Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/20/23


Area Forecast Discussion
National Weather Service Gaylord MI
1151 PM EDT Wed Apr 19 2023 .UPDATE... Issued at 950 PM EDT Wed Apr 19 2023 Looks like the main area of precipitation is almost out of the area and it looks to be mainly rain now. Looking upstream into Wisconsin, and looking through the HRRR pops, there looks to be a lull in the precipitation north of M-32, with the some rain beginning to form along the warm front to the south. Models showing that this will be the main trigger overnight, so have tweaked the pops and weather grids overnight. New grids will be finished shortly. Most everything else looks good. && .NEAR TERM...(Through Tonight) Issued at 229 PM EDT Wed Apr 19 2023 High Impact Weather Potential: Scattered non-severe thunderstorms possible over northern lower Michigan tonight. Pattern Synopsis/Forecast: Early this afternoon, ribbon of surface high pressure across northern Michigan late last night into this morning continues to shove off to the east. Meanwhile, two areas of low pressure are positioned upstream -- one across the northern plains and another over the southern plains. A myriad of boundaries associated with these features are draped across the nation`s midsection with the primary player locally for late today/tonight focuses around a warm front currently draped from central IA eastward into northern IN. Coinciding H8 front draped quite a bit farther north into southern MI, which will continue to aid in increasing precipitation chances this afternoon through tonight as deeper moisture pushes into the area with strengthening isentropic ascent and mid-level fgen response. Primary Forecast Concerns: Shower/thunderstorm coverage. Initial precip chances making their way across Lake Michigan and into far northwest lower Michigan this afternoon in response to increasing deep moisture and isentropic ascent. These showers continue to push into western reaches of the forecast area over the next couple of hours with additional precipitation development expected this evening into the overnight hours as PWs gradually surge to 0.75-1.00" this evening, and perhaps upwards of 1" across southwestern areas overnight. Continued strengthening mid-level fgen looks to still be narrowly focused across northern lower Michigan with more widespread precip activity struggling to get into an appreciable portion of eastern upper tonight. Limited elevated instability and steepening mid-level lapse rates overnight suggest a few embedded thunderstorms remain a possibility tonight, and while locally heavy rainfall will be possible, not expecting any of these storms to be severe. Rain amounts tonight likely to vary widely across the forecast area. Less than a tenth of an inch expected over much of the eastern U.P. to as much as 0.50-0.75" over portions of northern lower. As is often the case with any convection, some localized higher amounts in excess of 1" can`t be ruled out. Low temps tonight generally in the 30s area-wide with some late night breezy easterly winds likely to develop -- most notable west of Interstate 75. && .SHORT TERM...(Thursday through Saturday) Issued at 229 PM EDT Wed Apr 19 2023 High Impact: Heavy rain and thunderstorms possible Thursday into Friday. An unsettled period of weather continues into the short period forecast timeframe. The forecast period begins with an area of developing low pressure over Iowa with Gulf moisture advecting ahead of it on southerly winds into the Great Lakes region with a warm front draping across the Straits area (once again). WAA precipitation will continue Thursday with thunderstorm chances through Friday. These thunderstorms will be mostly elevated with a warm nose aloft and will become more surface based and scattered just ahead and along the associated cold front of the still developing low pressure now over the western upper peninsula Thursday night. This is also when the MUCAPE is at the greatest with the least amount of CINH...around 600 J/kg with only single digit CINH. A south-southwesterly low-level jet over northern lower, along with descent mid-level lapse rates, and 0-6km bulk shear of 40-50kts will all be conducive to thunderstorm development. Although northern Michigan is only in SPC`s General thunderstorm outlook for this time frame...wouldn`t be surprised to see Marginal creep in on their future products issued, with wind being the greatest threat. Forecast soundings show PWATs exceeding 1.00" with skinny CAPE...this would correspond with WPCs Excessive Rainfall Outlook for day 2...mostly west of the I-75 corridor of northern lower Michigan where precipitation will be more persistent and timing is better for the heavier rain fall with convection initiated by the aforementioned cold front. This heavy rainfall could swell local streams and rivers and also cause ponding of water on roadways...making traveling dangerous at times. Northern Michigan then get`s dry-slotted behind the aforementioned cold front Friday...perhaps with light drizzle/shower at times through the afternoon...before deeper wrap around moisture brings another round of light showers and slightly colder than normal temperatures back to northern Michigan for close to the end of April as the northerly winds filter in colder temperatures Saturday. This colder air will begin mixing snow in with the rain Saturday afternoon. East-southeasterly winds will be gusty Thursday with gusts of 35- 40mph before diminishing Thursday night and veering to west- southwesterly by Friday morning. Winds then become fairly light before becoming west-northwesterly Saturday afternoon as a secondary cold front crosses through northern Michigan. .LONG TERM...(Saturday night through Wednesday) Issued at 229 PM EDT Wed Apr 19 2023 High Impact Weather Potential: Minimal at this time. Weather pattern remains fairly active into the long period forecast with hints in the long term models that another area of low pressure moves northward from Lake Erie late Friday night into early Saturday morning. This will continue nuisance type precipitation through much of the long term forecast with wave after wave pinwheeling along the long-wave trough over much of the CONUS. Temperatures will cool back to below normal for this time of the year...only reaching into the mid 40s and possibly the upper 30s through the weekend before warming to more normal for this time of the year to begin the next work week. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1145 PM EDT Wed Apr 19 2023 VFR CIGs and VSBYS are expected to continue through about 08z to 12z depending on the TAF site. The winds will increase overnight with gusts to 30 knots expected. After 12z, MVFR to IFR CIGS are expected with variable VSBYs (MVFR) with the rain, and potentially Thunder. There is potential over the next 24-36 hours for Low level wind shear as the warm air aloft pushes north into the region. TVC and MBL will see it first and it would spread over the region by the end of the day. && .MARINE... Issued at 229 PM EDT Wed Apr 19 2023 Developing easterly flow today as a warm front approaches the Great Lakes. This will set the stage for a relatively active period of weather from late today into the upcoming weekend with gusty winds at times resulting in marine headlines, along with several shower and thunderstorm chances. && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LH...Small Craft Advisory from 4 AM Thursday to 4 AM EDT Friday for LHZ345>348. LM...Small Craft Advisory until 4 AM EDT Friday for LMZ323-341-342- 344>346. LS...Small Craft Advisory from 4 AM Thursday to 4 AM EDT Friday for LSZ321-322. && $$ UPDATE...JSL NEAR TERM...MJG SHORT TERM...TJL LONG TERM...TJL AVIATION...JSL MARINE...MJG
