Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/16/22

National Weather Service Wakefield VA
915 PM EST Tue Nov 15 2022 .SYNOPSIS... Low pressure arriving from the southwest tonight will bring rain to the area through early Wednesday. Clearing and turning colder from Wednesday through the upcoming weekend. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 915 pm EST Tuesday... Temperatures are dropping a little more than forecast behind the front. In fact, temps seem to be dropping around 5 deg in an hour. FCI and CXE already 39 with RIC at 42. Will drop most areas along/west of I-95 into the upper 30s tonight while keeping upper 40s close to the coast. As of 800 pm EST Tuesday... Overall the forecast is in very good shape. The area of rain over region is quickly moving northeast ahead of the strong upper trough. In fact, the back edge of the precipitation is already moving into the southern VA Piedmont. Expect the rain to quickly taper off from west to east later this evening into the early morning hours. In fact, the latest HRRR has precip exiting into the Atlantic by 06z. Overall, this trend is handled well in the forecast and only minor tweaks are planned. Main change is to include SCHC thunder as far north as the northern neck and MD eastern shore this evening. A few lightning strikes were observed just east of RIC within the last hour likely from theta-e advection along and east of the surface trough axis. Any thunder chances should diminish by midnight. As of 245 PM EST Tuesday... Afternoon wx analysis shows low pressure centered over srn AL, with high pressure along the New England coast ridging SSW into VA and the Carolinas. A CAD setup is in place over the local area with WAA aloft. Clouds have increased over all areas, and light rain has begun in parts of the area. However, the main area of moderate rain is still to our west. Temperatures are only in the upper 30s from LKU-FVX, in the mid 40s-lower 50s along the I-95 corridor, and in the upper 50s-lower 60s in SE VA/NE NC. The low is progged to lift ENE over E GA and the coastal Carolinas this afternoon, before accelerating NE across the NC/VA coastal plain and along the Atlantic coast of the Delmarva Peninsula tonight into Wed morning. As hinted at above, the best forcing does not arrive until 5 to 9 PM (earliest west/latest east), bringing a period of steady, moderate rain to most of our area (although not as confident that the rain will be steady/continuous in SE VA and NE NC). The rain will continue for several hours before tapering off from SW to NE early Wed AM (and could be heavy at times). Rainfall totals still look to average 0.50-1.00", highest across our central VA Piedmont counties. With the low tracking along the VA/NC coastal plain tonight, temperatures will only fall a few degrees west of I-95. However, along and to the east of the low track, temperatures and dew points may rise into the mid 60s. This could allow for some marginal sfc-based instability to develop (with elevated CAPE extending a bit farther inland). As such, precipitation will likely become more showery in nature across the Hampton Roads area up to the VA eastern shore in the warm sector, versus a more stable (steady) stratiform rain farther inland. Will maintain thunder wording for the warm sector area this evening into the early portion of the overnight hours (23z-06z/7p-1a EST). After the low passes by, rain tapers to light rain/drizzle and winds become W-NW and temperatures will fall into the 40s near the coast by sunrise (while remaining in the upper 30s-mid 40s farther inland). Extensive low cloud cover will remain in place through the night. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/... As of 245 PM EST Tuesday... The low is progged to track NE along the New England coast on Wed, as partial clearing occurs from W-E during the day with downsloping WNW winds. Forecast highs range through the 50s on Wed. Cooler wx is expected during the remainder of the week as a couple of shortwaves track to our north and send additional shots of CAA our way, with the first shot expected Wed night (and the second holding off until late Fri/Fri night). Forecast highs on Thu/Fri generally range from the mid 40s-lower 50s. Lows Wed night in the upper 20s- upper 30s with a 5-10 mph WNW wind and partly cloudy skies on average. Skies will be mainly clear Thu/Thu night. It will be quite cold with temperatures falling into the 20s in most areas by Fri AM (cannot rule out localized upper teens in the typical cool spots in the central VA Piedmont...and NBM10Pct hints at this as well). && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... As of 245 PM EST Tuesday... Below normal temps and dry conditions continue through the weekend as strong Canadian high pressure pushes SE over the central CONUS, keeping a broad NW flow regime over the region. Cold Sat morning w/lows in the 20s inland and 30s at the coast. The axis of the 500 mb trough over the Midwest shifts east Sat aftn w/ some negligible height/thickness rises expected over the SE CONUS (aftn highs ranging from the low 40s NW to low 50s SE). Additionally, broad scale subsidence with this high will keep the area dry and shunt any disturbances well to the S/SE. Speaking of disturbances, the 15/1200Z guidance continues to keep the southern stream system (w/ accompanying weak wave low of pressure) well to S with little to no impacts on the area (outside of some high cirrus over the SE CWA). PoPs aob 10% areawide. Low pressure then develops over the Canadian Maritimes Sun-Mon, tightening pressure gradient and increasing NW winds (and CAA) for at least the beginning of the Thanksgiving week. Therefore, cooler Sun with highs in the low 40s NW to around 50 SE. As of now, Mon looks to be the coldest day of the extended period w/ highs in the low to mid 40s and lows in the upper teens/low 20s NW and even freezing conditions possible at the coast. Highs Tues in the 40s to low 50s w/ lows still chilly (but moderating some) in the low 20s to mid 30s. There are some indications of a warming trend and some precip later on in the week, but this is beyond the forecast period. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... As of 640 PM EST Tuesday... Flying conditions continue to deteriorate early this evening, as rain and low clouds spread across the region associated with low pressure over the SE states. IFR/LIFR conditions mostly along/west of I-95, but they will spread eastward in the next few hours. Visabilities will also lower to IFR this evening especailly at RIC and SBY. The good news is that this system is expected to move out of the area overnight, and will take the rain with it. This will allow lower VSBYs to improve late tonight, however CIGs will likely not rise to MVFR and VFR until around sunrise if not a little later. VFR conditions should prevail on Wed with W-NW winds of about 10 kt. Outlook: Once terminals return to VFR on Wed, expect predominate VFR/dry conditions to prevail through the upcoming weekend. && .MARINE... As of 245 PM EST Tuesday... Afternoon analysis indicates an area of high pressure continuing to move off to the northeast through New England and eastern Canada. Meanwhile, a surface low is moving across the Gulf coast states, with moisture extending up into our local area. This low will lift north/northeast along the Southeast/Mid-Atlantic coast later this evening into early Wednesday morning. This will create varying wind directions around the low pressure, periods of rain, and gusty winds. A scattered thunderstorm also can`t be ruled out later this evening. Currently, winds are east/northeast at 10-15kt with gusts up to 20kt. Expecting winds to become southeast this evening at 15- 20kt with gusts to 25kt possible as the low pressure passes through. Winds will gradually become southerly early Wednesday morning then northwesterly behind the system by sunrise Wednesday. Speeds will remain at 10-15kt with gusts to 20kt across the waters for most of the day on Wednesday. Waves are expected to be 2-3ft with seas building to 3-5ft. SCAs are in effect for all of the waters, except the northern portions of the rivers. The SCA for the Currituck Sound will drop off at 10pm tonight due to winds subsiding there, with the lower James dropping off a few hours later. The upper Bay and northern coastal waters will hang on to SCA conditions until Wednesday afternoon before subsiding. Seas of 4-5ft will linger across far northern coastal waters, warranting the SCA to remain in affect Wednesday evening. Northwesterly winds will subside to 10-15kt through the day on Wednesday. The northern Bay may hang on to winds right at the low end of SCA thresholds into Wednesday night, but it`s marginal and not widespread, so opted to not extend the SCA for now. Winds will pick up a bit more after sunrise on Thursday as a reinforcing surge of CAA pushes in thanks to a building area of high pressure. A shorter-lived SCA may be needed, primarily for the Bay. Seas don`t look to come up much during this period, staying around 2-4ft. Conditions then look to stay fairly benign through the remainder of the week and into the weekend. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...None. NC...None. VA...None. MARINE...Small Craft Advisory until 4 PM EST Wednesday for ANZ630-652- 654. Small Craft Advisory until 10 AM EST Wednesday for ANZ631-632- 634. Small Craft Advisory until 10 PM EST this evening for ANZ633. Small Craft Advisory until 1 AM EST Wednesday for ANZ638. Small Craft Advisory until 7 PM EST Wednesday for ANZ650. Small Craft Advisory until 4 AM EST Wednesday for ANZ656-658. && $$ SYNOPSIS...MAM NEAR TERM...ERI/MRD SHORT TERM...ERI/MAM LONG TERM...SW AVIATION...ERI/MRD MARINE...JKP
Area Forecast Discussion
National Weather Service Binghamton NY
1005 PM EST Tue Nov 15 2022 .SYNOPSIS... Winter weather advisories are in effect for all of Central NY and Northeast PA this evening and tonight. A period of snow, wintry mix, and rain will impact the area tonight into Wednesday morning. Conditions become colder with additional snow showers and lake effect snow Wednesday night through the end of the week. Remaining much colder than average into the weekend, with better chances for more snow showers on Sunday. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... A warm layer aloft is moving fairly rapidly northward with the changeover already occurred or will be occurring shortly across NE PA and the Southern Tier. This advance should continue to the north but slow some overnight. A pronounced dry slot has entered much of the region west of I-81 as well. Mesoscale modeling still shows the precipitation filling in further northwest after midnight. QPF amounts were adjusted a bit with some minor changes to snow and ice accumulations with the evening updates. Advanced in a second dry slot much quicker based on the latest runs of the HRRR as well toward sunrise. Previous discussion... The steady precip moves out of our area before 10 AM Wednesday, with just a few scattered rain showers possible into the afternoon hours. Temperatures should also rise into the 40s as winds shift west and scour out any remaining cold air pockets. Heading into Wednesday evening and Wednesday night, much colder air aloft moves overhead as 850mb temperatures fall back to around -8C overnight. This will get the lake effect machine going, although precip type could initially mix with rain Wednesday evening. Overnight the lake effect should change to all snow, and be mainly aligned along a shifting 270-290 degree flow. This will keep the steadiest bands of precip (snow) along and north of the NY Thruway most of the time. Right now we have 1-3 inches of snow in the forecast for northern Oneida Wednesday night. For the rest of the area expect just a few light rain or snow showers under partly cloudy skies overnight. Lows drop down into the upper 20s and lower 30s. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... A large upper level trough will be the main weather driver for this forecast period. During the day on Thursday, mostly westerly winds are expected across the region. This will develop 2 areas of lake effect snow showers. One off Lake Erie, reaching the Twin Tiers and Finger Lakes, and another off Lake Ontario, impacting areas along the Mohawk Valley and north. A few small shortwaves will ripple through during the day, allowing the bands to become a little more diffuse and spread the snow out over a larger area. Northern Oneida county will see the highest snow amounts, with 3-5 inches possible in the higher elevations of the southern Tug Hill area. Thursday night, a low pressure system swinging through the Great Lakes will bring SW flow across the region. This will shift the lake effect snow showers to the north, pushing the snow bands out of our region by Friday morning. There could be a few isolated showers that push through the northern Finger Lakes into northern Oneida county from Lake Erie during the day, but these showers are expected to be spotty and light in nature. Temperatures on Thursday will be warm enough to allow for a rain/snow mix across valley location during the late morning/early afternoon hours. Highs are expected to be in the mid 30s to low 40s but Wet bulb temps show enough evaporative cooling across the Mohawk and northern Finger Lakes to allow for snow flakes to mix in down to the valleys. A much cooler airmass moves into the area on Friday behind the low moving through the Great Lakes. Highs will be in the mid to upper 30s with Friday night lows crashing into the teens to low 20s across the area. && .LONG TERM /SATURDAY THROUGH TUESDAY/... SW flow remains across the area Saturday, keeping lake effect snow north of our CWA. An upper level trough will swing through the region on Sunday but there is currently not a lot of moisture coming in with it. An initial swath of light snow showers should move into CNY Sunday as the winds shift to WNW. A band of lake effect snow could set up for a few hours across Oneida county before a weak ridge builds in and brings WSW winds again. NW flow returns Tuesday with another chance for lake effect snow across the northern counties. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... 0Z Update... Snow has spread across the area with IFR to LIFR conditions expected through around 6Z. Warm air is advecting in aloft so ptypes will transition from snow to rain with a couple hour period of sleet and freezing rain. A dry slot moves in late after 10Z near AVP and moves north to RME by around 14Z helping to increase vis to MVFR at most terminals. Cigs will likely stay IFR and slowly rise to MVFR about 18Z with gusty west winds developing at all terminals in the afternoon. Lake effect rain showers will be possible at SYR in the afternoon. Outlook... Thursday through Saturday...Occasional restrictions possible due to lake effect snow showers, especially at SYR and RME...and perhaps occasionally at the other Central NY terminals. Sunday...Numerous snow showers across the region with associated restrictions. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...Winter Weather Advisory until 7 AM EST Wednesday for PAZ038>040. Winter Weather Advisory until 4 AM EST Wednesday for PAZ043- 044-047-048-072. NY...Winter Weather Advisory until 10 AM EST Wednesday for NYZ009- 036-037-045-046-057-062. Winter Weather Advisory until 7 AM EST Wednesday for NYZ015>018-022>025-044-055-056. && $$ SYNOPSIS...MJM NEAR TERM...MJM/MWG SHORT TERM...JTC LONG TERM...JTC AVIATION...AJG
Area Forecast Discussion
National Weather Service Boston/Norton MA
