/CLEAR CREEK/SUMMIT/NORTH AND WEST PARK COUNTIES ABOVE
9000 FEET-LARIMER AND BOULDER COUNTIES BETWEEN 6000 AND 9000 FEET-
JEFFERSON AND WEST DOUGLAS COUNTIES ABOVE 6000 FEET/GILPIN/CLEAR
CREEK/NORTHEAST PARK COUNTIES BELOW 9000 FEET-
CENTRAL AND SOUTHEAST PARK COUNTY-
LARIMER COUNTY BELOW 6000 FEET/NORTHWEST WELD COUNTY-
BOULDER AND JEFFERSON COUNTIES BELOW 6000 FEET/WEST BROOMFIELD
COUNTY-
NORTH DOUGLAS COUNTY BELOW 6000 FEET/DENVER/WEST ADAMS AND
ARAPAHOE COUNTIES/EAST BROOMFIELD COUNTY-
ELBERT/CENTRAL AND EAST DOUGLAS COUNTIES ABOVE 6000 FEET-
NORTHEAST WELD COUNTY-CENTRAL AND SOUTH WELD COUNTY-MORGAN COUNTY-
CENTRAL AND EAST ADAMS AND ARAPAHOE COUNTIES-
NORTH AND NORTHEAST ELBERT COUNTY BELOW 6000 FEET/NORTH LINCOLN
COUNTY-
SOUTHEAST ELBERT COUNTY BELOW 6000 FEET/SOUTH LINCOLN COUNTY-
LOGAN COUNTY-WASHINGTON COUNTY-SEDGWICK COUNTY-PHILLIPS COUNTY-
948 AM MDT FRI AUG 19 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST AND NORTH CENTRAL
COLORADO.

.DAY ONE...TODAY AND TONIGHT

SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG A COLD FRONT WHICH
WILL SWEEP SOUTHWARD ACROSS NORTHERN COLORADO THIS AFTERNOON AND
EARLY EVENING. EXPECT RAIN...SMALL HAIL AND GUSTY WINDS TO 45 MPH
WITH THE STORMS. AN ISOLATED SEVERE STORM IS ALSO POSSIBLE WITH
HAIL UP TO ONE INCH IN DIAMETER AND DAMAGING WINDS TO 60 MPH.

THUNDERSTORMS WILL DIMINISH FROM NORTH TO SOUTH DURING THE EVENING
HOURS AS HIGH PRESSURE BUILDS INTO THE AREA. TEMPERATURES WILL BE
MUCH COOLER TODAY WITH HIGHS IN THE 70S OVER LOWER ELEVATIONS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

DRIER AIR WILL MOVE OVER THE REGION THIS WEEKEND. OTHER THAN
ISOLATED THUNDERSTORMS OVER THE MOUNTIANS DRY CONDITIONS ARE
EXPECTED. MOISTURE WILL INCREASE NEXT WEEK BRINGING ISOLATED TO
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS EACH DAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED AFTER 1PM ACROSS THE PLAINS.