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 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