Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/23/19


Area Forecast Discussion
National Weather Service Bismarck ND
946 PM CDT Tue Oct 22 2019 .UPDATE... Issued at 930 PM CDT Tue Oct 22 2019 Update to the previous discussion about western North Dakota snow tonight: While there is an impressive burst of forcing displayed via recent RAP guidance (strong frontogenesis from 925mb through 600mb under divergence aloft and omega within the dendritic growth zone on forecast soundings), these forcings are short lived and are maximized within a very thin band stretching from southern McKenzie, through Stark, and into Sioux county...occurring in just a few hours between the 05Z-12Z time frame. Additionally surface temperatures within that potential zone are still currently quite warm with Dickinson and Watford City currently at 41 degrees. Thus the confidence that a band of heavy snow can persist and accumulate long enough to reach Winter Weather Advisory criteria (3-5 inches within 12 hours) is low. That said, there is a decent chance some spots within this area will see will see at least 3 inches overnight, it`s just that the spatial extent of this potential is very uncertain still. Obviously this will need continuous monitoring as short- term trends develop. The last update was to remove mention of thunder in the far southwest. Thunderstorms associated with the surface low have passed just to the south of Bowman county and additional thunderstorms are not expected. UPDATE Issued at 714 PM CDT Tue Oct 22 2019 This evening, a potent midlevel circulation was evident on water vapor imagery centered over central Montana. Modest warm air advection within the warm conveyor belt region was responsible for light rain in our far southwest counties this evening. Further west, a line of showers and scattered thunderstorms stretched over eastern Montana along the cold front associated with the aforementioned low. Steep low level lapse rates in southern Montana were responsible for efficient momentum transfer and 40-60 mph wind gusts. While RAP guidance keeps the steeper low level lapse rates (and thus a more favorable strong wind gust environment) in South Dakota and Wyoming, there is still a possibility for strong wind gusts accompanying showers/thunderstorms in the southwest counties in the next couple hours with current storm motions at around 50 mph. In the overnight hours, the midlevel low is forecast to move over a tightening baroclinic zone stretching from around McKenzie county through Sioux county. A quick burst of snow along this line of frontogenesis overnight should be enough to produce around 1 to 2 inches of accumulation overnight. Recent RAP runs have been a little more aggressive with QPF along a very narrow portion of this band, which may signal locally higher amounts may be possible where the greatest forcing of this band sets up. While no major changes were made to the forecast now, this will need to be watched as high-resolution guidance continues to flow in. && .SHORT TERM... Clear skies prevail across much of western North Dakota this afternoon with clouds gradually building in from the southwest late this afternoon. A rather fast moving H5 shortwave will traverse the western portions of the CWA tonight, with showers, mixed rain/snow and even a chance of an isolated thunderstorm. The best chances for measurable precipitation will occur mainly along and southwest of a line from Grenora to Linton. Upper limits of precipitation accumulation will generally be in the 0.25 to 0.50 inch range. Where we see a transition to snow, accumulations of up to 2 inches are possible, with the highest accumulations forecast generally along a corridor that runs from Watford City to Elgin. Although not widespread, areas where we see stronger convective activity could see higher snowfall totals up to 3 inches. The Bismarck area is expected to remain on the eastern side of the system, with lighter snowfall totals of less than one inch. Heading into Wednesday morning, light snow will change back over to rain and persist into the early afternoon. Look for high temperatures in the 30s to lower 40s. Low temperatures will fall into the middle to upper 20s Wednesday night into Thursday morning. .LONG TERM... We will see a bit of a reprieve in precipitation On Thursday and Friday before our next system moves into the region. Westerly flow will allow high temperatures to climb into the 40s for Thursday and into the 50s to near 60 degrees on Friday. A strong H5 low will move across southern Alberta and into Manitoba Heading into Saturday morning. This will facilitate another shortwave passage with an associated cold front that will dive southeastward out of Canada. We will likely reach our high temperatures early Saturday, with middle 40s along the International Border to upper 50s in south-central North Dakota along the South Dakota border. Precipitation is possible with the frontal passage; however, with rather dry antecedent conditions and overall lack of available moisture, our precipitation amounts will be quite low. Temperatures will fall dramatically following the front, with highs in the upper 20s to lower 30s Sunday through Tuesday. Lows during this time will be in the teens and 20s. The 850 mb temps for the Sunday through Tuesday period will range from -10C to -14C, focused especially on Sunday morning. A secondary push of cold air follows the first, with 850 mb temps as cold as -16C per the current guidance. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 714 PM CDT Tue Oct 22 2019 MVFR, transitioning to IFR, cigs possible for KDIK beginning at 05Z with rain transitioning to snow. Reduced visibilities will accompany the transition to snow overnight as well. Light snow possible at KISN and KBIS at 05Z-12Z, though less likely. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AE SHORT TERM...TLynch-FGF LONG TERM....TLynch-FGF AVIATION...AE
Area Forecast Discussion
National Weather Service Quad Cities IA IL
1042 PM CDT Tue Oct 22 2019 ...HYDROLOGY UPDATE... .SYNOPSIS... Issued at 230 PM CDT Tue Oct 22 2019 Dreary, windy and cool: those are the words I would use to describe how much of this day has felt so far. Thankfully, much nicer weather was not too far away! As of 2 PM, temperatures across the region ranged from 44 in Dubuque, to 57 in Macomb and Keokuk. Clouds were breaking and sunshine was out in full force across central and southeast Iowa. Unfortunately, it was still windy as we remain under the last bits of control of a strong, 988 hPa surface low pressure centered just east of the arrowhead of Minnesota. High pressure was not too far to the southwest, and it will just be enough to influence the first portion of the short term period. && .SHORT TERM...(This Evening through Wednesday Night) ISSUED AT 230 PM CDT Tue Oct 22 2019 Key Messages... 1) Windy conditions subsiding this evening and tonight. 2) Slight chance of rain showers north of I-80 Wednesday morning and afternoon. Winds should continue to subside as we head through the evening, as the low pressure loses its grip and the high pressure briefly takes over. Surface ridging evident on latest mesoanalysis will build over the area and will keep our weather dry & quiet through tonight. CAA will continue and we should see our temperatures drop to values cooler than previous nights. Currently advertise overnight lows ranging from the low 30s along/north of Highway 20, to mid/upper 30s south. Clouds will begin to build back over the area early Wednesday, and will limit afternoon highs to the low 50s along the Highway 20 corridor, to the the low 60s south of Highway 34. These clouds are associated with a clipper that will pass across the area Wednesday evening. Overall, guidance is not too impressive with this system, and is quite variable on placement of precip as well. The NAMnest and ARW support rain showers across the entire area, while the HRRR and NMM show more of a banded nature to the precipitation, with a focus more along and north of the Highway 20 corridor. I`m more inclined to follow the later, as global guidance advertises the best forcing and CVA with the shortwave aloft more into northeast Iowa and southwest Wisconsin. However, I will mention slight POPs down to the I-80 corridor as some of the guidance is supporting potential for drizzle due to extra lift from isentropic upglide around 925-850 hPa. Any precip that falls will be negligible at best, with the highest amounts expected to only be a few hundreths. High pressure will quickly, and briefly, build back across the area Wednesday night. Another system will begin to take shape over eastern Oklahoma, southwest Missouri and northwest Arkansas, and will be more of an influence in the long term period. .LONG TERM...(Thursday through Tuesday) ISSUED AT 230 PM CDT Tue Oct 22 2019 Key Messages... 1) Chance of rain showers over our far southeast CWA Thursday. 2) Generally dry and quiet through the weekend, slight chance of rain Sunday. 