1029 PM EST Tue Nov 15 2022 .SYNOPSIS... A coastal storm will bring a wintry mix along with some accumulating snow for parts of the interior tonight into early Wednesday. This will bring impacts to the Wednesday AM commute. A cold rain is expected across the coastal plain. Precipitation ends Wednesday afternoon from southwest to northeast. Midweek to early next week features below normal temperatures, and while we do have to watch a coastal low pressure passing well to our southeast Sunday night, much of the midweek to early next week period is dry. && .NEAR TERM /THROUGH WEDNESDAY/... 1020 PM Update... Have increased precipitation totals along with snowfall amounts in the latest update. Snowing a bit sooner/heavier in some spots, so have bumped up totals a bit to account for this. However, with this said am expecting a transition over to a wintry mix and eventually all rain from north to south into Wednesday morning. Still anticipating this to impact the Wed AM commute, so have not made any changes to the Winter Weather Advisory at this point. Lowered temps a bit in the latest update as well as we were a bit too warm compared to observations. Rest of the forecast is on track. 640 PM Update: With rather dry air in place (dewpoint depressions being some 10-15 degrees) ahead of leading edge of radar echoes now evident across the NY/CT/MA border, opted to reduce temperatures a few degrees to account for evaporative/wet-bulbing effects. Incorporated the cooler HRRR into the forecast across interior MA/CT to better reflect this rather temporary effect. Despite the radar returns the drier air in place should delay precip onset until about late evening (9-10pm) for western MA and northern CT, late-evening/midnight for parts of RI, eastern CT and central MA and with rain not arriving until midnight/early overnight in eastern MA. This did result in some small adjustments to forecast snow and ice accumulations across western MA and northern CT, but these adjustments were not significant enough to alter the overall message in any meaningful way. Forecast otherwise appears to be holding up with initial snow in the interior to transition over to a wintry mix and then to rain. Given limited accumulation and this type of p-type transition, it`s very possible that any snow which can accumulate in the higher terrain washes away. However travelers through the Berkshires, Litchfield Hills into northern portions of Worcester County overnight to pre-dawn should be aware of the potential for slippery and deteriorating road conditions with winter weather advisories in effect. Previous discussion: Clouds will continue to thicken and lower as warm advection aloft kicks in. This, ahead of our first nor`easter of the season which will bring a wintry mix of snow, sleet, freezing rain, and rain to interior southern New England overnight into Wednesday. At the synoptic scale we have a 500 mb ridge shifting offshore while a trough digs into the Midwest, Great Lakes, and eventually New England. At the surface this trough will generate a wave of low pressure over OH/TN valley and then a secondary low off the Mid- Atlantic coast after 00Z. This low then strengthens and passes over the Cape Cod canal on Wednesday. The inland track, well NW of the 70/40 benchmark, is not favorable for widespread wintry weather as much of the region will be on the warmer side of the low. The main concern with the overnight hours is a burst of snow initially, followed by a transition to sleet and freezing rain as the mid level warm advection that helped force precipitation initially will overspread the subfreezing surface air. Guidance has come into somewhat better agreement on timing of this warm surge, though the NAM continues to be the quickest. NBM seems to have a good handle on the transition. This period of wintry mix will be short lived but could cause slick roads, mainly above 1,000 ft before things change to rain everywhere by 7-9am. As for snowfall amounts, anywhere from a trace to an inch is possible in the Worcester hills with up to 2 inches in the highest elevations of the Berkshires. Even so, given the transition to rain, it shouldn`t stick around long for most. This is expected to be a very low impact event given the small, high elevation footprint. By late Wednesday morning/early afternoon the low will move into the Gulf of Maine with an end to the rain approaching from SW to NE as a dry slot moves overhead. This trajectory places southeast MA into the warm sector with S/SW flow in the afternoon. It keeps temperatures relatively mild there (in the low to mid 60) while northwest MA sits in the upper 30s; we`ll see quite the temperature gradient tomorrow. It also introduces a chance for some thunder embedded in the showers over southeast MA as CAPE values of 500 to 1000 J/kg will be briefly overhead. The main threat from any thunderstorm would be potential that it mixes down some strong winds from the 30-40 kt 925 mb jet overhead. && .SHORT TERM /WEDNESDAY NIGHT/... Overnight will be dry and much quieter as the low lifts into Nova Scotia. Dry westerly surface flow will keep skies clear much of the night with breezy winds as high as 10 to 15 mph, gustier along the coast. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Highlights: * Below normal temperatures with periods of blustery conditions. Highs in the 30s away from the coasts by Monday! * Have to watch a passing system well offshore late Sunday, but generally dry weather prevails. Details: Negative-EPO teleconnection pattern at 500 mb prevails through much of the long-term forecast period, associated with an amplified longwave trough across the northern and central Plains, OH Valley and the Northeast. Colder air to progressively spill eastward, with 925 mb temps starting around -1 to -3C on Thurs, then trending to -3 to -6C by Fri/Sat/Sun. 925 mb thermal trough and coldest air develops on Mon with 925 mb temps -6 to -9C! So the main story is the stretch of below normal temperatures, with temperatures trending colder each day. A couple of days of blustery conditions given the anomalously cold air mass seem possible as well which will add to chilly conditions; while Thurs and Fri should both feature rather blustery conditions, combo of stronger NW gusts and coldest temperatures appears around Mon in the wake of a departing/distant coastal low. High temperatures begin in the low 40s to near 50 on Thurs and Fri, mid 30s to mid 40s for the weekend and then low 30s to low 40s on Mon. These are about 5-10 degrees below mid-November climatology. Mainly dry weather prevails in this period, though we could see passing flurries in the Berkshires due to the moisture fetch from Lake Erie. Around Sunday into early Monday, there are some indications for a distant coastal low passing well to our southeast from the Carolinas that could brush southeast New England with precip but trends are further to the SE and thus capped PoP at no better than slight chance. Remains time to sort through the details regarding this but at the moment offering largely dry weather. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 00z TAF Update: Tonight: High confidence in trends, but moderate on the timing and p-type transition for western/interior airports. VFR initially, but rapid deterioration in conditions anticipated by 02-04z BAF/BDL and 03-05z for ORH with advancing wintry precip (mainly snow to brief wintry mix to rain). IFR to LIFR likely as this transition takes place. For the eastern airports, ceilings lower to MVFR 05-07z and quickly to IFR-LIFR levels 07-09z with all rain, becoming steady light to moderate intensity overnight/pre-dawn. Widespread IFR-LIFR conditions likely for all airports 09-12z Wed. NE to E winds 5-10 kt, with gusts around 20-25 kt across the coastal plain and the hilly terrain. Wednesday...High confidence. MVFR/IFR early will gradually improve to VFR as the rain exits during the afternoon. Potential for isolated thunderstorms for southeast MA terminals in the afternoon. Winds out of the NE at 10-20 kts to start, but will shift to the NW/WNW by the afternoon. Gusts of 15-30 kts. Wednesday Night...High confidence. VFR with breezy west winds 5-10 kts gusting to 20 kts at coastal terminals. KBOS Terminal...High Confidence in TAF. Rain predominates with wet runways and rising temperatures overnight. KBDL Terminal...High Confidence in TAF. Moderate confidence on exact timing of precipitation type transitioning. Not out of the question there is a brief window for freezing rain from 04-08Z, but confidence was not high enough to include at this point. Outlook /Thursday through Sunday/... Friday: VFR. Windy with areas of gusts up to 30 kt. Friday Night through Saturday Night: VFR. Breezy. Sunday: Mainly VFR, with local IFR possible. Breezy. Slight chance RA. Sunday Night: VFR. Breezy. Monday: Windy with areas of gusts up to 30 kt. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight through Wednesday night... Rain spreads in tonight into early Wednesday. Potential for some thunderstorms across the waters Wednesday morning. Rain tapers off during the afternoon. Winds out of the E/NE tonight increasing to 15-25 kts late. Winds shift to the SW by late Wednesday AM and W/WNW by late afternoon as a coastal low slides through. Wind gusts of 20-30 kts, with a brief period of Gale Force Gusts to 35 kts Wednesday AM. Small Craft Advisories are in effect from tonight into Wednesday night. Winds Wednesday night will out of the west, 15-20 kt, gusting to 25 kt. Seas building to 4-6 ft for the southern waters late tonight, 4-8 ft across all waters on Wednesday, decreasing a bit overnight. Outlook /Thursday through Sunday/... Friday: Moderate risk for Small Craft Advisory winds with gusts up to 30 kt. Local rough seas. Friday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Seas up to 5 ft. Saturday: Low risk for Small Craft Advisory winds with gusts up to 20 kt. Areas of seas approaching 5 ft. Saturday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain. Sunday: Winds less than 25 kt. Local rough seas. Slight chance of rain. Sunday Night: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Areas of rough seas. Slight chance of rain. Monday: Moderate risk for Small Craft Advisory winds with gusts up to 25 kt. Rough seas up to 9 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...Winter Weather Advisory until 10 AM EST Wednesday for CTZ002. MA...Winter Weather Advisory until 10 AM EST Wednesday for MAZ002>004-008-009-026. RI...None. MARINE...Small Craft Advisory until 1 AM EST Thursday for ANZ231-232- 235-237. Small Craft Advisory until 7 PM EST Wednesday for ANZ233-234. Small Craft Advisory until 1 PM EST Wednesday for ANZ236. Small Craft Advisory from 4 AM Wednesday to 7 AM EST Thursday for ANZ250-251. Small Craft Advisory until 7 AM EST Thursday for ANZ254>256. && $$ SYNOPSIS...BL/Loconto/BW NEAR TERM...BL/Loconto/BW SHORT TERM...BW LONG TERM...Loconto AVIATION...Loconto/BW MARINE...Loconto/BW
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1000 PM CST Tue Nov 15 2022 ...New AVIATION... .SHORT TERM... (Tonight through Wednesday night) Issued at 215 PM CST Tue Nov 15 2022 Cool, below average, temperatures along with west to east moving high level clouds will characterize the short term with the zonal flow aloft and surface high pressure settled across north-central Texas. Temperatures will be similar both today and Wednesday with highs generally holding in the 50s while the overnight lows will trend from the 30s into the low 40s. A north to northeasterly flow maintains given the positioning of the surface high with breezes around 10 to 15 mph during the day and 5 to 10 mph at night. A shortwave trough approaches the region into Thursday while South Texas starts to feel the influences of a coastal trough that forms off the Lower Texas coast. The rain footprint in South Texas may possibly advect northward enough to allow for some low end chance for rain across our southern counties from between 06Z and 12Z Thursday. && .LONG TERM... (Thursday through Tuesday) Issued at 215 PM CST Tue Nov 15 2022 Cool weather continues through the remainder of the week. A weak trough axis will move across the area on Thursday. Global guidance has been generally dry with this feature, although some of the 12Z GFS and ECMWF ensemble members are generating some light QPF across the region. The 12Z and 18Z HRRR are generating some QPF across southeastern areas of the CWA with precip type being rain. However, we could see a very low probability of sleet mixed in, conditional on precip actually developing, given the wet bulb potential and depth in the sub-cloud layer. If any sleet were to develop early Friday morning it would be more conversational, with no impacts given surface temperatures in the 40s. Another cold front should arrive Friday night with a coastal low developing off the lower Texas coast Saturday morning. Isentropic ascent over the cold airmass should lead to the development of light rain by Saturday morning, favoring southern and eastern areas of the CWA. We will need to watch the northern Hill Country closely, should any light precip develop that far north, as temperatures could be in the lower 30s. A few GFS and Canadian ensemble members hint at the possibility of a mixed precip type. But given the low confidence we are not including this in the official forecast at this time. The isentropic ascent looks to weaken and end across the region Saturday night. Southerly flow looks to finally return to the area by the end of the long-term period of the forecast but no significant warm up is expected. && .AVIATION... (06Z TAFS) Issued at 1000 PM CST Tue Nov 15 2022 VFR flying conditions prevail tonight through Wednesday night with CIGs above FL150. However, there may be FEW lower clouds, at times. At the I-35 sites, N-NE 3 to 7 KTs winds, except 7 to 12 KTs on Wednesday. At KDRT, NE-E winds at 4 to 7 KTs prevail. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 39 55 40 56 / 0 0 10 10 Austin Bergstrom Intl Airport 36 55 37 57 / 0 0 10 20 New Braunfels Muni Airport 40 57 40 59 / 0 0 10 20 Burnet Muni Airport 36 53 37 57 / 0 0 0 10 Del Rio Intl Airport 41 58 39 57 / 0 0 10 0 Georgetown Muni Airport 37 54 38 56 / 0 0 0 10 Hondo Muni Airport 39 58 38 59 / 0 0 10 10 San Marcos Muni Airport 38 56 39 57 / 0 0 10 20 La Grange - Fayette Regional 40 56 39 57 / 0 0 10 20 San Antonio Intl Airport 40 57 41 56 / 0 0 10 20 Stinson Muni Airport 42 58 43 57 / 0 0 10 20 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Brady Long-Term...76 Aviation...04
National Weather Service Hastings NE
559 PM CST Tue Nov 15 2022 .DISCUSSION...(This evening through Tuesday) Issued at 413 PM CST Tue Nov 15 2022 -- Key Messages: * We remain entrenched in a solidly-colder than normal temperature pattern through at least Saturday (maybe Sunday), before a decent rebound to at least near-normal (if not slightly above) normal readings commences by Monday (and maybe even as early as Sunday if some of the very latest models are onto anything). * Despite the upper air pattern being quite active these next few days, and despite the forecast being littered with various small chances for flurries and/or snow showers, the chances of actual MEASURABLE precip/snow are actually pretty low, and thus why we are largely expecting few (if any) travel impacts. * Our official 7-day is currently void of all precip mention (even flurries) Thurs night onward, and with high confidence of it staying that way so especially Sat night onward (that Thurs night-Sat period looks prone to MAYBE needing some flurry chances in later forecasts). * A peek slightly beyond our 7-day forecast into Wed-Fri of NEXT week (peak Thanksgiving travel) suggests that there COULD BE a large-scale low pressure system affecting our region. However, extended models models are (predictably) all over the place at them regarding possible impacts (if any!). Literally all we can say right now is that it`s not "guaranteed quiet", and that it`s a time frame to watch. -- More detailed overview/highlights of the entire 7-day forecast (including all discussion of Days 3-7 Fri-Tues) 1) General overview of the large-scale upper air pattern/model differences: At least through Day 7 (Tues), primary models (NAM/GFS/ECMWF) are in pretty darn decent agreement with the big picture. See paragraphs below for more details on the first 48 hours, but in short, we remain in a pronounced "troughy" pattern through Saturday, as a large-scale upper trough centered from eastern Canada into the Upper Midwest keeps sending one shortwave trough after another southward around its periphery, affecting our local area with (for sure) reinforcing shots of cold air and enhanced winds and (less so) period chances for light snow/flurries. Finally, starting around Sunday, we see a (surely welcomed by many) pattern change as the dominant troughing shifts east and puts us under more benign northwesterly and eventually more zonal (west-east) flow as low amplitude ridging develops in the central CONUS while the beginning stages of the POSSIBLE Thanksgiving time frame weather system start to take shape early in the week over the far western CONUS. 