####018006032#### FXUS63 KILX 221755 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 1255 PM CDT Mon Apr 22 2024 .KEY MESSAGES... - Rain chances return Monday night into Tuesday, with a 20% chance for an isolated storm. - Brief cool down for midweek with frost/freeze potential possible near and north of I-74 Thursday morning. There is a 40-70% chance for air temperatures to fall below 36 degrees. - A warmer and more active weather pattern arrives late in the week. Several chances for showers and storms exist late Thursday night through the weekend, including the potential for severe weather. && .UPDATE... Issued at 1030 AM CDT Mon Apr 22 2024 Forecast looks on track on this beautiful spring day, with just minor updates to sky cover grids. Ample sunshine this morning over central and southeast IL, and will see increasing mid/high clouds from the west this afternoon along with increasing sw breezes especially nw of I-70. Seasonable highs in the mid to upper 60s, so overall a delightful day. 07 && .DISCUSSION... Issued at 347 AM CDT Mon Apr 22 2024 A surface high is centered over the ArkLaTex region early this morning with surface ridging extending as far north as the eastern Great Lakes region. Gentle winds and clear skies under the high's presence have allowed temperatures to dip down into the 30s to low 40s as of 3 am, with frost formation still a threat through about sunrise. Winds are in the process of backing to the southwest as a surface low works across the southern portions of the Canadian Prairies, sending the surface high into the southeast US later today. A cold front associated with the low will approach from the west on Tuesday, sparking the development of rain showers overnight. The pressure gradient will tighten ahead of the front with wind gusts looking to approach 20-30 mph by this afternoon. Forecast soundings show deep mixing up to ~800 mb by this afternoon, which should mix down much warmer and drier air. High temperatures today should be near normal (mid to upper 60s), with dewpoints in the upper 20s to lower 30s. Precipitation later tonight could struggle to reach the ground initially due to the drier airmass in place, so ended up slowing down PoPs with likely chances (60% or higher) not expected until closer to sunrise Tuesday when stronger forcing with the front arrives. Thunderstorm chances look limited until Tuesday afternoon when the right front entrance region of a mid-level jet becomes centered over the middle Mississippi Valley. Despite this, limited amounts of moisture will keep instability meager and keep severe weather chances very low. Precipitation will end by Tuesday evening as the cold front pushes out of the area. Precipitation amounts look to be around 0.5 inch or less. Surface high pressure settles in behind the frontal passage, leading to a brief midweek cool down. Overnight lows Wednesday and Thursday morning will be unseasonably cool, with the threat of frost or freeze potential returning near/north of I-74 Thursday morning. The NBM has a 40-70% chance for low temperatures to hit or fall below 36 degrees. The cool down will be short lived with temperatures rebounding back above normal late in the week as upper ridging amplifies over the eastern CONUS positioning southwest flow overhead. The weather pattern will become more active late in the week and weekend as a few systems and upper disturbances work through the area. The first will be on Friday when a surface low lifting into the Northern Plains sends a warm front north through the area. Showers and storms will accompany the front early Friday morning as it quickly lifts north into the Great Lakes Region. Later in the day, a cold front will approach from the west, but looks to stall out before reaching the area. Because of this, instability Friday evening will be highest just west of the area, which is where storms should initiate. Strong wind shear and steepening lapse rates with an approaching negatively tilted upper wave could lead to a few strong to severe storms, with activity spreading into our CWA later that evening. The cold front will become mostly stationary somewhere over the Midwest states on Saturday and Sunday with variability on where exactly it will be. Further west, another strong Pacific trough will eject northward and spin up a surface low over the Plains states late Saturday night into Sunday. A few upper shortwaves will pivot northward along the aforementioned stationary boundary this weekend, bringing periods of showers and storms through the weekend before the main wave arrives sometime Sunday into Monday. Severe weather chances area a possibility through the weekend, though details remain fuzzy due to timing differences. NMA && .AVIATION... (For the 18z TAFs through 18z Tuesday Afternoon) Issued at 1245 PM CDT Mon Apr 22 2024 VFR conditions are forecast to continue through tonight across the central IL airports as broken high clouds lower to mid level ceilings between 8-15k ft during tonight, lowest at PIA and BMI. A northern stream short wave trof just north of MT/ND will track se into the Great Lakes Tue afternoon, and develop showers over central IL late tonight or during Tue morning. MVFR ceilings and possible vsbys expected to develop during Tue morning especially after 14Z with more widespread rain showers. Isolated thunderstorms possible Tue afternoon and mainly just after this 18Z TAF cycle. Breezy sw winds 12-18 kts with gusts 18-26 kts this afternoon to veer SSW during this evening and remain gusty tonight into Tue morning, as winds turn back SW Tue morning. 