Area Forecast Discussion
National Weather Service Cheyenne WY
630 PM MDT Wed Apr 19 2023 .UPDATE... Issued at 619 PM MDT Wed Apr 19 2023 Allowed High Wind Warnings at Arlington and Bordeaux to expire at 6 PM. Updates sent. && .SHORT TERM...(This evening through Friday night) Issued at 300 PM MDT Wed Apr 19 2023 The early afternoon GOES-W WV/VIS imagery showed a upper low over northeast MT, with a trough axis trailing southwest into UT. A short wave disturbance was moving east into central CO. Per the recent HRRR model runs, convective rain/snow showers were increasing in coverage over far southeast WY and southwest NE Panhandle, most concentrated along the I-80 corridor from the Summit east through Cheyenne and Kimball. Overall, road impacts will be minor with some slick/slushy spots. A quick inch of snow will accumulate on grassy surfaces under the heavier showers. Strong winds that redeveloped this morning along the Laramie Range and North Snowy Range Foothills were slow to subside. Peak gusts to 67 MPH were recorded at Douglas/KDGW, with 60 to 65 MPH at Arlington, Coleman (East Platte County), and Bordeaux. 12Z random forest guidance maintains strong winds at Bordeaux and Arlington until 00Z, so will extend the High Wind Warning until 6 PM. The High Wind Warnings for Arlington, Douglas, the I-80 Summit and Cheyenne were cancelled. Showers will persist along the I-80 corridor from Cheyenne to Sidney through early evening, tapering off by midnight. The MT upper low meanders east across the Dakotas, MN and western Great Lakes through Friday. A mean upper trough will be the dominant feature through the short term. Embedded short waves within the northwest flow aloft will promote an unsettled and cooler than normal weather pattern with occasional rain and snow showers, most numerous over the mountains. The Snowy and Sierra Madres may receive 5 to 10 inches, with 1 to 3 inches for the North Laramie Range and Ferris/Shirley/Seminoe mountains. Up to a half inch is possible for lower elevations. Elevated low level pressure/height gradients will promote blustery conditions Thursday and Friday with west to northwest winds gusting to 45 MPH. High temperatures Thursday and Friday will range from the 20s and 30s west to the 40s east. Low temperatures will be in the 20s, with teens for the western mountains and valleys. .LONG TERM...(Saturday through Wednesday) Issued at 300 PM MDT Wed Apr 19 2023 An active long term forecast period is in store starting with strong northwest flow Saturday as the low pressure system over the Great Lakes remains near stationary until Sunday afternoon. Dropped temperatures just a few degrees due to the northwest flow continually injecting cooler air into the area. Ridging begins to take back over Sunday, increasing temperatures, just in time for the next shortwave to push through. This is where the long range models could not be showing more different results. On one hand the ECMWF is showing a closed low developing in the PACNW and aggressively pushing southward, ingesting Gulf moisture as it makes its way in New Mexico/Colorado. With this solution, its possible if the low wiggles northward, and we receive the strong upslope flow and Gulf moisture, we could see a decent snow system! However, the GFS has the low pressure system as an open wave trough moving east across northern Wyoming and Montana, not closing off until it reaches the Dakotas and northern Nebraska. This would maybe give a few showers, but impacts would be limited to primarily northern portions of the CWA. In addition, our precipitation would more likely be rain as we don`t get as deep a push of colder/northern air. As the models are showing such different solutions, there is little to no confidence in what will actually develop. Stay tuned in the next few days when hopefully ensembles will begin to come together. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 525 PM MDT Wed Apr 19 2023 Wyoming TAFS...Northwest flow aloft will continue through the period producing scattered to broken clouds from 5000 to 15000 feet AGL. Surface wind gradients will be sufficient to produce wind gusts up to 36 knots. Nebraska TAFS...A weather disturbance will continue to produce localized MVFR conditions at Scottsbluff through 02Z with visibilities in rain and snow showers near 4 miles at times along with ceilings around 2000 feet. Otherwise, northwest flow aloft will prevail producing scattered to broken clouds from 6000 to 15000 feet AGL. Pressure gradients near the surface will produce wind gusts to 43 knots through early this evening, and to 33 knots after 15Z Thursday. && .FIRE WEATHER... Issued at 300 PM MDT Wed Apr 19 2023 Chilly temperatures, non-critical humidities, and occasional rain and snow showers through Saturday will preclude fire weather concerns. It will be blustery most days with periodic gusts up to 45 MPH at times. Milder temperatures and scattered showers are forecast early next week. && .CYS WATCHES/WARNINGS/ADVISORIES... WY...None. NE...None. && $$ UPDATE...GCC SHORT TERM...MAJ LONG TERM...LK AVIATION...RUBIN FIRE WEATHER...MAJ
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1156 PM EDT Wed Apr 19 2023 .AVIATION... Ongoing pattern of mid level moisture transport along an active elevated warm frontal zone will continue to support some pockets of light rain overnight, particularly at MBS. This activity will occur within an extensive canopy of mid level cloud, supporting prevailing VFR conditions with minimal disruption to visibility or reduction of cloud base below 6-8 kft. Winds hold from an easterly direction through the remainder of night. Tendency for mid level cloud to gradually thin Thursday, while maintenance of a dry low level environment limits diurnal cu potential. Winds gradually veering to southeast during the day in advance of a surface warm front. Convection may begin to encroach on MBS by Thursday evening, but generally dry conditions likely to hold across much of southeast Michigan until the cold front arrives late Thursday night/Friday morning. DTW THRESHOLD PROBABILITIES... * None. && .PREV DISCUSSION... Issued at 352 PM EDT Wed Apr 19 2023 DISCUSSION... Sunny skies earlier this afternoon are gradually giving way to cloud cover as amplified upper level ridging