Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/27/20

National Weather Service Albany NY
1011 PM EDT Thu Mar 26 2020 .SYNOPSIS... A weakening cold front will move into the region tonight as a weak disturbance passes to our south both bringing chances for showers to the area. Increasing sunshine Friday with fair weather expected into Saturday morning. Weather will be unsettled for the rest of the weekend with a cool and widespread rainfall, some snow possible across the higher terrain of the southern Adirondacks and southern Vermont. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 1000 PM EDT...Appears a bit of speed convergence just downstream of Lake Ontario where the line of showers has seen a little upward trend the past hour. Meanwhile, the main batch of rain across OH/PA remains on track along the I80 corridor and tracking east-southeast. HRRR not performing too well with radar observations as NAM3km performing a little better this evening. Expectations remain the same as downstream moisture is lacking at the moment per the 00Z ALY sounding so a weakening trend is still expected. There will be some upslope enhancement with respect to showers so we will keep PoPs in place there overnight. Otherwise, overnight the upstream mid level jet approaches where a little additional lift may bring a couple more showers south of I90 but even here the trends are for lower coverage. Prev Disc... Surface low centered just north of Lake Ontario will pass to our north this evening dragging its associated cold front into the region. The low level jet associated with the system will move across the North Country. Chances for showers for areas to the north and west of Capital District into this evening with likely pops across the northern portions of Herkimer and Hamilton counties early this evening. Chances diminish by midnight as the low level jet and low move away. However, a short wave moving through the fast flow across the region will pass to our south with a weak surface reflection. Have low chance pops for showers to the south of I-90 for the overnight. Will be mild tonight with extensive cloud cover. Lows from the upper 20s to lower 40s. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Ridging will build in behind this features with increasing sunshine Friday. Aloft broad ridging develops across the eastern CONUS ahead of a developing upper level low over the Plains. The stacked system will deepen as it heads northeastward int the Great Lakes Region with its warm front on the approach. System will begin to impact our region Saturday initially with increasing cloud followed by rain gradually overspreading the area from southwest to northeast especially late in the day into evening as the atmosphere moistens up. Expect a widespread rain across the entire forecast area by late evening. There is the chance for snow wet snow late at night across the higher southern Adirondacks and southern Vermont. Winds will be light with southeast flow increasing ahead of the approaching warm front Saturday night. The precipitation is expected to begun moderate in intensity overnight Saturday into Sunday morning with the focus for the heaviest precipitation across the southern Adirondacks and Mohawk Valley. && .LONG TERM /SUNDAY THROUGH THURSDAY/... The weather pattern looks active heading into the final days of March and early April with two main systems to keep an eye on. The first system looks to bring widespread rainfall Sunday with perhaps some snow accumulations in the mountains with the second system potentially developing near the coast for the middle of next week. Depending on its track and timing, the second system could bring wintry weather to the region but there is still large spread in the guidance. Otherwise, temperatures remain seasonable. Read on for details. We start the long term off on Sunday with a closed/mature parent low over the Upper Midwest or western Great Lakes with its associated 45- 50kt 850hPa jet in the warm sector nosing into the Northeast. The strong push of isentropic lift ahead of its surface warm front will have led to a widespread area of rainfall overnight which should linger into part of Sunday morning. By Sunday afternoon, the best warm air advection looks to shift into New England with the associated warm sector creeping towards eastern NY/western New England. Guidance shows a strengthening ~1030hPa high over northern Quebec with its cold air wedge remaining over northern New England. 