702 FXUS61 KPBZ 151402 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 1002 AM EDT Wed Apr 15 2026 .WHAT HAS CHANGED... The Slight and Marginal severe risk areas were pulled slightly north as compared to the previous forecast. Also, the Marginal Risk for Thursday has been expanded to encompass most of the forecast area. Potential storm placement and timing for today was refined slightly, focusing on areas north of I-70 after 21Z or so. && .KEY MESSAGES... 1) Slight Risk (level 2 of 5) of severe storms today north of I-70. Damaging wind is the main threat, although large hail and a tornado or two are possible. 2) Thursday features a Marginal Risk (level 1 of 5) of severe storms, with isolated damaging wind possible. After a break Friday, a stronger front could bring more severe weather Saturday. 3) Anomalously warm temperatures this week. Daily record high max and minimum temperatures will be challenged and possibly broken, especially today. && .DISCUSSION... KEY MESSAGE 1... A remnant MCV is progressing eastward across southwest PA during the overnight period. Earlier small hail-producing cells to the north of the MCV have moved east and dissipated, leaving a temporary lull in precipitation. Towards sunrise, what should be the weakening remnants of the Michigan QLCS will approach areas north of I-80. CAMs agree on this fading trend as the low- level environment should generally be hostile to convection at that time due to relatively meager MLCAPE and increasing MLCIN. Impact should be limited to brief heavy rain and perhaps modestly gusty wind. The environment will improve markedly during the daylight hours as southwest flow brings improved moisture flow into the region. The axis of highest moisture, featuring precipitable water values of 1.25 to 1.5 inches, will lie north of I-70. This is where the bulk of the storm activity and severe potential is forecast to occur this afternoon and evening, tracking E or ENE. Accordingly, along with some measure of surface heating, this should allow surface-based CAPE to easily reach the 1000-1500 J/kg range according to HREF means, with potential to reach 2000 J/kg in the event of stronger heating. Deep shear will be improved as compared to yesterday, reaching the 35-40 knot range for 0-6km values. Storm initiation likely occurs to our west, perhaps aided by a weak mid-level wave, with activity potentially spreading in from the west after 21Z or so. Storm mode could be mixed, with short line segments/bows, and potentially supercellular structures, especially if discrete storms can form earlier over our region along remnant boundaries. The main threat remains damaging wind gusts over most of the region. Better potential for large hail and perhaps a tornado or two lies generally north of Pittsburgh, where low- level SRH is maximized, LCLs are a bit lower, and CAPE in the hail growth zone is more abundant. The new SPC day 1 outlook is in good agreement with the above, leaving a Slight Risk (level 2 of 5) in place north of I-70. Also remember: the threat of flash flooding cannot be ignored, as isolated issues could occur in locations that are impacted by multiple storms. While the severe threat should largely subside by midnight due to diurnal stabilization, upstream convection could once again impact the region overnight into Thursday morning, at least in a weakening state. Such convection is tricky to time and depends at least partially on leftover boundaries from earlier activity. KEY MESSAGE 2... Thunderstorm potential continues on Thursday, as Great Lakes low pressure drags a weak frontal boundary or surface trough across the region. Although deep shear will be similar to Wednesday, more widespread cloud cover may hinder the buildup of instability. Less- favorable low-level hodographs and poor mid-level lapse rates point to lower tornado and hail potential, leaving isolated damaging wind as the most likely impact from the stronger storms. The SPC day 2 Marginal Risk (level 1 of 5) area was expanded to cover most of the forecast area north and west of Morgantown. A crossing shortwave accompanying the surface low, dipping into the Tennessee Valley, may finally dislodge the southeast CONUS ridge Thursday night while bringing overnight showers and storms to our region. Friday and Friday night may