Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/14/20

Area Forecast Discussion
National Weather Service Billings MT
216 PM MDT Mon Jul 13 2020 .DISCUSSION... Tonight through Tuesday night... 700 mb front and frontogenesis were progressing SE through the area this afternoon. So far, front was just producing a few showers over SE MT and one thunderstorm near Red Lodge. While there was little to no CAPE, thunder was still possible into tonight due to steep lapse rates. Pieces of vorticity and the 700 mb frontogenesis will keep some precipitation going tonight. Leaned on HRRR for tonight`s PoP forecast as it had a good handle on shower location. Thus, had chance PoPs across the southern tier through 06z, then had PoPs from S Big Horn County E and S later at night. Any gusty winds will die out early this evening. On Tuesday, cyclonic flow, vorticity and a weak cold front will bring a chance of precipitation to SE MT and Sheridan County. Again, CAPE will be lacking, but steep lapse rates will bring a low chance of thunder. Temps will be similar to today`s readings and humidities will be a little lower. Winds will be a bit gusty in some areas. Tuesday night will dry out under NW flow. Arthur Wednesday through Sunday... Look for a warming trend through the work week as 500mb heights gradually build at midweek. Pre-frontal warming will boost temps into the 90s by Friday before a weather system moves across Southern Canada. This system will drag a cold front over our region late Friday with a chance of thunderstorms developing along the front in the SE section of Montana. Conditions behind the front for the weekend look cooler. Saturday is generally dry, but a reinforcing upper trough crosses Montana on Sunday for an increased chance of showers and thunderstorms over the entire CWA. There could be some monsoonal moisture from the south available for that system Sunday as well which could lead to some heavy downpours. BT && .AVIATION... VFR will prevail through tonight and Tuesday. Isolated to scattered showers, with a few thunderstorms, will affect mainly southern areas, including KSHR, tonight. Cannot rule out MVFR conditions in the precipitation. Tuesday will be similar with a chance of showers and isolated thunderstorms over SE MT and the KSHR area. Expect areas of mountain obscuration over the NE Bighorns through Tuesday. There will be localized obscurations over the Beartooths/Absarokas this evening. Surface winds will be gusty over portions of the area on Tuesday. Arthur && .PRELIMINARY POINT TEMP/POPS... Tue Wed Thu Fri Sat Sun Mon ----------------------------------------------------------- BIL 052/079 052/086 056/093 062/093 060/086 059/079 056/081 10/U 00/U 00/U 02/T 22/T 24/T 34/T LVM 044/077 045/084 049/091 056/090 051/085 051/079 049/081 10/U 00/U 00/U 03/T 22/T 13/T 33/T HDN 053/080 049/087 054/095 061/096 059/088 058/082 055/083 10/U 00/U 00/U 01/B 21/U 23/T 33/T MLS 052/079 052/086 056/092 065/095 062/086 059/080 055/080 11/U 00/U 00/U 01/B 31/U 34/T 33/T 4BQ 053/078 052/086 056/092 064/097 061/088 059/081 055/080 22/T 00/U 00/U 01/U 21/U 34/T 44/T BHK 049/077 049/084 053/089 062/094 059/086 056/079 052/078 11/U 00/U 00/U 01/U 21/U 43/T 33/T SHR 051/078 049/087 054/093 060/097 058/090 056/084 052/082 43/T 10/U 00/U 01/U 22/T 24/T 44/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$
Area Forecast Discussion
National Weather Service Dodge City KS
601 PM CDT Mon Jul 13 2020 ...Updated aviation section... .SHORT TERM...(This evening through Tuesday) Issued at 312 PM CDT Mon Jul 13 2020 All of the convective allowing models drive a line of broken convection into west central Kansas by around 23-00 UTC this evening. The initial few hours may bring severe wind gusts well in excess of 60 mph, and hail locally in excess of 2 inches. There is no impressive moisture transport signal, so the mcs will likely weaken as it moves east across the area tonight with lightning and heavy rain as main threats the farther east it gets (say past 283). The best area for severe wind threat based on the HiRES and HRRR output looks to be Garden City and points west. The overnight cloud cover forecast will be a challenge as not all of the models are in agreement on extent of low cloud cover. GFSLamp does show potential for a period of low stratus as low as 100ft anywhere in the outflow area with increasing potential toward sunrise Tuesday. For Tuesday, the convection appears to develop over the Palmer Divide region and feed into the instability axis characterized by 60s+ dew points funneling from west central Kansas into northeast CO in the evening. The GFS models another widespread MCS across our area. By contrast the convective allowing models NMM/NAM4km/HRRR tend to develop discreet convection near a dryline farther southeast closer to late afternoon, so a few leading severe storms may impact the far southwest counties even earlier. .LONG TERM...(Tuesday night through Monday) Issued at 312 PM CDT Mon Jul 13 2020 By Wednesday evening, the ECMWF and GFS both model another convective round as moisture/dew point pooling looks maximized east to west across Kansas into southeast Colorado with weak upslope surface flow. There should be multiple locations for convection to develop on outflow boundaries by then as well. By Friday it looks like the pattern shifts enough to have weak troughing near the western state line and swrly winds and drier air working into sw Kansas. That should end the series of MCS activity and lead to much hotter temperatures again heading into the weekend. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 558 PM CDT Mon Jul 13 2020 Another round of storms will move through the TAF sites tonight bringing periods of MVFR to IFR conditions. Otherwise expect ceilings to remain at VFR. Winds will generally be light and from the southeast with the exception of in and around the aforementioned storms. && .PRELIMINARY POINT TEMPS/POPS... DDC 67 93 65 88 / 50 10 40 10 GCK 66 91 63 86 / 60 10 40 10 EHA 69 95 65 89 / 50 10 40 20 LBL 67 97 65 91 / 50 0 40 10 HYS 69 87 63 84 / 30 10 40 10 P28 72 97 70 92 / 20 10 20 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Russell LONG TERM...Russell AVIATION...Hovorka_42
Area Forecast Discussion
National Weather Service Duluth MN
1013 PM CDT Mon Jul 13 2020 .SHORT TERM...(This evening through Tuesday night) Issued at 351 PM CDT Mon Jul 13 2020 An approaching cold front will lead to developing showers and thunderstorms this evening. An upper level trough currently located over eastern Montana will continue to work its way eastward, which will help to provide additional lift. The combination of the cold front and upper level trough is expected to lead to thunderstorm development after 00Z this evening. The primary mode of these storms is expected to be linear, as CAMs have been in decent agreement. However, there is the potential for some discrete convection, primarily in the southwestern portion of the CWA. A few of these storms may be severe, particularly in the Brainerd Lakes area. Main hazards include damaging winds, large hail, isolated tornadoes, and very heavy rain. Assessing the environment this evening, the ingredients for severe convection are present. 0-6 km bulk shear values are forecasted to be between 40-50 knots. MLCAPE values are expected to be between 1500-2000 J/kg. This amount of instability should help to maintain the storms, but limit the ability for large hail development. Moisture advection is expected to be plentiful as a lower level jet from the south is expected to advect a moist airmass northward. PWAT values around 1.5 inches could potentially lead to very heavy rainfall. When assessing the potential for tornadoes, the Brainerd Lakes have the most favorable environment according to SPC. 0-1 km SRH from the HRRR has been quite impressive, with over 400 m2/s2 around the time of storm development. One potential limiting factor towards tornado development would be the high LCLs, which are currently forecasted to be above 2 km. Regardless, the risk for tornadoes is still present and will be something to watch for in the storms this evening. For Tuesday, showers and thunderstorms are possible, particularly in Northwest Wisconsin. A few of these storms may become severe in the afternoon. SPC currently has most of NW WI under a marginal risk for severe storms tomorrow. Looking at the environment, shear of 40-50 knots is possible, with MLCAPE values of 500-1000 J/kg. Possible threats include damaging winds, large hail, and a few isolated tornadoes. By Tuesday evening, the showers and thunderstorms will exit the area, leading to dry conditions for Tuesday night. Temperatures tomorrow are expected to feel much more comfortable, with highs being in the mid 70s. .LONG TERM...(Wednesday through Monday) Issued at 351 PM CDT Mon Jul 13 2020 A progressive pattern will be in place for the extended period while still maintaining above normal temperatures. Overall, broadscale moisture is limited through the week, but a large plume of rich PWAT air gets advected northward by the weekend. This will set the stage for another good opportunity for stronger storms - especially since shear becomes a lot more prevalent as flow turns zonal. So, Friday through Sunday may be an active period for storms. Afterwards, a drier air mass moves in and a weak upper level ridge tries to build to our west. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 657 PM CDT Mon Jul 13 2020 VFR conditions are currently in place with storms expected to arrive this evening and bring deteriorating conditions. The best chance for storms will be between 8PM and midnight and bring periods of MVFR and perhaps IFR conditions as they move through. Storms may be severe with damaging wind gusts and heavy rain as the primary threats. Some fog is expected to develop during the early morning hours with HIB being the most likely. A mix of MVFR and VFR conditions are expected for Tuesday as showers linger through the day. Winds will shift westerly overnight as a cold front passes along with the storms. && .MARINE... Issued at 1013 PM CDT Mon Jul 13 2020 A cold front over western Minnesota this evening will progress eastward during the next 24 hours. Thunderstorms are forecast to move over western Lake Superior early Tuesday morning. Some may be strong to severe. Winds will remain northeasterly initially and will veer southerly by 12Z Tuesday. Another round of thunderstorms is possible, mainly for the South Shore waters Tuesday afternoon. Some of those