Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/01/22

National Weather Service Albany NY
1055 PM EDT Tue May 31 2022 .SYNOPSIS... A cold front will move southwestward across the area and usher in cooler conditions tonight along with the potential for some scattered showers. Cool and cloudy weather Wednesday with showers along with some thunderstorms during the afternoon into the evening mainly west of the Hudson River. Some of the thunderstorms could become strong to severe. && .NEAR TERM /THROUGH TONIGHT/... A record high of 92 degrees for May 31 was tied at the Albany International Airport today. It has also reached 92 degrees on May 31 in Albany in 2013, 1937 and 1895. Poughkeepsie was close but missed the record high by one degree with a high of 93 today. As of 1030 pm...Forecast remains on track. Backdoor front making progress to the west with much cooler air being ushered in with its passage. Isolated to widely scattered storms are developing to our southwest as some CAMS indicated. Just some minor adjustments were needed. Previous Discussion [8 pm]...Backdoor cold front continues to makes progress southwestward into the local area. Showers and thunderstorms have been developing along the frontal zone across western New England. The focus now is over Windham County VT. The storms are moving to the southeast. Have maintained chance pops across the far northeastern portion of the forecast area. Based on some CAMS have added slight chance pops across the far southwest portion of the area for this evening. Otherwise adjusted temperatures and dew points based on observational data and blended into the latest guidance. Expecting temperatures to drop down into the 50s and lower 60s overnight in the of the backdoor front. Previous Discussion [2:30pm]...A toasty Tuesday afternoon continues with Albany already matching its daily record high of 92 degrees. The rest of eastern NY and western New England is also quite warm and humid with most in the mid to upper 80s with even low 90s in the Hudson Valley. Cooler temperatures in the low 80s can be found in the higher terrain of the southern Adirondacks with even upper 70s in the Upper Hudson Valley in the wake of a backdoor cold front. Not only is this front coming in from the north but it is also approaching from the east as it tracks through eastern MA and New Hampshire. The 12 UTC ALY sounding showed a pronounced capping inversion at about 785hPa and latest GOES16 satellite data show only shallow cumulus as most have already met their convective temperature with little vertical growth detected. The HRRR and RAP are performing the best in tracking the backdoor front and wind shift boundary and both indicate the potential for showers/storms in southern VT, esp near the Connecticut River Valley, into the Berkshires and Litchfield Hills after 21 UTC through early this evening. The main question will be if the incoming front will be able to provide enough lift to penetrate the capping inversion or if the inversion will prove too strong and limit updraft growth potential and prevent any storms from becoming strong/severe. SPC did introduce a marginal risk over our western New England areas for today into tonight for this exact reason and we will continue to monitor trends. We continued to limit any thunderstorm mention only to areas in the Upper Hudson Valley, southern VT and western MA/NW CT since the boundary will likely only reach these areas when their is sufficient daylight. Should any severe storms develop, damaging winds and large hail will be the main concerns but any strong storms will likely be isolated at best. Any storms weaken and diminish this evening but the backdoor front will continue marching inland, resulting in westerly winds shifting to the north or northeast. This will allow dew points and temperatures to drop and stratus clouds overspreading areas from northwest to southeast after Midnight. Temperatures should cool into the upper 50s to low 60s. Some patchy showers or drizzle are possible as well overnight under this marine influenced air mass. We will keep an eye on a potential "ridge roller" or decaying MCS late tonight into early tomorrow morning tracking over the ridge from southern Canada towards into Lake Ontario and potentially into the western Adirondacks mainly after 09 UTC. Showalters become negative during this period and after collaboration with BTV and BUF, continued our thunder mention in the grids mainly for Herkimer and Hamilton counties through early Wednesday morning. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... Clouds and cooler temperatures will overspread the region by tomorrow morning. Guidance continues to indicate that a shortwave embedded in the fast flow aloft or a "ridge roller" will ride overtop the amplified or spiky ridge positioned over western NY early tomorrow morning and with showalters falling below zero as it tracks into our western Adirondack zones, this implies we have to watch for an area of showers and thunderstorms due to a decaying MCS. General consensus timing wise for this to occur looks to be 10 UTC through 14-15 UTC with potential for showers to track into the Upper Hudson Valley and possibly southern VT; however, low stratus clouds in the wake of the backdoor front should limit thunderstorm potential mainly to areas west of the Hudson River. After any morning showers, most should experience a cooler and cloudy day as moisture trapped underneath the inversion maintain a stratus cloud deck. In fact, limited boundary layer mixing looks to prevent temperatures from warming up much above the morning lows. Current forecast shows highs only reaching into the mid to upper 60s with possibly near 70 in the Hudson Valley. Western New England, especially southern VT, should be the cool spot in the low to mid 60s. Otherwise, forecast soundings suggest winds may be a bit breezy in north/south oriented valleys sustained 5-15mph. While most of eastern NY and western New England will experience a much cooler/cloud day compared to today, the one exception looks to be the western Mohawk Valley and the northern/eastern Catskills where the backdoor cold front should loosens its grips and a warmer and more humid air mass from western/central NY can penetrate, especially after 17-18 UTC. Guidance has struggled in showing just how north this air mass can reach with some of the latest trends keeping further to our south and west in BGM`s area; however, there is enough uncertainty that we show temperatures reaching into the mid to upper 70s with dew points spiking into the low to mid 60s tomorrow afternoon ahead of an incoming cold front. Should this occur, a tight instability gradient will set-up in this area (as indicated on the latest HREF) and high res guidance suggests that showers and thunderstorms could develop and track along or just east of this gradient. While instability is questionable with just near or under 1000J/kg on the HREF, deep layer shear looks strong with 0-6km shear values near 35-45kts. Therefore, any storm clusters that develop tomorrow afternoon could become strong to severe with damaging winds and large hail the main hazards. However, with the stratus deck and backdoor front nearby, sufficient