Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/05/22

Area Forecast Discussion
National Weather Service Gaylord MI
925 PM EST Fri Feb 4 2022 .UPDATE... Issued at 925 PM EST Fri Feb 4 2022 Sharp upper level trough axis and weak surface reflection has reached Lake Michigan late this evening. With very little moisture to work with...only synoptic precip being produced by this system is very light snow showers/flurries across much of our CWA. Persistent mid Lake Michigan snow band is trying to push onshore across portions of our Lake Michigan shoreline around FKS and MBL as expected...but onshore push is being limited by the opposing land breeze. Expect this will remain the case as we head into the overnight hours. Expect majority of any accumulating snow will be limited to just these shoreline areas from FKS to MBL...with the rest of our CWA only receiving a dusting of new snow. Certainly expect another very cold night...but not as cold as last night. Overnight lows will fall into the single digits above and below zero. && .NEAR TERM...(Through Tonight) Issued at 336 PM EST Fri Feb 4 2022 ...Still cold, but not as cold as last night... High Impact Weather Potential...Minor. Cold temps/wind chills. Light snow accums parts of nw lower MI. A poorly defined 1026mb clipper low is over sw WI. The parent forcing shortwave is fairly vigorous, but broader MSLP across the region is quite high, and moisture availability is poor. Snow shower activity over ne WI has increased, as forcing moves in over residual lake effect processes in earlier ne low-level flow. There is a brief transition to weak sw to w 1000-850mb this afternoon and early evening, before convoluted and still light northerly flow returns by overnight. Main precip concern is whether lake effect banding can push onshore into nw lower MI. Temps/wind chills are the primary concern for most places. Stronger Lake MI lake effect band is evident on visible sat this afternoon, seen thru a thin veil of higher clouds. This band is slowly pressing eastward, and our low-level flow will remain weak enough for only slow motion to continue. As it gets closer to nw lower MI, the band will encounter a land breeze. This is at a relative minimum this afternoon, as land surface temps have `warmed` into the upper teens. As we move past peak diurnal heating, the land breeze circulation will strengthen as temps cool over land. There is probably a window this evening for some stronger snow showers to reach coastal Manistee Co, and perhaps as far north as the Dunes and Manitous. Will have 1-2" accums along the coast in these areas, highest near MBL. Think that by late evening/overnight, an increasingly dominant land breeze will push and keep the stronger band offshore. Recent HRRR runs largely jive with the above thinking. Cloud cover will initially be fairly extensive, though thin, with cirrostratus and some mid clouds. As the clipper digs se-ward, and northerly low-level flow returns, we will see partial clearing work in from the north toward midnight. Eastern upper and ne lower MI will see a period of mostly clear skies overnight (though lake clouds from Superior will spill back into eastern upper very late). This will contribute to cold temps again tonight, though not as much as last night. Mins will range from zero to 10 below in eastern upper, n central and ne lower MI. Single digits above zero in nw lower MI. Wind chills reach the mid minus teens in parts of eastern upper MI. && .SHORT TERM...(Saturday through Monday) Issued at 336 PM EST Fri Feb 4 2022 High Impact Weather Potential: Accumulating snow in eastern Upper Saturday afternoon/night...potential freezing drizzle across northern Lower late Saturday night into Sunday... Pattern Synopsis/Forecast: Last 24-48hrs has seen the upper level jet max depart the region up the SW-NE oriented flow as trough axis slides into the Great Lakes today...leaving Michigan under the left entrance region of the jet...typically favored for upper level convergence, sinking motion, and surface high pressure...which resulted in the bitterly cold lows last night across the area. Upstream...another strong (140+kt) upper- level jet max is riding the height/thermal gradient on the downstream side of ridging progressing eastward into the western Plains. A stronger shortwave crossing into British Columbia is temporarily smooshing the prevailing western ridge...but it is on the rebound behind it. Otherwise...a niblet of energy has disconnected from the flow and is dropping southward along the California coast. Shortwave dropping into the Upper Midwest is resulting in some mid- level moisture and a surface response (1028mb low) zipping