2) Temperature overview/changes versus previous forecast: This latest forecast honestly features very little change from previous Again, see below for more shorter term details, but in general we continue to be in the firm grip of the most pronounced/prolonged mid-November cold snap since 2014 (and one of the Top-5 coldest on record in the Tri Cities!) Highs are only aimed into the 30s Wed-Thu, bottom out in the 20s Friday, return to mainly 30s Sat and then finally start to go upward with more widespread at least lower 40s Sunday, followed by more widespread upper 40s (with at least limited 50s) Mon-Tues. If anything, latest model data (including ECMWF ensemble) suggests that our forecast for Sunday may actually be aimed a bit too cool (meaning much of the area could end closer to 50 than 40), so stay tuned for possible upward adjustments here. As for overnight low temps, most of the next week will feature teens to low 20s, but Thurs night in particular continues to be the overall coldest, with most of the CWA aimed down into the single digits. As a result, all signs point to Friday morning being perhaps the overall worst/least- pleasant of all recent/upcoming mornings, with cold temps and breezy winds sending wind chill values down into the -5 to -15 range. If these wind chills trend any worse/colder they will justify a formal mention in our Hazardous Weather Outlook (HWOGID), but at least for now we appear safe from Advisory criteria (chills of -20 or colder). 3) Precipitation overview: See later paragraphs for more details, but as noted in the Key Messages above, at least these next 48 hours (and possibly slightly beyond) will be prone to various subtle/"sneaky" chances for at least flurries, and possibly light coating of barely- measurable snow...thanks to the continuous parade of disturbances diving/rotating southward across our region. If any of these snow chances currently looked somewhat more organized with a more cohesive signal for accumulation potential of 1+ inch, we`d probably mention in our HWO. However, when the official snow forecast through the next 72 hours (as far out as we officially forecast snow amounts) has basically no expected accumulation for the vast majority of our coverage area (CWA), it`s pretty difficult to consider this HWO-worthy "hazardous weather". That being said, with such an active pattern aloft, we`ll have to watch closely to make sure we aren`t caught off guard by any sneaky/more organized snow bands that could put down just enough to slicken roads (IF this were to happen Thursday might be most favored especially in our southwest). As mentioned in Key Messages above, do not be surprised at least flurry chances eventually added for parts of the Thurs night-Saturday time frame before a higher- confidence stretch of more "guaranteed dry" weather kicks in Sunday-Tuesday. 4) Wind overview: Although we`ll have plenty of upcoming breezy days (sustained speeds commonly 10-20 MPH/gusts 20-30 MPH, fortunately MOST days should not be overly-WINDY (sustained 30+/gusts 45+). Deterministic and ensemble guidance is in pretty good agreement that the overall-windiest day still appears to be Thursday, as a reinforcing cold front slices through from the north. Our latest forecast calls for gusts up to around 35 MPH on Thursday, and could perhaps see later forecasts nudging gust potential up closer to 40 MPH for at least part of the day (something to watch). -- With the big picture highlights of the entire 7-day outlined above, will conclude with shorter term details focused solely on on these next 48 hours/4 forecast periods: - Current/recent weather scene as of 330 PM: Certainly no notable surprises today, as the vast majority of the CWA has remained precip-free the majority of the day. The exception was an area of flurries/light snow that traversed mainly our far northeast/east-central Nebraska zones this morning, even putting down a very light dusting in a few spots per web cams. In its wake, the middle part of the day featured quite a bit of sun that actually allowed high temps to (if anything) climb just barely higher than officially forecast, with official highs on track to range from mid-upper 30s in most Neb zones, to low-mid 40s in KS zones. In fact, today has likely been the overall "mildest" day that we`ll see until at least Sunday. However, in the wake of the sunnier mid-day period, just over mainly the past 1-2 hours the next batch of widespread mid level clouds has began invading our CWA from northwest-to-southeast, perhaps even squeezing out a few sprinkles/flurries from currently-light radar returns. Looking aloft, this latest batch of light activity is being driven along the southern reaches of a small-scale vort max/semi-closed low currently diving south- southeast across southeast SD. Wind- wise, speeds most of the day have averaged sustained 10-20 MPH/gusts to around 25+ MPH from the northwest. - This evening-overnight: In the big picture aloft, the aforementioned wave currently over southeast SD will track southeastward into central/southeast IA by sunrise. This track will certainly keep the MAIN batch of more organized/accumulating snow off to our east (mainly near/east of the NE/IA border). However, our CWA will be prone to more subtle/sneaky light precip on the backside of this main wave. Although lower-res/global models suggest pretty much a precip-free night, higher-res models (HRRR/NamNest) are more suggestive that at least a limited swath of light snow showers (possibly starting out as a touch of rain at the outset) will track east- southeastward through mainly the southwest half of our CWA (mainly south of the Tri Cities) especially pre-midnight, before departing our area into northeast KS later in the night. With the aforementioned light radar returns already present signaling the very start of this limited precip potential this evening, feel decent about introducing some low (20-30 percent) chances (PoPs) for snow showers to much of our southern CWA this evening, flanked by a mention of possible flurries. Any actual snow accumulation should be very minimal (no more than a few tenths of an inch at best), but perhaps enough in a few spots to turn things slightly white. In other departments, there is modest uncertainty regarding low temps tonight...mainly that they`d stay a bit warmer than expected in those areas that remain cloudy/mostly cloudy...but for now made little change from previous, aiming most of the CWA 10-16. Winds overnight will average sustained 5-15 MPH/gusts 10-20 MPH from the northwest. - Wednesday daytime: Aloft, the disturbance that gives us the "glancing blow" this evening-overnight will gradually depart east-southeast into the southern IL/IN area by sunset. As a result, expect at least the vast majority of the CWA to be precip-free through the day, with actually quite a bit of sunshine especially mid-morning through mid-late afternoon before a batch of higher clouds starts to invade from the north ahead of the next wave. As a result, the only official mention of precip during the day is a small mention of possible flurries in the morning in some far southwestern counties, mainly based on hints in higher-res models. Despite a decent amount of daytime sun, slightly colder low-level temps (versus today) should keep highs roughly 5 degrees cooler than today, aimed mainly low 30s northeast to mid 30s southwest. Another round of steady northwest breezes will also keep a bit