shifts to the east. Overnight lows settle into the 40s, some ten degrees warmer than this morning. This is indicative of the low and mid-level theta- e transport that is on the doorstep of the cwa, evident as a sharp moisture gradient per the Advected Layer Precipitable Water satellite product. Model moisture fields quantify this moisture increase with a nearly 20 degree dewpoint gradient along the feature. The ongoing moisture transport sets the stage for several rounds of precipitation over the next 48 hours, especially for northern portions of the cwa, with an active pattern continuing into the weekend. The first round of convection occurs tonight, associated with ongoing convection over southern Wisconsin that has become more west- east oriented corridor invof a developing h850 frontogenesis maximum over mid-Michigan. The expectation is for these showers/thunderstorms to move into the Tri Cities around 00z and expand in coverage through the evening for areas north of I-69 as isentropic ascent maximizes along the 296-302K surfaces. Nocturnal timing of convection combined with the surface warm front being well south of the state ensures stability below roughly h850, thus keeping showers and storms elevated through the overnight hours. Steep mid level lapse rates in excess of 7 C/km however may allow for a few hundred J/kg of MUCAPE or more to develop, particularly if cloud top cooling overachieves as noted in the previous discussion. Thunderstorms will thus be possible, and given relatively cold thermal profiles/deep layer shear around 40 knots, cannot rule out small hail if any storms become organized. The limiting factor to hail size will be the skinny CAPE profiles. More favorable dynamics arrive Thursday morning, as a 110 knot jet streak rounds the base of a stalled upper low circulating over the Dakotas. This results in the reinvigoration and northward progression of a previously weakened surface low over the Plains, which helps drive the surface warm front into lower Michigan and brings overnight shower/thunderstorms to an end around daybreak as the elevated frontal slope is displaced into northern lower Michigan. In terms of the warm front, first question is how far north it will actually get, with more bullish models such as the 19.12z HRRR pushing the front well into mid Michigan and bringing high temperatures into the low 80s. Other guidance, such as the NAM, is much more conservative and keeps the front along/south of I-94 keeping northern areas possibly in the 60s. Have therefore trended daytime highs cooler for northern locations, more in line with 12z MOS guidance, though forecast high temperatures may still be far too high if the front holds south. Second question with the warm front is whether convection will trigger along the front/within any existing warm sector. Instability will be on the weak side, as surface dewpoints struggle to reach 50 degrees, thus maintaining high-based LCLs which only moisten slightly invof moisture convergence along the warm front. On the other hand, continued period of marginally favorable deep shear and steep mid level lapse rates again present the possibility of a few organized storms. While some of the hi-res guidance is triggering thunderstorm activity around mid-day south of I-69, higher confidence exists for afternoon thunderstorms toward the Tri Cities/Thumb. Expectation is for just general thunderstorms as highlighted in the Day 2 SPC Outlook. Non-convective gusts on the order of 30mph are possible south of the warm front owing to efficient boundary layer mixing and a 30-35 knot low level jet. Shower and thunderstorm chances continue into Friday morning as a strong cold front sweeps through lower Michigan. Unfavorable overnight/early morning timing limits any severe threat, despite the strength of the forcing and ambient deep layer shear. The parent upper low and occluded surface low meander overhead, keeping rain chances going through the weekend. Passage of the cold front maintains cool temperatures through the weekend as well, with highs in the 50s. MARINE... Elevated showers and possible thunderstorms will move across Lake Huron this afternoon and evening associated with shortwave energy moving within the flow around the ridge. The diffuse high pressure sliding east today will keep winds on the lighter side as a warm front lifts northward into Lake Huron tomorrow. Increasing easterly flow will then develop tomorrow morning as a low pressure moves into Midwest and then arrives over western Lake Superior tomorrow evening. Gusts associated with this system will be greatest across northern Lake Huron and reach around 30 knots. A frontal boundary will then work into the central/southern Great Lakes tomorrow night and Friday resulting more rainfall and possible thunderstorms. The strength of the frontal passage will relatively weak with limited cold air advection in the immediate wake of the front. This will keep wind gusts below 20 knots for Friday. Greater cold air advection arrives on Saturday bringing an uptick in west to northwesterly winds. HYDROLOGY... An elevated frontal boundary brings shower and thunderstorm chances to areas north of I-69 overnight into Thursday morning. Heavy downpours will be possible with these storms, with potential for cells to repeatedly impact some locations. As such, highly localized totals to or in excess of an inch will be possible. Additional shower and thunderstorm chances exist Thursday afternoon and again Friday morning, with potential for heavy downpours as well. Minor flooding in flood prone locations, ponding of water on roadways, and minor rises to streams and creeks will be possible with thunderstorm activity. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...None. Lake Huron...None. Lake St Clair...None. Michigan waters of Lake Erie...None. && $$ AVIATION.....MR DISCUSSION...MV MARINE.......AA HYDROLOGY....MV You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Quad Cities IA IL