low level veering in the wind profile may be in place to support a tornado. SPC maintains a slight risk mainly in the Mohawk Valley, western Adirondacks and north/eastern Catskills with a marginal risk downstream for the rest of eastern NY. General thunder only for western New England where the effects of the backdoor front should limit the severe potential. As the cold front from west/central NY advances eastward mid to late afternoon tomorrow, showers/storms should push further into eastern NY but instability remains questionable given the stratus deck, limited sun and cooler air mass. We therefore only included slight chance thunder for areas east of the Hudson with little if any thunder mention in western New England. With PWATs near 1-1.50" tomorrow, any storm is capable of heavy downpours and should any area received multiple storm clusters, urban or poor drainage flooding may result. The cold front pushes eastward through the region Wed night with any showers ending by or shortly after midnight. A cooler and drier arrives overnight with lows in the 50s. High pressure takes control of the area Thursday with partly to mostly sunny skies and much more pleasant day as high temperatures peak in the mid to low 70s. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Guidance is in good general agreement with regards to the longwave pattern. Ridging shifts eastward off the East Coast with a trough over the Great Lakes into the Northeast as we head into the weekend. Over the weekend the flow is expected to flatten becoming zonal across the CONUS. Troughing is expected to develop over the Great Lakes Region with ridging developing downstream as we move into early next week. Also there is uncertainty about potential tropical development in the Gulf of Mexico; please refer to products issued by the National Hurricane Center about this potential development. A cold front on a gradual approach from the west is expected to finally reach and move across the region aided by short waves rotating about an upper low positioned just west of Hudson`s Bay and by a southern stream short wave which phases in resulting in the development of a low along the boundary. Expecting a period of showers Thursday night into Friday. There is a chance for some thunderstorms across the southern portion of the forecast area. A period of fair weather is expected Friday night through the weekend as a surface high shifts eastward and passing over the region. With zonal flow aloft looking at seasonable temperatures with highs in the 60s and 70s and lows in the 40s and 50s. Chances for showers are expected to return early next week with the approach of a low pressure system. However, the timing is uncertain so kept forecast simple with low chance pops Monday afternoon through Tuesday. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... Isolated showers along a frontal zone in central and western New England will remain mostly north and east of the TAF sites this evening. There is a very small (less than 20 percent) chance that one of these showers could briefly affect one of the sites but this chance is too low to include in any of the TAFs. Cigs will remain VFR through this evening with scattered to broken cloud cover. Lower clouds will move into the area from the east after midnight tonight as a backdoor front moves west across the region. Scattered to isolated showers will occur across the region Wednesday morning and these are covered with VCSH. The best chance for rain looks to be Wednesday afternoon into the evening, and there could even be some widely scattered thunderstorms late Wednesday as more organized clusters of showers move southeast along the stalled frontal zone. Cigs should remain mainly MVFR through the day Wednesday. Winds will be variable at less than 10 kts this evening, then east-southeast at 5 to 15 kts late tonight through Wednesday with a few higher gusts possible at ALB and PSF. Outlook... Wednesday Night: High Operational Impact. Likely SHRA. Thursday: Low Operational Impact. Slight Chance of SHRA. Thursday Night: High Operational Impact. Likely SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA. Friday Night: No Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: No Operational Impact. NO SIG WX. Sunday: No Operational Impact. NO SIG WX. && .FIRE WEATHER... After a dry Tuesday, some showers and isolated thunderstorms may reach into the southern Adirondacks late tonight into early tomorrow morning. Otherwise, tomorrow will be cooler and cloudy with additional showers and storms possible in the afternoon, mainly west of the Hudson River. Some storms may be strong to severe producing heavy downpours. Otherwise, RH values tonight rebound to 85 to 95 percent as skies become cloudy. Clouds stick around tomorrow with cooler temperatures and lower humidity. RH only drop to 60 to 75 percent tomorrow between the clouds, cooler temperatures and additional showers/storms. West to northwest winds shift to the north and northeast tonight becoming sustained to 5 to 10 mph. Winds shift to the south late tonight into tomorrow morning and turn breezy with sustained winds near 8 - 15mph, strongest in north-south oriented valley. Any strong to severe storms may produce damaging wind gusts. && .HYDROLOGY... Mainly dry weather through tonight with the exception of the western Adirondacks which may experience some showers and storms late tonight into tomorrow morning which may result in a soaking rain, especially if there are embedded storms. Then, some patchy drizzle or light showers are possible the rest of the morning but overall precip amounts look light. A cold front advancing eastward from west/central NY approaches tomorrow afternoon which looks to result in more widespread showers and storms for the western Mohawk Valley and northern and eastern Catskills especially for areas that break for more sunshine. Any storm can produce downpours and should any areas receive multiple rounds of thunderstorms, ponding of water may occur in urban or low lying areas. River and streams should not experience any impactful rises due to recent dry conditions. Next chance for showers then holds off until Thursday night into Friday, with southern areas possibly seeing over a half inch. Mainly dry weather is expected for the weekend. 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/Speciale NEAR TERM...IAA/Speciale SHORT TERM...Speciale LONG TERM...IAA AVIATION...MSE/KL FIRE WEATHER...Speciale HYDROLOGY...Frugis/Speciale
Area Forecast Discussion...UPDATED
National Weather Service Amarillo TX