feature a dry break as a smaller- scale 500mb ridge crosses. Then, one last round of strong to potentially severe storms will arrive with a stronger cold front Saturday afternoon/evening, followed by decreasing precipitation and more seasonable temperatures for Sunday. KEY MESSAGE 3... A anomalously strong (500mb heights at the 99th percentile) and stubborn ridge remains centered over Florida and extending across the southeast CONUS into Thursday, before being weakened some by upstream shortwave activity. It still appears that today will feature the best chances of record-breaking temperatures. Warm and moist southwest flow today will push 850mb temperatures into the 14 to 16C range, which will allow temperatures to rise into the mid 80s assuming decent sunshine/mixing. Such temperatures are most likely south of Pittsburgh away from the ridges, while areas to the north feature more cloud cover and better precipitation chances. This is reflected in NBM temperature record probabilities for today. Sites PHD (shorter climate record), HLG, and MGW all have 85% or greater probability of reaching record highs today according to statistical guidance. Probabilities for ZZV and PIT are lower given a bit better cloud/rain potential and longer climate histories. There are also decent probabilities both today and Thursday for record warm minimum temperatures, with PIT, PHD, and HLG featuring 70% or greater chance of setting such standards both days. Thursday remains warm, with 60% or greater probability of temperatures of 80 or higher south of I-80, but a bit more areawide cloud cover and shower activity may hinder the potential of record highs (probabilities drop below 30% areawide). The next best shot for these may be Saturday, with perhaps some sun and southwest flow ahead of an approaching front. The warmth definitively ends by Sunday behind this boundary. Minor heat risk continues areawide today and Thursday before retracting some on Friday. Heat impacts will primarily be felt by those who are extremely sensitive to heat and those without cooling/hydration. Speckled moderate risk areas are indicated today and Thursday especially, mainly in the Ohio and Mon river valleys. && .AVIATION /13Z WEDNESDAY THROUGH SUNDAY/... VFR and dry weather is expected into the afternoon with intermittent gusts into the high teens on average as the boundary layer deepens up to around 5kft. Latest ensemble guidance suggests the vast majority of the afternoon remains dry with convection capped off by warm air aloft. There is uncertainty in the late afternoon / evening timeframe regarding convection, as much depends on upstream conditions. Based off latest guidance and observed upper air soundings, a lean towards staying capped seems to be the right move through the afternoon. Thereafter, showers/storms are possible mostly north of KPIT into the evening if earlier upstream convection can act as a trigger. VFR is likely outside of any onsite convection. Latest ensemble guidance gives probabilities of any cig/vis restrictions in the single digits over the TAF period. Outlook... The Upper Ohio River Valley will remain positioned near the upper ridge axis throughout the week and make it liable for multiple shortwave crossing to foster periodic showers/thunderstorms and precip-driven restrictions. A pattern shift is unlikely to occur until late Sunday into Monday before confidence becomes high again on a prolonged period of dry, VFR weather. && .CLIMATE... See below for record max highs and max lows this week: Today, April 15th: Max High Max Low Pittsburgh, PA: 85F (1883) 61F (1967) Wheeling, WV: 82F (2010) 59F (2002) Morgantown, WV: 86F (1993) 65F (1967) New Philadelphia, OH: 82F (2010) 58F (2023) Zanesville, OH: 85F (1941) 61F (1972) DuBois, PA: 79F (2003) 56F (2002) Thursday, April 16th: Max High Max Low Pittsburgh, PA: 86F (2002) 63F (2017) Wheeling, WV: 86F (1945) 64F (2002) Morgantown, WV: 88F (2002) 64F (2012) New Philadelphia, OH: 85F (2002) 62F (2017) Zanesville, OH: 86F (2002) 65F (1912) DuBois, PA: 82F (2012) 59F (1976) Friday, April 17th: Max High Max Low Pittsburgh, PA: 87F (1896) 63F (1896) Wheeling, WV: 84F (2002) 64F (2002) Morgantown, WV: 89F (1976) 64F (1960) New Philadelphia, OH: 84F (2002) 60F (1982) Zanesville, OH: 88F (1896) 66F (1896) DuBois, PA: 