925hPa isotherms show that the surface warm front may get hung up along the Berkshires and Greens which would keep boundary layer flow southeasterly for most areas east of the Hudson. As a result, the warm sector may only have an influence over part of our area, mainly the western Mohawk Valley, Schoharie County, eastern Catskills and perhaps the mid-Hudson Valley. Add in the cloud coverage and continued chance for some showers and temperatures on Sunday may only reach into the 40s for most with low to mid 50s in the areas where the warm sector can reach. Despite unimpressive temperatures, we notice some elevated instability arriving in the warm sector. If this instability can be realized by the approaching cold front late Sunday PM/evening, some rumbles of thunder may occur. After collaborating with BGM and BOX and consulting the latest SPC guidance, we decided to leave out slight chance thunder for now but we will continue to monitor future trends. The mature/occluded parent low looks like it opens up as it tracks into Ontario with most members of guidance showing a secondary low developing near the triple point, tracking into southern New England/Long Island by Sunday afternoon/evening. As a result, we kept likely and high end chance POPs in the forecast through the day. Should this secondary low develop, another period of steady/moderate rainfall may develop on its northern quadrant. Overall, total rainfall from Sunday into Sunday night looks to range 0.25 to 1.00 inches but given that the 850hPa +v wind and PWAT anomalies range 2-3 standard deviations above normal, some locally higher amounts are possible due to the strong moisture fetch off the Atlantic. The combination of widespread rainfall plus mild air leading to snow melt may result in rises on some rivers. See our hydro discussion for more details. The steadiest rainfall looks to wind down by Sunday night but the pseudo-warm sector in the wake of the occluded boundary looks to overspread the region Sunday night which keeps temperatures somewhat mild in the upper 30s to low 40s. By Monday the closed parent low moves overhead, keeping our region in the moist, cyclonic flow pattern. Expect cloudy skies to persist with continue chance for some showers but the westerly flow regime should keep temperatures seasonable in the upper 40s to low 50s. The true cold front finally moves through Monday night with the wind regime becoming northwesterly which should usher in a cooler air mass. Overnight lows should thus respond accordingly and fall into the 30s through the region with some 20s possible in the higher terrain. Tuesday should be dry but slight cooler than Monday as a Canadian high takes control of the area. Guidance still points to a potential coastal system for the middle of next week which will be contingent upon a potent southern stream shortwave which looks to originate from the Pacific. The ECWMF continues to be the most aggressive with the shortwave which results in a stronger latent heat release out ahead of it and thus amplifies the downstream ridging. A more amplified pattern looks to allow the shortwave to track further northeast and undergoes cyclogenesis off the mid-Atlantic coast. However, the CMC and GFS are not as aggressive and thus keep the 500hPa pattern flatter, allowing the shortwave to track off the Carolina coast which leaves the Northeast mainly unscathed. Should the ECWMF be correct, enough cooler air may be available on the system`s northwest quadrant that wintry mix may be possible over the higher terrain/hill towns of eastern NY/western New England. For now, we followed suit with the previous forecast and placed widespread chance POPs for Wednesday into Thursday. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... VFR conditions into the evening hours as cold front approaches. Proximity to this front will lower ceilings down to MVFR later tonight with some showers. At this time, valley locations appear lower probabilities to keep VCSH, with KPSF into an upslope conditions for a TEMPO group overnight. Cold front is expected to be south Friday morning with VFR conditions on a northerly wind around 10kts. Outlook... Friday Night: No Operational Impact. NO SIG WX. Saturday: Moderate Operational Impact. Chance of RA. Saturday Night: High Operational Impact. Definite RA. Sunday: High Operational Impact. Definite RA. Sunday Night: High Operational Impact. Likely RA. Monday: Moderate Operational Impact. Chance of RA. Monday Night: Moderate Operational Impact. Chance of RA. Tuesday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... A weakening cold front will move into the region tonight as a weak disturbance passes to our south both bringing chances for showers to the area. Increasing sunshine Friday with fair weather expected into Saturday morning. Weather will be unsettled for the rest of the weekend with a cool and widespread rainfall, some snow possible across the higher terrain of the southern Adirondacks and southern Vermont. && .HYDROLOGY... Widespread hydrology problems are not expected int the weekend. Any