Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/14/23


Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
911 PM CDT Tue Jun 13 2023 .UPDATE... Issued at 910 PM CDT Tue Jun 13 2023 Current forecast is on track, therefore no changes made at this time. && .SHORT TERM...(This Evening through Wednesday Night) Issued at 210 PM CDT Tue Jun 13 2023 Another dry and quiet short term period is in store for us. Currently, we are seeing hazy, milky, skies with the elevated smoke moving down from Canada. Temperatures are in the mid to high 80s with winds out of the north to northwest at about 10 mph. Expect smokey skies to continue through the short term period. HRRR smoke also has a plume of near surface smoke heading toward our area for Wednesday. The highest concentration looks to be over the eastern half of the CWA. Added some areas of haze moving northeast to southwest across the area tomorrow. Late Wednesday night, a front starts to move into the area from the west bringing a chance of showers and storms to our far western areas. Temperatures Wednesday will be in the mid 80s and possibly reaching 90 in some areas. Gusts Wednesday afternoon could reach 25 mph west river, otherwise light easterly winds. .LONG TERM...(Thursday through Tuesday) Issued at 210 PM CDT Tue Jun 13 2023 Overall, for the vast majority of the long term, the deterministic models are in fair agreement. A split-flow, semi progressive mid level pattern is expected across the forecast area. As a system aloft lifts from the Northern Rockies and into SC Canada, an associated cold front will slide east over the Dakotas Thursday/Friday and into Minnesota on Saturday. Ahead of the system there`ll be an increase in moisture/instability, but MLCAPEs should stay mostly below 1k j/kg. With deep layer shear remaining rather weak, severe opportunities look low. Rain chances do however look pretty decent, with 24hr probs of a quarter inch or more pegging 50 percent over the region. After the weekend, conditions will likely turn dry again for a few days as a stout looking H7 thermal ridge advects north across much of the Dakotas, with temps of 10-13C over the region. This should lead to a period of capping over the region. Temps late this week and into the weekend will favor near normal, but come next week expect rising temperatures under that mid level dome of warm air. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 624 PM CDT Tue Jun 13 2023 Terminals KABR,KATY,KPIR,KMBG VFR conditions will prevail across the area tonight and through the day Wednesday. Elevated smoke will remain over the area through the TAF period. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...Parkin SHORT TERM...KK LONG TERM...TDK AVIATION...Parkin
Area Forecast Discussion
National Weather Service La Crosse WI
1026 PM CDT Tue Jun 13 2023 .DISCUSSION...(This evening through Tuesday) Issued at 308 PM CDT Tue Jun 13 2023 Key Messages: - Scattered showers this afternoon and evening in central and north-central Wisconsin. - Another round of scattered showers in central and north-central Wisconsin from Wednesday afternoon into evening - Additional showers and scattered storms from Friday into early next week. This afternoon and evening... A shortwave trough will rotate south across Wisconsin this afternoon and evening. This system will produce showers across central and north-central Wisconsin. Additional rainfall will be up to a half inch. Wednesday afternoon and night... A backdoor cold front will move southwest and south across the area. There should be even convergence and moisture transport into central and north-central Wisconsin to generate isolated to scattered showers and maybe a few storms. Rainfall amounts will be generally less than a tenth of an inch. The HRRR continues to show that the vertically integrated smoke will be increasing across the area during the day. The concentrations will be the highest during the afternoon and evening. Much of this smoke will be elevated. Friday through early next week... The models continue to show that the upper level ridge will break down and a closed low will then move through the region during the weekend. The upper level ridge will then reestablish itself north and northwest of the area early next week. While the models are in general agreement, there is quite a bit of uncertainty on the track of the upper level low and its speed. Also on how close it will be to the area for early next week. As a result, there is uncertainty with the timing of precipitation. CAPE values are generally less than 1K J/kg and the 0-3 km and 0-6 km shear remain weak, so not expecting any organized severe weather. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1026 PM CDT Tue Jun 13 2023 VFR conditions are expected with mid/high clouds gradually diminishing overnight. Smoke from Canadian wildfires will move across the area Wednesday and Wednesday night, but impacts to surface visibility are uncertain, so maintained VFR conditions. There is a small (~10%) chance for a shower/storm late Wednesday afternoon/early evening, but confidence in any impacts to TAF sites is low. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DISCUSSION...Boyne AVIATION...JM
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
1027 PM CDT Tue Jun 13 2023 .UPDATE... Issued at 1025 PM CDT Tue Jun 13 2023 Isolated thunderstorm activity has ended across the north. The rest of the night looks to be dry with lows generally in the 50s. Areas of surface smoke from wildfires in Canada are starting to enter the northeastern part of the state. This surface smoke could enter into north central North Dakota tonight, while smoke aloft looks to be found across much of the area. The 00z HRRR surface smoke forecast run has come in with slightly less surface smoke during the day on Wednesday, yet maintains smoke Wednesday night in the east and some central portions. Have made some slight adjustments as a result, yet smoke may still be found in eastern portions during the day Wednesday. UPDATE Issued at 659 PM CDT Tue Jun 13 2023 Minimal updates needed so far this evening. Isolated thunderstorms continue along a weak boundary across the north. There is a pocket of weak instability along this boundary, however there is very limited shear in the atmosphere. Thus heavy rain, gusty winds, and perhaps some mall hail will be the main threat with these storms. Severe weather is not expected at this time. Smoke continues to be found aloft. CIMSS Natural Color RGB showing the surface smoke still in Canada at this time. 18z HRRR near surface forecast still showing the potential to enter into eastern areas Wednesday through Wednesday night. Decided to add in some mention of smoke during this time period to cover this potential increase in smoke. && .SHORT TERM...(This Evening through Wednesday) Issued at 235 PM CDT Tue Jun 13 2023 At the upper levels, a ridge axis is currently located over eastern Montana and a closed low is centered over Michigan. Dry air associated with the ridge will keep the area mild and mostly precipitation free through the short term forecast period. The one exception may be across portions of the north later this afternoon and into the early evening when a weak backdoor cool front dips into the northeast and north central. Here, we could see an isolated thunderstorm or two in the vicinity of the front before sunset. RAP trends suggest that MLCAPE here will top out in the 250 to 1000 J/kg range with little to no shear. Thus, severe weather is not much of a concern and convection will be very hit and miss. Smoke aloft from Canadian wildfires will continue to cover the region and may keep high temperatures a bit cooler than originally thought (but still above normal). Tonight`s lows will generally be in the 50s. Wednesday will be similar to today: mainly dry and possibly a touch warmer depending on how the smoke forecast evolves. The ridge axis will cross the state overnight and tomorrow, promoting another day with highs in the 80s. Normally, we would probably see some lower 90s in this pattern, but more smoke aloft will likely keep temperatures a few degrees cooler. The RAP and HRRR smoke models also suggest that we could see a return of some near surface smoke late tonight through Wednesday, especially across the eastern half of the state. For now, we only have some higher sky cover in the forecast to account for hazy skies, but we may need to end up putting some smoke in the gridded forecast for tomorrow at some point if we see surface visibilities starting to drop. .LONG TERM...