Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/08/19

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
502 PM MST Thu Nov 7 2019 .AVIATION... 00Z TAF CYCLE Areas of fog and IFR/LIFR conditions are likely tonight, mainly for central and ern NM. At this point, KABQ, KAEG and KSAF are the most likely terminals to see at least brief, possibly dense, fog toward sunrise Friday. Elsewhere, low stratus clouds will be the rule, especially east of the central mt chain. The fog and low clouds are forecast to gradually dissipate during the late morning and early afternoon Friday. Winds will remain light for all TAF locales through Friday. 33 && .PREV DISCUSSION...256 PM MST Thu Nov 7 2019... .SYNOPSIS... A gloomy day across central and eastern New Mexico today will turn brighter Friday after cloud cover burns off in the morning. High temperatures will trend warmer with readings closer to normal for most of the area. Southeast New Mexico will remain cool where clouds take the longest to burn off Friday. The remainder of the weekend looks very nice with above normal temperatures, light winds, and clear skies. A strong back door cold front will move into New Mexico Sunday night and Veterans Day with much colder air through Tuesday. && .DISCUSSION... Cold and moist upslope flow over eastern NM has allowed widespread low cigs with patchy fog to continue over the area today. A strong 1034 mb surface high over west Texas will slide east overnight as an 80-100 kt upper level jet moves eastward into the Great Plains. Low level flow will slowly veer south then southwest by Friday morning while much drier mid and upper level air slides overhead. This will help erode low clouds and freezing fog along and east of the central mt chain through noon. The HRRR fog product and RAP boundary layer and surface wind profiles will remain favorable for dense freezing fog to persist in the area from around Clines Corners to Ruidoso overnight. A Freezing Fog Advisory has been issued for this area with potential expansion into Guadalupe County and the Caprock. Much drier air will invade the region from the northwest on Friday as strong upper level high pressure builds into the Four Corners region. This dry airmass with clear skies and light winds will lead to a delightful weekend for most of the area with temps warming above normal. The main exception will be over far southeastern NM where low clouds may linger through Friday afternoon, followed by more fog within the Pecos Valley of Chaves County Saturday morning. The next back door cold front will slide into northeast NM Sunday afternoon. This will be a stronger front than the most recent and surge west into the RGV through Veterans Day. Temperatures will trend below normal again for the entire area along with another round of low clouds over eastern NM. An upper level low will be taking shape over northern Mexico through this period however it looks too far south to result in any mentionable precip chances for northern and central NM at this time. Guyer && .FIRE WEATHER... There are no critical fire weather conditions forecast for the next 7 days. However, widespread poor ventilation rates are forecast to remain through Saturday. Temperatures today have been well below normal for most, but will quickly rebound to above normal values by the weekend. Dry conditions persist Friday and Saturday under clearer skies, and vent rates will briefly trend up across southern and eastern NM Sunday. However, temperatures and vent rates will fall again behind a cold front that will move through the area during the day Sunday. The cold front coinciding with a moisture increase from the south could produce a few rain and snow showers in the east on Monday, but precipitation is expected to remain light. 15 && .ABQ WATCHES/WARNINGS/ADVISORIES... Freezing Fog Advisory until 4 AM MST Friday for the following zones... NMZ223-226-239. && $$ 52
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
941 PM EST Thu Nov 7 2019 .UPDATE... Upper trough axis making steady progress across the lower peninsula this evening - this motion prompting a slight veering of the 0-1 km wind field with time. This process effectively eliminating the lake Michigan moisture flux locally, as the resulting lower level drying works into the increasing nocturnal stability to yield a steady decline in both strato cu coverage and snowflake production across the Saginaw valley and thumb region. There remains a transient window roughly 10-14z tomorrow morning for a burst of moderate intensity Lake Huron derived snowfall to glance across the eastern thumb shoreline, as the existing lake aggregate trough and corresponding convergence boundary pivot south-southeast. Recent HRRR guidance more definitive now in keeping the bulk of this response just offshore. This solution now in better agreement with other model output, and absent of radar evidence to prove otherwise yet, this leaves no compelling reason to deviate from the going forecast of a couple of inches across a small geographic footprint along the immediate shorelines of eastern Huron and Sanilac counties. && .PREV DISCUSSION... Issued at 643 PM EST Thu Nov 7 2019 AVIATION... A cold northwest flow will govern