Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/25/22


Area Forecast Discussion
National Weather Service Duluth MN
959 PM CDT Thu Mar 24 2022 .DISCUSSION...(This evening through Wednesday) Issued at 434 PM CDT Thu Mar 24 2022 Summary: a cold front will move through the Northland tonight, leading to increasing chances of a mix of rain and snow. Strong northwest winds are expected Friday, along with a low risk of snow squalls over east-central Minnesota into northwest Wisconsin. Another messy spring storm system is possible for the Tuesday through Thursday time frame, with a plethora of precipitation types possible. Conditions for the remainder of the day will largely be dry and quiet, thanks to a high pressure ridge axis that will translate through the region. Increasing clouds are expected this evening and overnight as a compact mid-level shortwave trough, with a decent area of positive vorticity advection, moves into the Northland. An attendant cold front will accompany the shortwave trough and will be the catalyst for increasing chances of light precipitation. NAM and RAP model soundings indicate precipitation types will be either rain or snow, or a mix of both. Additionally, there may be a brief period of light drizzle/freezing drizzle along the front, but ice accumulations should be limited. The front will eventually exit the region by mid-day Friday, but strong cold air advection on northwest winds will usher in behind the front. Chances of light snow showers will linger during the day Friday, as a saturated dendritic snow growth layer will remain in place. We have been looking at the potential for snow squalls across our southern areas during the morning and early afternoon hours. Both the NAM and RAP models are indicating surface-based CAPE around 30 to 70 J/kg, as well as some modestly steep low- level lapse rates. The isallobaric pressure couplet doesn`t appear to be very strong, which is favorable for snow squalls if there is a strong pressure couplet. Additionally, there is a modest FGEN band across our south during the morning hours. This is not the best set-up for snow squalls I`ve ever seen, but some of the ingredients are progged to be in place. So, it appears there is a lower risk for snow squalls tomorrow morning/early afternoon. In any case, a tight surface pressure gradient will be in place post fropa, so gusty northwest winds around 25 to 35 mph will be possible. There may be a few areas of blowing snow, but it isn`t anticipated to be widespread. Chances of light snow will come to an end Friday night, although the strong cold air advection, and favorable wind direction, will help support a prolonged period of lake-effect snow along the Lake Superior snowbelt region at least through Saturday morning. Drier conditions are expected for the remainder of the day Saturday through Monday. The main story over the weekend will be colder temperatures, with overnight lows in the single digits Saturday night and again Sunday night. Attention then turns to the potential for another messy spring system that is slated to move through the region, beginning Tuesday, lasting through Thursday. A longwave trough will develop along the western CONUS, which could lead to the development of a Colorado Low. There is significant uncertainty with this prolonged system, particularly when it comes to both precipitation amounts and types. The bulk of the precipitation looks to begin to fall starting Tuesday night, lasting through Wednesday night. It seems there are some discrepancies among the global models on the path of the Colorado Low, which will have significant implications on precipitation type and amounts. Definitely a system to keep an eye on! && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 643 PM CDT Thu Mar 24 2022 VFR conditions will start the period with cloud cover increasing this evening ahead of an approaching cold front. A line of rain and snow showers will pass through the region tonight as the cold front moves through. MVFR vsbys will be possible along this line of precip, with a chance for IFR vsbys in BRD. Northwest winds behind this cold front are likely to be strong tomorrow, particularly around the Brainerd Lakes area. MVFR stratus is unlikely to dissipate throughout the remainder of the period. In addition, light snow showers are likely throughout the day for most terminals. && .MARINE... Issued at 959 PM CDT Thu Mar 24 2022 10 PM Update: Expanded the Gale Watch to include the outer Apostle Islands, where wind gusts Friday evening may reach up to 35 knots. Otherwise, no major forecast changes were made since the previous update. Previous discussion: Light and variable winds will continue through the evening hours today, thanks to a high pressure ridge axis that will move across the region. Southwest winds will start to strengthen during the very early morning hours Friday ahead of a cold front that will sweep from west to east across western Lake Superior tonight through Friday morning. As the cold front moves through, winds will gradually turn more northwesterly during the daylight hours Friday, and strengthen even further. Northwest winds of 15 to 25 knots, with gusts to around 30 knots are expected, which will lead to hazardous conditions