precipitation will be light and mainly rain tonight into Friday. Widespread precipitation is expected Saturday afternoon into Sunday night as low pressure approaches and moves through. At this time, QPF amounts of half to an inch along and south of I-90 with 1 to 2 inches to the north with the higher amounts across the southern Adirondacks. Some wet snow could initially occur for some higher elevations where the greatest QPF is expected. Significant rises are expected Sunday into Monday due to runoff from rain and some snow melt. Minor flooding could occur in the upper Hudson basins including Sacandaga River at Hope and Schroon River at Riverbank. However, there is uncertainty in QPF and more so in snowmelt; will have to watch trends in guidance over the next few days. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...IAA NEAR TERM...IAA/BGM SHORT TERM...IAA LONG TERM...Speciale AVIATION...Frugis/BGM FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service Caribou ME
914 PM EDT Thu Mar 26 2020 .SYNOPSIS... Weak low pressure will cross the area overnight. High pressure will build into the area Friday into Saturday. Low pressure will approach Sunday then slide south of the region on Monday. High pressure will approach the region from the west on Tuesday. && .NEAR TERM /THROUGH FRIDAY/... 9:14 pm update: Satellite pictures and observations indicate high and mid level clouds streaming into the FA from the west. Clouds will lower and thicken tonight with snow to develop very late this evening and overnight across mainly the northern half of the FA. The highest snowfall totals will be to the north of a small low that will track across central portions of the CWA late tonight into early Friday morning. Area radars show some returns moving into the area, but it will take some time before precipitation reaches the ground. The 00z KCAR sounding showed a lot of dry air below 500 millibars, and dew points are relatively low and mostly in the teens. No significant changes to the ongoing forecast, just some minor tweaks based on the latest observations. Previous discussion: For tonight....Clouds will be on the increase and lower during the evening hrs in advance of low pres moving in from the west. Initially precipitation will evaporate as it falls through a dry column w/evaporative cooling aiding in lower temps.The column is expected to moisten up w/precip reaching the sfc, mostly in the form of snow, w/the highest probabilities across the n and w. The NAM and HRRR line up quite well w/the latest radar and temperature profiles. Mdl soundings support deep moisture through 10k ft w/ese flow through 7k ft. Sfc low slides across the central areas overnight w/the bulk of the precip being on the northern end of the low. Decent llvl convergence and and upper level trof interacting w/the sfc will aid in additional forcing for snow. Even though overall, the expectation is for 1-2 inches of snow on the average. There is potential for some sites to close in on 3 inches w/a brief period of snow into the early morning hrs on Friday. On Friday, low pres will quickly pass on to the se w/the upper trof swinging across the region. The is the potential for that brief burst of snow mentioned above to set in the morning hrs as the upper trof swings through. The NAM and GFS show the potential for some upper level instability as the upper levels cool and llvls warm some. Snow ratios could climb higher than 12:1 in the area of instability, leading to an additional inch of snow in some parts across the northern areas before ending. NW winds to take hold in the afternoon. The GFS points to winds picking up out of the NNW at 10-20 mph w/gusts 25-30 mph. The NAM is not as strong showing gust potential to 20 mph. Decided to split the difference and go w/10-15 mph. Daytime temperatures will be 5 to almost 10 degrees cooler than they have been over the last few days, especially across Northern Maine. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... Precip will be tapering off early Friday night as high pressure approaches from the west. Lingering NW flow will aid in overnight lows dropping towards the teens in the North Woods and lower to mid-20s elsewhere. The immediate coast will hover right around freezing w/ most locales trending towards mostly clear skies. Although the late March sun isnt the strongest, expect a nice rebound in temperatures during the day as the high passes overhead for a beautiful Saturday. Overnight, clouds will again be on the increase as a disturbance approaches from the southwest. Timing of the thicker cloud cover will play a role in Sat night lows, but overall added return flow will keep it a few degrees warmer than Fri night. A mature storm system will cross the Great Lakes on Sunday with moisture