storms may also be strong. The cold front is forecast to pass over the lake during the morning hours and winds will veer southwesterly by late morning and westerly by mid- afternoon. Wind speeds will typically remain light, less than 12 knots, except locally stronger near thunderstorms. Weak high pressure will build across the region in the wake of the cool front for Tuesday night and Wednesday. Winds will remain southwesterly at 5 to 12 knots through Wednesday. && .PRELIMINARY POINT TEMPS/POPS... DLH 62 73 54 81 / 90 60 0 0 INL 59 75 55 80 / 100 30 0 0 BRD 60 73 53 80 / 100 50 0 0 HYR 65 75 52 81 / 80 90 10 0 ASX 65 78 55 83 / 80 90 20 0 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...Beach Hazards Statement until 10 PM CDT this evening for WIZ001. MN...Beach Hazards Statement until 10 PM CDT this evening for MNZ037. LS...None. && $$ SHORT TERM...Unruh/JJM LONG TERM...Wolfe AVIATION...BJH MARINE...Huyck
National Weather Service Hastings NE
626 PM CDT Mon Jul 13 2020 .SHORT TERM...(This evening through Tuesday) Issued at 226 PM CDT Mon Jul 13 2020 Main concern in the short-term is the threat for severe storms this evening. A few thunderstorms are already starting to bubble up over the Nebraska panhandle, and these are expected to become more numerous later this afternoon, especially in the vicinity of the cold front draped across the Sandhills. SBCAPE in this area is around 4000J/kg, which will initially support threat for large hail, but CAMs agree that these storms will evolve into more of a wind threat as they organize into one or more cold-pool driven clusters. Even so, there is certainly some uncertainty on how far south and east the severe threat extends. Some models, especially the HRRR, appear to weaken updrafts rather quickly as storms enter central Nebraska. There may be a couple factors leading to this. The first may be increased inhibition farther south and east, and the second may be lackluster wind shear for overnight MCS maintenance. All that being said, the bottom line is that we should still be prepared for the possibility of damaging wind, particularly for locations northwest of a line from Cambridge to Grand Island to Fullerton. Unfortunately, this certainly won`t be a widespread rainfall producer. Rainfall amounts are looking pretty meager on the latest HRRR runs. Many locations, especially south of I-80, will stay dry or mostly dry. A few showers or thunderstorms could linger into the morning hours of Tuesday, but I expect it to be primarily dry. More notably, the cold front will sweep through the area Tuesday morning ushering in northerly winds and significantly cooler, drier air. The latest model blend also hints strongly at some stratus building in behind the front as well. Given this stratus and the timing of the front, we will likely end up with a very large spread in temperatures. Northern zones may only reach the low 70s, while the far south could reach the low 90s just ahead of the front around midday. .LONG TERM...(Tuesday night through Monday) Issued at 226 PM CDT Mon Jul 13 2020 Despite the drier post-frontal airmass, chances for rain and thunderstorms return Tuesday evening and overnight as a compact wave rounds the base of the upper trough and we move into the right- entrance region of a 100kt upper level jet. In fact, we could end up with more widespread precip with this event than this evening. SPC has kept the entire area in a marginal risk during this timeframe, which seems reasonable given the RAP showing around 3000J/kg of CAPE and 30kts of bulk shear. Mild temperatures continue on Wednesday as surface high pressure slides southward into the area. This should also quell any chance for thunderstorms Wednesday or Wednesday night. We will start to see warmth and moisture return on Thursday, and a few thunderstorms are possible again Thursday evening and overnight. The warmup continues Friday and Saturday, with highs expected to push well into the 90s to low 100s by Saturday. Most areas will have heat index values of at least 100 degrees, and some could top 105, especially on Saturday. Heat headlines will need to be considered later this week. Despite the increasing heat/humidity, 700mb temperatures around 16C should keep us effectively capped and dry during this period. A shortwave approaching from the NW CONUS is then anticipated to bring the next chances for storms, and possibly a minor cooldown in the Sunday or Monday timeframe. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday) Issued at 624 PM CDT Mon Jul 13 2020 Thunderstorms will be moving in from the west during the evening. KEAR will have better chances for thunderstorms than KGRI. MVFR ceilings are expected behind a cold front that moves through late tonight/early Tuesday morning. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...Mangels LONG TERM...Mangels AVIATION...JCB
Area Forecast Discussion
National Weather Service Marquette MI