conditions through the overnight period. This pattern will favor a gradually diminishing coverage of strato cu within a drying low level environment this evening, encouraged by the loss of daytime heating and a less favorable downstream trajectory for the ongoing lake Michigan moisture flux to manifest additional cloud. A prevailing modest northwest wind will veer to westerly Friday as high pressure settles across the region. Dry low level conditions favor plenty of open sky during the daylight period, with simply a limited coverage of afternoon diurnal strato cu. DTW THRESHOLD PROBABILITIES... * Low in ceilings at or below 5000 ft prior to midnight. PREV DISCUSSION... Issued at 339 PM EST Thu Nov 7 2019 DISCUSSION... Upper level trough axis/cold pool (-24 C at 700 MB) sliding through the Central Great Lakes this evening/tonight. Pronounced low level anti-cyclonic flow over the bulk of southern Lower Michigan today has kept snow shower activity out of southeast Michigan thus far (through 2 PM), with decent amount of sunshine allowing temps to rebound into the 30s. However, it appears the Lake Superior-Lake Michigan-Saginaw Bay connection will be in full effect this evening. 12z NAM sounding is very impressive for BAD AXE, with good low to mid level lapse rates, with capes up to 50 J/kg and very impressive cloud depths progged to reach close to 12 kft, with a brief window of good supersaturation with respect to ice. Confidence is high there will be numerous convective snow showers around Saginaw Bay this evening, and have ramped up pops north of M-46. A quick localized inch or two of snow is possible over the northern thumb region with sufficient cape intersecting the DGZ, but most places probably just picking up half an inch or less due to short duration. Attention overnight/Friday morning will turn to Lake Huron and whether the convergence band/lake induced thermal trough will glance the eastern shoreline of the Thumb Region. If the high building into northern Ontario overnight is a bit stronger, than could see the HRRR/ARW solutions materialize, which would be worthy of snow headlines with 850 MB temps of -12 to -14 C over the Lake Huron water temps still 8 C. Some concern/probability approaching 50 percent to issue Winter Storm Watch for Huron County in the 9-16z window, just in case the band makes better inroads into the eastern shoreline, supporting localized heavy snow of 5+ inches. However, preference is to favor the bulk of the solutions (NAM, etc) and keep enough of a northwest component to keep the main Lake Huron band mainly offshore. Will allow for a quick brush to the shoreline Friday AM (localized <3") before the surface ridge moves in Friday afternoon. Inherited mins tonight around 20 degrees looks good based on guidance, with highs back into the 30s for tomorrow. Building heights and low level warm advection will support a modest warmup over the Weekend as wave of low pressure tracks through the northern Great Lakes. Isentropic ascent/warm advection pattern perhaps supporting a little bit of light snow and/or rain showers by Saturday Evening/Night. The extended forecast begins with ongoing rain showers Sunday morning, but there could be frozen hydrometeors mixed in early on as surface temps turn positive (degrees C) beneath narrowly saturated low-levels. Ice nucleation will be relatively inefficient aloft as the column becomes subsaturated wrt to ice in the DGZ, so actual precip type may be more of a rain/ice pellet mix. Sunday will be the warmest day of the total forecast period as highs creep into the 40s CWA-wide. A cold front will cross through during the afternoon with a good FGEN axis allowing for another bout of rain, but with the colder air punch, a change over to all snow is expected by dark. Winds back to the northwest and polar air surges through the Great Lakes in the wake of the cold front as an upper level jet streak pivots south locking in the polar air mass. Precip chances continue on Monday as the right entrance region of a jet streak fuels stronger upper level divergence generating broader ascent. 850 mb temperatures now plunge to near -20 C which suggest sub-freezing high temps on Monday. Given northerly low-level winds east of I-75, there could be a period of lake effect snow showers which could provide a good dose of snowfall, particularly in the Thumb as an inverted surface trough helps increase low-level convergence. Additional forcing will be provided by a shortwave trough deepening within the broader longwave feature packing a good dose of higher mid-level vorticity which will keep snow shower possibilities into the early morning hours on Tuesday. Surface ridge axis pushes into the Great Lakes from the Missouri Valley on Tuesday as an expansive high builds east centering over southern Illinois. Drier conditions will slowly take hold late Tuesday and into early Wednesday as surface temps stay chilly. The next trough moves through on Thursday, but moisture quality is still a question mark before zonal flow backs to the southwest and another inverted trough develops over Lake Huron. MARINE... Gusty west-northwest winds will prevail through the rest of the evening before slowly weakening during the night and Friday morning as high pressure nudges into the area from the west. Ongoing snow squalls across Lake Huron will persist into the morning with the cold air overhead. Southwest winds will strengthening Friday night and into the day Saturday as a cold front slides into the northern Great Lakes. Wind gusts are expected to remain below gale force. However there is a high probability that gusts will reach 25 knots, with up to 30 knots over the open waters of Lake Huron. Subtle weakening of the wind field is forecast on Sunday before the actual passage of the arctic cold front across the region late Sunday into Sunday night. Winds will veer to the northwest with the passage of this front. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...Lakeshore Flood Advisory until noon EST Friday for MIZ049. Lake Huron...Small Craft Advisory until 10 AM EST Friday for LHZ421-441>443. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ UPDATE.......MR AVIATION.....MR DISCUSSION...SF/KK MARINE.......SC You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
549 PM CST Thu Nov 7 2019 .SHORT TERM...(This evening through Friday night) Issued at 210 PM CST Thu Nov 7 2019 Main concern in the short term is the overall temperature trend. Stratocumulus over the eastern CWA should gradually dissipate this evening as drier air works in from the west. Some mid clouds are dropping fairly rapidly southeast and will likely clear the southwest CWA by early evening. The surface ridge builds east tonight and should provide mainly clear conditions along with light wind. Temperatures should drop off to the single digits again tonight over most of the snow covered areas. We even saw some slightly below zero readings in south central MN last night. This cold core should move east into Friday morning and southerly winds are expected to increase with pressure falls and overall pressure gradient increasing. Will be breezy west and south into the afternoon and should help erode some of the cold air. Mainly mid/high level clouds around much of the day should limit overall sunshine potential. Highs Friday afternoon should rise to the lower 40s in the far southwest with 30s generally elsewhere. Decreasing winds Friday night with the area seeing warmer temperatures. Lows should remain in the 20s overnight. .LONG TERM...(Saturday through Thursday) Issued at 210 PM CST Thu Nov 7 2019 The period will commence with MN/WI squarely within the warm sector portion of a quick-moving clipper shifting east across the international border on Saturday. While relatively deeper moisture will be found in northern MN into the Great Lakes, a weak surface trough dropping south from the main low will make for enough lift to produce isolated to scattered rain/snow showers over mainly central MN into western WI Saturday night into Sunday. Not looking for anything significant by any means with this weak and progressive system. Its associated cold front will drop southeast through the region Saturday night, followed on its heels by a 1048mb western Canadian high pressure airmass which will slide into the Central Plains through early next week. A few snow showers are possible in southwestern MN Sunday but by and large the WFO MPX coverage area will remain dry late Sunday thru Wednesday. That being said, this high pressure area will drag in arctic air into the region which may well be cold enough to set record low maximum temperatures early next week. H925-H850 temps still look to drop to around -20 deg C which when blended to the surface would produce highs in the teens Monday-Tuesday. In addition, lows Sunday night and Monday night would drop to the single digits. Combined with winds around 10mph, wind chills will drop to the single digits below zero. A small recovery is expected for the middle portion of next week with the broad longwave trough moving east but this will also bring in another clipper-type system from western Canada into the Northern Plains Wednesday then into the Great Lakes Thursday. Still plenty of uncertainty with this system as the operational models have had different tracks of this system. Nevertheless, profiles are showing plenty of cold air sufficient for snow Wednesday into Thursday, just a matter of how much and where, which should be resolved in the coming days. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 549 PM CST Thu Nov 7 2019 As high pressure slides east overnight, we will see light winds quickly turn to a southerly direction. As this happens, band of clouds over southwest MN will work northeast. Models have a poor handle on this shallow cloud layer, but followed the idea of the RAP for bringing this northeast across MN through the night. This cloud layer will bring the potential for 2 or 3 hours of MVFR cigs as it moves through a location. After that, just ample mid/upper clouds for Friday. KMSP...Currently, threat for MVFR cigs (likely around 025) at MSP exists between 13z and 16z. Confidence in rest of TAF is high. /OUTLOOK FOR KMSP/ Sat...MVFR. Chc IFR. Slgt chc rasn. Wind SW at 5-10 kts. Sun...Chc MVFR cigs early. Wind NNW 10G20 kts. Mon...VFR. Wind NW 10-15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. && $$ SHORT TERM...DWE LONG TERM...JPC AVIATION...MPG