ahead of it tracking through the forecast area. Sunday begins dry as precip chances increase first across the Central Highlands and Bangor Region in the morning. NE advancement becomes obstructed by the exiting area of high pressure, causing a drift to the southeast as a secondary coastal low takes over from the primary along the Ontario/Quebec border. While precipitation is expected to overrun most of Maine, temperatures will be the main item impacted by this translation. Trends have been cooler, with mostly snow expected across the north and a wide area of rain/snow mix for the remainder of the forecast area. As the secondary low develops, enhancement of southerly flow across Downeast through to Southern Aroostook may carry the more mild marine layer further inland and north, albeit for a short period of time. While much of the thermal profile is supportive of snow, warming towards the surface (below 950mb) may make snow damp. This also sets the table to watch CAD influence as to northward extent of warm air. Precip remains in the area as remnant moisture from primary low tracks across the state Monday afternoon. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... High pressure to the north maintains easterly flow at the surface, with dry air eroding remaining precip Monday night into Tuesday. While the easterly flow is dry, it isnt particularly cool, as temperatures remain about normal for the end of March. Dry conditions are then expected Wednesday as moisture is concentrated north and south of New England. The next chance for precipitation comes towards the end of the week as a potential system exits the Mid-atlantic. Kept PoPs at slight chance given the fluctuations in guidance as well as only light QPF indicated through Thursday night/Friday morning. && .AVIATION /01Z FRIDAY THROUGH TUESDAY/... NEAR TERM: VFR this evening dropping to MVFR after midnight across the northern terminals w/snow and then to IFR overnight into Friday morning. KBGR to KBHB will conditions go to MVFR after midnight into Friday morning w/a few snow showers. Otherwise, conditions look like they will improve to VFR by Friday afternoon. SHORT TERM: Friday night and Sat: MVFR becoming VFR north, VFR Downeast. Light NW wind. Saturday night: VFR. Light SE wind. Sunday and Sunday night: Lowering to IFR from south to north in light snow mixing with rain. Southeast wind increasing 10-15 kt. Monday: IFR in snow and rain across all TAF sites. Winds shifting east and northeast, becoming light. Monday night and Tues: Winds becoming north as conditions improve from IFR to MVFR and eventually VFR Tues afternoon. && .MARINE... NEAR TERM: The wind has been diminishing a bit as expected, but expect that the seas will build with some long period swell from an offshore storm. Decided to stay w/seas of 4-7 ft overnight into Friday morning. Conditions look like they will drop off below SCA thresholds by Friday afternoon w/winds becoming NW at 10 kt or so. Seas will respond accordingly subsiding to less than 5 ft by later in the afternoon. SHORT TERM: Below SCA conditions expected Saturday through Sunday. SCA winds arrive Sunday evening and overnight as waves build 6-8 ft through Monday and Mon night. Winds and seas begin to slacken Tuesday morning. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory until 11 AM EDT Friday for ANZ050-051. && $$ Near Term...CB/Hewitt Short Term...Cornwell Long Term...Cornwell Aviation...CB/Hewitt/Cornwell Marine...CB/Hewitt/Cornwell
Area Forecast Discussion
National Weather Service Cheyenne WY
934 PM MDT Thu Mar 26 2020 .UPDATE... Issued at 917 PM MDT Thu Mar 26 2020 Scattered snow showers west of the Laramie Range tonight, causing difficult traveling conditions in spots. A Winter Storm Warning is already in place for the Sierra Madre and Snowy Mountain Ranges where snow has already begun to accumulate. By tomorrow morning, precipitation will spread east of the Laramie Range. Areas just east of the Laramie Range will see a wintry mix while the Panhandle will start off the day with rain showers. However, temperatures will drop as a cold front passes through the High Plains mid-afternoon with all precipitation changing over to snow/wintry mix as the cold air mass builds into the region. Still a lot of discrepancy between model guidance related to precipitation amounts and frontal timing, so only updated the next few hours with guidance from the HRRR model which seems to have a great handle on current weather patterns and conditions. All Warnings and Advisories appear on track. && .SHORT TERM...