in the air (generally sustained 10-20 MPH/gusting to around 25). - Wednesday night: Aloft, the the next in the parade of shortwave troughs will slide south-southeastward through the Dakotas. Here locally, the pre- midnight hours should feature a steady increase in mid-high clouds from the north, but likely no precip. However, between midnight and sunrise Thurs it appears that especially the northwest half of our CWA could be prone to another round of at least scattered flurries/light snow showers, and have introduced slight chances to cover this. Due to the combo of increasing clouds and weak warm air advection in the low levels (on fairly light westerly breezes), low temps should hold up a good 5-10 degrees milder than tonight, with most of the CWA aimed a few degree either side of 20. - Thursday daytime: The bottom line is that this just won`t be a very pleasant day. As the day wears on, the upper wave over the Dakotas will arrive into Nebraska, sending a decent cold front southward through our area by mid-late morning, and (as mentioned above) kicking up a period of enhanced winds sustained generally 15-25 MPH/gusting 35+ MPH. Temps may actually fall a few degrees in the afternoon, but prior to the main push of colder air official highs are aimed upper 30s far north to mid-upper 30s far south. Precip-wise, think there is good chance of passing flurries, and this mention has been expanded CWA-wide for at least part of the day. The main question mark is whether there is a chance for a bit more organized area of snow showers with maybe even a touch of light accumulation. At least for now, this would appear most favored in our far southwestern CWA, but with overall-better chances for a light dusting of wind-blown snow focusing just barely to our west across western NE/northwest KS. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 544 PM CST Tue Nov 15 2022 Expect VFR ceilings this evening, potentially becoming MVFR for much of the morning hours. This evening, expect scattered clouds around 5k ft and overcast skies around 9k ft. Overnight, the RAP and HRRR models both indicate MVFR ceilings to move in around 16/09Z, so included that in the TAF at both sites. If that occurs, it will probably stick around through much of the morning. During the afternoon, expect just a few high clouds in otherwise clear skies. Winds will be out of the northwest much of the night at 10 kts or less, increasing Wednesday morning to gust to around 20 kts. Right around the end of the TAF period, winds will become westerly at less than 10 kts. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ AVIATION...Hickford
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
556 PM CST Tue Nov 15 2022 .SHORT TERM... Issued at 311 PM CST Tue Nov 15 2022 Through Wednesday night... Main issues in the short term are the threat for lake effect snow in far northeast Illinois tonight, and snow showers/lake effect snow in northwest Indiana Wednesday. Have cancelled much of the Winter Weather Advisory early. Surface obs and webcams show most of the precipitation has switched over to rain this afternoon, except along the Wisconsin border, and even there, webcams are showing roads to mainly be wet. Have hung onto the advisory for Lake County. Observations at Waukegan are still below a mile in snow, with 1-hour precip totals of 0.11" between 2-3 pm suggesting snow accumulations upward of an inch. Webcams in this area still show some slushy roads. Band of snow continues to edge westward in southeast corner of Wisconsin, extending southeast to near Evanston. Latest HRRR shows this continuing for a few more hours and and breaking up somewhat this evening, before the trough axis starts to shift southward overnight. Another inch or two of snow is possible over Lake County, though the latest HRRR run has started to keep the heaviest snow showers just offshore overnight. Will have to keep an eye on future runs to see how established this trend remains. Upper low over South Dakota will open up some as it drops into western Iowa overnight, with a strong trough swinging across the western Great Lakes region on Wednesday. Snow showers expected to become fairly widespread over northern Illinois by midday as MUCAPE`s increase to around 100 J/kg. Toward mid/late afternoon, surface winds over the lake turn more northwest and the northwest Indiana lake effect snow threat increases. Am expecting 1-2" across portions of Lake and Porter Counties afternoon and evening, though the main corridor looks to set up just east of there. Elsewhere, a few tenths of accumulations are expected with the snow showers, though gusty winds and visibility drops will accompany these showers. Geelhart && .LONG TERM... Issued at 311 PM CST Tue Nov 15 2022 Thursday through Tuesday... A couple systems will sweep across the Great Lakes late week, as the unseasonably cold Arctic air continues over the region. Additional snow showers are expected Thursday as one wave passes, though perhaps not quite as widespread as the previous day. A stronger clipper system sweeps through on Saturday. Bulk of the precipitation from this latter system looks to largely stay to the north of the metro, but some 20/30-ish PoPs will be included close to the lake. Coldest of the Arctic outbreak is expected late week, as ECMWF extreme forecast index is on the extreme end (-0.9 or so) on Friday. Highs are only expected to be in the lower to mid 20s on Friday and again on Sunday. As a comparison, this would be about 10 degrees below the normal lows for Friday, and the record cold- high temperatures are 19 at Chicago and Rockford back in 2014. Mercifully, the pattern finally starts to change early next week, as the upper flow starts to come more from the Pacific. Highs return to the 40s in many areas by Tuesday, and the 8-14 day outlook covering the period through Thanksgiving favors above normal temperatures. Geelhart && .AVIATION... For the 00Z TAFs... Aviation Forecast Concerns: * Prolonged period of light snow, with a mix of rain/snow this evening with marginal near-surface temp/wetbulbs before column slowly cools. * Scattered heavier snow showers expected just north/northeast of ORD and MDW this evening. Scattered heavier snow showers Wednesday midday/afternoon. * Though brief LIFR ceilings possible this evening, mainly IFR cloud bases expected through Wednesday morning before a gradual improvement to MVFR, except IFR in snow showers through the afternoon. Visibilities generally IFR/MVFR with some fog as well. Weak area of surface low pressure over IN/OH/KY will track slowly northeast into the eastern Great Lakes through Wednesday morning, while weaker surface trough lingers across southern WI/northern IL through the period. Nearly saturated low levels will produce persistent light precipitation within this trough, initially in the form of light rain/snow this evening but eventually transitioning to mainly light snow tonight as low level winds turn more west-northwesterly and the column slowly cools. Area of lake effect/enhanced precip (mainly snow) over eastern Lake county and northeast Cook county IL (just N/NE of ORD and MDW) is expected to remain largely north/northeast of the Chicago terminals, and eventually shift into northwest IN Wednesday. However, a series of mid-level waves will modulate lightly higher precip/light snow intensity this evening and again Wednesday midday/afternoon. Forecast soundings depict some cooling aloft Wednesday which may support more convective-like snow showers, with intermittent IFR visibilities. Snow/snow shower coverage should diminish Wednesday evening as the main upper trough begins to shift off to the east of the area. This should allow improvement to VFR visibilities and gradually lifting MVFR ceilings by that time. Surface winds are currently in the process of becoming more west- northwesterly early this evening, and should remain there for the duration of the forecast period. Winds will increase gradually to around 10 kt Wednesday, and some gusts into the 15 kt range can`t be ruled out in the afternoon. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...Winter Weather Advisory...ILZ006 until 6 AM Wednesday. IN...None. LM...Small Craft Advisory...IL nearshore waters until 9 PM Tuesday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