83F (2002) 60F (2002) Saturday, April 18th: Max High Max Low Pittsburgh, PA: 90F (1896) 64F (1896) Wheeling, WV: 85F (2025) 63F (2002) Morgantown, WV: 92F (1976) 64F (2013) New Philadelphia, OH: 86F (1976) 57F (2019) Zanesville, OH: 92F (1896) 66F (1896) DuBois, PA: 87F (1976) 61F (2002) && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...CL AVIATION...88  351 FXUS62 KTAE 151408 AFDTAE Area Forecast Discussion National Weather Service Tallahassee FL 1008 AM EDT Wed Apr 15 2026 ...New UPDATE... .KEY MESSAGES... Issued at 1005 AM EDT Wed Apr 15 2026 - Patchy fog is possible this morning over the Florida Panhandle and Southeast Alabama, mainly for areas west of the Ochlockonee River. If encountering fog while driving, slow down, use low beam headlights, and increase braking distance. - Little or no rain is expected through this weekend. Drought conditions will worsen. Fire concerns will remain elevated. Use extreme caution with any outdoor burning. Please heed burn bans where they are in effect. - Above normal temperatures will continue through this weekend, with lower 90s likely late this week. && .UPDATE... Issued at 1005 AM EDT Wed Apr 15 2026 Forecast is on track no changes are needed. && .SHORT TERM AND LONG TERM... (Today through Tuesday) Issued at 251 AM EDT Wed Apr 15 2026 An upper level ridge over the northeast Gulf dominates the upper level pattern into the weekend before it begins to break down in advance of several upper level troughs early next week. Ahead of these systems, very warm temperatures will prevail. Our warmest days of the period will be Friday and Saturday in advance of an approaching cold front on Sunday/Monday. High temperatures will likely approach 90 in many locations, especially those across the Florida Big Bend and southern Georgia. The main forecast concerns through the next 7 days will be the continuation of a very dry pattern and increasing fire concerns, especially this weekend and early next week. While the frontal system will bring slightly cooler temperatures and a brief chance for rain, it will not be enough to temper fire danger. Much of the rain chances will be confined to southeast Alabama but even in these locations, forecast rain chances and rainfall amounts are quite low (less than 20% and only a few hundredths of an inch of rain possible). Given that this next front is highly likely to be a dry cold front, and the potential for relative humidities in the teens with 10 to 15 mph winds, we could see the potential for critical (also known as Red Flag) fire weather conditions during that time period. && .AVIATION... (12Z TAFS) Issued at 644 AM EDT Wed Apr 15 2026 Dense fog is ongoing and bringing prevailing LIFR/VLIFR conditions to ECP. All other terminals remain in VFR and will remain that way through much of the day and evening. For ECP, fog is expected to lift by mid-morning with VFR conditions prevailing afterwards. South winds will develop through the day at all terminals. && .MARINE... Issued at 251 AM EDT Wed Apr 15 2026 Surface high pressure will firmly be in place over the next few days. Light to gentle winds out of the south/southeast are expected over the waters this week, with wave heights at around 1 to 2 feet. Seabreezes will likely develop and push inland each afternoon. The next period of elevated marine concerns won't be until late Sunday and Monday as a cold front sweeps through area waters and brings northeasterly winds; potentially to cautionary/advisory levels. && .FIRE WEATHER... Issued at 251 AM EDT Wed Apr 15 2026 Hot and dry conditions will characterize the rest of the week as strong upper level ridging persists over the region. Transport winds will be light (5-10mph) and out of the south/southwest through the forecast period. Dispersions will be higher today, primarily for the western half of the region across southeast Alabama and the Panhandle. Higher dispersions on Thursday are limited to our northernmost counties with moderate dispersions elsewhere. Afternoon minimum RHs will likely dip into the high-20%/low-30% each day this week. Considering this alongside the antecedent drought conditions and hot high temperatures expected, fire weather concerns can be expected each day despite the weak transport winds. While uncertainty remains high at these longer lead times, some