657 PM CDT Tue May 31 2022 .AVIATION... For the 00Z TAFs, a fairly complicated forecast with low confidence in details through late Wednesday afternoon. Confidence is lowest in precipitation prospects during this cycle. Based on latest model guidance, greatest threat for precipitation is at KGUY, followed by KDHT and KAMA. Thunderstorms are possible through tonight. However, whether or not any terminal site will be impacted is problematic at this time due to high uncertainty in coverage should any storms develop. Finally, expect MVFR to IFR cigs to develop late tonight and persist through Wednesday afternoon in the wake of a cold frontal passage. 02 && .PREV DISCUSSION... /Issued 259 PM CDT Tue May 31 2022/ SHORT TERM...Today through Tomorrow. Bottom Line Up Top: Conditions will be favorable for severe storms along and south of a quasi-stationary front this afternoon into early this evening. The front is currently setup from near Morton, TX to Clarendon, TX, to Seiling, OK. Very large hail and damaging winds are the main threats, with a low tornado threat. Flash flooding could also occur as some training of storms is possible along the front. Another round of storm activity is possible late in the evening and overnight and this would expand to include most of the Panhandles with scattered coverage. These storms would pose more of a large hail threat and could linger into the morning hours Tuesday. Details: The latest upper level analysis places a shortwave trough and possible closed low over the central part of the NE/UT state line. A belt of modest southwesterly winds extends from northern New Mexico up into southeast Nebraska. At the surface, a cold front has stalled near Morton to Clarendon to Seiling. Dew points behind the cold front were in the 40s, but along and ahead of the front dew points were in the 60 to 65 range. A cumulus field was already noted within the moist warm sector near the front. Lift should become sufficient for CI by around 21z, and this is when storms could erupt and quickly become severe given large MLCAPE of 2000 to 3000 J/kg. Effective shear early in the convective cycle is modest with values around 35 to 45 knots. This is mostly due to the veering wind profiles. The stronger southwesterlies aloft remain north of the area. A few supercells may develop along the front late this afternoon, but with the mean flow being largely parallel to the front, some training and clustering of storms is possible (which could lead to flash flooding given PWATs in the 90th percentile range). Any supercell that does stay discrete could quickly become capable of baseball size hail and damaging winds of 70 mph (locally higher). Storms will likely produce some strong outflow winds given DCAPE on the order of 1500 J/kg and LCL values around 1500 m. Clustering storms will likely become outflow dominant, with additional storms possibly forming on the outflow going into early evening. The tornado threat does not look as concerning based on the latest data which keeps low level SRH on the marginal side and LCLs on the high side. However, going into the evening the low level jet does increase as surface winds become more easterly (these easterly winds may be largely due to outflow). The net effect is to greatly increase hodograph lengths and curvature in the lowest 3km. If any storms become rooted at the surface, a tornado threat would exist after dark. However, this seems unlikely unless the most aggressive model (RAP) verifies with very large moisture/theta-E advection. Current thinking is that the RAP is way to high on the near surface moisture due to convective feedback. If dew points rise to near 70 in the Texas Panhandle late this evening, then the RAP scenario may unfold. Otherwise, storms that form overnight behind the front would be elevated and pose more of a large hail threat. This large hail threat overnight could be a bit more expansive than currently advertised if moisture advection is more robust, especially considering the deep layer shear increases in response to a secondary 500mb jet streak in the area. This overnight round of elevated convection could linger into the morning hours Tuesday, mostly favoring the northern and eastern half of the combined Panhandles where isentropic lift will be maximized. Widespread stratus will form overnight along and north of the front as moisture increases (also helped by rain cooled air). This could lead to some periods of drizzle as well through the morning hours. There is some indication that clouds will erode near the frontal boundary which should remain draped across the far southeast zones tomorrow afternoon. If this does happen, destabilization would occur quickly and another round of storms, possibly severe, could materialize (parameters are expected to be similar to today`s). Ward LONG TERM...Wednesday night through Tuesday. For Wednesday night, latest model trends continue support the scenario that the heaviest and most extensive precipitation will shift southward further downstate as cool surface high pressure builds into the region. As a result, a decent north to south pop gradient is expected, ranging from slight chance values across the OK Panhandle to likely values in the far southeast TX Panhandle. Mainly light amounts of QPF are foreseen Wednesday night. For Thursday and Thursday night, some lingering showers are possible Thursday morning across the southern Texas Panhandle, with slight chance pops utilized. Thursday afternoon will likely be dry for all of the OK and TX Panhandles. The next minor upper level shortwave trof is then anticipated to track into eastern NM and eastern CO Thursday afternoon, and should assist in the development of showers and thunderstorms over the higher terrain of eastern NM and eastern CO late in the afternoon, then move eastward into the forecast area Thursday night. Chance pops offered by the NBM for this time frame look plausible and were incorporated into the grids. A near repeat performance is foreseen later Friday afternoon and night as yet another minor upper level shortwave trof tracks through the area from eastern CO and eastern NM. Showers and thunderstorms should develop over eastern NM and eastern CO Friday afternoon, then head eastward into the OK and TX Panhandles late Friday afternoon and night. NBM pops capture this scenario and were utilized. Dry weather and warmer temperatures are forecast to return to the area Saturday through Monday as a flat ridge of high pressure prevails. A weak cold front may impact the region Monday night into Tuesday with pops across northern zones during this time period based on the progged upper level pattern. 02 && .AMA WATCHES/WARNINGS/ADVISORIES... TX...None. OK...None. && $$
Area Forecast Discussion
National Weather Service Grand Rapids MI
955 PM EDT Tue May 31 2022 LATEST UPDATE... Mesoscale Discussion .MESOSCALE DISCUSSION... Issued at 956 PM EDT Tue May 31 2022 The convection is behaving largely as expected. While there are a few isolated storms over lower Michigan, mostly between MKG and MBS, a broken line of storms, that have recently developed from eastern upper Michigan, across northern Lake Michigan, to near MKE to RFD. There is still 1500 to 2000 j/kg of mix layer cape ahead of this line over WI and IL. Over MI it is more like 1000 to 1500 j/kg. There is still 30 to 50 knots of effective bulk shear but that is forecast to decrease to under 25 knots after midnight. I expect the storms to continue to fill in over the next few hours as the storms head toward Southwest Michigan. Most areas should see at least some rain overnight. SPC has taken our area out of the slight risk for severe storms and put is in the marginal risk and that is indeed what I am thinking it what our risk into to the early morning hours is. During the early morning hours the HRRR model sounding still show 1000 to 1500 j/kg of cape with an EL near 200 mb. There is unidirectional shear and down draft capes are in the 300 to 600 j/kg range through 3 am. There is not much of a low level inversion shown on the model sounding even at 2-3 am. This means straight line wind gusts are still possible (20 to 40 j/kg of CIN through 3 am). We also have enough cape in the DGZ to suggest large hail is possible till around 3 am with a few of these storms. The bottom line is I still expect most area to get at least rain showers overnight as the front comes through. Thunderstorms will be around till 4 am (ish). An isolated severe storm is not out the question. This would mean large hail and wind gusts to 60 mph are still possible, if that does in fact happens at all, it will be very isolated. After 3-4 am the showers should mostly be south of I-96. && .DISCUSSION...