southeastward across the Upper Mississippi Valley...through broad areas of ~1040mb surface high pressure attempting to control much of the northern and central CONUS. Stationary boundary extends northwestward into Alberta (where else?? Seems like it`s been there forever now...) from this surface low, along the baroclinic zone aloft another area of ~1040mb surface high pressure slides southeastward into the central Canadian Prairies/northern Plains...upstream from the area of cold and dry surface high pressure that moved through last night. This extremely cold and dry airmass overwhelming the Great Lakes results in lake aggregate effects showing up on the surface analysis, as latent heating from the lakes results in a hydrostatically lowered pressure overhead. (This is slightly harder to see now that the clipper system is dropping in.) Baroclinic zone across the southeastern US as trough axis swings into the Great Lakes today results in a continuation of the SW-NE oriented surface boundary and low pressure slowly trekking eastward through the Appalachians this morning...taking the bulk of the moisture along with it. Going forward...will look for trough axis to swing through the Great Lakes today/tonight...with a brief ridge moving in ahead of the next shortwave niblet diving into the flow with a strengthening jet max moving in as well. As this niblet moves into the Great Lakes Saturday night into Sunday...ridge across the west coast will rebound...allowing troughing to take hold of the central CONUS for a time. However...additional niblets getting underhand-pitched up the flow by the general area of upper level low heights over the western Pacific will again shift suppress/shift the ridge eastward going into Sunday and Monday. This will force the trough axis through the Great Lakes going into the next upstream niblet chugs through the Canadian Prairies/Northern Plains early next week. Primary Forecast Concerns: Winds Saturday and Saturday night...Snow potential Saturday through the period...freezing drizzle potential later Saturday night into Sunday... Warm advection will commence Saturday as low-level winds become more southerly with time, veering with height. Pressure gradient will tighten as well...suggesting that sustained winds will be a bit stronger through the period. If we mix up to 925mb...could be looking at gales along the Lake Michigan there are signals for stronger winds even up at that level off the will have to keep that in mind for our Lake Michigan zones (which will be where better mixing would be expected anyway). Even so...with somewhat stronger southerly surface winds in play Saturday night...could be looking at some blowing snow concerns along US-2 in Mackinac county, as snow gets blown off the ice cover up there in northern Lake Michigan. Weakening pressure gradient Sunday will result in decreasing winds with time. jet max moves through the may briefly support some upward forcing with left exit quadrant dynamics in play...though it doesn`t appear overly strong attm. Best forcing aloft appears to be attributable to the shortwave itself as it comes on scene later Saturday night...with niblets of energy passing by to our southwest. There may be some low-level convergence across southern Mackinac county early on Saturday morning...apparently largely attributable to mesoscale may have to keep an eye on that, perhaps even for our Lake Michigan coastline a little further south (though nothing overly impressive noted attm). flow becomes more southwesterly and then southerly with time...will look for better boundary layer convergence across the central UP, with a long fetch over a majority of the length of Lake Michigan. These signals only grow stronger with time Saturday evening ahead of the surface system, waning to some degree through the remainder of the night. Winds appear to become slightly more southwesterly with time Saturday night into early Sunday morning...which should shift the position of the band eastward with time through the night, and lead to some potentially higher snowfall totals in the Tip of the Mitt for early Sunday. The shifting winds may help mitigate snowfall totals to some we`ll be more evenly watering the garden, as opposed to putting a firehose on the garden all night Saturday night. Mid-level moisture begins to spread into the region through the afternoon Saturday into Saturday night...and do see a response in boundary layer moisture with time as well...likely mainly in the way of warm advection processes as top down saturation occurs (aided in S flow areas by existing boundary layer moisture leading to seeder feeder processes). Over-lake instability appears greatest