(Wednesday Night through Tuesday) Issued at 235 PM CDT Tue Jun 13 2023 As the upper ridge axis continues to move east, we transition to southwest flow aloft across most of western and central North Dakota by Wednesday night. A leading wave and associated frontal system will move from eastern Montana into the far west overnight, bringing with it chances for showers and thunderstorms. Chances for showers and storms will then spread into the central part of the state through the day on Thursday as the front moves across. Much of the central will see MLCAPE values in the 1500 to 2500 J/kg range by the afternoon hours, but the best shear will lag behind the front to the west. Colorado State University (CSU) Machine-Learning Probabilities do have a weak signal for some marginally severe hail across the south central on Thursday afternoon, but widespread severe weather is not expected. Precipitation chances will then move off into the east Thursday night, diminishing through the day on Friday. With the front coming through, there will be a wider temperature range across the state on Thursday with highs ranging from the mid 70s west to the lower 90s over the southern James River Valley near the South Dakota border. Highs on Friday will mainly be in the 70s with a few lower 80s across the James River Valley. Lows Thursday and Friday night will mainly be in the 50s but some upper 40s will be possible southwest. Low amplitude ridging builds back in late Friday into Saturday, promoting another warm up through the weekend with mainly dry conditions. However, we move back into persistent southwest flow aloft towards the end of the weekend as the next longwave trough digs into the Pacific Northwest. This will mean increasing chances for showers and thunderstorms again late Sunday and into the beginning of the work week. While, it is still way too far out for specific details, CSU Machine-Learning Probabilities are starting to pick up on at least small severe weather chances across western and central North Dakota Monday and Tuesday. A quick glance at the global ensembles and deterministic models does seem to confirm this as we may see some better instability/shear overlap than we have in the season thus far. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 659 PM CDT Tue Jun 13 2023 VFR conditions are expected through the forecast period. An isolated thunderstorm may be found across the north this evening, although confidence was too low to include in the TAFs at this time. VFR conditions look to continue tomorrow. Some showers and thunderstorms may then develop across the west tomorrow afternoon and evening. Smoke will remain aloft across much of the area during the forecast period. It may mix down to the surface tomorrow through tomorrow evening, especially in the east. At this time, confidence was only high enough to include smoke in the KJMS TAF. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Anglin SHORT TERM...ZH LONG TERM...ZH AVIATION...Anglin
Area Forecast Discussion
National Weather Service Boston/Norton MA
1030 PM EDT Tue Jun 13 2023 .SYNOPSIS... Low clouds and fog move back in overnight for the eastern half of the region, while western areas could clear out. fog and low clouds clear early tomorrow morning giving away to mostly sunny skies. Thunderstorms develop tomorrow afternoon, some of which may be severe. Our weather pattern then turns more unsettled for late in the week through the weekend with scattered showers and thundershowers during the daytime hours, with somewhat more coverage Friday and Saturday afternoons. However neither day is a washout. Seasonable temperatures are anticipated with a tendency for cooler than normal weather for early next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 1030 PM update... Low clouds continue to move into northeast MA with clear to partly clear skies further west. No significant changes to the forecast. Previous Discussion... With just enough instability, a couple heavier showers and thundershowers developed along a convergence zone between west flow across interior MA and an advancing sea-breeze/onshore flow seen well on composite radar mosaic imagery draped from about Ashburnham MA SSE through the Foxboro/Norwood vicinity. These are pretty low topped and won`t pose a risk to develop further or produce any worse weather other than brief downpours, these showers coming to an end shortly with sundown and drifting into a more stable air mass across northeast MA. Otherwise, while most of CT and western MA should be high and dry tonight, after coordination with NWS Gray/Portland I did opt to hoist a Dense Fog Advisory for most of eastern MA into the Boston- Providence I-95 corridor through 9 AM Wed. Much of coastal ME/NH has been socked in with fog/mist under a cooler maritime airmass. PBL cooling is evident tonight across most of eastern MA and into northern sections of RI, with model BUFKIT soundings from the HRRR and RAP-13km showing trapped shallow moisture and anticipated very narrow dewpoint depressions. The North Shore and at times Boston/Logan Airport has seen varying visibilities in fog, but expect as boundary layer cools that fog should begin to expand SSW with time into the late-evening and overnight hrs. It is uncertain how long the fog risk may last as winds flip to NW/WNW early overnight to the pre-dawn hrs and that could bring rising visibilities sooner than the Advisory would indicate; either way, it looks as though at least a portion of the Wed AM commute should be impacted by low visibilities. May need to consider expanding the Advisory further into the South Coast and the Cape and Islands but have better confidence on fog becoming the most dense in the Advisory area. Previous discussion: Latest surface analysis shows a low over central MA which is brining easterly on shore flow helping keep low clouds and fog near the eastern coasts. Areas inland have started to see pockets of sunshine with the strong June sun angle able to burn off some of the low clouds and fog. With the forcing of the surface low, some of the hi-res CAMS have some showers forming over eastern MA and RI, however, with the dry slot in the mid levels, any showers that try to form will get cut off at 700mb. Any precip likely remains more drizzle then rain. Overnight, the surface low begins to push east of the region shifting the winds to the NE then NW. This will allow low status and fog to redevelop over the eastern half of the region. Meanwhile the western half of the region could see some clearing overnight. This will allow overnight temps to remain warmer in the upper 50s for eastern MA and RI, while Western MA and CT likely see lows drop into the low 50s. Fog and low status likely burn off quickly after sunrise with temps recovering quickly with the strong June sun angle. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Highlights... * Showers and a few strong to severe thunderstorms Wednesday afternoon, temperatures are seasonably warm with highs 75 to 80 degrees. Wednesday: A quiet morning across southern New England with some linger areas of fog, but do anticipate that to lift quickly and reveal a mixture of sun & clouds. Any clearing will be short-lived as high & mid clouds do return ahead of an approaching surface low pressure system. As advertised, we are expecting storms to develop during the afternoon, from west to east, after 18z/2 PM. What has changed since the previous update, much of southern New England has been placed under a marginal risk for severe weather (about 5% chance for severe winds). Latest 12z CAMs do show initiation across eastern New York between 11 AM and 1 PM, then entering western Connecticut and Massachusetts between 1 PM and 3 PM. Do think the stronger storms will be confined to the west part of our CWA. Forecast soundings indicate CAPE values between 800 and 1200 J/kg not out of the question we may experience higher values if we are able hold onto the sunshine during the late morning. Never the less, low level lapse rates remain steep enough at 8 to 8.5 c/km, though the mid-level lapse rates are less impressive around 6 to 6.5 c/km. The surface to 6km shear is not as impressive at ~30 knots. But, with sufficient CAPE, we may be able to overcome the lower shear. As you can imagine, Wednesday is not a blockbuster severe weather day, but there are enough parameters to justify a couple strong to severe storms. Greatest concerns with these storms would be damaging straight-line winds and frequent lightning. Can`t rule out some smaller hail stones with the cold pool aloft from the mid-level low, though the positioning may be a little too far to the west. Those who have outdoor plans schedule tomorrow afternoon should monitor conditions and have a plan to seek shelter inside if they hear thunder. The line of storms exit off the eastern shore of Massachusetts around or just after sunset. Temperatures Wednesday afternoon are seasonable to slightly above normal in the mid to upper-70s, not out of the question the metro west of Boston nears 80 degrees. Wednesday Night: Outside of a couple lingering showers, drying conditions overnight. Areas that see heavy rain may experience some patchy fog as clouds clear from the southwest overnight. South winds overnight turn more west which will usher in drier airmass. Temperatures fall into the mid to upper-50s. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Highlights: * Unsettled Thurs thru the weekend with diurnal rain/thunder chances, tending more numerous for Fri and Sat. Neither day is a washout and severe weather is not anticipated. * Seasonable temps through the weekend, but trending cooler than normal early next week with onshore flow. Details: Thursday through Sunday: Heading into an overall unsettled weather pattern for the rest of the workweek into the weekend, as Southern New England becomes increasingly governed by longwave troughing at 500 mb. Under this trough pattern, we expect there to be several opportunities for clouds and mainly diurnally-driven shower and t-storm chances. While there is a mention of showers and isolated storms each day, it`s not likely to be wet during the entire period with several periods of dry weather. Uncertainties revolve more around the strength and timing of individual shortwave disturbances in the longwave trough pattern and that will affect the coverage of showers and t-storms. It appears that Fri into Sat will offer better overall rain chances, as a shortwave trough moves in from the Gt Lakes Fri/Fri night and closes off into an upper low over Southern New England for the rest of the weekend. More specific to Fri, showers and some storms may increase in number especially later in the day as the aforementioned shortwave its divergent height pattern aloft acts on what looks to be limited convective instability. This instability seems to be limited by weak lapse rates and a generous coverage of at least mid level cloudiness that will serve to temper daytime heating. Wind profiles/shear also look limited so the impression I get is a more limited risk for strong-severe storms; instead more general, garden-variety storms and their related risk for lightning and local downpours. With somewhat cooler temperature profiles and continued cloud cover, may see hit-or-miss showers and isolated t-storms during the daytime hrs this weekend but at the moment it is more of a look of "showers to dodge" vs a washout on any specific day. Temperatures overall in this period trend a little cooler each day around seasonable or slightly cooler than seasonable levels. Humidity levels should be tolerable too, with dewpoints in the mid 50s to low 60s. Early Next Week: A bit more uncertainty in the 500 mb pattern and its evolution renders reduced confidence in the forecast at this range. Cooler than normal weather looks favored though as onshore flow increases for Mon and Tue, with more clouds than sun with more limited rain chances. && .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 timing of fog and stratus for eastern MA and RI. VFR in the interior (mainly west of ORH) with light W winds. Elsewhere however, IFR to LIFR (possible VLIFR) fog and stratus to expand S/SW from coastal NH and the North Shore of MA, to include BOS, BED, ORH and PVD. Fog and stratus may develop across the Cape and Islands overnight too, but it`s less certain how low visibilities may get. NE winds 5-8 kt to lighten and become light NW by daybreak. Wednesday...High confidence. VFR. Scattered showers and thunderstorms during the afternoon and evening, some of which could be strong to severe. Southerly winds 5 to 10 kts. KBOS Terminal...High confidence in TAF/trends but moderate timing. LIFR in fog to continue and may become locally dense overnight; unclear on specific improvement timing but categories should improve through the 10-12z window. Possible aftn SHRA/VCTS but left as VCSH for now with better confidence west of BED. KBDL Terminal...High confidence in TAF. VFR tonight, low prob for radiational BR/FG. Sct TS possible starting ~18z Wed, could be strong. Indicated PROB30 in TAF to reflect TS risk. Outlook /Thursday through Sunday/... Thursday: VFR. Slight chance SHRA. Thursday Night: VFR. Friday: Mainly VFR, with local MVFR possible. SHRA likely, isolated TSRA. Friday Night: Mainly VFR, with local IFR possible. Chance SHRA. Saturday: Mainly VFR, with local IFR possible. Chance SHRA, isolated TSRA. Saturday Night: Mainly VFR, with local IFR possible. Chance SHRA. Sunday: Mainly VFR, with local IFR possible. Chance SHRA, isolated TSRA. && .MARINE... Forecaster Confidence Levels: Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. Tonight...High Confidence. Spot shower, otherwise a mainly dry night. Areas of fog develop overnight with reduced vsby. Seas building for southern waters 3 to 5 feet, while eastern waters are 2 to 4 feet. Winds become light and variable for the first half of the night, then becoming west/southwest between 8 and 15 knots. Wednesday...High Confidence. Areas of fog early, improving vsby throughout the morning. Showers and isolated thunder mid afternoon into evening. Stronger storms may reduce vsby, produce stronger gusts, and rough seas. Otherwise, winds are south 10 to 15 knots with gusts below SCA criteria. Seas generally between 2 and 4 feet. Wednesday night...High Confidence. Periods of rain and storms linger into the first-half of the night then diminish during the second-half. Areas of low vsby with patchy fog possible, but not as widespread as previous nights. Winds are south, but becoming west by the end of the night less than 15 knots. Seas building to near 5 feet off shore, otherwise 2 to 4 feet. Outlook /Thursday through Sunday/... Thursday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers. Thursday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Friday through Saturday: Winds less than 25 kt. Chance of rain showers. Saturday Night through Sunday: Winds less than 25 kt. Slight chance of rain showers. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...Dense Fog Advisory until 9 AM EDT Wednesday for MAZ005>007- 013>019. RI...Dense Fog Advisory until 9 AM EDT Wednesday for RIZ001-002. MARINE...None. && $$ SYNOPSIS...Loconto/Dooley/KP NEAR TERM...BW/KP SHORT TERM...Dooley LONG TERM...Loconto AVIATION...Loconto/Dooley/KP MARINE...Loconto/Dooley/KP
Area Forecast Discussion
National Weather Service Burlington VT
1022 PM EDT Tue Jun 13 2023 .SYNOPSIS... Spotty drizzle or rain showers will continue this evening across northern Vermont, and then a foggy start to Wednesday is expected. Widespread showers and thunderstorms will shift northeast and bring the potential for additional moderate to heavy rain across the region. An upper low will linger over the region bringing intervals of rain and the potential for hit or miss afternoon thunderstorms through the end of the week into the weekend. Temperatures will remain seasonable in the 70s throughout the week. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... As of 1018 PM EDT Tuesday...Have cut back on fog across the Champlain Valley as GOES 16 IR satl imagery shows cooling cloud tops associated with ulvl jet max crossing acrs our central cwa this evening. This energy aloft, combined with weak sfc convergence has resulted in showers prevailing over central VT with some development possible into parts of the CPV. Based on crnt satl/water vapor trends and latest 00z HRRR have updated to place chance pops back into the CPV and delayed the development of fog until 06z for most of VT. Given clearing skies and light winds, expecting fog to develop within the next hour or so at SLK and deeper valleys of the dacks. Once the rain lifts northeast of VT, areas of fog wl develop with lows ranging from lower 40s to upper 50s. Previous discussion follows: Outside of southern Vermont and the St. Lawrence Valley, northern New York and most of Vermont have experienced a dreary day. The frontal occlusion that passed through early this morning did wind up stalling across the region, trapping shallow moisture across Vermont. Sharp, low-level convergence has been producing spotty drizzle or showers from the eastern slopes of the northern Adirondacks east across the upper half of Vermont with a broken strip of heavier showers from Orange County Vermont up through Orleans County. This has kept afternoon temperatures a bit cooler across the region as well with mainly upper 60s, though with a few 70s east due to the lack of eastward progression from the occluded front. Eventually, we will see precipitation exit northeast of the area. Beneath the upper low, a pocket of clearing skies should yield excellent conditions for the development of fog across the region, even in some of the less fog prone areas. The fog should end fairly quickly with the approach of our next system early tomorrow morning. Overnight lows should settle in the mid 50s in Vermont, with mid 40s to lower 50s across northern New York. For Wednesday, there has been a notable shift northward in the track of surface low pressure ejecting northeast as it rounds the large upper level low. This means that we have even higher chances of showers and thunderstorms for tomorrow. CAPE values of 500 to 750 J/kg and about 25 knots of 0-6km shear suggest some level of organization is possible, with several mesoscale models hinting at the potential for some broken, linear segments and some northward lifting parallel stratiform rains in convection to the south. Given the excellent upper level diffluence, this seems