608 PM CDT Wed Apr 19 2023 ...00Z AVIATION UPDATE... .SYNOPSIS... Issued at 253 PM CDT Wed Apr 19 2023 Radar shows some small showers/storms still over the eastern CWA, while some clearing was seen on satellite in parts of central and east central IA. A warm front was located roughly along I80. There is a wide range in temperatures, with upper 40s and 50s north of the warm front to lower 70s south. && .SHORT TERM...(This evening through Thursday) Issued at 253 PM CDT Wed Apr 19 2023 Focus remains in the active storm chances tonight and tomorrow. Tonight, the early evening will be quiet, with some new scattered storms possibly developing along and north of the front toward mid evening. Latest CAMs have this lingering over the area with more organized activity in central Iowa. This bleeds eastward into the western area late tonight towards midnight and moves east along and north of I80 through the overnight hours. This is still expected to be in a diminishing phase as it works east, but can`t rule out the possibility of some upscale growth into several line segments with a large hail and damaging wind threat. SPC has our far western portions of the CWA, west of a line from Fairfield to Cedar Rapids, in a slight risk, level 2 of 5, for severe storms tonight, with the rest in a Marginal risk. If storms develop this evening, any storm near or crossing the warm front will pose a tornado threat as well. Thursday, a cold front will be moving relatively quickly through the area during the late morning and afternoon hours. The expected ongoing morning activity may still pose a hail and wind threat early Thursday morning. High uncertainty remains with how things will unfold for any renewed storms in the late AM early PM along/ahead of the cold front. If any cloud breaks are seen in the morning, more destabilization will occur with a higher threat for strong to severe storms. SPC has the eastern CWA in a Marginal risk for tomorrow with the main threats damaging winds and tornadoes. At this time the current time frame appears to be from late morning into mid to late afternoon. Latest HRRR has activity east of the area by 6pm. .LONG TERM...(Thursday night through Wednesday) Issued at 253 PM CDT Wed Apr 19 2023 Thursday night through Monday, mainly dry conditions will be common with much colder temperatures expected, especially over the weekend. The forecast blend has come in dry for Friday afternoon, however, some models show some showers developing with a reinforcing cold fropa. Some POPs may be needed later for the eastern CWA for this. It will be windy from the west with highs in the 50s NW to low to mid 60s SE. Friday night, will be cold with lows in the lower 30s NW to mid 30s elsewhere. Saturday, some slight POPs are focused on the east and north parts of the CWA as some spokes of energy pivot across the area in cyclonic flow. Highs Saturday will be in the 40s. Saturday night through Monday it will be dry, but near or below freezing temperatures will be seen each night/early morning. High temperatures will see a gradually warm up, with mid 50s to mid 60s by Monday. Tuesday, the forecast blend brings in rain chances back into the area. Temperatures will remain in the upper 50s to low 60s. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 605 PM CDT Wed Apr 19 2023 VFR conditions to start the period will become more predominantly MVFR with potentially some IFR in showers and storms later tonight and Thursday ahead of a lifting warm front followed by a cold frontal passage. Precip timing and winds will subsequently be challenges, as the warm front has retreated some and may not lift until Thursday morning when surface low pressure to our west pulls northward. There appears to be 3 main precip windows.. the first late this evening with warm advection attendant to branch of LLJ... the second overnight and Thursday AM with weakening band(s) of convection from our west which could contain strong gusty winds and hail, and the third ahead of the cold front Thursday PM. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...14 SHORT TERM...14 LONG TERM...14 AVIATION...05
Area Forecast Discussion
National Weather Service Grand Forks ND
708 PM CDT Wed Apr 19 2023 .UPDATE... Issued at 708 PM CDT Wed Apr 19 2023 Lots of echoes on radar early this evening, but not seeing much reaching the ground yet. The most substantial echoes are over eastern South Dakota toward the Twin Cities area, spreading northeastward. Based on these current trends, not sure if any of this activity will affect this FA, or head up toward Duluth. The latest HRRR has been trending the activity toward Duluth. The previous runs had a fairly decent batch of precipitation moving northward through areas east of the Red River Valley this evening. Since it appears the drier route seems to be matching current trends better, that would mean most of the rest of the night would stay mainly dry. More precipitation would become likely toward sunrise on Thursday. Will monitor trends a little while longer this evening before making any big shifts toward the drier route. && .SHORT TERM...(This evening through Friday) Issued at 330 PM CDT Wed Apr 19 2023 Very complex forecast with low confidence in what impacts will actually occur. Upper low currently rotating over northeastern MT will move slowly out into the Western Plains overnight. The surface low that brought the winter weather to northwestern ND earlier today will begin to fill in, with a stronger low starting to take over to the south over IA. In between, our CWA will be in the occlusion/mid level baroclinic zone for much of the night. Instability and thunderstorm potential will be mostly to our south and southeast, but could see a few rumbles make it into west central MN. With a lack of any cold air advection and clouds and winds staying up overnight, air temperatures will stay fairly mild overnight and may not drop below the freezing mark. Road temps may also be fairly mild overnight, so if any mixed precip falls like a few of the CAMs indicate, not sure how much impact there will be. Will hold off on any winter impact products for the moment. By tomorrow, the upper low starts to move into the Dakotas, and colder air starts to come down behind the surface low as it lifts off towards Lake Superior, although the strongest cold air advection will hold off until Thursday night into Friday. There will be a delicate balance during the day on Thursday between colder air starting to come in, strong April insolation, and warm ground temperatures. As precip transitions to snow, not sure how much will melt immediately and how much sticks around. NBM has some fairly high probabilities of over 4 inches by 00Z Friday, however, while that may very well fall, there is a chance that some or none of it will accumulate. Further south across southeastern ND and west central MN, there will still the possibility of rain mixing in even as cold air arrives. More cold air will be arriving Thursday night into Friday as the upper low wraps up over the area, but precipitation rates do not look as strong and there will be mainly lingering light snow. Ensemble spread and uncertainty are high even as the system is rapidly approaching. Model snow totals at Hallock range from an inch to 20 inches. Confidence in any of the snow totals is very low. NBM is has 60 to 80 percent probabilities of 6 inches or more mainly along and north of Highway 2 corridor. Winds will be picking up Thursday night into Friday, but with a mix or wet snow along with fairly warm temps think that blowing snow impacts will not be too high. With large uncertainty will keep the watch going, and continue to message in the graphics the probability of 6 inches or more rather than the raw snow total amounts. .LONG TERM...