Hail and Damaging Winds in North Dakota, July 6, 2016

Area Forecast Discussion
National Weather Service Bismarck ND
206 PM CDT WED JUL 6 2016

.UPDATE...
Issued at 206 PM CDT Wed Jul 6 2016

Quick update to accommodate the issuance of a severe thunderstorm
watch for parts of southwest ND through 8 PM MDT (02 UTC). There
is considerable uncertainty in the magnitude of destabilization
which will take place in southwest ND yet this afternoon as the
surface observations show a fragmented moisture pattern in place
with a pocket of dewpoints only in the 40s F around Dickinson.
However, vigorous convection has developed upstream in eastern
MT and it is propagating toward southwest ND. RAP guidance calls
for 500-1000 J/kg of MLCAPE developing across southwest ND this
afternoon if dewpoints do manage to rise further into the 50s F
in at least the extreme southwest corner of the state. Thus, we
had enough concern for potential severe storms given effective
bulk wind differences around 50 kt for issuance of the watch in
collaboration with SPC. We considered adding Stark and Hettinger
Counties into the initial watch, too, but chose to refrain from
doing so at this point given uncertainties about the downstream
destabilization, especially once stronger convection initiates
across SD and potentially further disrupts moisture advection.
We will watch trends and may add those counties into the watch
later if necessary.

UPDATE Issued at 1207 PM CDT Wed Jul 6 2016

No significant changes needed with this update. Did warm
temperatures a bit where clouds are lacking based on latest
trends and tweaked precipitation chances through the afternoon.
Latest iterations of the HRRR remain consistent with a strong to
severe storm or two along the North Dakota/South Dakota border
later this afternoon.

UPDATE Issued at 833 AM CDT Wed Jul 6 2016

The forecast looks to generally be on track. Expected warm air
advection showers and thunderstorms have developed further over
southeastern Montana and northwestern South Dakota. These continue
to slowly move towards the southwestern counties of North Dakota,
but did delay precipitation chances a little more based off the
current radar and satellite trends. Otherwise, we just blended
the latest observations to the previous forecast.

The biggest challenge for today will be if any strong to severe
storms can skirt the southwestern/south central parts of the
state later this afternoon and into the evening. Marginally severe
hail would be the main threat, which matches the latest SPC
thinking in their day one outlook well.

UPDATE Issued at 629 AM CDT Wed Jul 6 2016

Weak high pressure remains over western and central ND early this
morning. This has allowed temperatures to drop into the mid and
upper 40s across a good portion of the west this morning. Clouds
and showers are slow to move into the area and have continued
this trend. We lowered pops a bit and limited their progression
north and east this morning. Otherwise no significant updates to
the going forecast.

&&

.SHORT TERM...(Today and tonight)
Issued at 232 AM CDT Wed Jul 6 2016

The main forecast issue in the short term period will be
precipitation chances and potential for strong to severe storms
today and Thursday.

Currently...an upper level low is spinning over far southeast
British Columbia into far northwest Montana. Broad southwest flow
continues from beneath the upper low into the northern and central
plains. Convection overnight has been concentrated along an
area of low pressure over the northern high plains of northeast
Wyoming and western South Dakota and then tracking eastward along
a quasi-stationary boundary draped across the central plains.

Today...Low pressure is expected to deepen over the northern high
plains of eastern Montana into northeast Wyoming in advance of the
upper low tracking through the northern Rockies. Lead shortwave
energy is expected to bring increasing clouds across western and
central North Dakota today with isolated to scattered showers
beginning in the southwest portion of the state and spreading
northeast. Meso-scale and global models have been backing off on
the extent of initial shower activity as it spreads across the
forecast area today and have generally followed this trend
bringing slight chance to chance pops slowly north and east across
the forecast area today.

The main threat for severe weather appears to be across the far
southwest by mid to late afternoon. Although the best moisture and
instability will be farther south, there looks to be a window of
opportunity where we will see moderate cape and strong shear over
southeast Montana into western South Dakota, including the far
southwest portion of North Dakota. Some of the meso-scale models
are indicating convection firing from east central Montana into
northwest South Dakota, including southwest North Dakota. If we
under-perform on the amount of cloud cover and shower activity
this morning and early afternoon, think the threat for strong to
severe storms increases over our southwest given the increased
insolation. Will certainly have to monitor through the day. Have
bumped up pops over the southwest late this afternoon.

Tonight and Thursday...there are still many uncertainties about
how convection will play out tonight with global models indicating
more action across South Dakota into Nebraska, possibly leaving a
lull in the action across North Dakota. But some of the meso-
scale models are still indicating convection over western and
south central ND this evening. By the time we reach the overnight
hours into Thursday, the upper low approaches North Dakota and
overall mid level forcing increases across the forecast area. Thus
our favored areas for shower and thunderstorm activity early
thursday will be across the west, then shifting into central ND
by thursday afternoon. The overall severe potential appears to be
limited on Thursday except perhaps across the far south central
into James River Valley Thursday afternoon in an axis of better
moisture and instability.

