Hail and Damaging Winds in North Dakota, September 7, 2016

Area Forecast Discussion
National Weather Service Grand Forks ND
102 PM CDT WED SEP 7 2016

.UPDATE...
Issued at 102 PM CDT Wed Sep 7 2016

Concern will be severe thunderstorm potential this afternoon.
Water vapor imagery indicates a robust shortwave entering the
western Dakotas...expected to continue propagating eastward.
Forcing from this feature will lead to an area of thunderstorms
across much of the region this afternoon and evening...quickly
moving through the FA from west to east. Main uncertainty is
severe potential. Increasing clouds are limiting heating...which
will limit instability. With that said...forcing from the upper
wave will be strong...combined with strong deep layer shear will
lead to a high shear/low CAPE event. Current CAM guidance
indicates bowing segments within the overall line of
thunderstorms...with strong winds probably the main threat. In
addition...0-3km shear vector will be west/southwest
30-40knts...favorable for some type of tornado potential. Main
message...still expect a few severe storms this
afternoon...especially across southeast North Dakota into west
central Minnesota (or along and south of the surface low track).

&&

.SHORT TERM...(Today and tonight)
Issued at 340 AM CDT Wed Sep 7 2016

Convection timing and strength this afternoon and tonight will be
the main forecast problem for the period.

High pressure remains over much of the forecast area and dew
points are still in the upper 40s and 50s as of 2 AM CDT. However,
better moisture with 60s dew points is just to our southern
border, and surface winds will shift around to the southeast
throughout the morning. The upper trough currently over MT is
progressing rapidly to the east, and should move into the Western
Plains by late afternoon. This will help push the surface trough
axis currently over eastern MT/WY eastward and into the western
CWA by late afternoon. While temps may be limited a bit by
increasing clouds, still think we should get into the upper 60s to
low 70s across the southwestern counties. This should help
instability get up to around 1500 J/kg by this afternoon. While
this is not insanely high, there will be 50 kts of deep layer bulk
shear and upper support will be good for storm development. The
NSSL WRF and HRRR both bring some fairly significant storms into
our southern counties by 20Z or so. The WRF runs show mostly
convection in a linear bow, but with the low level wind profile
bringing some nicely curved hodographs there will be a threat of
tornadoes possible at least in our southern counties.

The system will be quickly moving, with the surface low moving
into MN by early evening and off to the east of our counties after
midnight. The NAM puts out some high QPF values in a similar track
over areas that received heavy rain Sunday night. However the
other global models are further south with the heaviest rain. In
addition, with the quick movement of the system think that unless
we get cells training over each other that flooding will not be
too much of a problem. Rain should end from west to east during
the night with only a few lingering showers near Lake of the Woods
by early Thursday morning. Lows will be mostly in the 50s.

.LONG TERM...(Thursday through Tuesday)
Issued at 340 AM CDT Wed Sep 7 2016

Thursday through Friday...Southwesterly flow aloft continues with
several decent shortwave troughs moving through. Think that most
of the day on Thursday should be fairly quiet, but one of the
shortwaves will help push a surface trough into the Red River
Valley Thursday night. Moisture recovery will not be as good and
much of the upper support will be to our south or north so kept
POPs a bit lower in the 20-40 percent range. The surface low will
move east during the day on Friday but the main upper trough will
still be pushing through and models are indicating some signs of
mid level frontogenesis behind the surface boundary. Will keep
chance POPs going for Friday and then taper them off Friday night
as the upper trough digs into the Upper Mississippi Valley. Temps
should be near seasonal averages on Thursday in the upper 60s to
mid 70s but a bit cooler for Friday.

For Saturday...upper level trof shifts over the area in the wake of
a cold front. Thus...expect cooler temperatures across the region to
start the weekend. Precipitation ends as surface high pressure
builds in...allowing for more pleasant conditions along with light
winds.