(This evening through Friday) Issued at 230 PM MDT Thu Mar 26 2020 Very difficult forecast the next 24-36 hours as models continue to be all over the place concerning snow amounts and locations. Currently...Surface front now located over northern Colorado this afternoon. Inverted surface trough from the low along the Laramie Range. Isolated to widely scattered showers being observed from Rawlins to Lusk this afternoon. Upper low that will affect the area seen on water vapor imagery moving into the Sacramento area of central California. A low confidence forecast over the next 24 hours as models are all over the place on where precipitation is going to develop and how much snow is going to fall. Hopefully with this low coming onshore...the 00Z and later model runs will become more in alignment with each other. GFS now has 700mb low tracking into the southern Panhandle Friday afternoon. Wrap around moisture to the northwest of the low along a line from Alliance to Cheyenne. Latest ECMWF further south with the low...placing the heavier qpf further south. Nam has highest qpf over the northern Panhandle. Each of these solutions have different temperature profiles which will really impact rain to snow turnover times. So decided to hold off on most winter headlines for the Panhandle and east of the Laramie Range as snow accumulations are so varied. One area we do feel confident in is the Summit and eastern foothills...which has been consistently forecast for heavy snow. Still getting 6-8 inches and should be cold enough that all this precip falls as snow. Decided to upgrade earlier watches to warnings for WY116 and WY117. Thinking here is most locations east of the Laramie Range will see snow Friday...but given that a lot of the snow will occur during the day...impacts should be minimal off the Laramie Range. We do have a period from 00Z to 12Z Saturday that more heavier snow could occur as temperatures cool. So we may need to issue some short fused winter headlines for more areas in southeastern plains and into the Panhandle. .LONG TERM...(Saturday through Wednesday) Issued at 430 AM MDT Thu Mar 26 2020 Strong upper low over the east-central Plains will track northeast across the Upper Midwest by Sunday. Meanwhile, a upper ridge to the west will slide east over the Rockies and High Plains Sunday as the next Pacific trough moves east from the southern Great Basin Sunday through the central/southern Rockies Monday, with most of the precipitation passing to the south of the CWA. There will be slight chances of rain and high elevation snow showers Sunday through Monday. After cooler than normal temperatures Saturday, temperatures will gradually warm through the first half of next week. Breezy west to northwest winds will prevail each day. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 524 PM MDT Thu Mar 26 2020 Wyoming TAFS...VFR at Rawlins, with occasional MVFR until 06Z. Wind gusts to 25 knots until 02Z. VFR at Laramie until 09Z, then MVFR until 18Z, then IFR. Wind gusts to 30 knots until 03Z. VFR at Cheyenne until 09Z, then MVFR until 14Z, then IFR. Nebraska TAFS...VFR at Chadron until 04Z, then MVFR until 09Z, then IFR. VFR at Alliance until 06Z, then MVFR until 09Z, then IFR until 17Z, then MVFR. VFR at Scottsbluff until 08Z, then MVFR until 14Z, then IFR until 18Z, then MVFR. VFR at Sidney until 08Z, then MVFR until 09Z, then IFR. && .FIRE WEATHER... Issued at 230 PM MDT Thu Mar 26 2020 Stationary front over northern Colorado this afternoon allowing colder temperatures and more a moist lower layer of air to remain over most locations. This front will lift north into southeast WYoming over the next 12 to 24 hours as a low pressure system tracks across Colorado. The interaction of the front and upper level low will create widespread mountain snow and valley rains...eventually turning over to all snow Friday. Most if not all locations expected to see snow accumulations. Snow ends Saturday morning as the low tracks into central Nebraska by noon. Drier, breezy and milder weather is expected Sunday through Wednesday with minimum relative humidities between 25 and 35 percent. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...Winter Storm Warning until 6 PM MDT Friday for WYZ112-114. Winter Weather Advisory from 6 AM Friday to 5 AM MDT Saturday for WYZ103. Winter Weather Advisory from noon Friday to 5 AM MDT Saturday for WYZ106-107-118-119. Winter Storm Warning from 6 AM Friday to 5 AM MDT Saturday for WYZ116-117. NE...None. && $$ UPDATE...AB SHORT TERM...GCC LONG TERM...MAJ AVIATION...RUBIN FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Lincoln IL