(Friday night through Wednesday) Issued at 330 PM CDT Wed Apr 19 2023 Overview: Some light precipitation may linger early Saturday morning as the system moves East. From Sunday through Tuesday we still remain abnormally cold with temperatures in the mid 30`s. Some light precipitation possible mid-next week. Discussion: As the upper-level low moves over the Great lakes region Saturday morning the RRV and North-Central Minnesota could still see some lingering precipitation ending around noon. A surface high moves over our region late saturday leaving us dry until Tuesday. Sunday into Monday, A low pressure system enters the Pacific Northwest to drive our weather pattern for the rest of the week. This causes another short duration ridge to set up over the Northern Plains Sunday continuing until Tuesday. There is some uncertainty as to the storm track and preceding impacts as it crosses the Rockies and ejects into the Central Plains. Looking at the Ensembles versus the Deterministic Models there are two potential scenarios that could exist for the later half of the week into next weekend. The first scenarios is backed by the deterministic models where the Low ejects across the Southern Plains and remains on a Southern tracks as a strong high-pressure system resides over the Northern Plains forming a small ridging pattern over the Northern Plains keeping us relatively dry for the remainder of the week. The second scenarios which is supported by half of the grand/super ensembles shows the Low pressure system ejecting from the Rockies and taking a more Northern track which would impact the Northern Plains for the remainder of the week. This scenario is based on the High pressure system not setting up or moving off to the east following this weeks low. The LREF is showing about a 60% chance of no precipitation for the later mid-week and a 40% chance of receiving precipitation up to 0.5inch. This means a slight majority of the ensembles are favoring the first scenario but the second scenario could be as equally as likely but maybe small accumulations from the system.&& .AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon) Issued at 1250 PM CDT Wed Apr 19 2023 Lower VFR to MVFR at most sites although KDVL is already down to IFR. Should see a slow deterioration of conditions down to MVFR and then IFR overnight. There is a bit of a break in precipitation this afternoon but will see some rain and snow moving in along with the IFR ceilings tonight into tomorrow morning. Mostly have vis staying in the 1-5SM range at the lowest, but could see some lower vis less than 1SM with heavier snow bands in the last 6 hours of the TAF period. However, not confident enough to include at this point. Winds will shift around from the east and southeast to the northeast. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 708 PM CDT Wed Apr 19 2023 The main story is that MVFR to IFR conditions are anticipated for the entire TAF period. The ceilings in these ranges are already here. When the visibility drops into the same ranges depends on when any precipitation begins again. Current trends seem to favor a drier route overnight, with precipitation picking up and becoming more widespread again on Thursday morning. By that point, most locations would see more snow than rain or mixed precipitation. && .HYDROLOGY... Issued at 330 PM CDT Wed Apr 19 2023 Snowmelt continues across the Red River basin, and meltwater continues to push into the river systems. Much of the snowpack from northwest MN has melted and has worked its way through a portion of the MN Tributaries already, there are still pockets of older winter snowpack over eastern ND and the Red River Valley in MN (though they are greatly diminished). Temperatures well below normal continue through this weekend, before moderation precipitation expected next week. This may act to slow river responses as temperatures fall well below freezing each night. An active precipitation pattern remains in place through Friday, with periods of rain or a wintry mix. There is an increasing signal for snowfall accumulation to occur later Thursday into Friday. Liquid equivalent (QPF) values over 1" are possible along and north of the highway 2 corridor (northeast ND/far northwest MN), but if much of this falls as snow it could help delay this entering the river system. Overland flooding continues across much of the area. Areal flood warnings remain in effect. These cover locations where overland flooding impacts are ongoing, or to account for an increase in overland flooding as snowmelt continues and precipitation could exacerbate impacts. Ice jams appear to have moved downstream from Neche and Crookston and those sites are showing more stable trends. Downstream of Neche, ice jam impacts may increase as river ice on the Pembina River reaches the Red River. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...Winter Storm Watch from Thursday morning through Friday morning for NDZ007-008-016-027-054. MN...Winter Storm Watch from Thursday morning through Friday morning for MNZ001-004>009-013>017. && $$ UPDATE...Godon SHORT TERM...JR LONG TERM...MM AVIATION...Godon HYDROLOGY...DJR
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
840 PM CDT Wed Apr 19 2023 ...Short Term Update... .UPDATE... Issued at 836 PM CDT Wed Apr 19 2023 Showers and thunderstorms arrive from the west over the next 2-3 hours. This will initially be just a wind threat (and perhaps some blowing dust). There have been several observations of gusts over 60 MPH in SW Neb already. As storms move eastward into better instability (roughly Highway 281), the hail threat will increase. The wind threat will also continue as models show storms going going more upscale. The peak timing for severe weather is 11pm to 3am. && .DISCUSSION...(This evening through Wednesday) Issued at 420 PM CDT Wed Apr 19 2023 Key Messages: * Scattered strong to severe storms possible tonight, mainly SE half/third of the forecast area. Large hail is the primary concern, with a secondary/lesser threat for damaging wind. * Main concerns shift to fire weather Thu and Fri amidst windy/breezy conditions, low relative humidity, and below normal temperatures. * Below normal temperatures continue into the extended. Need to start highlighting frost/freeze concerns for the spring season as the growing season has effectively begun for most of the area given recent warmth. Coldest nights/mornings will be Fri-Sat and Sat-Sun. * Relatively dry pattern until better chance for moisture Mon night into Wed AM. Forecast Details: Will discuss fire weather concerns over the next 48-72 hours in dedicated fire weather section below. Right off the bat, the main concern will be potential for strong to severe storms to develop over far SE portions of the CWA as early as this afternoon, though latest model trends are for a mostly overnight event as the main upper level shortwave interacts with the elevated front. Current sfc analysis places the primary sfc front from near SUX, to between JYR/LNK, to near HJH, and just W of CNK. Thus, nearly the entire CWA is in cooler and/or drier post-frontal air mass, and W fringes of primary CU field is already to BIE to SLN. Also, special 20Z TOP sounding shows a lot of CINH still to work through, which