07 && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$ ####018007315#### FXUS63 KLBF 221758 AFDLBF Area Forecast Discussion National Weather Service North Platte NE 1258 PM CDT Mon Apr 22 2024 .KEY MESSAGES... - Breezy at times today with high temperatures generally in the 60s and potential for some isolated rain showers and general thunderstorms across portions of central Nebraska tonight. - Seasonal temperatures continue through the week with highs generally in the 60s to lower 70s. - Unsettled weather conditions likely for Thursday into the weekend with widespread accumulating rain likely (>80% chance for total rainfall of 0.25" or more) across western and north central Nebraska. However, the severe threat remains uncertain at this time. && .SYNOPSIS... Issued at 400 AM CDT Mon Apr 22 2024 Recent GOES-16 WV imagery and RAP 500-mb analysis showed deep low pressure centered over the Hudson Bay with a trough extending south into the Great Lakes and New England. Just to the south of this feature, a shortwave trough was evident across the Mid- Mississippi Valley. Another upper-level low pressure system was advancing southeast across Saskatchewan with multiple shortwaves traversing along the base of the trough over the northern Rockies into the northern Plains. A transitory upper- level ridge was noted in between the two Canadian upper-level low pressure systems across the Upper Midwest region. Weak upper-level ridging was noted over the west coast with an upper- level trough digging south from the Gulf of Alaska. At the surface, low pressure was centered over Saskatchewan with an attendant cold front draped southwest across the northern Plains, nudging into northwest Nebraska. Surface high pressure was holding strong over the Middle Mississippi Valley and southern Plains. A rather robust (40+ kts) southwesterly low- level jet (LLJ) has developed with the surface pressure gradient (SPG) tightening between the two surface features. As a result, south-southwesterly winds have strengthened overnight with periodic gusts of 20 to 30 mph. At 4 AM CT, temperatures ranged from 43 at Imperial to 49 at Valentine. && .SHORT TERM /THROUGH TUESDAY NIGHT/... Issued at 400 AM CDT Mon Apr 22 2024 Today and Tonight... As the aforementioned surface low continues southeast into Manitoba, the attendant cold front will quickly sweep across western and north central Nebraska. Winds will veer towards the northwest behind the frontal passage with 3 to 4 mb/3 hour pressure rises resulting in brief period of gusty winds this morning into the mid-afternoon hours. Widespread gusts of 20 to 30 mph are expected with the strongest gusts up to 40 mph across the Nebraska/South Dakota border. However, pressure falls quickly fill into the area allowing the gusty winds to subside through the evening. Seasonal temperatures are in store for western and north central Nebraska today with highs in the 60s to lower 70s across southwest Nebraska. Latest model guidance continues to suggest light rain and general thunderstorms developing after sunrise across southeast Nebraska due to a weak area of mid-level warm air advection (WAA) behind the front. It appears the bulk of this activity will reside to the south and east of the forecast area, however, some isolated activity cannot be ruled out for portions of central Nebraska through the overnight hours. The severe threat appears minimal with any activity that does develop across our area given limited moisture and instability. Overnight temperatures fall into the mid 30s to mid 40s across western and north central Nebraska. Tuesday and Tuesday night... Despite temperatures being a few degrees cooler, an almost identical forecast as compared to today is on tap for the area on Tuesday. Dry and quiet conditions are expected during the day, though breezy at times due to a tightened SPG. Northwest winds gusting 20 to 30 mph will be common for most locations with the strongest gusts up to 35 mph expected across north central Nebraska. Daytime highs will climb into near 60 degrees to lower 70s range under mostly clear skies. A weak upper-level shortwave tracking out of the central Rockies will bring a fairly quick-hitting chance for precipitation Tuesday night across the southern Panhandle into southwest Nebraska. Confidence remains rather low on the potential for precipitation due limited moisture and weak forcing across the area. Similar to tonight, low temperatures in the mid 30s to low 40s are expected with winds veering towards the south on the backside of the departing surface high pressure. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Issued at 400 AM CDT Mon Apr 22 2024 On Wednesday, upper-level ridging will build back into the central CONUS with a deepening upper-level trough of low pressure off the California coast. Daytime temperatures warm back into the at to slightly above normal range of mid 60s to low 70s on Wednesday and Thursday. The flow aloft will transition to southwesterly on Thursday as the previously mentioned upper-level trough tracks into the Four Corners region. As the upper-level trough approaches the central Rockies, strong lee-cyclogenesis is expected to occur across southeast Colorado, driven by strong mid-level height falls and upper-level divergence under the left exit region of the 250mb jet streak. This will be the mark of a series of disturbances traversing through the region through the weekend bringing continuous rain and thunderstorm chances to the area. While there is quite a bit of spread amongst models on exact timing of each of the individual disturbances, there will certainly be some breaks in the precipitation during this period. Although questions remain, confidence continues to grow on the potential for widespread wetting rain during this period. NBM Probabilities indicate an 80% chance or greater for 72 hour 0.25"+ liquid equivalent precipitation across all of western and north central Nebraska. When looking at probabilities for 0.5"+, the greatest probabilities of >60% exists across much of the area. While the severe threat remains uncertain at this time, embedded thunderstorms appear possible which would result in locally higher amounts to be possible with the potential for thunderstorms during this period. Will continue to monitor this timeframe as specific details become more clear with subsequent forecasts. && .AVIATION /18Z TAFS THROUGH 18Z TUESDAY/... Issued at 1257 PM CDT Mon Apr 22 2024 Quiet aviation conditions are expected through Tuesday morning. Skies remain mostly clear with only increasing high clouds expected by late Tuesday morning. Winds become strong on Tuesday across northern Nebraska with northwest gusts up to 25 to 30 knots. A few light rain showers could be possible tonight, but confidence remains too low to put it in the forecast at this time. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Viken SHORT TERM...Viken LONG TERM...Viken AVIATION...Kulik ####018008528#### FXUS63 KLOT 221759 AFDLOT Area Forecast Discussion National Weather Service Chicago/Romeoville, IL 1259 PM CDT Mon Apr 22 2024 .KEY MESSAGES... - Gusty southwest winds today, along very low RH, leading to an elevated fire danger. - Low-topped showers and a few thunderstorms Tuesday afternoon. Monitoring a low but non-zero severe threat late in the day NW of I-55. - Frost may develop again late Wednesday night. - Warmer by the end of the week with periodic showers and storms Friday into next weekend. && .DISCUSSION... Issued at 253 AM CDT Mon Apr 22 2024 Through Tuesday The surface pressure gradient will tighten up over the region today as high pressure continues to build south across the Lower Mississippi River Valley as an upstream low scoots across Manitoba. Gusty southwesterly winds will be the result today as relatively deep boundary layer mixing taps into 30 knot flow around 800 mb. Expecting gusts up to 35 mph across northwest Illinois, and in the 25 to 30 mph range across NW Indiana where the gradient flow will be a bit weaker. Additionally, have dropped afternoon dewpoints closer to the stronger-mixing guidance such as the HRRR, RAP, and RDPS, with this suite of guidance handling Sunday's dewpoint trends much better than the globals. Mid-level moisture changes little today, suggesting a similar mixing-out of dewpoints in the mid 20s, and wouldn't be surprised if these end up even a bit lower than currently advertised. The one caveat to this will be how quickly the thick/opaque cirrus arrives, with some potential for this to tamp down on mixing a bit, but all indications at this point are that this won't do much to curtail the RH fall. With this in mind, even with the ongoing greenup, fine fuel moistures are low (8 percent measured at both the Midewin and Indiana Dunes RAWS sites Sunday afternoon), so we'll continue to highlight the elevated threat for fire spread today. A lead wing of warm advection will develop this evening and overnight in advance of the aforementioned low which will be pinwheeling across the Minnesota Arrowhead region. With a still parched boundary layer, coverage of shower activity may remain pretty sparse with a good deal of sub-cloud evaporation likely. Have cut PoPs during the overnight hours as a result. By early Tuesday morning, the combination of better jet dynamics, mid-level moistening, and enhanced 700 mb convergence/f-gen will lead to an expansion of steadier precipitation south of I-80. Coverage looks high enough to justify an introduction of categorical PoPs, and given the magnitude of convergence, some isolated rainfall amounts over an inch appear possible. On the northern periphery of the main area of rain, a consistent signal for gusty winds exists in the guidance suite with plentiful sub- cloud evaporation and steeper near-surface lapse rates. On Tuesday afternoon, and particularly very late in the afternoon, we're monitoring a low but non-zero severe weather potential in advance of an incoming cold front. While surface dewpoints will only be in the mid 40s to perhaps near 50 degrees, 500 mb temperatures