3) Temperatures trending colder for next week. System developing over the lower Mississippi Valley Wednesday night will graze our southern CWA Thursday afternoon and evening. This seems to be more hinted by the American models, while the CMC and ECMWF are less aggressive on any system impact to our area. Overall, quiet and dry conditions are primarily expected for the area Thursday through Saturday as broad high pressure moves overhead. Temperatures will return to near normal as southerly return flow helps afternoon highs jump into the 50s/near 60. Next chance of rain may be Saturday night and Sunday as guidance shows a shortwave quickly ejecting out of the lower Rockies into the Mississippi River Valley. The CMC and ECMWF advertise impacts to our area and have remained fairly consistent. Meanwhile, the 12z GFS advertises no system with high pressure firmly in place and the system much further east (towards the Mid Atlantic states). For now, will maintain slight chance to chance of POPs across the area. If precipitation were to fall, temperatures would favor rain as the type. Another system may impact the area Monday night and Tuesday, but this is only being driven by the ECMWF thus far, so expect further adjustments. Behind this system, a strong, deep trough is progged by all long range guidance to build south from Alberta and Saskatchewan into the Rockies. This will move east and usher cold temperatures (agreement of 850 hPa temperatures around -10 C Wednesday morning) into the eastern Great Plains and Midwest by mid to late next week, just in time for Halloween (ghost costume in a comforter perhaps?). While this is a bit far out, some raw guidance is hinting at afternoon highs on some days in the upper 30s to low 40s for the period, with blended guidance not too far behind. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) ISSUED AT 619 PM CDT Tue Oct 22 2019 Gusty west winds will diminish to around 10 kts early this evening at all sites with clear skies and VFR conditions through the rest of the night. A fast moving low pressure system will return cloud cover Wednesday and bring a round of light showers or sprinkles. These are most likely to impact the CID and DBQ terminals, where PROB30 groups were used. With limited moisture, cloud bases are expected to remain high enough to keep conditions VFR through the day. && .HYDROLOGY... Issued at 1041 PM CDT Tue Oct 22 2019 This evening`s forecast no longer has the Dubuque Railroad Bridge gage exceeding flood stage within the next week. This is now in line with previous day`s forecasts keeping the river below flood stage. With only light rainfall expected over the next several days upstream, this forecast is likely to change little and thus the flood watch has been cancelled. Otherwise, forecasts remain on track with most sites on the Mississippi continuing to slowly fall, then becoming steady or resuming a rising trend toward the end of the month as flow from recent heavy rainfall in WI and MN makes its way downstream. On the Rock River, Joslin is still forecast to drop below flood stage Saturday. && .CLIMATE... ISSUED AT 230 PM CDT Tue Oct 22 2019 Long range guidance shows a strong upper level trough building south from Canada into the Great Plains and Midwest by mid next week. This trough will usher in cold air across the area that is atypical of what is normally seen for late October/early November. The Climate Prediction Center maintains a high probability (60-70%) of below normal temperatures for the period (Oct 29 - Nov 4). && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Speck SHORT TERM...Speck LONG TERM...Speck AVIATION...Sheets HYDROLOGY...Sheets CLIMATE...Speck
Area Forecast Discussion
National Weather Service Green Bay WI
1035 PM CDT Tue Oct 22 2019 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Wednesday Issued at 254 PM CDT Tue Oct 22 2019 The latest RAP analysis and satellite/radar imagery show a strong area of low pressure lifting north of Lake Superior early this afternoon. Deep moisture within cyclonic flow continues to wrap around the low, and provide periods of showers and drizzle. Winds have been gusting up to about 35 mph at times, highest over northeast WI and might increase slightly around mid-afternoon, but should remain below wind advisory criteria of 45 mph. Looking upstream, widespread low overcast extends west into Minnesota and south into east-central Illinois. Forecast concerns revolve around strong wind potential and light precip trends. Tonight...Low pressure will continue to lift northeast over northern Ontario. Deep cyclonic flow will continue, however, with thermal troughing and a strengthening inversion supporting low overcast to persist through much of the night. It`s possible central WI and the downsloping areas of northeast WI could see some holes in the clouds develop late. Forecast soundings remain support of areas of light rain and drizzle persisting into the evening as saturation folds over the top of the inversion. But as the low moves away, should see light precip chances diminish and lift north through the night. After peaking late this afternoon, should see winds gradually diminish through the night as well. Temps wont fall much due to cloud cover and the breezy conditions, with lows falling into the middle 30s to near 40 by the Lake. Wednesday...Though low pressure will continue to move farther away from the region, the low overcast will be slow to lift north, and