will only give boundary even more time to shift E. So pretty confident that initial storm threat/convective watch remain E of the CWA through late eve. Later tonight, as the primary upper trough axis shifts E from the Four Corners onto the High Plains, expect elevated convection to blossom along the H7-H85 front in response to large scale ascent and incr deep moisture convergence. General signal from various models is that a swath of MUCAPE 500-1000 J/kg will focus mainly S/SE/E of the Tri-Cities, owing to sufficient moisture pooling along elevated front and steep mid to upper level lapse rates. BUFKIT forecast soundings from around HSI, S and E, shows uncapped instability to parcels based between H8-H7, with about 30-40kt of effective shear between 2-7km. This should be sufficient for large hail with strongest/most persistent cores. Latest HRRR/HREF suggests greatest risk being in the 03Z to 09Z time frame. Latest SPC Day 1 Convective Outlook highlights areas with greatest risk pretty well, though both the Marginal and Enhances lines are probably a bit generous in their W/NW extent. The fact that storms should be elevated precludes more than an iso dmg wind threat. Main story Thu to Fri will be much cooler temperatures strong NW winds, esp. Thu AM and Fri during the daytime hrs. Despite the cooler temps, fire weather will still be a concern (see below) given dry, downsloping air mass. Have added slgt chc PoPs to Thu aftn/early eve given potential for diurnally driven shallow convection to work its way in from the W, similar to what HRRR simulated reflectivity shows. Agree with 12Z EC that QPF should be trace to only a few hundredths. Can`t rule out some similar "popcorn" sprinkles/lgt shwrs Fri aftn, too, but not enough confidence to include such a low-end potential at this time. Below normal temperatures continue into the weekend and likely bottom out Sat into Sat night. Latest regional coordination and local data now places most of our CWA firmly into the spring growing season. Anecdotally speaking, have noticed a rapid uptick in green-up and blooming trees locally, and several greenhouses have opened up for the season. Thus, will start advertising/messaging frost/freeze concerns more prominently going forward. The first risk of near-freezing temps will come for areas around the Tri-Cities, but esp. N/W, Thu night into Fri AM. Even though some of these zones may fall to around 30 degrees, these areas are arguably the least advanced into the growing season of the local forecast area, and a decent W/NW wind will probably preclude frost development. A much harder, and more widespread, freeze is forecast for both Fri night-Sat AM, and Sat night-Sun AM in which lows area wide will likely fall below 30 degrees, and possibly down to around 20 degrees in favored cold spots in Valley and Dawson Counties. Wind will probably be too strong for frost Fri night, but ridge axis moving overhead Sat night-Sun AM should make frost formation more favorable. Will likely need headlines to address these impacts within the next 24 hours. Slight warming trend develops Sun and continues into Mon ahead of next upper disturbance. However, even with this warming trend, temps will likely remain mostly near to below normal. In fact, not seeing much, if any, appreciable signal for widespread and/or sustained above normal temperatures through the end of the month. So wouldn`t be shocked if more frost/freeze concerns return late next week. Otherwise, main thing to watch next week will be potential for much-needed pcpn Mon night into Wed AM with our next upper trough. Both deterministic and ensemble output suggests there will be pockets of decent moisture somewhere in, or nearby the local forecast area, with latest trends favoring our KS zones to get the more precip compared to our NE zones. In fact, 12Z EPS gives better than 50/50 chance for at least half an inch of moisture with this system. While probably not a major concern given overall pattern, some deterministic data suggests non-zero chc for wet snow to mix in far W/NW zones towards end of event. Obviously, persistent cloud cover and Erly winds would keep temps cool for late April, highs perhaps only upper 40s to 50s Tue. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Friday) Issued at 618 PM CDT Wed Apr 19 2023 Thunderstorms are trending farther southeast for tonight, but cannot rule out a brief period of VCTS at GRI. Northwest winds becoming increasingly gusty overnight into Thursday morning before gradually decreasing in the afternoon. && .FIRE WEATHER... Issued at 415 PM CDT Wed Apr 19 2023 Near-critical to critical fire weather will be possible each day through early this weekend. Have had areas along and W of Hwy 183 reach near-critical conditions for several hours today, and even a few hours of critical conditions at ODX and LXN. Fortunately, should have decr in wind speeds between now and when the front arrives late eve. Cold front slams through the area tonight, which will bring strong NW wind gusts of 30-40 MPH, perhaps even higher SW of the Tri- Cities. Winds will back off some for the daytime hrs Thu, but still remain brzy. Expect min RHs to dip to around 20 to 30 percent area wide, with perhaps far SW zones dipping into upper teens for a few hrs in the aftn. These areas would also be most likely to miss out on very lgt "popcorn" sprinkles/lgt shwrs during the aftn. Given some uncertainty in temps/cloud cover, and effect on RH, decided to hold off on headline and message in HWO. Fire weather concerns will probably peak on Fri as this is when there will be most significant overlap of strong winds (sustained 20-30 MPH, gusts 30-45 MPH), and once again down to around upper teens to upper 20s percent. Fri aftn also presents lesser risk for sprinkles. At least near critical conditions could continue into Sat with continued dry, breezy NW flow. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ UPDATE...Mangels DISCUSSION...Thies AVIATION...Mangels FIRE WEATHER...Thies
Area Forecast Discussion
National Weather Service Goodland KS