By Sunday night into Tuesday...the pattern continues to be
progressive as an upper level ridge shifts across the northern
plains. Surface high pressure retreats to the east allowing return
of southerly flow. Therefore...will see warmer temperatures
spreading across the region ahead of another system...and increased
chances of showers or storms for the Monday time frame.
Otherwise...cooler and more tranquil weather is expected to end the
period.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 102 PM CDT Wed Sep 7 2016

Main hazard will be thunderstorms. A line of thunderstorms will
move through the region this afternoon/evening...and will likely
be fairly widespread affecting all TAF sites.

&&

.FGF Watches/Warnings/Advisories...
ND...None.
MN...None.
&&

UPDATE...TG
SHORT TERM...JR
LONG TERM...JR/Hopkins
AVIATION...TG

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GRAND FORKS ND
523 AM CDT WED SEP 7 2016

MNZ001>009-013>017-022>024-027>032-040-NDZ006>008-014>016-024-
026>030-038-039-049-052>054-081030-
WEST POLK-NORMAN-CLAY-KITTSON-ROSEAU-LAKE OF THE WOODS-
WEST MARSHALL-EAST MARSHALL-NORTH BELTRAMI-PENNINGTON-RED LAKE-
EAST POLK-NORTH CLEARWATER-SOUTH BELTRAMI-MAHNOMEN-
SOUTH CLEARWATER-HUBBARD-WEST BECKER-EAST BECKER-WILKIN-
WEST OTTER TAIL-EAST OTTER TAIL-WADENA-GRANT-TOWNER-CAVALIER-
PEMBINA-BENSON-RAMSEY-EASTERN WALSH COUNTY-EDDY-NELSON-
GRAND FORKS-GRIGGS-STEELE-TRAILL-BARNES-CASS-RANSOM-SARGENT-
RICHLAND-WESTERN WALSH COUNTY-
523 AM CDT WED SEP 7 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN NORTH
DAKOTA...WEST CENTRAL AND NORTHWEST MINNESOTA.

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY ACROSS
PORTIONS OF SOUTHEASTERN NORTH DAKOTA AND WEST CENTRAL MINNESOTA.
STORMS WILL PUSH INTO EASTERN NORTH DAKOTA BY MID AFTERNOON, WITH
THE STRONGEST STORMS ON THE SOUTHERN END. DAMAGING WINDS WILL BE
THE MAIN THREAT, BUT HAIL AND EVEN TORNADOES ARE POSSIBLE. THE
STORMS WILL PUSH EASTWARD DURING THE EVENING, BRINGING THE SEVERE
THREAT INTO WEST CENTRAL MINNESOTA. STORMS WILL BEGIN TO WEAKEN
AFTER MIDNIGHT AND LIFT NORTHEASTWARD OUT OF THE AREA.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

ADDITIONAL THUNDERSTORMS ARE POSSIBLE THURSDAY NIGHT AND FRIDAY
AND A SLIGHT CHANCE FOR THUNDERSTORMS AGAIN ON MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED ALONG AND SOUTH OF THE I-94
CORRIDOR.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE EASTERN ND/GRAND FORKS ND
240 PM CDT WED SEP 7 2016

NDZ038-039-049-052-072045-
BARNES-RANSOM-CASS-SARGENT-
240 PM CDT WED SEP 7 2016

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT RANSOM...SOUTHEASTERN
BARNES...NORTHWESTERN SARGENT AND SOUTHWESTERN CASS COUNTIES...

AT 239 PM CDT...RADAR INDICATED STRONG THUNDERSTORMS WERE LOCATED
ALONG A LINE EXTENDING FROM NEAR LITTLE YELLOWSTONE TO NEAR CRETE.
MOVEMENT WAS NORTHEAST AT 35 MPH.

WIND GUSTS UP TO 50 MPH AND HALF INCH HAIL ARE POSSIBLE WITH THESE
STORMS.

LOCATIONS IMPACTED INCLUDE...
LISBON...ENDERLIN...GWINNER...MILNOR...SHELDON...
FORT RANSOM AND NOME.

THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO
STATIONS AND AVAILABLE TELEVISION STATIONS FOR ADDITIONAL INFORMATION
AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4628 9801 4628 9802 4664 9804 4682 9746
      4618 9743 4609 9801
TIME...MOT...LOC 1939Z 243DEG 31KT 4663 9803 4615 9800

GUST