reasonable, and the potential for higher rainfall rates will be monitored closely. The potential for stronger storms appears limited due to marginal lapse rates from poor surface heating and our placement in the northeast quadrant of the incoming surface low. Probabilistic data from the HREF suggests about a 10 percent chance of rainfall rates exceeding 1 inch in a 6 hour time frame. Given the recent rains, the main impact would mainly be ponding across urban and poor drainage basins, but we will keep an eye on convective development tomorrow. Rainfall amounts should stay around 0.50-0.67", but the probability of exceeding an inch along the spine of the Greens and patches in the Adirondacks range from 10 to 20 percent. The extent of showers will decrease Wednesday night, but activity will remain possible as the upper low tracks overhead. There doesn`t appear to be much clearing, and have left fog out for now. Overnight lows will probably also be a bit warmer as a result, mostly in the 50s, but with a few spots in the upper 40s (mainly SLK). && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... As of 401 PM EDT Tuesday...A closed upper low will depart from the region and head eastward towards the Maine coast by Thursday morning. Although chances of rain are lower in the morning, by the afternoon scattered showers are expected to develop as a surface boundary drops down from Canada. Some thunderstorms are possible during the afternoon, especially given the sufficient CAPE values (up to 900 J/kg), particularly in northern portions of the forecast area. Showers will dwindle Thursday night with the loss of daytime heating. Temperatures will be fairly seasonable, with highs in the 70s and lows in the upper 40s to mid 50s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 401 PM EDT Tuesday...Persistence continues to be the forecast as the unsettled weather pattern continues thanks to upper level troughiness. Another closed upper low looks to impact the region towards the very end of the week into the weekend, bringing along chances for widespread showers. The generally unsettled pattern continues through the remainder of the weekend into next week, with possible showers in the afternoon and evenings, tapering off into the overnight hours. Model guidance diverges as we head into next week, however at this point it seems likely that the somewhat unsettled weather will continue. Temperatures will be a few degrees cooler than normal for the end of the week, but will warm up as we head into next week. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Through 00Z Thursday...A frontal occlusion stalled over the area, and is decaying. Spotty showers continue in eastern VT with the broad southerly flow but should exit the region around midnight. Some clearing has taken place across NY and will slowly rotate eastward in VT. Some drier air across NY with decent dewpoint spreads but really saturated across VT. Any clearing will likely mean the development of fog, possibly dense where greater clearing exists for a period. Low level saturation should easily allow for stratus deck to redevelop with winds basically calm or light and variable. Mentioned BCFG or VCFG for most locations, and explicitly mentioned 1/2SM to 2SM visibility at the most fog prone terminals. The next system approaches from the southwest around 10-12z, which will scatter the fog with incoming clouds around 5000-7000 ft agl and south to southeast winds 4 to 8 knots. Precipitation will arrive after 15z Wednesday with VFR conditions expected. Outlook... Wednesday Night: Mainly VFR, with areas MVFR possible. Likely SHRA. Thursday: Mainly VFR, with areas MVFR possible. Chance SHRA, Slight chance TSRA. Thursday Night: VFR. Chance SHRA. Friday: VFR. Likely SHRA, Slight chance TSRA. Friday Night: MVFR/IFR conditions possible. Chance SHRA. Saturday: Mainly MVFR, with areas IFR possible. Chance SHRA, Slight chance TSRA. Saturday Night: Mainly MVFR, with local IFR possible. Chance SHRA. Sunday: Mainly MVFR, with local IFR possible. Chance SHRA, Slight chance TSRA. && .BTV WATCHES/WARNINGS/ADVISORIES... VT...None. NY...None. && $$ SYNOPSIS...Haynes NEAR TERM...Haynes/Taber SHORT TERM...Kremer LONG TERM...Kremer AVIATION...Haynes/SLW
Area Forecast Discussion
National Weather Service Columbia SC
840 PM EDT Tue Jun 13 2023 .SYNOPSIS... A frontal boundary will remain over the SE US over the next several days leading to multiple rounds of showers and thunderstorms through the middle of the week. A more typical diurnal pattern of scattered afternoon thunderstorms returns for late this week into the weekend. && .NEAR TERM /UNTIL 7 AM WEDNESDAY MORNING/... Weak surface trough across the area. Frontal boundary near the SC coast extending southwest across southern Ga then west across the Deep South. Convection has focused near the front this afternoon and radar at 00z showing convection moving off the Ga and south coast SC. A rather tight moisture gradient across the area with precipitable water below an inch in the Upstate and near 2 inches near Savannah. The drier air mass appears to be in place at the moment across the central and northern Midlands where dew points remain in the 50s. Late tonight, back to our west, an increasing SW flow at h85 is expected to lead to the front lifting north some. An upper shortwave is also progged to track east across the region. Latest CAM`s indicate a cluster of convection developing to the west which shifts east towards the CSRA late tonight or towards daybreak Wednesday. Minor adjustment to the pops late tonight based on the latest HRRR model....but forecast appears on track. With increasing clouds and mixing in the boundary layer, temps in the 60s overnight. && .SHORT TERM /7 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... A surface front will be across the cwa through the period. This will help with any surface convergence and moisture focusing. Pesky closed upper low that has been situated across the Great Lakes will be slowly moving back to the east through the day Wednesday. An initial shortwave moving through on westerly flow aloft across Ga will more than likely be producing some showers and thunderstorms across the CSRA early in the day, before moving off to the southeast by late morning. Severe threat appears on the weaker side with that activity. A second and potentially stronger shortwave moves across Ga and towards the Carolinas during the late afternoon and evening Wednesday. Instability will be higher, along with some shear, and can the potential for severe winds and hail can not be ruled out with this stronger shortwave as it moves along the surface front. Activity may linger some into Wednesday night before weakening but still leaving scattered showers for the remainder of the night. Temperatures will be more dependent upon convective cloud cover through the day, and highs in the mid 80s are expected. Thursday look to be a little less active as surface front moves back to the south. However it will still remain slow enough, especially over the southern cwa, to keep a mention of scattered showers and thunderstorms through the day. Lower more isolated shower and storm activity expected further north. Despite a weak frontal passage, highs Thursday may actually be a little warmer, with readings in the mid to upper 80s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Aloft, one closed low poised to rotate out of the Mid-Atlantic, but this will quickly be replaced by another closed low digging southward out of east-central Canada on Friday. So the upper pattern over our area may not change much through the period. Changes may be closer to the surface as slightly drier may move into the region on Friday. This will help to lower any rain chances into the weekend. Even so, still expecting the area to see more seasonal and diurnal showers/storms each afternoon/evening. Temperatures will remain on the warmer side into early next week, with highs climbing back up into the lower 90s in many areas. Next cool down may not occur until Tuesday with the approach of another cold front. Questions do exist as to whether that front will make it through the area though. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... VFR Conditions at all terminals currently with westerly winds becoming lighter this evening. A front remains to the south of the area with generally drier air in the low levels will prevent fog from developing tonight. A disturbance early Wednesday morning will generate some showers and possibly an isolated thunderstorm mainly in the CSRA with the guidance showing a chance for potentially brief MVFR ceiling and visibility restrictions at the Augusta terminals. A low level jet strengthens tonight but expected to remain below low level wind shear criteria but as winds mix out into the day tomorrow expect gusts between 20 to 25 kts out of the west during the afternoon. Another disturbance moves into the area late Wednesday afternoon with higher chance for thunderstorms to develop near the terminals. Confidence in timing remains limited with HiRes models generally favoring evening into Wednesday night. For now have left the mention of ts out of all terminals. EXTENDED AVIATION OUTLOOK...Potential for scattered thunderstorms into Wednesday night. Otherwise, scattered showers and thunderstorms, along with some potential for late night early morning fog/stratus, possible through the period. Some potential for slightly drier air may reduce convective chances Fri into the wee. && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. && $$