800 PM EDT Mon Jul 13 2020 .SHORT TERM...(This evening through Tuesday) Issued at 417 PM EDT MON JUL 13 2020 WV imagery and RAP analysis indicated a mid/upper level trough from northern Alberta/Saskatchewan into the western portion of the northern Plains with a downstream ridge from the southern MN and northwst WI to James Bay. Tsra have increase over the northeast corner of ND ahead of a shrtwv. At the surface, sse flow was increasing through MN and western Wi ahead of a trough/front over the eastern Dakotas. High pressure prevailed from Lake michigan and eastern Lake Superior into northern Ontario. Abundant cu has developed inland as lake breezes moved inland central and east. As upstream shrtwv and front move off to the east and a 30-40 knot LLJ develops, expect shra/tsra to increase in coverage through northern MN and eventually move through western Lake Superior into western Upper Michigan late tonight. MUCAPE values into the 500-1000 J/Kg could support some isold/sct thunderstorms. However, effective shear values and diminishing instability as the storms move to the east will be marginal to support more than small hail. After a lull in the shra/tsra by late morning, shra/tsra coverage should again increase during the afternoon as another shortwv and sfc wave lift toward the area. With abundant moisture inflow, PWAT values into the 1.5-2.0 inch range and potential for training with the inflow aligned with the storm motion, locally heavy rain may develop over the west half. Confidence in severe weather potential is lower despite impressive deep layer shear and SRH, as clouds and pcpn early in the day should limit heating enough to limit MLCAPE values at or below 500 J/Kg. .LONG TERM...(Tuesday night through Monday) Issued at 346 PM EDT MON JUL 13 2020 Two things that will highlight this forecast period will be cold front moving through Tuesday night into Wednesday and then a warmup heading into the upcoming weekend with above normal temperatures expected into next week. Cold front will be slowly making its way across the CWA Tuesday night into Wednesday as a line of showers, and a few thunderstorms, over the west will move across the central and eastern UP. CAMS has been consistently showing this line across the central late Tuesday, slowly reaching the east by Wednesday morning and then lingering over the east throughout Wednesday, while clearing over the west. Best chances of potential thunderstorms will be over the south central where MLCAPE values up to 750 J/kg. Don`t think any severe weather will occur but can`t rule out an isolated gusty wind threat with a LLJ moving through. Main threat of severe weather will stay south of the CWA, in Wisconsin. Some locally heavy rainfall may occur as well with PWAT values 1.5-2". WPC does have most of the UP under a MRGL risk of excessive rain for this period so something to keep an eye on. Precip finally moves out by early Thursday with dry conditions expected into the weekend. Upper-level ridging will begin to take control of our weather with southwesterly flow returning. This southwesterly flow will bring in warmer air across Upper Michigan. 850mb temperatures will likely be in the 16-19 C range, resulting in mostly mid to upper 80s Thursday and Friday across the UP, even along the lakeshores. Saturday is still on track to be the warmest day of the period with upper 80s to low 90s and more humid too with dewpoints mostly in the mid to upper 60s. Next chance of precip looks to be Saturday into Sunday but still inconsistent with timing, so will keep low-end POPs into Monday. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 759 PM EDT MON JUL 13 2020 VFR conditions will prevail through tonight. An approaching cold front will spread showers and possibly a thunderstorm into KIWD later tonight, with chances increasing closer to daybreak. Conditions at KIWD should fall below VFR near dawn as showers and thunderstorms overspread the area. Conditions may become IFR from noon onward at KIWD, however it will depend on rainfall rates from the passing showers / storms and if any fog forms. Included LLWS late tonight at KCMX as winds just off the surface really pick up from the SW with the approach of the cold front / surface trough. Conditions should then drop to MVFR as steadier showers move in Tuesday morning. IFR conditions are also possible at KCMX as well, given high enough rain rates from showers / storms and any possible fog that may develop. KSAW will start having chances for showers in the morning, with chances increasing into the afternoon when the front moves through. Conditions at KSAW should stay at VFR until the afternoon, when the heavier rainfall arrives. Additional isold thunderstorms will also be possible. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 417 PM EDT MON JUL 13 2020 A surface trough will move through the area tonight. Expect winds to become southeasterly at 15 to 20 kts. Winds become breezy ahead of an approaching front with southerly winds 20 to 25 knots and gusts up to 30 kts on Tuesday over the eastern half of the lake. Breezy conditions are expected across the west but not quite as strong, mainly around 15 kts with gusts to 20 kts Tuesday. Could not rule out some gale force gusts for higher platforms on Tuesday over the east. A front will move across the area from west to east Tuesday night into Wednesday, winds behind the front will shift southwesterly at 10 to 15 knots. Winds look to remain southwesterly and mainly below 15 kts for the rest of the week. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...JH AVIATION...TAP MARINE...TAP