will be cooling towards -25 to -30 C as the core of an impressive vort lobe approaches. These values are more typical of late January, and are under the 10th percentile for the date based on ILX's sounding climatology. This will provide a boost to available instability which would otherwise be much lower given the surface dewpoints. In addition, guidance is in very good agreement suggesting that low-level lapse rates will steepen markedly immediately ahead of the incoming front. All of this supports a narrow ribbon of instability (all below about 400 mb) along/ahead of the cold front, focusing along and northwest of I-55. Given the intense forcing associated with the incoming DCVA/height falls, would expect scattered low-topped showers and a few thunderstorms to develop given equilibrium levels around -25 C. Effective deep layer shear, while not terribly high and modulated by the lower ELs, may be just sufficient to facilitate a little updraft organization. Given the low freezing levels and steep mid-level and low-level lapse rates, any stronger/taller cores could support a threat for some marginally-severe (quarter- sized) hail and gusty winds. In addition, given the set-up and enhanced near-surface vorticity near the front, can't entirely rule out the potential for a hybrid supercell/landspout tornado potential with sufficient destabilization. The threat currently remains a bit too low/uncertain for an SPC day 2 severe delineation, but is something we'll be keeping an eye on given recent guidance trends. Carlaw Tuesday Night through Sunday: A cold front will be moving across the area Tuesday evening with a few lingering showers, possibly a thunderstorm across the eastern half or so of the area during the early evening. Winds will shift northerly behind this front and breezy conditions are expected with gusts into the mid 20 mph range into Wednesday. Higher gusts will be possible near Lake Michigan. Despite lows in the mid 30s for parts of the area by Wednesday morning, not expecting much frost formation due the stronger winds and at least partly cloudy skies for the eastern cwa. Highs Wednesday will be cooler, possibly only in the mid/upper 40s for northeast IL and northwest IN, 50s further inland. Areas of frost are expected for most of the area away from Chicago late Wednesday night into early Thursday morning with mainly clear skies and light winds. Lows generally in the lower 30s outside Chicago. Temps expected to rebound back into the lower 60s for highs Thursday with easterly flow keeping temps cooler near Lake Michigan. An unsettled and potentially active pattern is setting up across the region for the end of the week into this weekend. There remains uncertainty for timing/location and the initial rounds of potential precipitation may be delayed as drier easterly flow erodes their progress into the area. Eventually surface low pressure is expected to track northwest across the upper midwest on Saturday. Another surface low appears to develop over the Plains by Sunday, which lifts northwest Sunday night into Monday with another period of active weather possible for the local area. The blended pops are generally in the 60-70 percent range from Friday through Monday. While these may be fine for certain time periods, they are likely too high for several days in a row as there will be dry periods. However, from this distance, there is too much uncertainty to try to add detail to these higher pops. cms && .AVIATION /18Z TAFS THROUGH 00Z WEDNESDAY/... Issued at 1257 PM CDT Mon Apr 22 2024 The primary aviation weather concerns for the 18Z TAF period include: * Scattered showers likely Tuesday afternoon with a few thunderstorms possible Gusty SW winds will continue through the rest of today. Gusts will become less frequent this evening and overnight, but should continue to gust as high as 25 to near 30 kt at times. Winds will be similar in direction and magnitude during the day tomorrow, turning more westerly by late afternoon. A few pockets of light, non-impactful rain may move over the terminals late this evening and overnight. Conditions should be dry during the first half of the day tomorrow. A swath of widespread showers is expected to pass south of the terminals during the morning and afternoon, but there is a non-zero chance that a little bit of light rain could extend as far north as ORD or MDW. A better chance for rain comes in the late afternoon and early evening as a cold front swoops across the area. A few thunderstorms will also be possible during this time. Conditions are expected to remain VFR through the current period. Doom && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory until 10 PM CDT Wednesday for Winthrop Harbor IL to Burns Harbor IN. Small Craft Advisory from 10 PM this evening to 10 PM CDT Wednesday for Burns Harbor to Michigan City IN. && $$ Visit us at weather.gov/chicago ####018005910#### FXUS61 KBGM 221800 AFDBGM Area Forecast Discussion National Weather Service Binghamton NY 200 PM EDT Mon Apr 22 2024 .SYNOPSIS... An upper level storm system and associated cold front will bring scattered rain showers to the area Tuesday night into Wednesday. Dry and seasonable weather will finish out the work week, with additional rain showers arriving in time for the weekend. && .NEAR TERM /THROUGH TUESDAY NIGHT/... Clear skies will continue through the remainder of the day and into the evening, with high clouds increasing later tonight. Winds will shift around to the south by morning, and with a tightening pressure gradient and deeper mixing tomorrow, winds could gust around 25 to 30 mph in the afternoon. RH values will get a modest boost from the southerly flow, with Min RH values looking to range from 25 to 35 percent in the afternoon. The drier low level air mass will delay the onset of rain showers. A few could work into the Finger Lakes before dark, but most of the rain will hold off until the overnight hours and into Wednesday. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... 150 PM update... Main concerns in the short term are focused on the potential for rain showers and even a few isolated thunderstorms early in the day Wednesday with cooler and drier air moving in Wed night into Thursday. Broad upper level trough will be rotating through the Northeast U.S. Wednesday morning with an area of stratiform rain on the front end of the system. Modest, shallow isentropic lift within a relatively deep, moist air mass and weak upper level forcing will produce this wide area of rain Wed morning. Cold air moving in behind this feature will push in quickly aloft, which will induce an area of steep mid level lapse rates during the late morning and early afternoon hours. The air mass is not expected to be very unstable given the presence of rain and a fair amount of cloud cover. The most favorable time and location of weak instability will be from the Poconos and southern Catskills farther to the east and southeast in the afternoon. Given the cold air aloft and the potential for mixing later in the day, the main threats will likely be small hail and gusty winds in any storms that do form and mature. The cooler and drier air is expected to move in quickly from the northwest later in the day Wednesday. Surface temperatures will hold steady in the mid 40s to mid/upper 50s...and then slowly drop back into the lower to mid 40s by the late afternoon/evening hours. The large-scale wind field will be notable during the day with sustained NW winds 15 to 20 mph and gusts up to 30 mph, especially across the Finger Lakes. An abundance of clearing should occur Wed night, which will combine with light/calm winds to allow temperatures to fall into the mid 20s and lower 30s. The coldest air is expected to occur in the valley locations that decouple from the boundary layer. The quiet weather will persist into Thursday and the cooler air mass will remain, but plenty of sun and a high sun angle will allow high temperatures to climb into the mid to upper 50s close to 60. Winds will be substantially lower on Thursday, which will be a nice relief from the day before. && .LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/... 150 PM update... Large scale upper level ridging will move across the region Thu night into Friday, which will keep weather conditions very quiet and dry. Temperatures will slowly rebound with morning lows Friday starting out in the lower to mid 30s before rising into the upper 50s to mid 60s. The next deep low pressure system is expected to move into the Upper Midwest late Friday and begin to sweep a warm front north through the Ohio Valley and eastern Great Lakes Friday night into Saturday morning. This front may have a difficult time producing rain into the slow- moving dry air mass in the Northeast. Only minor deviation from the ensemble blend was to delay the onset of the higher chances of rain until later in the morning hours on Saturday. This incoming warm front will not only bring increase rain chances and clouds, but also notably warmer temperatures... especially on Sunday. Temperatures on Saturday will hover around average for this time of year with scattered rain showers, but on Sunday, the really warm air is expected to push farther north and push temperatures into the 70s for nearly all of the forecast are of northeast PA and central NY. This warm and unstable air mass will also trigger the potential for some scattered showers and thunderstorms later in the day. The warm air looks to remain in place going into at least the early part of next week. && .AVIATION /18Z MONDAY THROUGH SATURDAY/... Clear skies will persist into the evening hours, with high clouds increasing late tonight into Tuesday morning. Clouds will gradually thicken with lowering ceilings later in the afternoon, but VFR conditions will persist through the next 24 hours. Expect NW winds with a few gusts around 20 knots this afternoon, becoming light and variable overnight. Winds will turn southerly on Tuesday, and become increasingly gusty in the afternoon, with gusts topping out above 25 knots at times. Outlook... Tuesday night through Wednesday night...Occasional restrictions possible in rain showers. Thursday through Friday...Mainly VFR. Saturday...Restrictions possible in rain showers, especially in the afternoon and evening. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MPH NEAR TERM...MPH SHORT TERM...BJT LONG TERM...BJT AVIATION...JTC/MPH