may hang around northern WI through the afternoon. Meanwhile, any clearing that occurs over central and east-central WI looks to be short-lived as a shortwave trough will quickly move across the northern Mississippi Valley and into the western Great Lakes in the afternoon. It will bring a low chance of light rain into parts of central and east-central WI, mainly in the late afternoon hours. Highs ranging from the low 40s in the north to near 50 in the east. .LONG TERM...Wednesday Night Through Tuesday Issued at 254 PM CDT Tue Oct 22 2019 Cool and dry weather is expected Wednesday through Saturday as northwest upper flow prevails across the Great Lakes. Temperatures should range from 5 to 10 degrees below normal. The medium range models have differences as far as Saturday night and Sunday go. The GFS moves an upper trough across the Lower Ohio Valley keeping Wisconsin dry, while the ECMWF and GEM have a negatively tilted upper system lifting northeast across Illinois which would bring a chilly rain to the area. The jet energy for that system is still off the Pacific Coast so we do not have a lot of confidence in any of the model forecasts yet. && .AVIATION...for 06Z TAF Issuance Issued at 1028 PM CDT Tue Oct 22 2019 The strong low pressure system will continue to lift northeast away from the region through the TAF period. However, moist cyclonic flow will continue, resulting periods of light rain and drizzle across mainly north central WI into Wednesday morning. The rain may briefly mix with snow at times. CIGs and VSBYs will mainly be MVFR, but may briefly fall to IFR in north central WI overnight. MVFR conditions should prevail on Wednesday, except in eastern WI, where improvement to VFR is anticipated by late morning. Another system will pass by to our south Wednesday afternoon and evening, and may bring some light showers to parts of central WI and the Fox Valley. && .MARINE... Issued at 254 PM CDT Tue Oct 22 2019 After a lull this morning, southwest winds are projected to increase again but remain under gale force late this afternoon into this evening. If winds proceed as planned, think the gale warning will likely get downgraded to a small craft advisory on the Bay and possibly on the Lake too. Winds and waves that are hazardous to small craft will then likely continue until Wednesday afternoon. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......RDM AVIATION.......Kieckbusch MARINE.........MPC
Area Forecast Discussion
National Weather Service Marquette MI
742 PM EDT Tue Oct 22 2019 .SHORT TERM...(This evening through Wednesday) Issued at 555 PM EDT TUE OCT 22 2019 WV imagery and RAP analysis indicated a deep trough over the central CONUS with the mid/upper level low over Lake Superior. Weak shortwaves along with abundant moisture continued rotate around the low supporting area of sct showers that were moving through western Lake Superior and western Upper Michigan. At the surface, a 987 mb trough extended from nw of Thunder Bay Ontario to central Lake Superior. The tighter pres gradient farther to the south supported gales and high waves from Lake Michigan into portions of Delta and Schoolcraft counties. Tonight, expect sct/nmrs showers through this evening especially over the west. As colder air moves in with 850 mb temps dropping to near -5C with deep moisture over the area, westerly flow lake effect/enhanced rain showers will also affect western portions of Upper Michigan. Wet-bulb zero heights will drop off enough to allow some snow to mix with the rain over the higher terrain. Winds off of Lake Michigan will slowly diminish this evening allowing waves to subside enough to alleviate any remaining lakeshore flooding. Wednesday, as the mid level and sfc low lift northeast toward James Bay and weeken, expect the pcpn coverage and amouns to diminish. However, the deeper moisture will remain across the area along with cyclonic westerly low level winds. This will keep lake effect/enhanced pcpn going for mainly northwest portions of Upper Michigan. Highs will range from the lower 40s west to near 50 over the south and east. Wet-bulb zero heights will continue to support a mix of snow for the west with some minor accumulations on grassy areas possible. .LONG TERM...