Area Forecast Discussion
National Weather Service Cheyenne WY
614 PM MDT Tue Jun 13 2023 .SHORT TERM...(This evening through Thursday night) Issued at 245 PM MDT Tue Jun 13 2023 Forecast challenges deal with location of showers and storms through the short term. Surface analysis showing a surface high pressure across north central Colorado this afternoon with surface boundary form northeast Colorado to maybe near Cheyenne west to maybe Steamboat Colorado. Easterly winds east and north of this boundary across most of our northeastern CWA. Convection mainly confined to the Laramie Range and points west. Though Cheyenne just had a brief shower move through the past couple minutes. HRRR and RAP simulated radar for this afternoon keeps most convection west this afternoon. A brief respite in the rain expected Wednesday as a transitory upper ridge axis moves through the CWA. Showers will once again be limited to the mountains and points west of the Laramie Range. Next shortwave approaches the area from the west Wednesday night into Thursday. Timing of this shortwave is during the afternoon so look for showers and storms to be widespread across the entire CWA once again. PWATS are back up near .8 inches across southeast Wyoming and over 1 inch in the Panhandle Thursday afternoon. Tall/skinny CAPES again for southeast Wyoming sites indicating heavy rainfall. Maybe better chances for severe storms in the Panhandle. WPC has a Marginal Risk area for excessive rainfall highlighted for the entire CWA Thursday. This upper trough remains over the CWA Thursday night into Friday...so showers and storms could linger into the overnight hours into Friday morning. Given recent rainfall...may need another Flash Flood Watch for Thursday for some areas. .LONG TERM...(Friday through Monday) Issued at 335 AM MDT Tue Jun 13 2023 Friday...The next shortwave trough aloft moves across Wyoming and will combine with plenty of low and mid level moisture to help generate scattered to numerous showers and scattered thunderstorms in the afternoon and evening. Due to the increase in cloud cover and precipitation coverage, temperatures will be somewhat cooler compared to Thursday. Saturday...As the flow aloft turns northwest with a low amplitude shortwave ridge over Wyoming the atmosphere will dry out even more with only isolated afternoon thunderstorms possible mainly south of a Rawlins to Scottsbluff line. along with warmer temperatures due to 700 mb temperatures near 9 degrees Celsius and less cloud cover than Friday. Sunday...Maximum temperatures will warm even more for Father`s Day as the ridge axis aloft moves over the western High Plains states and southwest flow develops over our forecast area, establishing a decent surface lee trough with 700 mb temperatures near 14 degrees Celsius. It appears there will be enough low and mid level moisture combining with surface heating to produce isolated afternoon and evening showers and thunderstorms. Monday...Southwest flow aloft strengthens helping to further establish the surface lee side trough axis and producing more warm maximum temperatures with 700 mb temperatures near 15 degrees Celsius. Strong daytime heating will combine with enough low and mid level moisture to generate isolated late day showers and thunderstorms, most common along and west of Interstate 25. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 555 PM MDT Tue Jun 13 2023 VFR conditions expected across area terminals through the forecast period. Showers and thunderstorms will continue in the vicinity of southeast WY terminals early this evening before dissipating. SCT-BKN cumulus will also decrease in coverage over the next few hours across the NE Panhandle giving way to SKC. Southeast WY terminals will begin to see southwest winds increase Wednesday morning around 15-20 kt with scattered showers and thunderstorms developing in the afternoon. Coverage will be less like today was compared to earlier in the week and this past weekend, but kept VCTS in the TAFs for southeast WY terminals in the afternoon. && .FIRE WEATHER... Issued at 245 PM MDT Tue Jun 13 2023 Minimal fire weather concerns with recent moderate to heavy rains across most of southeast Wyoming and Nebraska Panhandle. There will be daily chances for showers and storms at least through the weekend before we begin to see possibly a drier pattern taking shape. Look for widespread wetting rains both Thursday and Friday with heavy rain possible. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ SHORT TERM...GCC LONG TERM...SAR AVIATION...MB FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Quad Cities IA IL
642 PM CDT Tue Jun 13 2023 ...00Z AVIATION UPDATE... .SHORT TERM...(This evening through Wednesday) Issued at 236 PM CDT Tue Jun 13 2023 [Key Messages] 1) Isolated to scattered rain showers/sprinkles still possible in the northeast CWA/NW IL through this evening. 2) Challenging temperature forecast/variability due to clouds and some smoke increasing aloft. How much smoke also a challenge. [Discussion] Tonight...Water vapor(WV) loop and upper air analysis were showing closed upper low portion of ongoing large blocking pattern, was located acrs the central to eastern GRT LKS. West flank vort spoke action was continuing to induce areas of showers acrs WI into northeast IL/NW IN, with a chance for some of the north central WI activity to clip the northeastern CWA thru mid evening. Mid level lapse rates and MUCAPEs marginal and removed thunder wording. A few sprinkles possible further to the west of this, battling dry air in the low to mid levels. Not much QPF expected with this rainfall if it can make into portions of the area. Then just varying amounts of mid and high clouds overnight making for variable low temp scenario, especially as sfc winds go light west to northwest. Generally low temps in the mid 50s to around 60. Wednesday...Upper air projections and ensemble handling suggest the upstream omega block high to slide eastward enough to nudge the GRT LKS upper low further to the east, probably enough to keep most of the area precip-free under more influence of short wave upper ridging. Some upper troffiness lingering enough for some spotty precip chances more to the northeast acrs portions of WI. What may be more of a factor will be the upper air pattern more conducive to advect smoke aloft down acrs portions of the region as the day progresses. The latest run RAP much more bullish in ducting some of this smoke to the sfc than the HRRR does, especially along and east of the MS RVR Valley. Low confidence in extent of this sfc ducting, but may go with areas of haze as a place holder in the more favored areas for now. But this may be overdoing it with the haze more perceived as an "aloft" phenomena, as opposed to a true sfc restriction. Fcst soundings continue to show inverted-V profiles for deep mixing, up over H8 MB. With increasing thicknesses, will play it warm with a lot of mid to upper 80s except for the northeast, but some concern of smoke and high clouds filtering insolation possibly limiting the true warm up potential. Wind profiles weaken, but the inverted-V soundings may still allow for an occasional gust up to 20 MPH. ..12.. .LONG TERM...(Wednesday night through next Tuesday) Issued at 236 PM CDT Tue Jun 13 2023 [Key Messages] 1) Dry heat Thursday and Friday 2) Rain chances return this weekend [Discussion] Wednesday night through Friday, mostly dry conditions will be common as high pressure moves through the area. A weak cold front will drop southward into the area on Thursday, as another upper low drops south out of Canada into the Great Lakes region. Some upper level energy is forecast to pivot down across southern WI and northern IL in the cyclonic flow, which may induce some showers and storms mainly to our NE. Slight POPs have been maintained in the Freeport, Sterling, and Princeton, IL areas for Thursday afternoon. Wildfire smoke is expected to be over the area resulting in a milkiness look to the sky. The RAP is indicating some better chances of smoke near the surface at times, which may need to be monitored. Friday, it will be dry ahead of the next potential rain-maker for the weekend. Highs will be in the upper 80s to low 90s Thursday, but with dew points in the 50s and a WNW breeze it will actually result in slightly lower heat index values. Friday, highs will be in the 80s, with dew points mainly in the mid 40s to mid 50s. The SW CWA may see humidity levels inch upwards towards late afternoon. Friday night through Tuesday, model guidance differs on bringing a trough and a series of surface lows across the Plains and through the mid and upper MS River Valley regions. While timing and placement details still need refinement, the overall blended forecast has slowed the onset and now has slight/low rain chances in the western CWA Friday evening through Saturday morning, and then brings chance POPS (40 to 50 percent) across the area Saturday afternoon through Sunday, with lower chances lingering beyond. Highs through the period will mainly be in the 80s. While there will be an increase in humidity, dew point values will remain unseasonably low with values in the 40s and 50s Saturday rising into the mid 50s to localized areas of mid 60s by Sunday and Monday. Further adjustments to this time period are expected as we get closer. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 642 PM CDT Tue Jun 13 2023 VFR conditions expected throughout the TAF period. We will continue to contend with some mid- to high-level cloud cover, with west to northwest winds less than 10 knots. There continues to be a low chance for haze from wildfire smoke possibly reducing visibilities Wednesday, but confidence is quite low on this, so will leave out of TAFs for now. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SHORT TERM...12 LONG TERM...14 AVIATION...Schultz
Area Forecast Discussion
National Weather Service Hanford CA
1235 PM PDT Tue Jun 13 2023 .SYNOPSIS...Lingering instability will provide for slight chances of showers and thunderstorms over the Sierra Nevada through Friday. Temperatures will slowly increase to around 4 to 8 degrees above normal by the end of the week. A low pressure system will then bring lower temperatures and some gusty winds for the start of next week. && .DISCUSSION... Weak low pressure remains over southern portions of California, while a high pressure ridge leans inland across the north. Most of central California remains in a northeasterly flow between the two synoptic features. High temperatures in this pattern today will increase a few degrees from Monday`s highs. Sufficient moisture and instability remains for another round of afternoon and evening thunderstorms over the Sierra Nevada. There is enough available moisture that WPC gives our Sierra zones a 5-14 percent probability for excessive rainfall. Latest HRRR runs are showing some locations in the Sierra with 1/2" to 3/4" hourly QPF amounts later this afternoon and early evening. Model ensemble members keep a weakening troughiness over our area, with gradually increasing heights and thicknesses through the end of the week leading to a continued gradual warming trend. A chance for thunderstorms and marginal risk for excessive rainfall continues over the Sierra Wednesday, tapering off through the end of the week with lingering thunderstorm chances confined mainly to the higher elevations in Tulare and Fresno counties Thursday and Friday. As temperatures gradually warm through the end of the week, National Blended Model guidance predicts high temperatures to be 4-8 degrees above seasonal averages by Saturday, with around 45 to 70 percent probabilities that highs will be least 95 degrees in the San Joaquin Valley. The ensemble model runs continue with similar solutions into the start of next week, as a developing low pressure system slips into the Pacific Northwest region and digs a trough along the west coast. This will bring lowering temperatures in a more westerly flow pattern, while also keeping the risk of thunderstorms near zero. Afternoon highs will return to near normal on Sunday, then top out around 6-10 degrees below normal on Monday. Probabilities are around 50 to 60 percent that highs Monday in the San Joaquin Valley will be no higher than 85 degrees. Tuesday`s highs are progged to trend just a few degrees upward from Monday but remain below normal values. In addition to the cooler temperatures, the trough will bring increased northwesterly winds for the start of next week. && .AVIATION...Areas of MVFR and mountain obscuring IFR conditions near showers and thunderstorms in the Sierra Nevada through 06Z Wed and again after 18Z Wed. Otherwise, VFR conditions will prevail across the central CA interior through at least the next 24 hours. && .AIR QUALITY ISSUES... None. && .CERTAINTY... The level of certainty for days 1 and 2 is high. The level of certainty for days 3 through 7 is high. Certainty levels include low...medium...and high. Please visit www.weather.gov/hnx/certainty.html for additional information and/or to provide feedback. && .HNX WATCHES/WARNINGS/ADVISORIES... None. && $$ public...JEB aviation....JEB weather.gov/hanford
Area Forecast Discussion
National Weather Service Wichita KS
626 PM CDT Tue Jun 13 2023 .SHORT TERM...(This evening through Friday) Issued at 237 PM CDT Tue Jun 13 2023 Key Points: * Another chance of widely scattered storms tonight. * Diurnal storm chances for Wed afternoon. * Better storm chances Thu night through early Fri. (Complex of storms) * Lingering storm chances into the weekend. * Summer heat returns late this weekend into next week. Fairly pleasant conditions were found across the plains states this afternoon, with temperatures about 5 degrees below seasonal averages. Seeing some convection beginning to develop over SW KS and SE CO late this afternoon, with some of the convection expected to trek east for the evening hours. Not sure how far east the SW KS will get, as instability diminishes for areas east of I-135. Will keep an afternoon pop in for any stray storm venturing east into central KS. Late this evening, propagation vectors suggest that if the SE CO convection evolves into a complex of storms (MCS) that it will drift SE into OK, staying SW of the forecast area. With that said, latest RAP shows some weak 850-700h moisture transport expected to increase across central and south central KS late this evening or overnight, just to the north of the MCS. So could see some widely scattered showers or storms develop with this moisture transport either late this evening or overnight. Will keep a low pop going for this chance. For Wed, could see some lingering morning isolated storms around, due to lingering 850-700h moisture transport, but think most of the morning showers/storms will dissipate early in the morning. A little uncertain on how Wed afternoon will play out, as some of the short term models suggest that diurnally driven showers/storms will be possible across southern KS, as a remnant Meso Convective Vort (MCV), may be drifting across southern KS for the daytime hours. Directional shear associated with the MCV with effective shear around 20-25kts may lead to a few strong storms, given MLCAPE values around 1000-1500 J/KG. This will probably be more of a meso situation, based on the position of the MCV. Expect most of Wed afternoon`s convective chances to be diurnally driven, with a quiet night expected Wed night. Weak mid level ridging is expected to move quickly across the area for late Wed through most of the daytime hours on Thu, with a warming trend back towards climo normals for temperatures. Both the GFS and ECMWF are similar in showing a shortwave moving out of the Rockies for Thu evening/night, which should lead to convection developing across the High Plains and western KS for Thu Evening. Both models suggest that this convection will grow upscale into some sort of eastward propagating MCS for Thu night, which will move east across most of the forecast area either late Thu evening or overnight Thu into early on Fri. Effective shear is a little better for Thu night, around 30-40kts, as this MCS moves across the area, with moderate instability expected to be in place, which may lead to this MCS being strong to severe along its leading edge late Thu evening. Could see some lingering showers/storms over the eastern half of the forecast area on Fri morning, otherwise expect most of the daytime hours on Fri to remain dry, as most of the area will be in a stable airmass from the previous nights MCS. Ketcham .LONG TERM...(Friday night through Tuesday) Issued at 237 PM CDT Tue Jun 13 2023 The unsettled weather pattern looks to continue for Fri night into the weekend. Latest medium models suggest that another MCS may come off of the High Plains for Fri night, and trek east-southeast across southern KS. There is also indications that another MCS could develop right over the forecast area across southern KS on Sat night as well. Summer type heat looks to move into the area towards the end of the weekend and into the beginning of next week, as the medium range models suggest mid/upper ridging will build across the plains. Ketcham && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 626 PM CDT Tue Jun 13 2023 Widely scattered convection will affect the I-70 corridor of central Kansas from Russell to Salina this evening. Isolated convection is possible later tonight into early Wednesday morning across central and southern Kansas. Otherwise, VFR conditions are expected to prevail away from any convection tonight and Wednesday with winds remaining light. KED && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 62 82 61 88 / 20 20 20 10 Hutchinson 60 82 60 88 / 20 20 20 20 Newton 61 82 61 88 / 20 20 20 20 ElDorado 60 82 61 88 / 20 20 20 10 Winfield-KWLD 61 82 61 88 / 20 20 20 10 Russell 59 84 58 88 / 30 20 20 30 Great Bend 59 81 58 86 / 30 20 20 30 Salina 60 85 59 91 / 20 20 20 20 McPherson 59 83 59 88 / 20 20 20 20 Coffeyville 62 84 62 89 / 20 20 20 10 Chanute 62 83 62 88 / 20 20 20 10 Iola 60 83 62 88 / 20 20 20 10 Parsons-KPPF 62 84 62 89 / 20 20 20 10 && .ICT WATCHES/WARNINGS/ADVISORIES...None. && $$ SHORT TERM...Ketcham LONG TERM...Ketcham AVIATION...KED
