Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/18/17

Area Forecast Discussion

National Weather Service Bismarck ND

 926 PM CDT Tue Oct 17 2017

.UPDATE...
Issued at 922 PM CDT Tue Oct 17 2017

Bumped up the winds and cloud cover a bit for tonight. This will
make temperature forecasting challenging as the winds are a big
determining factor in the temperatures tonight. With that said
left min temperatures alone as we already are a notch higher than
surrounding areas and cirrus will further thin out.

UPDATE Issued at 625 PM CDT Tue Oct 17 2017

Clear skies cover most of the region with some thin cirrus moving
into the the west. Update the winds a bit as the later
afternoon/early evening winds have been a bit gusty with good
linkage to winds aloft. Otherwise current forecast looks ok.

&&

.SHORT TERM...(This evening through Wednesday)
Issued at 214 PM CDT Tue Oct 17 2017

Strong winds tonight into Wednesday and potential critical fire
weather conditions Wednesday afternoon highlight the short term
forecast.

A strong cold front will enter western North Dakota between 05-07
UTC tonight, and propagate east into central North Dakota by
early Wednesday morning. Strong west to northwest winds are
expected behind this front. The main challenge is how mixed the
post-frontal surface to 825 mb layer will become tonight. The RAP
iterations through the day and 12 UTC NAM soundings at Williston
late tonight suggest that a small inversion may remain in place,
while the 12 UTC GFS has consistently shown near adiabatic lapse
rates throughout the layer. The GFS has also been consistently
stronger with its wind field, and would even support a small
window for gusts in excess of 50kts across northwest and north
central North Dakota late tonight into early Wednesday morning.
For now given uncertainty in mixing tonight, issued a Wind
Advisory for northwest and north central North Dakota into the
Upper James River Valley through Wednesday afternoon. Gusts of
45-50 mph are forecast. A local upgrade to a High Wind Warning
will have to be monitored based on upstream observations if
adiabatic lapse rates can be established during the night behind
the front.

See the Fire Weather Discussion below for details regarding
potential critical fire weather conditions on Wednesday.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 214 PM CDT Tue Oct 17 2017

Above normal temperatures Thursday and Friday highlight the
extended forecast.

An upper level ridge is forecast to build across the Northern
Plains and Upper Midwest Thursday transitioning to southwest flow
aloft on Friday. This favors an anomalously warm airmass
characterized by 850 mb mean temperatures between their 90-99th
percentiles for the period as forecast by the 00 UTC NAEFS. High
temperatures of 70 to 80 are forecast each day, above the 12 UTC
guidance consensus. A windy Saturday is possible behind a cold
front, which will have to be monitored for possible critical fire
weather conditions as fuels dry this week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 625 PM CDT Tue Oct 17 2017

The main hazard to aviation will be gusty surface winds late
tonight and Wednesday as a strong cold front sweeps through the
region. The strongest surface winds, 25KT to 40KT, are expected
across the north central and east, impacting KMOT- KJMS. Low level
wind shear is expected to impact all taf sites between 03z-15z.
VFR conditions will prevail for the 00Z forecast.


&&

.FIRE WEATHER...
Issued at 214 PM CDT Tue Oct 17 2017

A Fire Weather Watch is in effect for northern and much of central
North Dakota Wednesday.

For northern and much of central North Dakota, strong west to
northwest winds are forecast on Wednesday behind a cold front.
Sustained winds around 30 mph with gusts to 45 mph are forecast.
Afternoon relative humidity will fall to near 20 percent. While
high temperatures will only be in the 50s, dry and windy
conditions may lead to critical fire weather conditions across
northern and much of central North Dakota. Across southwest North
Dakota, winds will be weaker on Wednesday, sustained around 20 mph
with gusts to 30 mph.

Warm conditions are forecast again on Thursday and Friday with
highs of 70 to 80. However, winds are not expected to be strong
either day. A windy Saturday is possible behind a cold front,
however, there is some uncertainty if relative humidity will
reach critical levels.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Wednesday afternoon through Wednesday
evening for NDZ001>005-009>013-021>023-025-035>037.

Wind Advisory from 4 AM to 7 PM CDT Wednesday for NDZ003>005-
011>013-023-025.