greater fire weather concerns could develop over the weekend or early next week with the passage of a dry cold front. && .HYDROLOGY... Issued at 251 AM EDT Wed Apr 15 2026 No rain is expected for the next several days. Drought conditions will continue or worsen. For more local drought information & statements, visit the following websites: weather.gov/tae/LocalDrought weather.gov/tae/DroughtInformationStatement && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 89 60 89 58 / 0 0 0 0 Panama City 82 63 82 63 / 0 0 0 0 Dothan 87 59 87 60 / 0 0 0 0 Albany 89 61 88 60 / 0 0 0 0 Valdosta 91 60 91 58 / 0 0 0 0 Cross City 89 57 88 57 / 0 0 0 0 Apalachicola 77 64 78 63 / 0 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ SHORT TERM...Dobbs LONG TERM....Dobbs AVIATION...Dobbs MARINE...Dobbs FIRE WEATHER...Dobbs HYDROLOGY...Dobbs  086 FXUS61 KOKX 151436 AFDOKX Area Forecast Discussion National Weather Service New York NY 1036 AM EDT Wed Apr 15 2026 .WHAT HAS CHANGED... High temperatures were increased at the CT and NY coasts thru Thu. && .KEY MESSAGES... 1) Well above normal temperatures through Friday. 2) Showers and thunderstorms possible through Friday, mainly each afternoon and evening. 3) Strong cold front Sunday with temperatures returning to below normal Sunday night through Tuesday. && .DISCUSSION... .KEY MESSAGE 1... Like yesterday, boosted temps across the NY and CT coasts abv the NBM guidance, in some places by several degrees. Many of these spots verified even warmer than the adjustments made yesterday, but with onshore component flow, kept the fcst withing the MOS guideposts. Didn't alter the Fri numbers with an increasing likelihood of a shrtwv trof passing thru not only reducing heights but triggering shwrs and tstms. .KEY MESSAGE 2... With the H3 jet residing over QC thru Thu, the main zone for convective initiation and convergence should be N of the area thru the period. Supporting this, model timeheights show a good deal of synoptic subsidence over the area. Nevertheless, it remains possible that shwrs and tstms could reach the cwa based on sely storm motion, and the cold pool driven movement and redevelopment, and potential outflow boundaries. One feature to watch which could alter this setup today is the MCS near Lake Erie. It is modeled to track N of the area and dissipate today, but if this feature ends up further S it could end up being a trigger locally. For Fri, will still be watching the potential passage of shrtwv trof during the day. This could spark a round of svr if daytime timing is realized. The feature is still invof CO/NE so confidence in the exact timing is low attm. .KEY MESSAGE 3... A strong cold front is forecast to move through the region during Sunday, while there are still some timing difference, consenus is for a cold frontal passage Sunday afternoon. Showers will accompany the passage, with a chance of thunder as well. After a prolonged period of above normal temperatures, the cold front passage will return temperatures to several degrees below normal Sunday night through Tuesday. The AI-GFS has H85 temps around -12C at 12Z Tue. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... High pressure will remain in place to the south through the period. As weak low pressure and a trailing cold front move across upstate New York today, a prefrontal trough will extend southward into the area this afternoon and evening. VFR through much of the day today, with chance of showers/tstms and brief MVFR/IFR conditions with the prefrontal trough late today NW of the NYC metros, and spreading SE to all terminals into this evening. Timing uncertain and may need to be pushed forward into tonight. Light SW flow should become SW 10-15 kt inland and S along the coast by afternoon, with some gusts over 20 kt at the NYC metros north/west and with the sea breeze at KJFK/KISP. Winds diminish to less than 10 kt by 00Z-01Z Thu. LLWS possible late this evening after any showers/tstms pass, with WSW flow 35-40 kt at FL020. Fog with IFR cond also possible late tonight at KGON/KBDR/KISP, and MVFR cond at the NYC metros. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Chances for showers/tstms tonight may occur a couple of hrs later than forecast. .OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY... Thursday: Any early morning MVFR/IFR cond should improve quickly to VFR by 13Z. Friday: Chance of showers and possibly a tstm especially in the afternoon and early evening, with MVFR or lower cond. Saturday: VFR. Sunday: Chance of showers with MVFR cond possible. W winds G20kt in the afternoon. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Winds and seas are expected to remain blw SCA lvls thru Sat. A strong frontal sys will increase winds and waves by late in the day Sun, with SCA cond likely by Sun ngt. The SCA winds and waves are modeled to continue thru Mon. && .CLIMATE... Daily record high temperatures that could be reached: Wed, April 15: KEWR: 88/1960 KBDR: 81/1960 KNYC: 87/1941 KLGA: 86/1941 KJFK: 80/2006 KISP: 78/2024 Daily record high minimum temperatures that could be reached: Wed, April 15: KEWR: 60/2023 KBDR: 53/2012 KNYC: 67/1941 KLGA: 64/1941 KJFK: 58/1960 KISP: 56/2023 Thu, April 16: KEWR: 64/2002 KBDR: 53/2002 KNYC: 69/2002 KLGA: 68/2002 KJFK: 57/2002 KISP: 55/2012 Fri, April 17: KEWR: 68/2002 KBDR: 57/2002 KNYC: 74/2002 KLGA: 73/2002 KJFK: 60/2002. KISP: 61/2002 && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$  207 FXUS64 KHUN 151448 AFDHUN Area Forecast Discussion National Weather Service Huntsville AL 948 AM CDT Wed Apr 15 2026 ...New NEAR TERM, SHORT TERM... .KEY MESSAGES... Updated at 323 AM CDT Wed Apr 15 2026 - Low relative humidity values, dry fuels, and gusty winds will result in elevated fire weather conditions today. - There are low to medium chances (20-50%) of showers and thunderstorms on Thursday. - Medium chances (40-60%) of showers and thunderstorms on Saturday. && .NEAR TERM... (Rest of Today and Tonight) Issued at 948 AM CDT Wed Apr 15 2026 Currently, mostly clear skies are in place with temperatures in the upper 50s to upper 60s with a calm to gentle breeze less than 15 mph from the southwest. Temperatures today will gradually warm with highs reaching the low to mid 80s this afternoon. Upper level ridging continues to push eastward later today. Winds will become a little more breezy this afternoon with speeds of 10-15 mph and locally higher gusts of 15-20 MPH. Tonight's low temperatures will be in the upper 50s to lower 60s. && .SHORT TERM... (Thursday through Saturday) Issued at 948 AM CDT Wed Apr 15 2026 The upper level ridge continues pushing eastwards on Thursday resulting in a low to medium chance (10-40%) of showers and thunderstorms Thursday afternoon and evening. Rain chances are higher (30-40%) for middle Tennessee and northeastern Alabama. The thunderstorms are not anticipated to be severe and will result in very little precipitation totals for most, generally less than 0.10”. Aside from the rain, temperatures will be around 10 degrees warmer than normal with highs in the low to mid 80s. Overnight, temperatures will fall to the upper 50s and lower 60s. Dry conditions return on Friday and increasing temperatures reach the upper 80s to lower 90s across the Tennessee Valley which is around 13-16 degrees warmer than normal. The high temperatures Friday approach record highs set in 2006 of 90 degrees at HSV and 92 at MSL. Friday night temperatures will continue to be warm with lows in the low to mid 60s across the area. Be sure to drink plenty of water on Friday and take breaks in the shade. && .LONG TERM... (Saturday through Tuesday) Issued at 1040 PM CDT Tue Apr 14 2026 A deepening surface low is predicted to eject northeastward from Lake MI into the James Bay vicinity on Saturday/Saturday night in conjunction with a negatively-tilted shortwave (embedded within a broader trough extending from northern Canada into the southern Plains). Strengthening SSW flow is expected to occur throughout the cyclones warm sector, and will contribute to another warm day featuring highs in the mid 80s for our region. Latest extended range model data continues to suggest that showers and a few thunderstorms may develop by mid-day near a prefrontal surface trough extending from western KY into northern MS, and although some of this activity could spread eastward into the western portion of our CWFA late Saturday afternoon, it appears as if precipitation chances will be highest with passage of the cold front Saturday evening. Forecast soundings still depict a layer of warm/stable air aloft (rooted around 4-6 