to smaller vessels. Even stronger winds are possible along the North Shore late Friday into Saturday morning, generally from Silver Bay northeast towards Grand Portage, as strong downslope flow will be possible. Gale-force gusts around 35 to 45 knots are possible. Due to this gale-force gust potential, we have issued a Gale Watch for the aforementioned areas, with a Small Craft Advisory elsewhere across western Lake Superior. Winds will weaken during the day Saturday, but gusts may remain around Small Craft Advisory criteria. && .PRELIMINARY POINT TEMPS/POPS... DLH 30 33 12 25 / 70 30 20 0 INL 26 29 7 21 / 60 40 20 0 BRD 31 34 12 29 / 70 40 10 0 HYR 28 36 14 30 / 50 60 40 0 ASX 28 36 17 28 / 40 50 40 20 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...Small Craft Advisory from 10 AM Friday to 10 AM CDT Saturday for LSZ121-143-146>148. Small Craft Advisory from 8 AM Friday to 10 AM CDT Saturday for LSZ144-145. Gale Watch from Friday afternoon through Saturday morning for LSZ140>142-150. Small Craft Advisory from 11 AM to 4 PM CDT Friday for LSZ140>142. Small Craft Advisory from 10 AM to 4 PM CDT Friday for LSZ150. && $$ DISCUSSION...JTS AVIATION...Unruh MARINE...JTS/Unruh
Area Forecast Discussion
National Weather Service Wilmington NC
950 PM EDT Thu Mar 24 2022 .SYNOPSIS... Showers will taper off late tonight into early Friday as a cold front moves offshore. Expect windy and cooler conditions this weekend as high pressure moves east across the northern Gulf of Mexico, and deepening low pressure tracks north of the waters. Fair with near to below normal temperatures early next week, will be followed by a noticeable warmup into mid-week, as high pressure aloft strengthens. && .UPDATE... Frontal boundary was located off the coast of the Carolinas at 00Z, although the dewpoint boundary remained just west of I-95, aligned along a surface trough. Mid-level water vapor imagery shows two distinct swaths of moisture...one extending northeast from central FL, just off the GA/SC coasts, and across Cape Fear. A trailing swath extended from the eastern Gulf of Mexico, northeast across eastern GA. Deep southwest flow, as shown in the KLTX 88D VWP, will direct this moisture across the area through 06-09Z, where it will combine with some lift provided by the right rear entrance region of the upper jet to maintain scattered to numerous PoPs. Deep layer of dry air pushes to the coast by around 09Z and precip should be shutting down. Have mainly tweaked PoPs and dewpoints with this update to account for current trends. && .NEAR TERM /THROUGH FRIDAY/... Though not readily apparent in any satellite windows radar trends clearly show that deep moisture and ascent are shifting offshore. For the most part this trend should continue, though some higher res guidance like the HRRR want to bring another round of slightly heavier rain up the immediate coast. Tried to preserve that sentiment in POPs but have lowered QPF a fair amount. The synoptic front is drawing near however and so the rain had better get underway for the wetter solutions to verify. For similar reasons it would seem that POPs lingering along the immediate coast seem a bit pessimistic even if only by a few hours. Dry air advection will make for a return of sunshine on Friday while lingering surface troughiness to our west holds back any CAA. The afternoon should warm to 70 for most. && .SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/... `Clearing and Windy` may describe start of weekend as we get caught between two powerful features, strong SW-W wind Saturday trends to W-NW Saturday night. Skies apt to see full clearing sometime Friday night. Associated cold air advection will dip morning lows into the 40s Saturday. Deep mixing Saturday sets the stage for gusts to 40 mph during afternoon, not far from wind advisory criteria for gusts of 46 mph or better. Dry air coursing across southern periphery of upper low provides plenty sun to aid efficient mixing. The cooler air will hold max-T below 70 most places Saturday, but the downslope wind flow may allow a few sites just inland of the coast to reach 70s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Gusty NW winds and cold air advection to hold temperatures below normal Sunday, although this is accompanied by copious sunshine to help warm objects through conduction. Chilly early Sunday and Monday with morning lows in the 30s. Remainder of the extended forecast beyond early week look fair and mainly dry with short- wave ridging into mid week supporting a warm-up to near or a little above normal. Phasing streams bring a full latitude upper trough east of Mississippi River, and a decent chance of rain to area late next week. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Numerous showers will continue for the next 3-6 hours, scattering out in coverage from west to east. Drier air has already begun to filter into KFLO, reflected in 51 degree dewpoint at 23Z, and higher ceilings. Expect mainly VFR inland, with MVFR and tempo IFR along the coast through midnight, when the drier air makes it there. Precip should push out of the area by 08Z, with ceilings scattering out after sunrise. West winds will increase Friday especially once a little heating leads to deeper mixing in the vertical. Extended Outlook...VFR Friday into the weekend and Monday. && .MARINE... Through Friday Cold front still to our west and winds remain southwesterly but a clockwise veer is still expected. There may be a brief increase in the W to NW flow and a few gusts to 25kt may be possible but headlines should not return as they will be infrequent. Seas to hold fairly steady across the board with just a small shortening in period from the wind shift and a slightly larger nearshore/offshore wave due to the offshore flow component. Friday Night through Tuesday Difficult weekend for marine activities upcoming simply because of excessive wind Saturday and Sunday, and an advisory will likely be needed. Strong low pressure to the north and strong high pressure advancing from the WSW will induce strong SW-W winds Saturday, becoming NW Saturday night into Sunday. This change in direction will usher noticeably cooler air into the region. The good news given this windy forecast is that dryness in the atmosphere will result in fair weather with no showers or TSTMs this weekend over the 0-20 nm waters. Steep and growing WSW waves Saturday will turn from the WNW into Sunday, with 6-7 foot seas outer waters and gusty wind. Monday and Tuesday features improvement as winds die off and seas fall to 2 to 3 feet early next week. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS... UPDATE...CRM NEAR TERM...MBB SHORT TERM...MJC LONG TERM...MJC AVIATION...MBB/CRM MARINE...08/MBB
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
929 PM CDT Thu Mar 24 2022 .UPDATE... Issued at 929 PM CDT Thu Mar 24 2022 Overall, the forecast appears to be on track. Pesky showers and drizzle continue across northeastern Illinois, but a rough back edge appears to be developing in central Wisconsin and should pass through our area overnight. Attention then turns to the well- advertised threat for squalls tomorrow evening. A quick peek at the incoming 00Z guidance provides little change in forecast thinking with a cold-core low anchored by 500mb temps of -35C (700 mb of -17C) diving southeastward from Canada into the Great Lakes. In fact, the 00Z RAP matches an analog from 4/2/2016 during which squalls, some with lightning, produced 50 to 60 mph wind gusts across our area. In addition, confidence remains medium to high that westerly winds will gust 35 to 40 mph outside of squalls tomorrow evening. We`ll let the midnight crew take a full look at the 00Z guidance to make decisions on whether a Wind Advisory, as well as even stronger messaging on the squall threat, will be needed. Updated products have been sent. Borchardt && .SHORT TERM... Issued at 320 PM CDT Thu Mar 24 2022 Through Friday night... The primary forecast highlights during the period continue to focus on: -The likelihood of some very gusty west-northwesterly Friday afternoon and evening, potentially in excess of 40 mph at times. -Convective showers (Rain, snow and graupel) developing Friday afternoon and continuing into the evening, with locally higher wind gusts in excess of 50 mph. Cloudy and dreary conditions continue across the area this afternoon thanks to the pesky slow moving upper trough, and an associated surface frontal boundary in place across the region. Expect periods of light rain and drizzle to continue into this evening. Some wet snow will also mix in across my northern tier counties, especially north of I-88, where colder air is beginning to seep southward on the cold side of the surface boundary. Little to no accumulation is expected, however, as surface temperatures hover in the middle to upper 30s. While some areas of drizzle may persist tonight, much of the rain shower activity will be waning with time later this evening and overnight. Our next weather maker of interest for Friday`s weather is the mid/upper level PV anomaly currently transversing the the Canadian Rockies. Model and ensemble guidance continues to dig this feature southeastward into the Upper Midwest Friday morning, then across our area by early Friday evening. This features will induce strong height falls/cooling aloft overhead late in the day, resulting in rapidly steepening low and mid level lapse rates from the surface to around 700mb. Deep mixing and an increasing wind field will allow for the onset of very gusty west- southwesterly winds mid to late Friday afternoon, and likely persisting through the evening as cold air advection continues. I would not be surprised to see some gusts upwards of 40-45 mph outside of any convective showers that occur. For this reason, a wind advisory may be needed for parts of the area for late Friday and Friday evening. Will let the mid-shift get another look at this possibility. The other concern for Friday afternoon and evening continues to be the threat of convective showers (possibly even with lightning). These convective showers look to be initially in the form of rain and graupel Friday afternoon, but as wet-bulb zero heights quickly lower by early Friday evening snow and graupel will quickly become the primary precipitation type with these showers. Given the convective elements, with soundings even continuing to advertise a moist absolutely unstable layer (MAUL), along with the increasing wind field the threat