918 PM CST Tue Nov 15 2022 .UPDATE... Issued at 918 PM CST Tue Nov 15 2022 Radar and surface reports are showing some sprinkles and flurries from Quincy down into the St. Louis metro area at mid evening. This is occurring as a weak vort max rotates through the area on the south side of the Great Lakes upper low. This vort will move off to the east and latest RAP forecast soundings at STL and UIN are showing depth of moisture becoming shallow overnight. Have added mention a mix of sprinkles/flurries along and east of MS river through midnight and slowed clearing. Otherwise, rest of forecast looks on track. Britt && .SHORT TERM... (Through Late Wednesday Night) Issued at 244 PM CST Tue Nov 15 2022 Mean upper-level longwave troughing over is expected to remain over the upper Midwest and Great Lakes, leaving the Midwest in a regime of broad, deep cyclonic flow through Wednesday. Passage of a series of mid-level shortwave troughs within this regime, CAA in tandem with weak surface heating acting to steepen low-level lapse rates, and boundary-layer moisture will support scattered flurries or isolated snow showers at times through Wednesday. The greatest chances of flurries or snow showers will be this evening and again Wednesday morning through evening across much of IL and northeastern, central MO, coincident with subtle ascent leading the shortwave troughs. With the steep low-level lapse rates, the most intense snow showers could produce brief bursts of snow, possibly coating grass and untreated surfaces in very localized areas where surface temps remain below or near 32 F. However, most snow should struggle to accumulate. Coincidentally, stratocumulus should be prevalent for much of this time, with the exception of a brief period of scattering/clearing this evening into overnight as drier air is temporarily advected into the CWA and entrained into the stratus-bearing layer. How quickly stratocumulus expands back southeastward Wednesday morning into midday will have an impact on Wednesday`s high temps across the CWA, dictating how much insolation can occur. As such, high temps will range from the low-30s in northeastern MO/west-central IL to around 40 in southeastern MO, with more uncertainty between these areas. Regardless, temps will unseasonably cold and 15 to over 20 F below average for mid-November. To further exacerbate the cold, a tightening of the surface pressure gradient will result in sustained west-northwesterly winds around 15 mph, gusting to 20 to 25 mph on Wednesday. Pfahler .LONG TERM... (Thursday through Next Tuesday) Issued at 244 PM CST Tue Nov 15 2022 Mean upper-level longwave troughing over the upper Midwest and Great Lakes is advertised to make little eastward advancement through the rest of week, supporting broadly cyclonic flow to hold through the Midwest. At least two additional mid-level shortwave troughs are progged to pass over the Midwest around Thursday and Saturday as they navigate the cyclonic flow. Each of these troughs should force a cold front southeastward through the CWA, with short-lived pre- frontal low-level WAA and strong post-frontal low-level CAA. There is consensus among model guidance that the brunt of this CAA will be felt into Friday, with 850-hPa temps falling into the mid-negative teens C which are near or at the minimum of climatology at their valid times. Unsurprisingly, high temps may approach daily record minimums and hold in the 20s or 30s F. The frontal passages themselves will likely be dry, but scattered flurries, perhaps snow showers, could accompany post-frontal stratocumulus, especially Thursday afternoon/evening. During the second half of the weekend into early next week, global model guidance are in general agreement that mean upper-level troughing will finally depart the Great Lakes, with cyclonic flow over the Midwest giving way to more zonal flow. As large-scale subsidence intensifies in the wake of the trough, a broad surface/low-level anticyclone could become established across the eastern or southeastern CONUS and favor low-level southwesterly and eventual WAA into the Central Plains and Mid-Mississippi River Valley. This evolution would result in temps moderating toward average. Pfahler && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 519 PM CST Tue Nov 15 2022 High MVFR or low VFR ceilings are expected to persist most of the period at the airports. Flurries may occur at UIN early this evening at UIN. Flurries will also be possible during the day tomorrow at UIN and the St. Louis area terminals. Winds will be west-northwesterly through the period with gusts to around 20 knots starting on mid-morning Wednesday. Britt && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Marquette MI
639 PM EST Tue Nov 15 2022 .SHORT TERM...(This evening through Tonight) Issued at 248 PM EST TUE NOV 15 2022 The area of light snow this morning shifted northwest and weakened this morning. A second area of light snow with heavier areas of lake-enhanced snowfall is expanded across southern portions of our CWA between 1-3PM. Regional radar showed a better defined band aimed near Escanaba with an upwind connection to Lake Huron. An observer on the shoreline of the Garden Peninsula confirmed the p-type is all snow in this band, but 33F air temperatures were limiting accumulation. Automated sensors near the Green Bay shoreline also indicate temperatures in the 33-36F range suggesting snowfall will be limited along the immediate. Sunset and winds becoming northwesterly overnight should allow temperatures to cool to near or below freezing before snowfall ends. HREF guidance shows snowfall intensifying this afternoon and evening with embedded lake-effect bands off Lake MI gradually backing northeasterly this evening and overnight. Peak snowfall rates across southern Menominee County should occur this evening, but should linger into the overnight hours across the far southern portion of the county. As winds back northeasterly lake effect snow showers are expected to move into Marquette County too. HREF guidance show a shoreline parallel band developing into Marquette County as the land breeze intensifies this evening. An approaching shortwave/vort max suggests weak radar returns should continue expanding north across the UP. This light synoptic snow adds potential for seeder-feeder into lake effect showers adding to the fluff factor. Evening soundings suggests omega focused below the DGZ, but somewhat deeper lake- inversion heights and cooler temperatures should increasingly favor fluffy snowfall by Wednesday morning. Up to 4 inches of snow should fall across Marquette County, especially at higher elevations away from the lakeshore. As winds become more northerly Wednesday morning, lake effect snow showers could also work their way into Ironwood. .LONG TERM...