810 PM CDT Thu Mar 26 2020 .SYNOPSIS... Issued at 810 PM CDT Thu Mar 26 2020 Showers and thunderstorms will begin moving into central Illinois after midnight, with potential for large hail with the stronger storms. While a break in the showers and storms is expected toward late Friday morning, rain will become widespread again later in the day. A potent storm system will move into the region Saturday, bringing additional severe thunderstorms. Expect mild temperatures and an increasing temperature trend, reaching the 70s by Saturday afternoon. && .UPDATE... Issued at 810 PM CDT Thu Mar 26 2020 Frontal boundary is draped close to I-70 this evening, where temperatures remain in the 60s south of there. Further north, northeast winds are pushing cooler air southward, with 40s prevailing near Peoria and Galesburg. Some light rain and drizzle lingers from near Lincoln and Bloomington east, but has been fading as of late. Some updates were made a little while ago to adjust the rain trends through Thursday morning. Cluster of thunderstorms is expected to develop across eastern Kansas this evening, then track eastward. Latest HRRR model brings them into the western CWA toward 2 am, and moving across the area through sunrise. Freshly issued SPC Day1 outlook brought the slight risk into a good chunk of the south half of the CWA (Quincy-Decatur southeast) with a concern of large hail. && .SHORT TERM...(This evening through Friday) ISSUED AT 345 PM CDT Thu Mar 26 2020 A frontal boundary continues to sag slowly southward into central IL, held up by low pressure still in the vicinity of St. Louis. As this low moves eastward, the showers over northern and into parts of central IL should move eastward for a break in precipitation. The front will stall out just south of the area early Friday with showers and elevated thunderstorms forming north of the front again Friday morning, spreading northeastward into central IL. With mainly elevated instability and a strongly sheared environment in central IL, the main threat will be large hail, but there appears to be some wind threat also, mainly I-70 corridor southward closer to the surface front. Temperatures should feature a large range, with lows ranging from low to mid 40s I-72 northward, up to mid 50s south of I-70 tonight. Friday, highs should range from upper 50s/low 60s I-72/Danville northward, to near 70 south of I-70. .LONG TERM...(Friday night through Thursday) ISSUED AT 345 PM CDT Thu Mar 26 2020 A potent 988 mb low is forecast to lift from the central Plains into the vicinity of northeast Iowa Saturday, lifting a strong warm front through central IL, and bringing mid 60s dewpoints and associated 1000-1500 J/kg SBCAPE along with strong 70+ kt sfc-6km bulk shear. These ingredients combined with lift associated with the system could bring significant severe thunderstorm potential, and SPC indicates a slight risk for wind damage and hail. Timing should be late morning through afternoon, early evening in the east. Temperatures should rise to at least the low 70s, possibly higher if any sun can develop Saturday afternoon. Brisk southerly winds around 20 mph with higher gusts can be expected. Behind the cold front, temperatures will trend down strongly for Sunday, with highs in the mid 50s to low 60s, with dry conditions. Brisk 20-25 mph westerly winds and gusts well into the 30-40 mph range look likely for Sunday. Dry weather looks to prevail through Monday, then another southern stream system could potentially bring more rain as far northern as central IL midweek. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 624 PM CDT Thu Mar 26 2020 Area of visibility 1-2 miles covers most of the TAF sites at 23Z, with a broader stratus deck around 500 feet. Some modest improvement expected later this evening with MVFR conditions at most sites by about 04-05Z. However, deterioration is expected after about 07-08Z with an area of showers and scattered thunderstorms. Lingering rain should taper off some by late morning, though ceilings will remain below 2,000 feet through the afternoon. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SYNOPSIS...37/Geelhart SHORT TERM...37 LONG TERM...37 AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Paducah KY
921 PM CDT Thu Mar 26 2020 .UPDATE... Issued at 921 PM CDT Thu Mar 26 2020 The weak cold front has just entered the area to the north of Interstate 64 in southern Illinois. Thunderstorms remain possible north of the boundary late tonight into early Friday. The Slight Risk from SPC now comes right to the northwest corners of Jefferson and Wayne counties with the Marginal Risk now extending southward to a Perry County Missouri to Spencer County Indiana line. The latest HRRR keeps the convection north of our area, and most of the HREF members also keep it north. If something reaches the area, it will be elevated, but the shear would allow for elevate supercells with a large hail threat. We will continue to advertise the possibility of severe along and north of I-64, but it is not looking good at this point. UPDATE Issued at 744 PM CDT Thu Mar 26 2020 Updated aviation discussion. && .SHORT TERM...