kft AGL) for much of the day, which should gradually begin to erode Saturday evening as a narrow axis of dewpoints in the l-m 60s surges northward ahead of the front and synoptic scale forcing for ascent strengthens ahead of the approaching 500-mb trough. Should an updraft become sufficiently tall to take advantage of mid-level flow that will be increasing to 50-60 knots, brief strong wind gusts may occur. However, at this point, we expect generally weak/low- topped convection, followed by a 2-4 hour period of light postfrontal rain, with rainfall amounts ranging from 0.10-0.25" (SE) to 0.5-0.75" (NW). Present indications are that rain will end around or shortly before 12Z Sunday in the southeastern portion of the forecast area, with gusty NNW winds advecting a cooler, drier airmass into the region throughout the day. Highs on Sunday will fall back into the m-u 60s (even with abundant sunshine), followed by cool overnight lows in the l-m 40s. Prevailing NW flow aloft to the east of a longwave ridge across the western CONUS will ensure a continuation of dry weather on Monday/Tuesday, although a couple of weak disturbances traveling through the ridge may result in an increase in mid/high-level clouds. Regardless, the onset of SE return flow will lead to a gradual warming trend with highs returning to the mid 70s by the end of the period. && .AVIATION... (12Z TAFS) Issued at 534 AM CDT Wed Apr 15 2026 VFR conditions will prevail through the period with a mostly clear sky. Winds may become gusty out of the SSW/SW this afternoon between 15-20 kts, before weakening after sunset. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...None. TN...None. && $$ NEAR TERM...TG/17 SHORT TERM....TG/17 LONG TERM....70 AVIATION...AMP  263 FXUS63 KILX 151450 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 950 AM CDT Wed Apr 15 2026 .KEY MESSAGES... - A 60-80% chance of scattered thunderstorms exists throughout the day. This evening, especially after 4 PM and primarily north of Interstate 70, there is a Slight Risk (Level 2 out of 5) for severe weather. - Late Friday evening, areas generally west of Interstate 57 face a Slight Risk (Level 2 of 5) for another round of severe weather. - Significantly cooler weather returns this weekend. There will be a low (20-30%) chance for frost Saturday night north of Interstate 70, and a higher chance area-wide Sunday night. && .UPDATE... Issued at 950 AM CDT Wed Apr 15 2026 Upper troughing located over the central Plains will be the focus for severe weather chances later today. Shortwave energy ejecting out ahead of the main wave paired with a remnant outflow boundary has led to persistent shower and thunderstorm activity across the area this morning. The 12Z run of the HRRR has initialized this pretty well and shows it lifting off to our northeast as the shortwave exits later this morning. The severe threat with the morning storms appears low with limited instability available. However, heavy rain has been observed with with radar estimates showing pockets of 1-2"+ along a line from near Rushville to Oakford and into parts of southwest McLean county. A drier period shapes up for early this afternoon before the main upper trough approaches later today. Confidence in later thunderstorm coverage and timing still remains low, but the threat for flash flooding has increased. This is especially true if thunderstorms repeat over areas that picked up heavy rainfall this morning. CAMs show storm activity picking up in west-central Illinois as early as 20-21Z/3-4 pm. Despite somewhat better forcing than previous days, trust in CAMs is also low due to poor storm depiction the last few days. && .DISCUSSION... Issued at 313 AM CDT Wed Apr 15 2026 Two primary areas of convective activity are visible on the radar this morning. One area is situated across southeast Iowa and northern Illinois, near the main synoptic front. The second area is lifting across the Missouri Ozarks. Both are fueled by a low-level jet and shortwave energy ejecting ahead of the main upper trough, which is currently moving across the lee of the Rockies. Convective tops are notably warming over the Ozarks as this system encounters drier mid-level air, weaker instability, and reduced surface moisture convergence. As the shortwave/MCV continues its northeast