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
907 PM CDT Tue Jun 13 2023 .UPDATE... Issued at 906 PM CDT Tue Jun 13 2023 Going forecast is generally on track this evening, though did make some tweaks to pops/temps based on radar and surface obs trends since late afternoon. Have seen some more intense rainfall rates and amounts (half inch to in excess of an inch) across parts of Cook county and into northwest Indiana, though rainfall will be tapering off and ending from the north over the next few hours. RAP mesoanalysis data depicts a sharp low-level thermal/moisture gradient across southern WI, northeast IL and northern and central IN early this evening. The latest (and last substantial) in a series of vort lobes was wrapping cyclonically southeastward across the area within the western periphery of an upper low centered near southern Lake Huron. This vort lobe has focused forcing along the baroclinic zone across northeast IL/northwest IN this afternoon and evening, within an axis of 1.20"+ pwats and weak instability to produce areas of light/moderate rain and even brief locally heavy rates during the late afternoon/early evening hours. The mid-level vort lobe is progged to propagate off to the southeast of the forecast area through midnight however, allowing a southeastward shift and gradual end of rain. Did raise pops a bit through mid- evening for areas south of I-80 and into much of northwest Indiana as this occurs, with the bulk of the area dry after midnight. Low clouds do look to linger into Wednesday morning however, before the upper low slowly drifts far enough to our east to allow improving conditions later in the day. Temps should settle into the mid-upper 50s across the area overnight. Other than aforementioned tweaks to pops/rain coverage and hourly temp trends this evening, going forecast has a decent handle on things, and no other changes are warranted at this time. Ratzer && .SHORT TERM... Issued at 315 PM CDT Tue Jun 13 2023 Through Wednesday night... Key Forecast Messages: * Unseasonably cool with (mainly light) rain/showers northeast 1/3 of the area coming to an end in the evening * Canadian wildfire smoke returns on Wednesday with some haze possible The very well defined and unseasonably deep closed mid-upper low centered near Lake Huron this afternoon will slowly gyrate eastward through Wednesday. A lead vorticity maxima on the western side of the expansive circulation of the closed low generated the area of primarily light rain with occasional embedded moderate rates over northeast Illinois and northwest Indiana. Another vort max dropping south along the WI shore of Lake Michigan looks to enhance/reinforce some of the rain into early this evening for generally the same area that has observed rain this afternoon, so again primarily the northeast 1/3 of the CWA. Primarily light scattered showers will extend back a bit to the west and southwest of the coherent shield of light rain. Rain/showers will then gradually come to an end the remainder of the evening, for a dry overnight for most locales, and some breaks in the clouds, especially west. Forecast lows are in the mid to upper 50s. Wednesday will be warmer and trending sunnier with time, though likely filtered a bit by the return of upper level smoke from Canadian wildfires, as indicated by RAP/HRRR smoke forecasts. In addition, some boundary layer haze may occur from portions of northwest Illinois southward to portions of east central Illinois, per the near-surface smoke progs from the RAP/HRRR. Can`t rule out an isolated/stray shower Wednesday afternoon as mid to upper 50s dew points pool inland of the lake breeze. However, with little upper level support and convergence, will maintain a dry forecast officially. It will be a noticeably warmer day, especially west (locally mid 80s near/west of I-39) though still a bit below normal with eastward extent (70s to near 80), and onshore winds keeping lakeside locations primarily in the 60s for highs. Wednesday night will be tranquil with lows in the 50s to near 60. Castro && .LONG TERM... Issued at 315 PM CDT Tue Jun 13 2023 Thursday through Tuesday... By Thursday, the upper-level low that is currently bringing us our April-like weather will be over New England and the Canadian Maritimes, and another shortwave trough will scurry southeastward across Ontario Wednesday into Thursday to fill the void over the Great Lakes behind this upper low. This will help drive a cold front southward into our forecast area on Thursday, which will likely end up being "lake-charged" to some extent given the relatively cool water temperatures present across Lake Michigan (low 50s across interior portions of the lake and near 60 along the Illinois and Indiana lakeshore). The timing of this frontal passage will play a key role in dictating what Thursday`s high temperatures will be, but the majority of recent guidance suggests that the frontal passage will be late enough to allow most locations in our forecast area to reach the 80s, with low 90s not entirely out of the question either for some. If this were to indeed occur, then expect temperatures to quickly come crashing down behind the lake-charged front as the post-frontal lake- influenced air mass surges inland. There is a lower-end chance that some spotty showers and perhaps a storm or two could develop along the front as it progresses inland, but most, if not all, shower and storm activity should remain to our east where the core of the forcing support aloft associated with the shortwave will be. Cooler and drier conditions can be expected on Friday in the wake of the frontal passage, along with primarily cloud-free skies. Though, with flow through much of the column carrying a northerly component behind the front/shortwave, we`ll need to keep an eye on whether a renewed incursion of Canadian wildfire smoke will result in yet another period of milky/hazy skies heading into the weekend. Our weather for the weekend and into early next week will primarily depend on a shortwave that is progged to eject out of the Rockies into the central Plains on Friday and to what extent ridging/high pressure over the Midwest/Great Lakes can quash its eastward progression. 12Z deterministic and ensemble guidance was in fairly good agreement that most or all of our forecast area should remain dry now on Saturday, and the NBM PoPs have responded to that trend, though they still came in with some slight chance and low end chance probabilities due to some of the NBM`s time-lagged members. Have kept these for now, but suspect that most or all mentionable PoPs on Saturday will need to be removed one way or another if these recent forecast trends continue to hold in forthcoming guidance. Precipitation chances for Sunday into Monday are still less certain with the latest deterministic runs of the ECMWF and GFS still keeping us dry in spite of some continued support for precipitation during this time frame in the 12Z EPS and GEFS. Left the NBM`s chance PoPs for Sunday and Monday untouched for now given the existing spread in guidance, but suspect that they are probably overdone. Ogorek && .AVIATION... For the 00Z TAFs... Forecast concerns for the terminals... *Showers gradually tapering through the evening *Ceilings becoming MVFR behind the showers overnight before improving Wednesday morning *Lake breeze develops Wednesday afternoon An area of light to moderate showers continues to advance across northern Illinois and northwest Indiana this evening associated with a series of upper-level disturbances. These showers are expected to persist through early evening before tapering after 02z. While most showers will be light and cause minimal impacts, more robust showers will be capable of reducing visibilities for a brief period. As the showers exit ceilings are expected to lower to higher end MVFR conditions and remain as such through the night. However, there is some uncertainty in coverage of MVFR conditions, especially with westward extent, so there is a chance the sites further inland may remain VFR. Regardless, ceilings are expected to improve Wednesday morning with VFR conditions prevailing through the conclusion of the forecast period. Finally, the west-northwesterly winds will remain breezy through mid-evening with gusts in the low to mid 20 kt range. As gusts ease late this evening winds will become northwesterly overnight and remain as such through the day on Wednesday. However, a lake breeze is forecast to develop Wednesday afternoon and move inland which will turn winds easterly in its wake. At this time the lake breeze looks to arrive in the 19z to 21z timeframe which has been captured at the Chicago terminals, though slight changes in timing may occur if the lake breeze gets hung up as some guidance suggests. Yack && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ 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 Twin Cities/Chanhassen MN