during the daylight hours Saturday into early Saturday night...waning with time as temperatures aloft rise (thanks to warm advection). That being said...925mb temps look to remain around -8 to -10C for much of the northern half of Lake Michigan going into early Sunday morning, with even warmer temps approaching from the south by then, which may help shut the lake off for a time. Given that overlake instability will still be decent at the same time as deeper moisture and excellent low-level convergence will be in play...Saturday afternoon and particularly evening should see the highest snowfall rates and totals. Noting continued signals, per model-derived guidance, for upward motion pegged in a reasonably deep isothermal layer in the DGZ...snowfall rates and snow-to-liquid ratios (SLRs) could be rather impressive at times Saturday evening. (This, combined with the aforementioned stronger winds off Lake Michigan could make travel rather difficult for parts of US-2 along the coast in Mackinac county later Saturday into Saturday night.) Do note some signals that mid-level moisture may hold on a little firmer into Sunday than previous guidance had suggested...which may help mitigate the idea of freezing drizzle to some extent. That being said...there are still signals, particularly in model derived soundings, of some boundary layer moisture with cloud top temperatures around -10C or perhaps warmer. -10C is typically a lower/warmer bound for ice nuclei activation...though some ice nuclei may become activated at warmer temps than this. (And we have basically almost zero idea of what kind of ice nuclei are up there to know whether or not they`ll become activated and produce cloud ice vs. staying supercooled liquid droplets... the temperature thresholds are more of a probability of cloud ice thing, with higher probabilities of seeing cloud ice the colder your clouds are.) For the most part, looks like forcing in this layer should be relatively minimal late Saturday night into Sunday...but any sort of lift could produce freezing drizzle (such as upslope flow, which could be a problem for the interior higher terrain with south/southwesterly flow). Looks like the best chance for this freezing drizzle crud to take place will be very late Saturday night into Sunday morning into part of Sunday...until we get a little deeper moisture to colder temperatures aloft as the trough axis approaches and slides through, dragging better moisture aloft (as well as cooler temperatures aloft) along with it...supportive of a transition back to snow. Areas across eastern Upper and perhaps the Tip of the Mitt may remain all snow through the period...though there are some signals they may flirt with cloud top temps of -10C as well at times into Sunday. Definitely something to keep an eye temps will be warmer, but are not overly likely to break the freezing mark. Otherwise...looks like snow potential should continue on into Sunday night until the better moisture departs aloft going into Monday... with 850mb temps dropping Sunday night behind the slow-moving front/trough aloft...supportive of a) a potential uptick again in widespread snowfall as the trough moves in (increasing convergence/lift in areas of moisture), and b) perhaps some lake effect snow potential behind the system into Monday. Winds becoming more northerly with time Monday suggests any lake bands will ultimately shift more offshore through the day. May still see some kind of west/northwest flow lake effect through the night Sunday into early Monday. .LONG TERM...(Monday night through Friday) Issued at 336 PM EST Fri Feb 4 2022 High Impact Weather Potential: Minimal attm. Pattern Synopsis/Forecast: A fair bit of uncertainty comes into the fray for the start of the guidance isn`t quite sure how to handle that niblet moving through the Northern Plains/Canadian Prairies. A more coherent solution would lead to a stronger surface system with more warm advection ahead of it...whereas as a more out-of-phase, slightly more nebulous solution for troughing in the northern stream may not be quite as dramatic. Either way, there are still signals for troughing to return to the center of the country for a time toward the middle of next week. There is additional uncertainty with this, basically the same idea remains -- a more coherent and unified trough would allow for more direct cold advection into the northern US...whereas a less unified trough would be a little more like partially blocking the firehose of cold air. Will have to keep an eye on this going forward. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 611 PM EST Fri Feb 4 2022 Sharp upper level trough axis and weak surface reflection will swing thru Michigan this evening. Do not expect much in the way of synoptic snow...but weak low level flow will shift to west...which will likely push mid lake snow bands over Lake Michigan into portions of NW Lower Michigan tonight into Saturday morning... mainly around TVC and MBL. Conditions will drop to MVFR/IFR within some of these snow bands. More widespread snow will begin to develop from NW to SE Saturday afternoon ahead of a developing low pressure system moving out of the Northern Plains and into the Western Great Lakes. Again...mainly MVFR/IFR conditions are expected as this snow develops. Light/variable winds tonight into Saturday morning will become southerly at around 10 kts by Saturday afternoon ahead of that system. && .MARINE... Issued at 336 PM EST Fri Feb 4 2022 Light winds remain in place into early Saturday, as a weak clipper crosses the southern lakes. S to sw winds will ramp up considerably on Saturday, and gales are a distinct possibility on Lake MI for part of Sat evening. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...NONE. LM...GALE WATCH from Saturday evening through late Saturday night for LMZ341-342-344>346. LS...NONE. && $$ UPDATE...MR NEAR TERM...JZ SHORT TERM...FEF LONG TERM...FEF AVIATION...MR MARINE...JZ
Area Forecast Discussion
National Weather Service Green Bay WI
955 PM CST Fri Feb 4 2022 Updated aviation portion for 06Z TAF issuance .SYNOPSIS... Issued at 246 PM CST Fri Feb 4 2022 Light snow ending this evening, then another round of light snow possible Saturday into Saturday evening, mainly across the north. Temperatures stabilizing at near-to-above-normal levels. The fairly persistent strong ridging near the west coast of North America will flatten significantly as Pacific jet energy breaks through the ridge and sweeps east across the continent. This will will result in at least a temporary break in the flow of cold air from high latitudes into the northern CONUS. Temperatures will still undergo daily swings with the passage of individual weather systems, but should be above normal most of the time after tomorrow. The new pattern still looks unfavorable for significant precipitation, so below normal amounts expected for the next week. && .SHORT TERM...Tonight and Saturday Issued at 246 PM CST Fri Feb 4 2022 The latest RAP analysis and satellite/radar imagery show a digging shortwave and associated surface trough passing across the northern Mississippi Valley early this afternoon. Light snow has been gradually spreading east across northeast Wisconsin ahead of the shortwave. Meanwhile, a robust mid-lake snow band moved into northern Door county from northern Lake Michigan, briefly dropping visibilities at Ephraim to 1/4 mile. Looking upstream, the next clipper is moving into the Pacific northwest and poised to impact the region tomorrow. Forecast concerns mainly revolve around snow chances/trends followed by min temps tonight. Tonight...Light snow will be ending early in the evening across northeast Wisconsin as the shortwave trough axis shifts into northern Lake Michigan. Little to no additional accumulations are expected. Models appear to be a little too aggressive with the cloud cover tonight based on current satellite imagery, so think a several hour period of clearing will occur before high and mid clouds return late. As a result, remained on the cold side of the temperature guidance, particularly at the cold spots over the northwoods. Lows ranging from the mid teens below zero at Tomahawk to near 0 along the Lake Michigan shoreline. Saturday...The next clipper will rapidly move into Minnesota by the end of the afternoon. Models insist on a fgen band developing over far northern wisconsin by late morning before translating east to Door county in the afternoon. This area may be a little further north than previous forecasts, and shifted the highest chances north somewhat. Accumulations still look like 1-2 inches near the U.P. border will be possible, and up to an inch south of a Arbor Vitae to Wausaukee line. South winds will become breezy in the afternoon with gusts to 30 mph. Temperatures will rebound into the mid teens north to the low 20s south. .LONG TERM...Saturday Night Through Friday Issued at 246 PM CST Fri Feb 4 2022 Fairly quiet weather is expected throughout the long-term portion of the forecast. There will be at least a few light precipitation events, but the timing of those is nearly impossible to pin down after Saturday evening due to the increasingly zonal flow. The medium range model ensembles had been fairly consistent in showing a consolidation/re-amplification of the eastern Pacific ridge by the end of next