(Tonight through Saturday night) Issued at 325 PM CDT Thu Mar 26 2020 A frontal system will work its way slowly south toward the I-64 corridor later tonight/early Friday. This will allow for increasing cloud cover once again, and scattered showers/isolated thunderstorms could be on the increase across northern counties closest to the frontal boundary later tonight. 12Z SPC CAMS differ on the storm threat up along the I-64 corridor late tonight into early Friday, but the HRR/ARW and NSSL do suggest at least some potential for scattered convection along the surface boundary. An 850 mb low level jet is expected to develop along the front Friday night, which will likely enhance the heavy rainfall potential just north of our forecast area. As the boundary lifts north as a warm front during the overnight hours, most of the precip should go with it, giving most locations a break of precip in the warm sector for most of the night into the day Saturday. A cold front will then approach the region from the west Saturday afternoon. Will need to monitor for at least some potential for a few severe storms as the front pushes through, but there remains uncertainty at this time as to the locations of the best dynamics and instability. Right now, it appears the best overall dynamics will stay north of our area, closer to the warm front/cold front/sfc low triple point. The higher instability may stay farther south over the Gulf states. Still, it bears monitoring over the next 24-36 hours. .LONG TERM...(Sunday through Thursday) Issued at 325 PM CDT Thu Mar 26 2020 Sunday will definitely be the pick day of the weekend for those seeking outdoor activity. Though it will be quite breezy with westerly winds gusting 25-30 mph, there should be plenty of sunshine as high pressure scoots east through Dixie. Afternoon temps should make it into the mid and upper 60s. The main story in the long term forecast lies with the storm system early next week, namely Monday night into Tuesday. A rather deep mid/upper level low will eject east from the Four Corners region Monday. Gulf moisture will be pulled northward by the southerly flow ahead of a developing surface low over the southern Plains. Cloud cover will increase through the day ahead of the system. Rainfall will reach Southeast Missouri Monday by evening and then spread through the rest of the area overnight. The surface low now looks as though it may pass close enough to our southeastern counties to warrant at least a mention of thunder over much of the region. Of course, the highest chc of getting into the thunderstorm action will be closest to the sfc low, over western KY. Though rainfall amounts are not expected to be terribly excessive at this time, a good one to two inches appears possible, mainly over our south/southeast counties. Some lighter wrap around precip is possible with Tuesday night and into Wed as the upper system moves off to the east. && .AVIATION... Issued at 744 PM CDT Thu Mar 26 2020 A cold front will sink southward about halfway through the region overnight. VFR conditions will prevail through midnight, after which low level moisture out of the southwest is forecast to develop into a low cloud deck over most of southeastern MO and locations mainly north of the OH River. By around daybreak, MVFR cigs will be common there, with pockets of IFR possible for a few hours either side of 12Z. MVFR cigs will spread across the remainder of the region throughout the morning, and cigs should start to show some improvement out of the south late in the afternoon as the front retreats back to the north. Scattered shower activity is forecast to develop near daybreak in the northern half of the region, and linger through the afternoon. Isolated tstms are possible. At this time, there appeared to be enough of a signal to at least include a mid-morning mention of thunder in the KMVN and KEVV TAFs. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ UPDATE...DRS SHORT TERM...GM LONG TERM...GM AVIATION...DB
Area Forecast Discussion
National Weather Service Springfield MO
951 PM CDT Thu Mar 26 2020 .UPDATE... Issued at 945 PM CDT Thu Mar 26 2020 00Z high res model guidance, for the most part, is in good agreement in developing elevated convection from northeast KS into the KC metro between now and 11 pm. Radar trends seem to back this up right now. Increased moisture/low level jet with steep lapse rates above 850mb will support some strong/severe storms with large hail potential. It LOOKS like the initial convection will be north of our counties, but will need to watch trends. High res 00z nam seems like an outlier with convection developing farther south. For now HRRR generally looks good which is similar to other 00z guidance in developing convection closer to the I-70 corridor. Some guidance does develop storms far south into our northern counties later tonight with some convectively induced outflow boundary, but confidence for this is lower given stable lower levels. Will monitor, but by this time (4 to 5am) storms should be weakening. && .SHORT TERM...