(This evening through next Tuesday) Issued at 242 PM EDT Tue May 31 2022 -- Potential remains for a few strong to severe storms tonight -- A couple of light showers have tried to form this afternoon. One formed along the edge of the lake shadow when some enhanced cumulus have been found, and a couple of have formed up across the NW area. They have not had much luck sustaining themselves so far. Deep layer shear is on the weaker side this afternoon. We continue to expect that numerous showers with scattered thunderstorms will form later this evening. As mentioned in the previous discussion, we do lose the sfc based instability toward dark as one would expect. However, models continue to indicate that we will keep as much as 1500-2000 J/kg of most unstable CAPE that will be elevated in nature. This, combined with a better band of convergence developing over the area with the front coming in, and the mesoscale ridging diminishes downwind of Lake Michigan a bit. Effective deep layer shear values are forecast to increase a bit into the evening to around 35 to 40 knots as mid level winds increase. This will help to increase the potential of a few better organized storms. With elevated storms, the threat of wind and tornadoes go down a bit. Parameters for hail are not all that impressive as mid level lapse rates are only around 6.5 C/km tonight. The shear may help that cause a bit. The wind threat is there a bit, as forecast soundings indicate that the sfc based inversion as rather shallow and weak in nature. There is some low level shear in place, but the sfc inversion should keep tornado potential quite limited, but not zero. -- Chance of rain South on Thursday -- There may be a residual shower early in the morning across the far southern portion of the area toward Jackson. The front slows down a bit, and a weak wave of low pressure will ride along it and keep the chance in early. We will then see clouds decrease through the day as high pressure move in. The front will continue to slowly sink south, but it will remain just close enough to bring another chance of rain on Thursday. This occurs as another short wave embedded in the flow will emerge from the Rockies and move south of the state on Thursday. There is general troughing over the entire state on Thursday, but the better energy will be south of the area, and will induce some rain showers north of the front. This rain should stay mostly south of I-96 on Thursday. -- Cooler next weekend with rain chances around Sunday -- The trough moving through the area on Thursday, will move east of the area by Friday morning. NW flow aloft will persist, but we will see upper heights build as the upper ridge axis builds toward the area. At the sfc high pressure will be moving overhead, helping to diminish the cloud cover and keep the area dry, yet cool. 850 mb temps will be dropping to around +2 to +4C which supports highs only in the mid to upper 60s. Return flow eventually sets up by Saturday, and helps temperatures start to recover a bit. At some point between Saturday and Sunday, we will see rain chances increase. We will see another wave emerge from the Plains, and send a nice surge of warm and moist air up over the area. This warm air advection will be focusing along a warm front to produce showers and storms. The chance will then hold on potentially through Monday, before the supporting wave would exit the area. This whole scenario is a bit uncertain, due to indirect effects from the Tropical System Agatha. If this system emerges over the Caribbean and strengthens like the Euro, it will slow up the upper air pattern over the area. If it does not develop as much like the GFS, the upper air a pattern will be more progressive up our way. Tough to say exactly how this will pan out at a week out. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 723 PM EDT Tue May 31 2022 At 7 pm we have gusty southwest winds with cirrus clouds over Southwest Lower Michigan. The surface cold front is over eastern Iowa into southern Wisconsin. An area of convection is developing as I write this, just in front of that surface cold front, near the greatest mid level instability and best upper level shear. I expect this area of convection to increase in coverage and move over our TAF sites in the 03z to 09z time frame. I would think most of our TAF sites should get at least 15 to 30 minutes of convection in that time frame so I put a "TEMPO" group to suggest what does happen will not last long. Once the front comes through, a weak wave forms on the front. This may result in MVFR/IFR cigs for the I-94 TAF sites more so than the I-96 TAF sites. This will have to be watched to see how extensive if gets, if it happens at all. Skies should clear by afternoon for all TAF sites. && .MARINE... Issued at 242 PM EDT Tue May 31 2022 We will hold on to the Small Craft Advisory and Beach Hazards Statement from Grand Haven and northward through tonight. As expected, winds and waves have been just shy of criteria through today, with no expected increase tonight. The winds and waves might take a part of Wednesday to come down significantly, but they should be down below criteria by daybreak Wednesday. Our next marine headline event looks to come in the Thursday night/Friday time frame with the next wave of low pressure riding along the front to our south. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...Beach Hazards Statement until 6 AM EDT Wednesday for MIZ037-043- 050. LM...Small Craft Advisory until 6 AM EDT Wednesday for LMZ847>849. && $$ MESOSCALE...WDM DISCUSSION...NJJ AVIATION...WDM MARINE...NJJ
Area Forecast Discussion
National Weather Service Lincoln IL