week. There is still some support for that in the latest runs, but it has lessened considerably from what it was a few days ago. So the longer range temperature trends are now more uncertain, and it`s hard to even estimate when the next substantial precipitation event will affect the area. && .AVIATION...for 06Z TAF Issuance Issued at 949 PM CST Fri Feb 4 2022 High/mid clouds will return overnight into Saturday morning, with IFR conditions developing across far northern WI as light to occasionally moderate snow overspreads the area in the late morning and afternoon hours. Light snow will likely persist into the evening hours. The RHI TAF site will be most affected by the snow, though AUW and CWA may see a brief period of light snow around midday, and other locations may see some flurries in the afternoon. Light and variable winds are expected overnight, followed by gusty south winds Saturday afternoon and evening. A period of LLWS may occur at some of the TAF sites Saturday evening. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS.......Skowronski SHORT TERM.....MPC LONG TERM......Skowronski AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Indianapolis IN
1034 PM EST Fri Feb 4 2022 ...Updated Aviation Discussion... .Forecast Update... Issued at 921 PM EST Fri Feb 4 2022 Had to make quite a bit of changes for the rest of the night. Ramped up cloud cover and slowed down clearing from west to east based on obs and satellite trends. This necessitates raising temperatures a few degrees overnight and matches better with our neighbor offices. Even so, temperatures will bottom out near zero and wind chills will be below zero. The next change was to bring in light snow or flurries to northern sections based on recent obs, radar returns and HRRR soundings. Lafayette, Kokomo, Frankfort and Crawfordsville were all currently reporting light snow or flurries. Judging by the quick movement, lack of deep moisture and radar echo strength, little or no accumulation is expected. && .Short Term...(This evening through Saturday night) Issued at 212 PM EST Fri Feb 4 2022 * Cold temperatures this weekend * Wind chill values below zero tonight. Surface analysis early this afternoon shows a strong ridge of high pressure stretching from the southern plains to lower Michigan...providing a cold NW surface flow across Central Indiana. A weak area of low pressure was found over western WI with a trailing cold front across IA to NB. GOES16 shows high clouds drifting east across Indiana with clearing skies found upstream under the ridge axis over MO and IA. Radar shows any lingering flurries have exited the area to the east. At this wind chill advisory appears to be needed as winds are expected to remain near 5knts or less overnight...producing wind chill values in the 0 to -10F range. Will adjust as needed if winds end up being stronger than anticipated. Tonight... The surface ridge is expected to push east of Indiana along with a deep trailing trough within the flow aloft. This will allow winds to become more westerly overnight. This westerly flow riding over the cold air in place at the surface will lead to stratocu formation overnight as forecast soundings hint at lower level saturation this evening and early overnight. Still with fresh snow in place across the area along with 850mb temps near -16 and light winds a cold night is ahead. Forecast soundings show the arrival of startocu this evening but clear it out after 09Z...allowing for a few hours of radiational cooling. Thus will trend toward a mostly cloudy evening with decreasing clouds overnight. Given the previously mentioned features in play...will trend lows at or below the NBM. Saturday and Saturday night... Models suggest mainly zonal flow in place on Saturday and Saturday Night with little in the way of forcing dynamics available. Weak ridging appears to push across Indiana within the mid levels with subsidence as a weak low pushes across Ontario...well north of Indiana. Within the lower levels...warm air advection begins on Saturday as the cold air previously in place begins to exit east...and by Saturday night a warm front associated with the low to the north is suggested to push across Indiana. This will allow 850mb temps to rise to -2C by Sunday morning. Forecast soundings through the Saturday and Saturday night remain dry...suggesting subsidence. Again...given the fresh snow and still cold air in place...will trend highs and lows at or below the NBM. && .Long Term...