(This evening through Saturday) Warm and sunny conditions were observed over extreme southeast Kansas and the Missouri Ozarks. Temperatures were in the upper 70s and low 80s as Gulf moisture continued to stream in. This moisture along with decent instability will set the stage for some organized thunderstorms tonight. Most likely areas north of a line from Girard Kansas to Salem Missouri will have the best chances at receiving these storms. Large hail up to the size of golf balls will be the primary severe hazard, although damaging winds can not be ruled out given how warm the lower trop is. We think these storms will lay down an outflow boundary that will shift into southern Missouri for Friday. A moist and unstable airmass will remain in place, which complicates Friday`s convective forecast. SPC has shifted the slight risk further north and west, with a marginal risk for most of the Ozarks. Any storms that develop will have chances for organization given the shear and cape combination. Tornadoes may be more difficult to come by as models are suggesting limited amounts of low level cape, and critical angles are not quite ideal for streamwise vorticity. There is also a cap that could limit the amount of storms. We still need to watch Friday and Friday nights environment very closely in case localized environments can develop in the short term that may be more conducive to tornadoes. Therefore we kept all modes in the Hazardous Weather Outlook, with a limited mention of a tornado possible. Storms will exit the eastern Ozarks Saturday morning as the region becomes dry slotted. This frontal system will cool us a little bit for Saturday night, with lows in the 40s. .LONG TERM...(Sunday through Thursday) Sunday could be a decent day for outdoor activities with sunshine and highs in the 60s. A speed max will then approach the region Monday into Monday night. Clouds will increase during the day on Monday, with widespread showers and thunderstorms spreading in Monday night into Tuesday morning. We will need to monitor the risk for flooding with this system as convective elements could lead to rainfall amounts ranging from 0.5 inch to 1.5 inches. Given the widespread nature of this rain combined with wet antecedent conditions and elevated streamflows, some flooding is a good bet. As of now the medium range models are signaling a short window of dry weather for Wednesday into Thursday of next week. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 655 PM CDT Thu Mar 26 2020 KSGF/KJLN/KBBG tafs: VFR to start but lower clouds with mvfr/ifr ceilings will be possible after 09z as moisture increases near and north of a west-east oriented front that will nearly stationary over southern MO. The front will lift northward late in the period with some improvement in ceilings along with increasing south winds. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ UPDATE...DSA SHORT TERM...Cramer LONG TERM...Cramer AVIATION...DSA
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
802 PM EDT Thu Mar 26 2020 .UPDATE... Latest RAP model has a mid/upper level ridge centered aloft the Gulf of Mexico that sprawls over the Deep South and east to the Bahamas through Fri. High pressure off the southeast U.S. coast this evening slides out over the open Atlantic while stretching back across FL to the Gulf of Mexico as the week ends. These features provide a stable...warm...and generally dry air mass. However there will be adequate low level moisture for late night patchy fog and a few low clouds. Temperatures run above normal by 5 to 10 degrees. The current west winds become light and variable to calm over night then east to southeast in the morning...but shifting to westerly near the coast in the afternoon. && .AVIATION... 27/00Z TAFs. VFR prevails although with limited BR/ST 09-15Z. However LAL and PGD will see some MVFR conditions. W winds become NW then L&V to calm BTWN 03-15Z. AFT 15Z SE winds pick up then shift to SW...AOB 10KT. && .MARINE... High pressure continues across the Gulf through early next week with southeasterly and southerly winds at 10 knots or less. Although winds become onshore and enhanced somewhat near the coast in the afternoons. && .Preliminary Point Temps/PoPs... TPA 87 68 89 68 / 0 0 0 0 FMY 87 67 89 67 / 0 0 0 0 GIF 89 67 92 65 / 0 0 0 0 SRQ 86 68 87 67 / 0 0 0 0 BKV 89 64 91 62 / 0 0 0 0 SPG 86 69 88 69 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ UPDATE/AVIATION/MARINE...09/Rude UPPER AIR...13/Oglesby DECISION SUPPORT...13/Oglesby