(Wednesday through Tuesday) Issued at 310 PM EST TUE NOV 15 2022 As a low pressure continues to lift NE through southern Ontario into New England Wednesday, expect lake-enhanced snow over the north central and east to dwindle throughout the day, with winds shifting from the NE to N by the afternoon and NW by Wednesday evening. Meanwhile, a shortwave low over northern Manitoba drops southwards towards the area. Ahead of the shortwave`s arrival, CAMs guidance shows a mesolow forming over western Lake Superior Wednesday evening. As the shortwave low moves over the lake Wednesday night into Thursday, expect the mesolow to move east. While CAMs guidance is kinda all over the place with the placement and movement of the mesolow, it does look like that it will bring some heavy snowfall to the Keweenaw Peninsula late Wednesday night/Thursday morning; indeed, if the HRRR and Canadian suite of guidance comes to fruition, heavy snowfall rates could be seen from Ironwood up to the Keweenaw Wednesday night into Thursday night. Otherwise, some light snowfall could be seen across Upper MI Thursday as the shortwave passes into northern Lake MI, save for some lake-enhanced snowfall over the SE`rn UP due to a second mesolow forming over northern Lake MI. As the shortwave low leaves the region Thursday night into Friday, expect light snow showers to continue across most of the area, save for near the Lake Superior shoreline, where some enhanced snowfall rates could be seen. Behind this shortwave, another shortwave low looks to immediately follow over Lake Superior Saturday. Some lake-enhanced snowfall is expected in the W snow belts early Saturday before transitioning to the NW snow belts by late in the day; would not be surprised to see some more moderate to heavy snowfall rates in these snow belts Saturday, especially in the east late in the day as some convergence of the winds east of Marquette may help to increase the rates. In addition, expect anomalously cold temps to move into the region this weekend; ensemble guidance has temps approaching the 1st percentile of model climatology. Therefore, we may see highs in the 20s this weekend and lows in the single digits (particularly in the cloud- free areas). One positive aspect about the recent snowfall is that it should help to insulate underground pipes this weekend. One more shortwave may move through the area next Monday, before ridging builds in from the southwest early next week. Expect the anomalously cold temps to warm up to near normal by the end of the forecast period as the ridging brings some WAA across the region. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 626 PM EST TUE NOV 15 2022 MVFR cigs are expected to prevail at all TAF sites with easterly winds backing northerly by the end of the TAF period. Lake effect snow showers are expected to become more numerous overnight at SAW as winds back northeasterly. Brief reductions to IFR cigs/vsby are possible within the more intense snow showers. More northerly winds late in the TAF period could bring snow showers into IWD too. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 310 PM EST TUE NOV 15 2022 Easterly gusts of 20 to 25 knots around Isle Royale and north of the Keweenaw become light winds of 20 knots or less later tonight as winds back northeast. Winds look to pick back up again around a mesolow over the western lake Wednesday night is it travels east towards the Keweenaw Peninsula. Some winds of 20 to 25 knots, with a few gusts up to 30 knots, are possible around this mesolow. Behind this mesolow, some westerly winds up to 25 knots could be seen Wednesday night into Thursday. As a shortwave moves over Lake Superior Thursday, expect the winds to generally become 20 knots or less (save around the mesolow). As CAA pumps into the region Friday, some northwesterly winds of 20 to 25 knots are expected to move across the lake, backing to the west by Friday night. Immediately following this shortwave, another shortwave looks to bring northwest to northerly winds of 20 to 25 knots across the lake Saturday into Sunday. One last shortwave moving through the lake next Monday looks to back the winds to the southwest and west Sunday night and Monday, before ridging lowers winds to 20 knots or less as we head into the middle of next week. Some moderate freezing spray is possible Saturday night and Sunday across Lake Superior due to the anomalously cold temps expected. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Weather Advisory until 1 AM EST Wednesday for MIZ012. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...EK LONG TERM...TAP AVIATION...Voss MARINE...TAP
Area Forecast Discussion
National Weather Service Morristown TN
1045 PM EST Tue Nov 15 2022 ...New UPDATE... .UPDATE... Issued at 1039 PM EST Tue Nov 15 2022 Longwave troughing across the region with low-level NW flow is resulting in CAA in the low-levels and a strong inversion around 5k ft with clouds just beneath this layer. Cool and cloudy conditions continue through the remainder of the night before some breaks in the clouds are expected on Wednesday afternoon. && .SHORT TERM... (This evening through Wednesday) Issued at 313 PM EST Tue Nov 15 2022 Key Messages: 1. Lingering precipitation will continue to decrease overnight, ending as light snow showers in the mountains by early Wednesday morning. Little to no accumulations are expected. 2. Significantly below average temperatures continue. Discussion: After rain all day today, precipitation will continue to diminish in intensity and coverage. HRRR shows precip clearing out of the entire area including our Virginia counties by this evening, which lines up with diminishing low-level moisture. Even without the rain, the evening will be soggy and moist with lingering saturation near the surface. Some upslope flow, combined with marginal low-level moisture may lead to lingering precipitation in the mountains that will change to light snow late tonight as CAA takes place. 850mb flow is not ideal for a NW flow event as it is fairly westerly and 20 kts or less. Yesterday I compared the high temperatures to normal November values, but perhaps I should compare it to our January averages (48/30 at Knoxville), brr. The good news is this rain should really help out the soils with the dry period we had endured previously. Ultimately the low responsible for our wet period is translating up to the Mid-Atlantic tonight and heading to Canada on Wednesday. Meanwhile the upper trough pivots from the Central Plains to the Ohio River. A 500 mb shortwave will round the broader trough tomorrow, and the HRRR has shown some light snow showers in Kentucky beginning Wednesday afternoon, so perhaps a few flurries make it into the very northern tier of our region going into Wednesday evening. && .LONG TERM... (Wednesday night through next Tuesday) Issued at 313 PM EST Tue Nov 15 2022 Key Messages: 1. A few flurries/light snow showers possible Wednesday night into Thursday morning, mainly across the east TN and southwest VA mountains. 2. Well below normal temperatures continue through this weekend with dry conditions. Discussion: Not a whole lot to talk about during the long term. We begin the period on Wednesday night with an additional short wave rolling through the existing long wave trough. Weak moisture associated with this feature, combined with upslope flow, could produce a few flurries/light snow showers across the higher peaks of the east TN and southwest VA mountains. Again, moisture is very limited so only a few isolated locations could see a dusting at best. Also put in some flurries across the northern Cumberland Plateau and along the TN/KY line, though there is less confidence of occurrence for these areas. Otherwise, all other locations are expected to be dry. Additionally, a reinforcing shot of cold air moves in behind the short wave and will drop temperatures on Thursday with highs in the upper 30s to lower 40s. We remain in the longwave trough Sunday with dry conditions and well below normal temperatures, around 15 to 20 degrees below normal. By Monday/Tuesday the flow becomes more zonal and we begin to warm back up. Highs on Tuesday are back into the lower 50s, but this is still around 10 degrees below normal. && .AVIATION... (00Z TAFS) Issued at 628 PM EST Tue Nov 15 2022 Poor flight conditions continue tonight with low clouds and lower vis at all sites this evening. MVFR conditions are forecast to prevail tonight with some IFR cigs at times, especially at TYS and TRI. Light winds increase from the west late in the period with increasing cigs. Expect to have VFR conditions at CHA and TYS by late Wednesday afternoon, but MVFR cigs remain at TRI through the end of the period. && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 36 48 28 45 / 10 0 0 0 Knoxville McGhee Tyson Airport, TN 35 45 26 43 / 20 0 0 0 Oak Ridge, TN 35 45 25 43 / 10 0 0 0 Tri Cities Airport, TN 35 42 24 40 / 30 0 0 10 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. && $$ SHORT TERM...JB LONG TERM....SR AVIATION...JB