Wind Advisory from 2 AM to 4 PM CDT Wednesday for NDZ001-002-009-
010.

&&

$$

UPDATE...WAA
SHORT TERM...PA
LONG TERM...PA
AVIATION...WAA
FIRE WEATHER...PA



Area Forecast Discussion

National Weather Service Hastings NE

 626 PM CDT Tue Oct 17 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 315 PM CDT Tue Oct 17 2017

Potentially Hazards Weather: None.

Aloft: Multiple ob platforms and RAP model inits indicated low
amplitude WNW flow over the CONUS with a modest anticyclonic
curvature over the W. A benign shrtwv trof was over the Panhandle
and this trof will cross the CWA tonight with nothing more than a
few high clouds. The tail end of a potent trof over Srn Canada
will cross the rgn in the PM tomorrow. Low amplitude WNW flow will
cont.

Surface: Strong high pres was over the Ern USA with return flow
over the Plns. A cool front moved onshore into the Pac NW this
AM. The CWA will remain the warm sector until this front moves
thru tomorrow. Weak high pres will rapidly develop over the rgn
behind this front tomorrow afternoon.

Rest of this afternoon: Gorgeous. Get out an enjoy it! Temps will
peak around 4 PM.

Tonight: A few high clds around before midnight then clearing.
Svrl degs warmer than last night. Lgt S winds.

Wed: Sct cirroform clouds thru early afternoon ahead of the
trof...then clearing as it moves thru. The fcst may not have
enough clouds in it prior to 18Z. It may be p/cldy not m/sunny.
Winds will pick up in CAA from the Tri-Cities N and W. Gusts up
to 25 kts from LXN-ODX.

Most of S-cntrl Neb will be svrl degs cooler than today. From Hwy
136 down into N-cntrl KS...temps will be similar to today.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 315 PM CDT Tue Oct 17 2017

Potentially Hazards Weather: Windy Fri...espcly over N-cntrl KS.
Then a slight chance for a few isolated storms Fri night into Sat
morning.

A ridge will cross the rgn Thu with SW flow aloft remaining thru
Sat. A substantial pattern-changing trof passage will occur Sat
night. NW flow will prevail next week as a longwave ridge develops
over the Wrn USA with a trof in the E.

The CWA will remain in the warm sector until a strong cool front
crosses Sat AM. This front will be devoid of precip until it gets
E and S of the CWA. So don`t expect much rain. This front will
come thru dry for most locations. The main mitigating factors will
be 1) a cap as differential advection advects an EML over the
low-lvl moisture...and 2) poor frontal timing. Frontal ascent will
break the cap just to our E and S late Sat PM.

This scant opportunity for rain is it for the next 7 days.

We will probably have the fronts associated with a clipper diving
thru Sun night into Mon but they will be moisture-starved as
well.

Temps: cont`d way above normal Thu-Fri. Sat`s cool frontal
passage will return temps back to near normal thru Tue.

Raised low temps Fri AM in strong pres grad/mechanical mixing
(using average of model 2m temps)...and we are now fcstg record
tying or record breaking warm lows.

...Records...
GRI: 59 in 1953 (current fcst: 59)
HSI: 57 in 2015 (current fcst: 59)

Wind: Windy from the S Fri and then from the NW Sat. Fri 30G45
mph likely across the Srn fringe of the CWA (Plainville-
Beloit)...but if the EC/GFS/NAM 850 mb wind fields are right and
there is plenty of sun...winds may be in that range for much more
of the CWA.

A possible snag with this idea is that a band of stratus is fcst
to form from Hwy 281 E. If the 12Z NAM is right and it lingers
thru much of the day...it will suppress mixing and hold winds
down there.

&&

.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday)
Issued at 624 PM CDT Tue Oct 17 2017

Dry weather and VFR conditions are forecast for this TAF period.
Any clouds passing through mainly later tonight and into tomorrow
morning are expected to be in the upper levels, above 15k ft.
Winds will become more southerly in the next hour or so, remaining
that way until later tonight, when they turn more westerly ahead
of an approaching front, then to the north-northwest by late
morning once the front passes. Sustained speeds behind the front
around 15 MPH will be possible.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&

$$

SHORT TERM...Kelley
LONG TERM...Kelley
AVIATION...ADP