(Sunday through Friday) Issued at 212 PM EST Fri Feb 4 2022 Highlights: -- CAA with NW flow and building high pressure will lead to a dry and chilly to start next week -- Weak clipper system possible late next week, providing small chances for precipitation and slightly warmer temperatures. A persistent ridge over the US west coast will keep the mean steering flow out of the NW for the Ohio Valle through the long term. However, meridional influences will keep conditions fluctuating every couple of days. To begin the long term, a weak low level wave will be exiting, with moderate CAA in its wake. This will drop temperatures below normal once again for Sunday and Monday with highs in the mid 30s to mid 20s. With strong subsidence in the low levels, any cloud cover will be in the upper levels, with no precipitation expected. Shifting to mid-week, a low amplitude disturbance will approach the upper Midwest, shifting the low level flow towards the SW. This should create a pattern conducive to warming with highs back into the upper 30s and low 40s. This wave looks rather dry with not enough prolonged southerly flow for adequate moisture return, but some upper to mid level cloud cover is likely. By the end of the week, ensemble variability is high leading to much lower forecast confidence. Some ensemble members are picking up on a stronger wave with marginal moisture return, leading to PoPs on Friday. Still without anything nearing a model consensus, chances remain low at this time. && .Aviation...(06Z TAF Issuance) Issued at 1034 PM EST Fri Feb 4 2022 IMPACTS: - VFR flying conditions are expected through the TAF period. - Winds will be less than 10 knots and start off 270-310 degrees, then shift to 180-210 degrees after 18z. DISCUSSION: High pressure and drying column will combine for VFR flying conditions through the TAF period. Winds will be less than 10 knots and switch from west and northwest to south and southwest this afternoon. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ Update...MK Short Term...Puma Long Term...Updike Aviation...MK
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
513 PM MST Fri Feb 4 2022 .DISCUSSION...(This Evening Through Friday) Issued at 131 PM MST Fri Feb 4 2022 The upper trough has shifted to the eastern CONUS, while a ridge builds over the west, and a shortwave pushes into the Pacific NW. Morning flurries have disappeared, and skies are mostly sunny. At the surface, high pressure sits over the central Dakotas, with a trough over MT/WY, and a warm front draped across our CWA. West of the front, winds are southwesterly and breezy, and temperatures are in the 30s; east of the front, winds are easterly and light, with temperatures in the teens. Pacific NW shortwave will approach the northern plains tonight. Initially, only weak CAA and some gusty winds are expected on Saturday. Models disagree about wind strength: GFS ensemble and HRRR show advisory criteria winds likely across northwestern SD, but MOS guidance and ECMWF ensemble are more marginal. Forecast soundings still indicate 50+ kt 850 mb winds early Saturday morning, but decreasing winds aloft once mixing starts. Likeliest place for strong winds will be across NW SD where the pressure gradients will be tighter, so will issue a Wind Advisory there. Secondary piece of energy associated with the shortwave will push colder air into the region Saturday night into Sunday, and this combined with moisture advection, light snow will develop. Froude number is indicative of upslope enhancement over the northern Hills Saturday evening through Sunday morning, and models continue to slightly increase forecast snow amounts. Over the past few days, the NBM 50th percentile has increased from 0.5 to 3 inches; now the 90th percentile is up to 6 inches over the Black Hills. An advisory may be needed later. Also looks like there could be some light snow showers just about anywhere on the plains, so broadbrushed slight chance pops. Little to no accumulations are expected on the plains. Warm air advection resumes briefly late Sunday into Monday, allowing highs Monday to reach the 40s and 50s. However, the active pattern returns for the rest of the week, resulting in breezy periods and occasional snow showers. Moisture will be limited, so any snow accumulations should be light. && .AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening) Issued At 411 PM MST Fri Feb 4 2022 VFR conditions will continue through the TAF forecast period. A period of low level wind shear is expected across western South Dakota overnight. Gusty northwest winds will be found across the area on Saturday, with the strongest winds across the plains north of the Black Hills. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...Wind Advisory from 8 AM to 5 PM MST Saturday for SDZ001-002-012- 013-073. WY...None. && $$ DISCUSSION...Pojorlie AVIATION...7