858 PM CDT Tue May 31 2022 .SYNOPSIS... Issued at 319 PM CDT Tue May 31 2022 Scattered showers and thunderstorms are expected to develop near the Mississippi River this evening and track southeast tonight. A few storms could be strong to severe, mainly west of the Illinois River. The cold front will result in a broad range of temperatures on Wednesday, with areas north of I-70 in the 70s and areas south of I- 70 in the mid-80s. Showers may linger Wednesday, with the best chance for rain being south of I-72. && .UPDATE... Issued at 858 PM CDT Tue May 31 2022 A broken line of convection has developed along an advancing cold front from northwest Illinois into north-central Missouri this evening: however, the chance for severe weather continues to dwindle as daytime instability wanes and deep-layer shear decreases. Latest mesoanalysis indicates MLCAPEs of 1500-2000J/kg across the western half of the KILX CWA...with much higher values in excess of 2500J/kg noted well upstream across Oklahoma into southwest Missouri. With instability steadily decreasing and the nocturnal low-level jet progged to strengthen well W/SW of Illinois tonight, do not think the current line of convection will have much fuel to work with as it gradually shifts eastward into central Illinois. May see a few cells with gusty winds/small hail, but overall severe threat looks low. The more significant thunderstorm activity will focus across Oklahoma into Arkansas/Missouri as it is fed by the LLJ. Some of this convection may reach areas along/south of I-72 late tonight, but will be in a much weakened state as it arrives. Made updates to hourly PoPs, mainly to delay arrival of precip chances. Based on current trends, areas east of I-55 will remain dry until after midnight. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 319 PM CDT Tue May 31 2022 An occluded 988-mb low pressure system remains located just north of MN as of 2pm/19z, with its cold front remaining draped across WI and into east-central IA. Assessing today`s convective prospects remains a challenge. Extensive cirrus has persisted through the day west of I-55, and has been most dense west of the IL River. As a result, temps were only in the upper 70s (as of 2pm) west of the IL River as opposed to mid-80s near I-55 and upper 80s across eastern IL. That leaves questions as to how much destabilization will occur, and the latest RAP analysis shows SBCIN still present across west-central IL, which is the area that was originally expected to be most conducive for svr wx this evening. There are also a few weak MCVs tracking northwest through the area. The stronger of these tracked near the far NW corner of the CWA as of 2pm/19z, and helped invigorate some showers between the IL River and I-55 along a remnant outflow boundary. However, these showers dissipated almost as quickly as they formed as the ascent provided by the MCV shifted away. Visible satellite has shown some thinning of the cirrus shield, perhaps caused by subsidence behind this MCV, so there may still be a window for sufficient destabilization to occur. While CAMs have not had the best handle on today`s evolution, one noteworthy trend has been a shift towards later storm development and subsequent movement into our CWA. The latest runs now keep most of the activity west of the CWA through 00z. Overall, confidence in the severe threat has waned. Storms are expected to develop later in the day, in an area that has remained beneath dense cirrus for much of the day, and not push into the ILX CWA until late evening when any instability that does manage to develop is trending downward. While the severe threat isn`t zero, the coverage of strong storms may less than initially anticipated, especially with eastward extent into the CWA overnight. The environment remains supportive of heavy rain, as 850-mb moisture transport is focused ahead of the front, with 850-mb flow nearly parallel to the front. The latest RAP shows PWAT values around 1.7" this afternoon, and some deterministic models have PWAT values approaching 2", which would be in the 99th percentile relative to the climatology. The 12z HREF shows the potential for localized QPF maximums of 2" west of I-55 through Wed AM, and just west of the ILX CWA there are max QPF values in excess of 4", although these values may be a tad overdone given the shift in expectations since the 12z models ran this morning. Flash flood guidance suggests that more than 2" of rain in 3 hours would lead to problems. Despite a supportive environment, there are a few factors limiting a greater flash flood threat. Antecedent soil moisture is quite low, only 10- 20%. Additionally, the axis of convection shifts southeast as the front advances through overnight, keeping storms from lingering over any one location for too long. Waning instability should result in rainfall rates trending downward overnight as well. Uncertainties in the frontal timing linger and impact the forecast for Wednesday. The current expectation is that the front will be near I-72 corridor by sunrise Wed, then shift into SE IL. Additional showers and storms will be possible along the frontal zone Wed afternoon/evening as a shortwave tracks from the west- central Plains towards the Great Lakes. The presence of the front will lead to a broad range of high temps on Wed, with areas NW of the IL River only in the low 70s while areas south of I-70 reach the mid-80s. .LONG TERM...(Wednesday night through Tuesday) ISSUED AT 319 PM CDT Tue May 31 2022 Depending on where the frontal boundary stalls, some precip chances could linger Wed night into Thurs. High pressure building over the central Plains will result in a few cool, dry days. Temps will be in the low 70s on Thursday, then recover into the upper 70s by Friday as a weakening, broad sfc high shifts directly over IL. Into the weekend, an upper level low remains anchored over the Canadian Prairie to the north of Minnesota, while upper level ridging builds over the Rockies. As disturbances drop through the northwest flow over the northern Plains late this weekend and into early next week, they could provide precip chances across central IL. No significant heat waves are expected through the current long term period (through June 7th), with highs in the upper 70s to mid 80s from Saturday through early next week. That trend appears likely to continue, as the latest CPC outlook (valid June 8-14) favors below normal temperatures. Normal highs for the second week of June are in the low to mid 80s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 644 PM CDT Tue May 31 2022 Main aviation forecast concern continues to focus on convective development this evening into tonight. 2330z/630pm radar mosaic shows scattered showers/thunder beginning to develop along a cold front near the Mississippi River: however, areal coverage remains minimal at this time. Think this activity will develop/spread northeastward over the next few hours...first impacting KPIA after 03z. HRRR/NAM suggest a broken band of convection gradually working its way further E/SE as the night progresses...potentially reaching KBMI/KSPI by around 07z and further east to KCMI by 09z. Given low confidence forecast, have maintained just VCTS at the terminals until radar trends become more apparent. As was noted by the previous forecast package, it appears a period of MVFR ceilings will develop once the cold front passes late tonight into Wednesday morning. Winds will initially be S/SW with gusts over 20kt at both KDEC/KCMI early, then will veer to NW and drop below 10kt after FROPA late tonight. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barnes SYNOPSIS...Erwin SHORT TERM...Erwin LONG TERM...Erwin AVIATION...Barnes
National Weather Service Jackson KY