track out of the Ozarks and into the Mid-Mississippi Valley later this morning, it is expected to interact with outflow boundaries from decaying northern storms that will have drifted south of the main synoptic front. The net effect will be an area of re-blossoming convection over central Illinois this morning. While a tenuous low-level jet may sustain this activity into the early afternoon, the severe threat remains low due to relatively poor lapse rates and shallow CAPE profiles. Thunderstorm activity is expected to briefly lull this afternoon as the shortwave/MCV departs and subsidence occurs, leaving a somewhat worked-over warm sector. However, this lull may be short-lived due to quickly increasing synoptic ascent within a difluent zone ahead of the main upper-level shortwave moving into the lower Missouri valley. Conditions are expected to become more favorable for severe weather, particularly west of Interstate 55, where CAPE profiles will become chubbier as mid-level lapse rates steepen ahead of the main upper-level shortwave and near a residual Elevated Mixed Layer (EML). With better CAPE and deep-layer shear of 30 knots or greater, supercell and multicell clusters are possible across west- central Illinois. Modeled hodographs from the HREF Mean suggest straight or N-shaped profiles, which are more indicative of splitting supercells capable of producing large hail and damaging winds. While it is uncertain if these storms will be surface-rooted or elevated, an intensifying low-level jet this evening will increase Storm Relative Helicity (SRH) and result in a more curved hodograph. This introduces a tornado threat if storms manage to become surface-rooted. Regardless of storm initiation/evolution for the late afternoon through early evening period, CAM output becomes more consistent by tonight that additional storms upstream will congeal and grow upscale into a linear MCS overtime as the effective surface boundary sags southward into central Illinois. In addition to the severe weather threat, there is a low potential for localized flash flooding, particularly if storms repeatedly track over the same area. The latest HREF QPF LPMM highlights a narrow area in east-central Illinois that could see 3-5 inches of rain through Thursday morning. This is notable, as current 6-hour flash flood guidance suggests that general flooding issues could arise after 2.5-3 inches of rain. A break from storm activity is expected across the entire region on Thursday, driven by synoptic-scale subsidence following the departure of the upper trough. However, the threat of thunderstorms returns over the weekend, specifically beginning Friday night and lasting into Saturday. This renewed activity is tied to a compact shortwave trough lifting across the Mid-Mississippi Valley, preceding a more robust, pivoting trough and its associated cold front. Despite the frontal passage occurring during a diurnally unfavorable time, the parameter space for CAPE and shear appears sufficiently volatile to support an organized risk of severe weather which lasts through the overnight hours as the convection grows upscale along the front. A significant cooling trend is expected from Saturday night through Monday following the passage of the cold front, as the previous week's warm, moist air mass is displaced. Latest NBM guidance indicates a concern for widespread frost, with low temperatures Saturday and Sunday night anticipated to fall into the 30s. By the middle of next week, temperatures are forecast to quickly rebound into the lower 70s. This warming trend is due to an upper-level pattern exhibiting some blockiness, allowing an amplified ridge axis to build into the region. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 548 AM CDT Wed Apr 15 2026 Multiple periods of showers and thunderstorms will push across the central Illinois terminals throughout the TAF period. Timing when these may impact a particular terminal remains very low confidence at this point, resulting in an extended period of PROB30 for TSRA through tonight. Away from storms, VFR conditions are expected. Southwest winds will continue through the period, gusting to 25 kt at times. && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$ KEY MESSAGES...MJA UPDATE...NMA DISCUSSION...MJA AVIATION...MJA