(Wednesday night through Tuesday) Issued at 403 PM EDT TUE OCT 22 2019 Long term period starts off with the persistent upper level low thats been impacting our region since the wind/lakeshore flooding event Monday. Beginning Wednesday night, the low will be over the southern fringes of Hudson Bay and an associated shortwave will be pulled over Lake Superior bringing the chance for some lake effect rain/snow showers to the NW/W lake effect belts. Dry air will settle in behind it and high pressure eventually settling in on Friday. There is a weak shortwave signal Friday, but given the amount of dry air that will need to be overcome, don`t expect much in the way of precipitation. Following this shortwave`s exit, southwesterly flow and subsidence will set in Friday afternoon through Saturday. Toward the later part of the period beginning Sunday there is a chance for another low pressure moving across the region, but at the moment models are diverging on any kind of consensus. Wednesday night through early Thursday, a shortwave associated with our outgoing upper level low will move through the region. CAA will settle 850 temps ~-6 to -8 C. With Lake Superior temps hovering near +7C (delta ~13C), it should be unstable enough for some lake effect rain showers to develop in the northwest/west lake effect belts. Nothing impressive is expected due to low inversion heights near 5k feet and some low level dry air in place ahead of the shortwave, so any development will likely be light and scattered in nature. Wetbulb zero heights look low enough to keep precip as snow away from the shorelines in Gogebic and Ontonagon into the central interior, and even the Michigamme Highlands if precip makes it that far inland. Accumulations look high enough to cause perhaps a dusting but given surface temperatures staying above freezing, its likely everything will melt during the day Thursday. Warmer temps in the Keweenaw Peninsula will likely make precip a mix and out east and primarily rain. Friday morning looks chilly, with 850 temps of -6 to -8C over the region, expect lows to hover near freezing with the typical interior cold spots seeing 20s and maybe some upper teens. A 2nd shortwave moving through Friday will need to overcome some low level dry air before any precip reaches the surface. Lower inversion heights will also make any development harder to sustain. Temperatures will be cold enough aloft for a potential mix of rain/snow in the Copper Country, but with southwesterly flow setting in during the day, surface warming into the low 40s will be enough to melt any accumulations. Increasing subsidence with a building high pressure will create a couple of nice dry days beginning Friday afternoon. Saturday, with increased mixing up to ~2k feet, some gusty winds will be possible during the afternoon hours. Temperatures will climb into the low 50s. Models begin to diverge from here, with the GFS bringing a low up from the central/southern Plains toward the lower Great lakes and east coast beginning early Friday while the ECMWF and Canadian have this progression beginning Saturday and keeping the system much more west, bringing the Upper Great Lakes the potential for another shot of rain. Until the models reach more of a consensus on the placement and timing of this low, I`m going to keep POPs low. Saturday night into Sunday, another low will move across middle-Canada toward James Bay. Given the uncertainty in the placement of the earlier low, its hard to say if the flow through the shortwave will be enough to develop any lake effect showers. Similarly, keeping POPs low. Behind the low, cold temperatures move in. Right now highs for the early half of the week look only to climb into the 30s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 742 PM EDT TUE OCT 22 2019 Low-level moisture and an area of low pressure over Lake Superior will continue to bring transient -SHRA throughout the UP and all TAF sites. Overnight, -SHRASN will become more lake-induced rather than from the low pressure, so expecting SAW to become dry, with a chance at VFR. As pockets of showers move through, latest obs show the chance for vsbys to fall into IFR briefly, so have included a tempo at IWD and CMX to account for this. Until this low continues further north late tomorrow, expect gusty conditions across all TAF sites. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 555 PM EDT TUE OCT 22 2019 The low pressure system that created storm-force gusts yesterday has moved north of Lake Superior this afternoon as the gradient relaxes. WNW winds are expected to continue through tomorrow evening, gusting up to 30 knots with a few gale-force gusts throughout the next 24 hours or so. Expect this low to slowly moving north, reaching James Bay by Thursday. During this time, winds are expected to slow relax to 20 knots from the NW by Friday morning. High pressure moving through the Central Plains later this week will switch winds more from the SW for this upcoming weekend with winds gusting up to 25 knots on Saturday and Sunday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Lakeshore Flood Advisory until 8 PM EDT this evening for MIZ013. Lakeshore Flood Warning until midnight EDT tonight for MIZ014. Lake Superior... None. Lake Michigan... Gale Warning until 8 PM EDT this evening for LMZ221-248-250. && $$ SHORT TERM...JLB LONG TERM...JP AVIATION...JAW MARINE...JAW