732 PM EDT Tue May 31 2022 .UPDATE... Issued at 728 PM EDT TUE MAY 31 2022 Forecast continues to remain on-track. Updated PoP based on some of the convective activity in Letcher and Pike counties. Also, updated dry grids based on the latest observations. && .SHORT TERM...(This evening through Wednesday night) Issued at 333 PM EDT TUE MAY 31 2022 The afternoon surface analysis reveals an area of high pressure just to our east and southeast remains in control of the weather here in eastern Kentucky. This keeps the region under generally southerly flow at the surface and dewpoints in the low to mid 60s. The mid-level ridging and dry are aloft will keep most dry this afternoon and evening, but noting slightly more growth the the cumulus nearer the VA border. However, these will remain anemic given the aforementioned dry air and capping inversion. Any shower (less than 20 percent chance) will relent with loss of daytime heating and resultant loss of steeper low level lapse rates. This will give way to mostly clear skies tonight, with slight 5 degree cooler temperatures felt in the valleys versus the ridges. This will result in mainly river valley developing late tonight under weak winds and high pressure. Wednesday, expect any fog that develops overnight to dissipate around 9 to 10 AM. Some of the CAMs have shown signs of isolated showers toward dawn, and cant completely rule this out with chances generally 15 percent or less. We will see a shift in the pattern through the day Wednesday, as stronger upper level ridging shifts SW southwest allowing heights to begin falling ahead of a shortwave in the Lower Ohio Valley. This in conjunction with an approaching cold front will help to weaken the capping inversion through the afternoon and evening. This could lead to more shower and even thunderstorm development late Wednesday afternoon into Wednesday evening. The greatest chances of convection Wednesday afternoon will be in areas north of the Mountain Parkway. The shear seems to lack, with effective shear maybe reaching 30 knots, but MUCAPE values do climb into the 1000 to 2000 J/kg range which could lead a some more vigorous updrafts. Either way looks like better shear to the north and west and likely little if any severe weather expected in eastern Kentucky for Wednesday. Wednesday night this front will sag southward and become more ill defined as it does so. Either way continued decreasing heights will keep shower and thunderstorm chances rolling through the night. The coverage still seems best in the northern parts of the CWA generally along and north of the Mountain Parkway, where chances peak at 50 to 60 percent. Increasing clouds and showers will keep splits under control with lows in the mid 60s for most. .LONG TERM...(Thursday through Tuesday) Issued at 315 PM EDT TUE MAY 31 2022 The long term period will start out with an upper level trough axis extending from the mid Mississippi Valley, northward through central Canada. Shortwave ridging will cover the upper Northeast while a high pressure center sits over southwestern Texas and Mexico with ridging extending northward through the PNW. This trough will support a strong surface low over central Canada and a secondary low in the Northeast. A cold front will be draped from upstate New York back southwest through the Ohio and Tennessee Valleys, and the lower Mississippi Valley and southern Plains. Showers and storms will be possible along and ahead of the cold front. The SPC has placed all of eastern Kentucky in a day 3 marginal risk for severe thunderstorms. CAMs show scattered thunderstorms developing along the boundary Thursday afternoon, however, the environmental set-up is not certain at this point. Model soundings differ greatly in terms of instability with the NAM likely overdoing the MLCAPE with over 2500 J/kg while the RAP is more reasonable with around 1500 J/kg. Cloud cover will be on the increase ahead of the cold front and will be a big factor in how much instability we see. The main threat will be strong wind gusts, however, DCAPE values are marginal across the area with the best values around 900 J/kg over the Cumberland region. The best chance for severe weather will likely be where models show the highest CAPE values, over the southwest portion of the CWA. Overall, confidence in severe potential is currently low but will continue to be monitored. The trough axis will swing to the east through the end off the week leaving behind quasi-zonal flow across the Ohio Valley and Southeast US. Surface high pressure will move in from the west and will bring a period of dry weather to the area through Saturday night. Multiple shortwaves will move across the central CONUS and will bring the chance for showers and storms Sunday afternoon, though models are not in the best agreement currently. Highs will start off in the mid to upper 70s as cloud cover and a passing cold front keep conditions cool on Thursday and Friday. A warm up is expected this weekend and into the beginning of the next work week with highs bouncing back into the mid to upper 80s Monday and Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) ISSUED AT 732 PM EDT TUE MAY 31 2022 VFR conditions will prevail through the TAF period as high pressure continues to remain overhead. With mostly clear skies, areas of fog will be possible at terminals KJKL and KSME. Added VCFG to the remaining terminals. MVFR conditions will be possible wherever fog develops. Areas of convection return tomorrow afternoon but look to remain away from all terminals. Otherwise, once the fog burns off; VFR conditions will be reestablished. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...VORST SHORT TERM...DJ LONG TERM...BATZ AVIATION...VORST
Area Forecast Discussion
National Weather Service North Platte NE
630 PM CDT Tue May 31 2022 .SHORT TERM...(This evening through Wednesday night) Issued at 332 PM CDT Tue May 31 2022 An upper level disturbance swinging through UT this afternoon will move east through Colorado tonight and briefly emerge onto the cntl High Plains Wednesday morning and then drop south into KS and the srn Plains. The model soundings show north winds in the boundary layer and moist westerlies aloft. This strongly suggests a top down saturation process which can delay the arrival rainfall at the sfc by several hours. It also produces diabatic warming favoring stratiform rain processes. The forecast guards southwestern Nebraska-along and west of highway 61- with likely rain chances but drops rain chances north and east. The RAP model shows strong frontogenesis developing across KS Wednesday and this should focus the best rainfall south. The forecast therefore discounts the northern solution- the very wet SREF, and leans toward the HREF for QPF. Temperatures tonight and Wednesday are based on the short term model blend plus bias correction. The expected cloud cover during this time favors less diurnal temperature range. The short blend is good at this vs the guidance blend which favors a larger diurnal range. Skies should clear Wednesday afternoon and evening and the models show 850-300mb RH falling to around 40 percent. This should open the window for radiational cooling so the guidance blend is in place. .LONG TERM...