1058 PM CDT Tue Jun 13 2023 .DISCUSSION...(This evening through Tuesday) Issued at 237 PM CDT Tue Jun 13 2023 KEY MESSAGES: - Another round of smoke will push in tonight into Thursday. - Dry until Friday when shower and thunderstorm chances increase for the weekend. Widespread beneficial rains are not expected for the foreseeable future. - Very warm temperatures continue through the period. A large upper low over the Great Lakes continues to spin. Rain and extensive cloud cover are remaining to the east and it isn`t bringing much sensible weather here aside from northwest winds at the moment. That will change later tonight and especially late Wednesday into Thursday as smoke from southern Canada is advected in. HRRR-Smoke suggests some of this may be surface-based across west central MN Wednesday night, but haze is expected area wide. Temperatures shouldn`t be impacted Wednesday with one finger of elevated smoke pushing through tonight and the brunt of the next round arriving late in the day Wednesday. Highs Wednesday look quite warm with 925 mb temps of +24 to +25C and should see some 90 degree highs. A backdoor cold front will sag southwest Thursday and set up an impressive temperature gradient in the afternoon somewhere along the Mississippi River. Highs in the low 90s are likely across western MN with only 70s across north central WI. High pressure over Lake Superior will reinforce the flow off the lake and temperatures may drop into the 60s there in the afternoon. Shower and thunderstorm chances increase for the weekend, but widespread rain is not expected. Weak disturbances will weaken the central U.S. ridge for a couple days and should support diurnal convection. By Sunday, the nucleus of the those disturbances will dive southeast into the southeastern U.S. and the Omega pattern will strengthen once again into early next week. Deep troughs on either coast with an amplified ridge across the central U.S. spells trouble for any decent rain chances locally for some time. It also means the possibility for an extended period of hot weather with drought likely expanding. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1051 PM CDT Tue Jun 13 2023 Main change for the 6z TAFs was to get more aggressive with dropping visibilities behind the cold front currently moving south across northern MN. This is based on what we`re seeing from the 00z HRRR Near-Surface smoke forecast, which is currently correlating well with the IFR/MVFR visibilities we`re seeing up along the international border. Besides the smoke, the CAMs continue to hint at the potential for a stray shower in the afternoon more or less lined up along the I-94 corridor, though the threat of that happening continues to be too low to include in any of the TAFs. KMSP...If the current relationship between surface visibilities and the HRRR near-surface smoke concentrations holds, then MSP will likely see IFR visibilities in smoke starting as early as 20z. Was not ready to go quite that aggressive with surface visibilities, but do feel it worthy to at least drop vis down into MVFR levels when the HRRR shows the thicker smoke moving in with the cold front. /OUTLOOK FOR KMSP/ Thu...VFR. Winds NE 5-10 kts. Fri...VFR. Chc MVFR/TSRA in evening. Winds SE 5-10 kts. Sat...VFR. Chc MVFR/TSRA. Winds S 5-10 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...Borghoff AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
752 PM EDT Tue Jun 13 2023 .SHORT TERM...(This evening through Tonight) Issued at 356 PM EDT TUE JUN 13 2023 Satellite imagery/RAP analysis indicates a surface low still rotating over eastern Upper Michigan, resulting in scattered rain showers through tonight across central and eastern portions of the UP. Highest rainfall amounts will remain concentrated over northern Baraga and Marquette Counties through this evening, then weakening in intensity as the surface low pushes eastward. Nonetheless, a stalled frontal boundary tonight will keep rain chances in the forecast across the eastern half, but additional QPF amounts will be less then a tenth of an inch over those counties. Best chances for any fog formation tonight will remain confined to the south/southeast counties. Look for overnight lows generally in the mid to upper 40s. .LONG TERM...(Wednesday through Tuesday) Issued at 336 PM EDT TUE JUN 13 2023 By Wednesday morning, the 500mb trough and surface low are vertically stacked and moving east over the Lower Great Lakes. Synoptic forcing for precipitation departs for the day Wednesday, bringing an end to a pretty rainy period for the UP, though the moisture was helpful for mitigating fire weather concerns. Despite the lack of widespread precipitation during the day, RH`s will hold at or above 50 percent, meaning little to no fire weather concerns Wednesday. It is worth noting that the CAMs consistently bring diurnal convective initiation Wednesday afternoon to Dickinson and Menominee counties for a few hours, though HREF solutions vastly differ on whether those areas will have 1,000+ J/kg of SBCAPE or none. With flow aloft 30kt or less for the entire column via RAP soundings and low level backing and an otherwise stright hodograph, expecting just popup thunderstorms with no severe potential, but worth monitoring if the HREF as a whole trends towards higher instability solutions. Wednesday night, a fast-moving shortwave sends a cold front diving southward from Ontario towards the eastern portions of Lake Superior and Upper Michigan, bringing some precip chances back into the forecast for Thursday morning. QPF should be fairly low, with GEFS chances for measurable 24-hr QPF ending Friday morning being only around 20-50 percent for the central and eastern UP. Once the shortwave departs and the trough as a whole departs to the east, 500mb ridging builds across the east half of the CONUS and quiet weather is expected for the remainder of the long term forecast. With large-scale subsidence clearing skies out, Friday morning`s temperatures could fall to the mid 30s, bringing frost potential for a handful of hours around sunrise. Some patchy fog will also be possible in spots as the pressure gradient relaxes and morning winds become weak. The 06Z GEFS only showing a couple of ensemble members bringing any precip to KERY between Thursday and the following Thursday, and only a few more ensemble members bringing precip over the weekend to the central and western UP. Any precip will likely have to come from diurnal convection as positive 500mb height anomalies over northern Ontario and Lake Superior soar into the teens of dam under the ridge. Ensembles are gradually coming into more agreement of a persistent Hudson Bay High setting up for the start of next week. With perhaps a week of inconsistent at best precipitation out west and virtually no precipitation expected for the central and east the next week, renewed fire weather concerns may be possible. A return to the 80s for highs is expected by early next week UP-wide, and for the interior UP as soon as Saturday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 737 PM EDT TUE JUN 13 2023 Surface low pressure and associated shower activity will gradually slide se of the area as conditions trend upward through the forecast period. Expect VFR conditions through the forecast period at both IWD and CMX. SAW will see continued scattered showers and IFR conditions at least thru this evening under a northerly onshore flow off Lake Superior. As showers taper off later tonight at SAW there could even be a trend toward LIFR conditions in developing stratus/fog. SAW will then improve through late Wed morning reaching VFR by afternoon. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 336 PM EDT TUE JUN 13 2023 A 1000mb low over Lake Superior this afternoon will bring in northerly winds 15 to 25 knots through this evening and after a brief break overnight, gusty northerly winds return Wednesday. Thursday`s winds gradually decrease as surface ridging builds south across the lake. Friday afternoon, wind gusts over 20 knots will be limited to the extreme east and west Friday afternoon due to local effects. Otherwise, under a Hudson Bay High, wind gusts remain below 20 knots. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Beach Hazards Statement until 10 PM EDT this evening for MIZ005- 006. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...TDUD LONG TERM...GS AVIATION...Voss MARINE...GS