for heavy snow squalls will exist over northern IL Friday evening. There is even some concern for localized slushy snow accumulations Friday evening due to the possibility of very heavy rates in the convective showers. Also, similar to warm season convection, this activity could lead to localized enhanced wind gusts in excess of 50 mph. All together, this could result in some dangerous snow squalls that disrupt travel conditions for a period across parts of northern IL Friday evening. Very low visibilities and strong winds (50+ mph) look to be the primary hazards within these convective snow showers, but some localized minor slushy accumulation could also lead to slick roads. Conditions should improve overnight Friday night, though breezy northwesterly winds will continue into Saturday. Temperatures will fall into the mid to upper 20s by early Saturday morning. KJB && .LONG TERM... Issued at 247 PM CDT Thu Mar 24 2022 Saturday through Thursday... A quickly developing subsidence inversion will end any lingering light snow across the eastern CWA by late morning. Otherwise, expect blustery and unseasonably cold conditions with NW gusts to around 25 mph and temps in the mid to upper 30s. Conditions will remain unseasonably cold through Sunday as the low-level cold air core brushes the area to the northeast. Temps will struggle to rise out of the mid 30s even under mostly sunny skies. A substantial spread in guidance with the handling of a deep western CONUS trough through much of next week continues to plague the forecast as we close out March. Guidance does agree on some generalities, including the establishment of a pronounced NW to SW low-level baroclinic zone across the mid-MS Valley under strong NW flow aloft Monday into Tuesday. While there is an initial overall lack of deep-layer moisture, the juxtaposition of an upper-jet entrance over the low-level baroclinic zone should induce enough F- gen to generate a persistent and somewhat stagnant axis of light rain/snow across the area late Monday night into Tuesday. The baroclinic zone will likely then stall over the northern CWA or lift north of the area as a warm front Wednesday in response to a strong surface low developing over the central Great Plains. Model disagreements in the handling of the associated deep western CONUS trough quickly results in diverging solutions by Wednesday. A large spread in both deterministic and ensemble solutions, even within individual ensemble suites, limits the ability to provide specifics at this time. But, all signs point to an active mid-week and especially Wednesday across the region. Kluber && .AVIATION... For the 00Z TAFs... Aviation weather concerns for 00Z TAFs: * Continued MVFR ceilings, occasionally dropping to IFR in light rain and drizzle this evening. Precipitations will end early Friday morning, although MVFR CIGs will remain into Friday. * Strong westerly winds Friday afternoon, with gusts up to 40+ kt expected. * In addition to strong, gusty winds, there`s a chance of wintery mixed precipitation turning into snow showers Friday afternoon into Friday evening. A busy TAF period with several moving parts. Presently a surface low is moving through the forecast area with light rain and MVFR CIGs. A shallow cold front has pushed in from the northeast and is located over ORD at 00Z, bringing northeasterly winds and IFR ceilings to ORD and sites north of ORD. This front is expected to shift off to the east, allowing ORD`s winds to become west to northwesterly, with all sites seeing northwesterly winds throughout tonight. MVFR CIGs with occasional IFR CIGs will remain throughout tonight, becoming predominantly MVFR a few hours after midnight as most of the precipitation moves off the the east. MVFR CIGs are forecast to remain in place throughout the rest of tonight into Friday afternoon. The break in weather will be brief as a rather strong system is forecasted to move into the area Friday. Strong northwesterly winds are expected with this system, with gusts beginning in the late morning, and continuing to strengthen through the afternoon, with gusts of 40 kt, or higher, being possible in the afternoon. In addition to the strong winds, showers are expected, some of which may be strong. There is a possibility of graupel with these showers due to the very cold air aloft and strong instability. Colder air will arrive behind a cold front later Friday afternoon into evening, creating some moments of rain showers mixed with snow before transitioning to snow showers Friday evening. The chance for snow showers will start to decrease after Friday midnight, with lingering chances in northwest Indiana into Saturday morning. BKL && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Gale Warning...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...4 PM Friday to 1 AM Saturday. Small Craft Advisory...LMZ740-LMZ741-LMZ742...1 AM Saturday to 7 PM Saturday. Small Craft Advisory...LMZ743-LMZ744-LMZ745...1 AM Saturday to 4 PM Sunday. && $$ Visit us at weather.gov/chicago Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSChicago www.twitter.com/NWSChicago www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service New York NY