(Thursday through Tuesday) Issued at 332 PM CDT Tue May 31 2022 The models show a warm front lifting into Nebraska Friday and remaining nearly stationary through Monday or later. The GFS model shows cooler air to north pushing the front well south of region Tuesday while the ECM and GEM continue to hold the front across Nebraska. Thus, the focus for thunderstorms will be in place and given moisture and upper level forcing, storms should develop. The models continue to show a high latitude block forming across Canada and this should set up a belt of strong westerlies across wrn and ncntl Nebraska. In fact, GFS shows a low bulk Richardson number suggesting the return moisture and instability is too low to support widespread thunderstorm development. POPs are limited to 50 percent Friday through Monday for this reason. Given the instability and bulk shear developing on the cntl High Plains in the GFS and ECM models, isolated to perhaps scattered severe storm development is possible daily Friday and beyond. SPC will examine this potential throughout the week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 630 PM CDT Tue May 31 2022 Mid-level cloud cover continues tonight and into tomorrow across southwest Nebraska with rain chances increasing toward dawn. Brief drops to MVFR are possible mid-late morning at KLBF. Farther north, terminals should remain in VFR and dry with primarily high cloud cover for tomorrow. Gusty north winds early this evening taper after sunset and stay around 10 kts tomorrow. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Snively
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
811 PM CDT Tue May 31 2022 .UPDATE... Issued at 807 PM CDT Tue May 31 2022 Continuing to monitor a gradual uptick in showers and some storms into the evening, with a limited/isolated severe potential. Since 5 P.M., there has been a slow but steady increase in showers and some storms in the confluence zone along and about 100 miles ahead of the cold front. This zone is within a plume of high moisture in the 0-3 km layer, as sampled by the 00Z DVN sounding, and shown by surface dew points around or just above 70. The vertical profile on that DVN sounding was uncapped, with 1,500 J/kg of mlCAPE, but lapse rates in mid-levels are fairly poor (6.5C/km through most of the depth). With the moisture, including PWATs of 1.5-1.7 inches, would think there will continue to be a gradual uptick in at least shower coverage and probably in intensity of a few cells through 10-11 P.M. There is 35-45 kt of deep layer shear analyzed in the northwest quarter of Illinois, so some organization has been seen with storms, even despite meager lapse rates, and with some isolated cells, that probably will continue. Forward motion on the cells is largely parallel to the boundary/confluence axes, so even though shear orientation to these boundaries favors discrete/semi-discrete cells, it hasn`t taken long for cells to merge into small clusters if they can sustain themselves...and thus far few have done that. Aircraft soundings from over the Chicago metro indicate still some capping in place, so while there have been some cumuliform clouds along some boundaries seen on radar reflectivity, they have not materialized into any convective cells. This also means the activity to our west may struggle as it gets toward and especially east of I-55. But prior to then, through 11 PM or so, there remains a chance for a couple stronger to possibly one or two severe storms. That includes with a couple of the clusters from western Illinois into northeast Missouri, which on GOES-16 water vapor imagery looks like may have a mid-level sheared wave supporting them too. If some of those clusters track over the same area, it would not take much for an isolated 1-2 inch rainfall occurrence given the moist profiles. Overall, this is more in-line with an SPC level 1 of 5 (Marginal) Risk, and accordingly, that`s the level now with their 01Z updated outlook. MTF && .SHORT TERM... Issued at 315 PM CDT Tue May 31 2022 Through Wednesday... Main focus/concern: * Threat for any strong to severe thunderstorms through mid to late evening, with threat window about 6 PM to 11 PM The local radar picture is currently devoid of any convection, likely owing to suppression on the backside of the core of the MCV lifting into Wisconsin. In addition, as noted earlier, extensive mid and high cloud cover has limited stronger destabilization despite temperatures in the lower to mid 80s northwest of I-55 and mid to upper 80s near and southeast of I-55 amidst dew points in the 60s. It appears likely that there`s at least some lingering mid-level capping. Most recent HRRR run initialized well and now focuses main convective threat toward and beyond sunset. Another important item of note to the late day and evening severe weather threat is the lack of surface convergence with the cold front draped west of the Mississippi River. The cold front currently serves more as a moisture discontinuity with generally southwest winds on either side of it. It thus appears that the anticipated thunderstorm uptick in the early evening will be tied to forcing related to upstream convection across Missouri, which may be tied to a 700 mb wave. If any modestly robust MCV can emerge from this area, that would certainly assist in scattered to numerous showers and storms developing. A northwesterly wind shift is now not expected until after midnight behind the front, hence the above thinking on more mesoscale influences resulting in convection blossoming and then gradually building east and southeast. The lack of stronger large scale forcing and low-level convergence does cast uncertainty on convective coverage this evening, though as noted, continued message of scattered to numerous t-storms with likely PoPs. Turning to the severe threat, the thinking hasn`t changed from midnight shift of an overall decreased threat. It appears that debris cloudiness will remain extensive enough to continue limit strong with inc r destabilization through the daylight hours, and the strongest effective shear will remain near or northwest of the northwest CWA. With signs pointing toward more of an evening timing, we`ll then have to contend with diurnal decrease of SB/MLCAPE after sunset. While SPC maintained a level 2 (slight) severe risk in their 20z update, suspect trends point to more of an isolated level 1 (marginal) severe threat for hail and damaging winds. If convective coverage becomes widespread enough this evening, can`t rule out an isolated/localized flooding threat, though confidence is also low in this regard. Assuming anticipated convective coverage this evening comes to fruition, it should gradually wane after midnight as cold front finally makes southeastward progress. The cold front will clear the entire CWA to the south tomorrow morning and then slow its progress to the south of I-70 on Wednesday. Lingering weak elevated instability north of the surface front could enable a few rogue thunderstorms for southeast CWA sections primarily during the morning, but otherwise looking at a cooler but pleasant and primarily dry day for most under partly to mostly cloudy skies. Have some slight to chance PoPs for the southeast 1/3 to account for isolated to widely scattered showers pushing in at times. Highs will be in the 70s inland but only in the 60s near the lake as onshore flow persists through the day with high pressure over the Great Lakes. Dew points will