1005 PM MDT Wed Apr 19 2023 .UPDATE... Issued at 805 PM MDT Wed Apr 19 2023 Red Flag Warning for Cheyenne county Colorado has been allowed to expire. No other changes at present time. UPDATE Issued at 656 PM MDT Wed Apr 19 2023 Cheyenne, Rawlins, Gove and Thomas counties have been added to the Blowing Dust Advisory. Spotter reports and webcams reporting visibilities down to about 1/2 mile. No other changes made. UPDATE Issued at 555 PM MDT Wed Apr 19 2023 A Blowing Dust Advisory is in effect for the southwest 1/2 of the forecast area through 03z. Web cam in Limon showed a wall of dust accompanying a cold front moving through with visibilities briefly down to 1 mile. Extrapolation of the strongest 1 and 3 hour pressure rise couplet from the GFS would take this "wall" of dust southeast through the Blowing Dust Advisory Area from now through about 03z. Locally lower visibilities are possible, especially over open fields. Its expected that the restricted visibilities will last up to an hour or so. Northwest winds gusting up to 65 mph will also be possible. A High Wind Warning is in effect and matches well with current thinking. && .SHORT TERM...(This evening through Friday Morning) Issued at 255 PM MDT Wed Apr 19 2023 A complicated forecast is in store for this evening and overnight, as the potential is there for multi hazards across the area. Synoptically a large trough is ejecting onto the plains an advancing cold front currently situated roughly from Denver through the Nebraska panhandle will be the focus for wind, dust and perhaps some severe this evening through tonight. Starting with the wind potential, forecast guidance continues to be on track with the timing of the front moving into NW Yuma county around 22Z. As the front continues to move into the area, virtually all guidance including the RAP show strong pressure rises of ~5mb over 1 hour and ~11mb over 3 hours to occur across the CWA. This along with Hi-RES guidance and forecast soundings suggesting 50-55 knot flow just off the surface along the front has increased my confidence in 60+ mph non thunderstorm winds occurring as the front tracks to the SE. As a result a High Wind Warning has been issued for Kit Carson and Cheyenne counties in Colorado along with Sherman, Thomas, Wallace, Logan, Wichita and Greeley counties in Kansas. The 60+ mph wind potential will end NW to SE through the evening as the warning runs through 09Z. For the dust potential, office research does show favorable parameters across western portions of Cheyenne county Colorado with the exception of 2-2.5km lapse rates being to high. Since those lapse rates are to high there essentially will not be a "lid" helping keep dust confined to the surface. SW winds are expected to increase to near 45 mph through the evening leading to some blowing dust potential, especially near open fields through the evening. As for the cold front, office research is favorable of strong 0-2km lapse rates ahead of the front especially across Yuma and Dundy counties along with more favorable 2-2.5km lapse rates to help "cap" dust near the surface , winds however are not in the area of favored rapid pressure rises as what is suggested to occur as this more across Southern Yuma into Kit Carson county. There is the potential for a significant dust event, perhaps a Haboob, developing this late afternoon into the evening. I do have low confidence in this occurring as there will some precipitation just behind the front along with some cloud cover developing along the Palmer Divide currently; plus the overall office blowing dust parameters are not as clear cut as the December 2nd Haboob showed. The cold front will continue to move to SE along with the dust and strong wind potential throughout the evening. Overall though I do have fairly high confidence in some blowing dust occurring due to the multiple days of warm and breezy conditions, along with the very strong winds that are forecasted but my overall confidence in how widespread and significant it may be is low. As for the severe potential, I am currently expecting the potential for some storms, perhaps QLCS with embedded supercells to develop along the cold front as it interacts with the slightly better moisture across the eastern portions of the area. Overall confidence in severe thunderstorms to occur is low, however some recent runs of the CAMS do suggest a storm or a line of storms developing Phillips through Gove County around 06Z. The main threats if severe thunderstorms were to develop would be damaging winds and large hail. There is also potential for severe wind gusts associated with showers/virga to the north of where the High Wind Warning is currently issued for. This may be a similar situation to this past Thursday where many reports of 60+ mph winds occurred with passing showers and virga. Overall confidence in that occurring is low as the wind field is better to the south, where the High Wind Warning is located. Moving onto the fire weather concerns, a Red Flag Warning is currently in effect for Cheyenne County Colorado as winds are expected to turn to the SW and gust to 45 mph during the late afternoon and evening hours. RH values will range from 10-15% as well. A corridor of diurnal cumulus has been developing along the Palmer Divide which may lead to some dry lightning concerns as well, especially if an updraft can sustain itself for a bit. The cold front is forecast to move into Cheyenne county Colorado around 01- 02Z creating a sudden wind shift to the NW along with stronger winds. If a fire were to be ongoing this would lead to a very dangerous situation due to unpredictable fire spread. As mentioned above office dust parameters are favoring the potential for some localized significant reductions in visibility which would increase the response time for first responders if a fire were to be ongoing. Finally into Thursday, overall temperatures will be cooler with highs in the 50s to low 60s across the area. Winds will be breezy to gusty especially during the morning hours with some gusts up to 40 mph possible. A very dry airmass will be moving in from the west resulting in dew points falling into the single digits which as a result will have RH values fall into the mid teens. A Fire Weather Watch has been issued for Kit Carson, Cheyenne counties in Colorado along with Wallace, Logan, Greeley and Wichita counties in Kansas. .LONG TERM...(Friday through Wednesday) Issued at 155 PM MDT Wed Apr 19 2023 Main focus for this period of the forecast is the chances for rainfall early next week. Cooler than normal weather is expected for the start of the period. The upper level flow will be from the northwest to the Plains. This will direct the cooler air from Canada southward behind a cold front Friday. This flow pattern remains in place through Saturday before changing. As such record to near record lows may occur Friday night and Saturday night. A surface high remains over the forecast area through Sunday. The upper level flow becomes more zonal Sunday. This will allow WAA to move over the forecast area. Meanwhile laminar upper level flow will move over the forecast area. After Sunday the upper level flow becomes more uncertain due to models disagreeing with how fast the next short wave trough/closed low will move. The latest ECMWF has a deeper, more pronounced closed low. The closed low is also further west than what was seen yesterday. The latest track takes the closed low over the Four Corners Region then over the Southern Plains, completely missing the forecast area. The GFS is not as deep with the trough, and has it positioned further north of the ECMWF closed low. This trough has slowed some from the last couple of model runs as it moves southeast. The GFS continues to move the trough over the forecast area next week. Looking at the GEFS and ECMWF ensembles, both show chances for precipitation. However the GEFS has better chances for precipitation (specifically probability for more than 0.10") than what was seen yesterday. In addition, the forecast consensus blend for this timeframe has increased both the chances for rainfall and the amount of rainfall. This is still too far out to become too confident with rainfall potential. However the trend is encouraging to see. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1005 PM MDT Wed Apr 19 2023 KGLD...VFR conditions are expected through the period. Northwest winds gusting 30 to 40kts are expected from taf issuance through about 01z, falling below 12kts after 02z. KMCK...VFR conditions are expected through the period. Northwest winds gusting 35 to 45kts are expected from taf issuance through 01z, falling below 12kts after 02z. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...High Wind Warning until 3 AM MDT /4 AM CDT/ Thursday for KSZ013- 014-027>029-041-042. Fire Weather Watch from Thursday morning through Thursday evening for KSZ027-028-041-042. CO...High Wind Warning until 3 AM MDT Thursday for COZ091-092. Fire Weather Watch from Thursday morning through Thursday evening for COZ253-254. NE...NONE. && $$ UPDATE...99 SHORT TERM...Trigg LONG TERM...JTL AVIATION...99
Area Forecast Discussion
National Weather Service Jackson MS
907 PM CDT Wed Apr 19 2023 ...New MESOSCALE UPDATE... .MESOSCALE UPDATE... Issued at 843 PM CDT Wed Apr 19 2023 Not much has changed from the previous forecast. Surface ridging and high pressure remains in control across the ArkLaMiss tonight. Lows for tonight will be in the 50s area wide with clear to mostly clear skies. Patchy fog will be possible across the Pine Belt region late tonight as low-level moisture begins to increase however, with the latest HRRR guidance, dense fog probability is low. A Limited graphic may be added with later forecasts but will continue to hold off for now. /JNE/ && .DISCUSSION... Issued at 324 PM CDT Wed Apr 19 2023 Tonight & Thursday... Tonight: Sfc/low-level high will be centered over the Appalachians to Atlantic seaboard. Shortwave ridging will build in the area overnight at 500mb, keeping a nice dry & cool fcst on tap overnight. With some increased gradient between the Atlantic seaboard sfc high & developing low over the Plains into the Mid-W, some gradient winds will persist, but especially W of I-55 corridor. Lows will be near normal in the W in the mid 50s while cooler in the E in the low 50s. There is potential for some patchy fog in the Pine Belt & even some locally dense near daybreak. HREF indicate some decent probs (i.e. >40%) of dense fog, but with this being a transition day to increased low-level moisture, will hold off to see if trends persist before introducing in the HWO. Kept patchy fog mentioned in the grids. Thursday: As a strong upper low/jet energy eject ENE out of the high Plains, Mid W into the Upper MS Valley, strong sfc low will develop over the Mid W to Upper MS Valley. This will help sfc low deepen to around 995-1000mb. With an increased gradient & low-level jet (LLJ), expect strong WAA to pick up into Thurs aftn. With increased low- level thermo warmth, expect highs to warm nicely into the low-mid 80s. Front should remain off to the NW with rain chances looking to hold off until Thurs evening. There looks to be enough low-level dryness in the low-level 850-925mb level & increased 3-4mb gradient, for some low-end fire danger concerns to increase. Efficient mixing (i.e. RHs falling into the mid-upper 20% range), combined with some increased wind around 10-15mph, with some gusts around 20-25mph. Based upon how today has mixed out well & the winds have been slightly higher than anticipated, conditions look to persist & become more favorable into Thurs aftn. Added a "Limited" to the HWO for areas along & east of I-55 to along the I-20 corridor & north. Areas in central to northern & eastern fire districts should practice extra caution with open burning due to limited fire danger from low humidity & increased gusty gradient winds. /DC/ Thursday night through Friday... The forecast for the extended period looks to remain the same with a few minor adjustments made to the forecast. Showers and thunderstorms should start to become more widespread across our forecast area by Thursday evening as the cold front continues to slowly shifts east across the ArkLaMiss region. Friday continues to be the best chance for severe weather as the front continues to track east across the forecast area. Guidance is in much better agreement regarding the severity of this event; however, there is still some disagreement with model guidance regarding the timing of this system. Regardless, went ahead and increased the precipitation grids just slightly in order to map out the timing of this storm system. The parameters have weakened slightly since the previous day with SBCAPE value now peaking between 912-1220 J/kg. With decent 700-500mb lapse rates near 6.9 C/km along with weakened deep layer shear, we have downgraded the "Slight" risk (2/5) to a "Marginal" risk (1/5) for severe weather for Friday in the HWO. Damaging wind gusts up to 60 mph along with hail up to quarter ball size appear to be the primary concern with this storm system. A brief tornado cannot be ruled out. A few of these storms could produce locally heavy rainfall at times. Global ensemble guidance continue show a weak QPF signal for much of Friday. Nevertheless, we are continuing to advertise a "Limited" threat for flash flooding for much of the forecast area, particularly for later Friday and Friday night as previously discussed. Rainfall amounts between two to three inches will be possible especially inflow lying and urban areas. Saturday through next Wednesday... A few lingering showers and storms could occur on Saturday as a main convection pushes east towards Alabama. Dry weather should return on Sunday with cooler conditions in wake of the front. Expect similar conditions on Monday with afternoon highs peaking in the upper 60s. The next system should occur next Wednesday as guidance highlights a shortwave trough tracking east across the southeast region, however, model guidance are in disagreement with each other regarding the timing of this new system. /CJR/ && .AVIATION... (00Z TAFS) Issued at 616 PM CDT Wed Apr 19 2023 VFR conditions will prevail at all sites through the period except for HBG and PIB where BR/FG is anticipated late tonight/early tomorrow morning. Patchy FG/BR will be possible across HBG and PIB between 11-13z. LIFR to MVFR conditions will prevail during that time at those sites. Cigs/vis will improve to VFR around 15z. Winds will mainly be south with occasional gusts at times mainly tomorrow afternoon. /JNE/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 56 84 62 76 / 0 0 20 80 Meridian 52 85 57 77 / 0 0 0 50 Vicksburg 57 85 64 76 / 0 0 40 90 Hattiesburg 54 84 61 78 / 10 0 0 50 Natchez 59 83 64 75 / 0 10 30 90 Greenville 58 84 63 74 / 0 10 70 90 Greenwood 57 84 63 76 / 0 0 40 90 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. && $$ JNE/CR/JNE