859 PM EDT Thu Mar 24 2022 .SYNOPSIS... A complex frontal system and associated low pressure pass across the region tonight. A surface trough passes on Friday followed by a series of cold fronts this weekend. High pressure then through the middle of next week, followed by a possible frontal system affecting the region mid to late next week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Showers expanding across eastern PA and southern NJ in association with an area of low pressure over the northern Delmarva. A few lightning strikes were also noted across eastern PA with weak elevated instability. The combination of the region lying on the periphery of the right entrance of an upper jet and approaching shortwave over the Ohio Valley will send the aforementioned low across eastern LI late tonight. The associated warm front may try to lift across a portion of eastern Long Island as the low moves nearby. The low should then quickly lift north and east into New England overnight, moving towards the coast of Maine by day break Friday morning. Showers will overspread from south to north the next few hours. becoming widespread 03-04z. Some elevated instability is indicated on forecast soundings and will continue to mention isolated thunderstorms. The HRRR has been very consistent with the timing and coverage of activity this evening and have followed it closely overall. The activity will quickly move north of the area between 06-08z before ending by 10z out east. The showers and embedded thunderstorms will move quickly so am not anticipating any hydrologic issues despite some brief locally heavy downpours. Average rainfall amounts of 0.25 to 0.50 inches are forecast with locally higher amounts possible. Mostly cloudy conditions then prevail into Friday morning. Lows will be in the 40s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Upper trough axis passes offshore on Friday, with the flow briefly flattening within the broader mean trough. Mostly cloudy conditions to start will become partly cloudy for the rest of the day. The flow will generally be out of the W or WSW, which should help boost temperatures back above normal in the upper 50s and lower 60s. Another strong vortmax dives out of Canada over the Great Lakes Friday night. This energy will help amplify the heights along the east coast by early Saturday morning. This should start increasing clouds, but dry conditions will prevail. Lows should end up above normal in the upper 30s inland to the lower and middle 40s elsewhere. && .LONG TERM /SATURDAY THROUGH THURSDAY/... H5 trof plows thru the area late Sat. At least sct shwrs can be expected. If the timing holds and the energy arrives at peak heating as the models suggest, would expect some tstms as well in the aftn and early eve. Some hail possible with cold temps aloft. Much colder Sun thru Tue. A hard freeze can be expected Sun ngt and Mon ngt. A bit more model uncertainty for Wed and Thu regarding how fast polar front retreats nwd. As a result, the NBM was followed.. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... Low pressure approaches from the southwest this evening and will pass across eastern Long Island during the early morning hours. A surface trough moves through Friday afternoon. Widespread LIFR/IFR conditions are forecast for much of the night with a steady rain to move into the area around or after 02Z, overspreading the terminals from SW to NE. An isolated thunderstorm will be possible during this time with VCTS mentioned for all but KSWF. Conditions dry out in the 06Z to 09Z timeframe. MVFR and then VFR conditions return toward 12Z Friday. NE winds 5-10 kt will veer around to the W/NW late as low pressure lifts to the NE. W/SW winds on Friday will increases to 10 to 15 kt with G20kt in the afternoon. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments possible for category changes through tonight and early Friday. Timing of any TS may be off 1-2 hours with most probable timeframe around 03z. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... .Friday Night...VFR. W G20kt possible early. .Saturday...Chance of MVFR in showers. W/SW winds 10-15kt G15-20kt. .Sunday through Tuesday...VFR. NW winds G20-25kt. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Winds this evening remain around 20 kt or less. Winds should then mostly stay below 25 kt overnight, but there could be some occasional gusts to 25 kt late tonight or early Friday morning on the ocean east of Moriches Inlet. Winds should continue to stay below SCA levels Friday and Friday night. Ocean seas will remain elevated above 5 ft through Friday night. The SCA on the ocean has been extended through 22z Friday for now, but will likely be needed through the weekend as elevated seas look to continue. The best chance for SCA winds on the protected waters during this same period is Sun-Mon. && .HYDROLOGY... Showers and isolated thunderstorms are expected tonight. Locally heavy downpours are possible, but fast movement of the system will prevent any hydrologic impacts. No hydrologic impacts expected from Friday through the middle of next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 PM EDT Friday for ANZ350-353-355. && $$ SYNOPSIS...JMC/DS NEAR TERM...DS SHORT TERM...DS LONG TERM...JMC AVIATION...DW MARINE...JMC/DS HYDROLOGY...JMC/DS