By Thursday night precipitation tapers off over eastern portions
of central ND with upper level ridging and surface high pressure
in control through Friday. By late Friday night precipitation
chances re-appear in the west, on the nose of a strong low level
jet and return flow ahead of another upper level low.

.LONG TERM...(Thursday through Tuesday)
Issued at 232 AM CDT Wed Jul 6 2016

Highlights in the long term include a warmer and more humid weekend
which will keep thunderstorm chances in the forecast.

The 00z GFS and ECMWF are in good agreement depicting an upper level
low off the Pacific Northwest coast on Saturday morning, with an
upper level ridge over the Red River Valley area. This places
western and central North Dakota in a regime of southwesterly flow
aloft. The upper low digs south into the Pacific Northwest states by
Sunday, and crosses east across the Rockies and emerging into the
western plains by Monday. The low then deepens as it begins to lift
northeastward into Saskatchewan Tuesday.

At the surface, low pressure will be the dominant feature over the
western plains. This will allow increasing southerly flow, with the
development of a definite strong low level jet, and bring plenty of
low level moisture into the Northern Plains. Dewpoint temperatures
Saturday through Monday appear to rise well into the 60s with lower
70s some areas.

The Saturday night through Sunday night timeframe appears to offer
the best timing for the risk for severe storms. The increasing low
level moisture and strong wind shear from a strong low level jet and
approaching strengthening upper level low will lead to increased
CAPE and bulk shear. Forecast CAPE values are well over 3000 J/Kg,
and 0-6Km bulk shear values are forecast to be in the 40-50 knot
range. SPC has highlighted this period with an uncommon mention of a
risk of severe storms in the day 5 outlook period.

The timing of the upper low track suggests that Monday night/Tuesday
will bring relief from the very humid regime as dry air moves into
our area as the upper low lifts northeastward and allows a dry
westerly flow. Thunderstorm chances become much lower by this time
as well.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1207 PM CDT Wed Jul 6 2016

Showers and a few thunderstorms will gradually spread over
western and central North Dakota this afternoon, from eastern
Montana and northwestern South Dakota. Expect more numerous
showers with embedded thunderstorms in the overnight and morning
hours. VFR conditions should prevail until around 12z Thursday,
when ceilings at KISN/KDIK/KMOT will likely lower into MVFR
categories. Isolated IFR visibilities and gusty winds cannot be
ruled out under any heavier thunderstorms cores.

&&

.BIS Watches/Warnings/Advisories...
NONE.
&&

UPDATE...CJS
SHORT TERM...TWH
LONG TERM...JV
AVIATION...ZH

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE BISMARCK ND
1151 AM CDT WED JUL 6 2016

NDZ031>033-040-041-043-044-071700-
GOLDEN VALLEY-BILLINGS-STARK-SLOPE-HETTINGER-BOWMAN-ADAMS-
1051 AM MDT WED JUL 6 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST NORTH
DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS TODAY AND TONIGHT. A FEW
STORMS COULD BECOME STRONG TO SEVERE THIS AFTERNOON INTO THIS
EVENING. HOWEVER...THE PROBABILITY FOR WIDESPREAD HAZARDOUS
WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CHANCE OF THUNDERSTORMS THURSDAY AND THEN AGAIN
SATURDAY THROUGH TUESDAY. CURRENT OUTLOOKS POINT TO A CHANCE OF
SEVERE STORMS ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

NDZ001>005-009>013-017>023-025-034>037-042-045>048-050-051-071700-
DIVIDE-BURKE-RENVILLE-BOTTINEAU-ROLETTE-WILLIAMS-MOUNTRAIL-WARD-
MCHENRY-PIERCE-MCKENZIE-DUNN-MERCER-OLIVER-MCLEAN-SHERIDAN-WELLS-
FOSTER-MORTON-BURLEIGH-KIDDER-STUTSMAN-GRANT-SIOUX-EMMONS-LOGAN-
LA MOURE-MCINTOSH-DICKEY-
1151 AM CDT WED JUL 6 2016 /1051 AM MDT WED JUL 6 2016/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL
NORTH DAKOTA...NORTHWEST NORTH DAKOTA...SOUTH CENTRAL NORTH
DAKOTA...SOUTHEAST NORTH DAKOTA AND SOUTHWEST NORTH DAKOTA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

THERE IS A CHANCE OF THUNDERSTORMS TODAY AND TONIGHT. THE
PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CHANCE OF THUNDERSTORMS THURSDAY AND THEN AGAIN
SATURDAY THROUGH TUESDAY. CURRENT OUTLOOKS POINT TO A CHANCE OF
SEVERE STORMS ON SUNDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

ZH/TWH

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BISMARCK ND
1016 AM CDT WED JUL 6 2016

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 PM     HAIL             7 S GARDENA             48.61N 100.47W
07/05/2016  E1.00 INCH       MCHENRY            ND   PUBLIC

            A LARGE AMOUNT OF HAIL FELL. MOST WAS PEA TO
            ONE-HALF INCH IN DIAMETER, BUT A FEW
            HAILSTONES WERE UP TO THE SIZE OF QUARTERS.
            TIME ESTIMATED. .

&&

CJS