be quite comfortable and in the 50s for most locations. Castro && .LONG TERM... Issued at 328 PM CDT Tue May 31 2022 Wednesday night through Tuesday... Wednesday night, a broad center of low pressure is forecast to trek across the Ohio River basin with a swath of showers and thunderstorms along its northern periphery. Several of these showers will fall over the CWA Wednesday night and early Thursday morning. The greater rain chances will exist in the southern and southeastern portions of the CWA with far less confidence in rain occurring along and north of I-88. This also corresponds to the greatest potential for seeing a couple of thunderstorms with most, if not all, of the storm activity expected to be confined to areas south of I-80. Any storms that manage to pop up should be just your run of the mill thunderstorms with very little instability present inhibiting the chance for any strong storms. The ideal timeframe for rain out of this system is roughly 2AM- 7AM meaning a few showers could accompany your Thursday morning commute, especially if that commute is southeast of I-55. Following this early morning rain chance, the rest of Thursday will be dry with clearing skies as some drier air works its way in aloft with the trough digging in. Meanwhile, cool northerly low-level flow and height falls aloft through the morning will keep temperatures in the lower and middle 70`s on Thursday with areas closer to the lake getting stuck in the 60`s. With the trough axis slated to pass through the CWA Thursday afternoon, some WAA aloft in the mid and upper levels will help temperatures climb into the middle and upper 70`s on Friday. A large center of high pressure descending from the windward side of the aforementioned through will keep conditions dry through Friday and most of Saturday. Temperatures will climb an additional couple of degrees on Saturday, although onshore flow will keep communities closer to the IL lakeshore down in the 60`s again. Saturday evening and night, a weak, developing warm frontal boundary will propagate into Upper Midwest and park itself over southern Wisconsin becoming quasi-stationary through Sunday. Isolated showers are forecast to pop up along this boundary and fall on the CWA as early as Saturday evening with coverage expected to expand to more scattered showers for much of Sunday. The rain chances will continue into Monday with the broad low pressure center expected to pass over on Monday. A second, more organized center of low pressure will pass through central IL on Tuesday keeping shower chances rolling through Tuesday as well. Thunderstorm chances through the weekend appear minimal with little instability found near and south of the frontal boundary. A fair amount of instability building in ahead of the low pressure center makes Monday afternoon and evening our best chance for seeing thunderstorms early next week. However, a nearly zonal shear profile and mediocre thermodynamic profile should keep storms light and brief. Temperatures on Sunday and Monday will reach the middle 70`s to lower 80`s before dropping a few degrees following the Low passage on Tuesday. Doom && .AVIATION... For the 00Z TAFs... The primary aviation weather concerns through the 00Z TAF period are as follows: - The potential for showers and thunderstorms this evening - Winds shifting to near-northerly overnight tonight, then onto easterly early Wednesday afternoon Following a dry Tuesday thus far, a line of convective showers is building across eastern IA and far northwestern IL. These showers will be moving through the area mid to late evening with some additional showers potentially popping up ahead of this existing line and reaching the terminals as early as around 01Z. It appears that there will be some thunderstorms embedded in these showers as well, however thunderstorm coverage and intensity are still not entirely certain. While strong to severe thunderstorms are certainly still possible, best guess is that these will be just some routine gusty storms with one or two isolated stronger storms. A few rounds of showers and storms appear possible, primarily between 02Z and 06Z over Chicagoland. Isolated light showers could then continue into the predawn hours of Wednesday morning. VFR conditions should prevail through this event, although some guidance suggests that we could see cigs drop into high-end MVFR territory for brief periods underneath some of these showers. Meanwhile, gusts near 20-25 kts will hang on through around sundown before winds drop below 10 kts for the overnight. Winds will then shift from SW to NNW overnight and hang there through the morning. By early-mid afternoon, winds will turn east of north over ORD and MDW and continue from an easterly direction at near or under 10 kts through the remainder of the TAF period. Following tonight`s rain event, VFR conditions can be expected for the entirety of Wednesday. Doom && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...nearshore waters until 9 PM Tuesday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Lubbock TX
622 PM CDT Tue May 31 2022 .AVIATION... Overall VFR conditions are expected to prevail through much of tonight into mid morning. Some convection will be possible at CDS and possibly PVW and could lower VIS and CIG to MVFR or IFR temporarily. Storms will also be capable of producing very large hail over 3 inches in diameter and wind gusts over 60 knots. MVFR CIGs are expected to move over all terminals mid to late tomorrow morning after a cold front pushes through the region. && .PREV DISCUSSION... /issued 220 PM CDT Tue May 31 2022/ SHORT TERM... 18Z upper air analysis depicts a vertically stacked/occluding cyclone over the southern Manitoba/Ontario border, with a trailing mid-level cold front extending west-southwestward into the central Great Plains and into the Great Basin as per 12Z 500 mb objective maps and recent RAP analysis. A secondary cyclone, although less amplified, was centered over the central Great Basin with a series of smaller-scale shortwave perturbations detected on the latest water vapory imagery that were rotating east-northeastward towards the region. At the surface, a quasi-stationary front was anchored from southwest-to-northeast across the CWA along a line from Denver City to Tulia and extending towards the I-40 corridor as per recent West Texas Mesonet data and the shallow cumulus field demarcating its position. The dryline intersects the quasi-stationary front across far southeastern New Mexico, and is not expected to propagate eastward this afternoon as the airmass becomes increasingly barotropic with southward extent from the front and as larger-scale forcing for ascent remains displaced over the west-central Great Plains region. West Texas Mesonet data and WSR-88D VWPs from KLBB indicate that surface-to-low-level flow is parallel to the frontal position across the moist sector, with winds shifting to the north in wake of the front with speeds generally between 10-20 mph across the post- and pre-frontal sectors with steady pressure tendencies. This has resulted in weak convergence in vicinity of the stalled front, evident by the shallow cu field despite the influx of strong, diabatic heating. The 12Z MAF RAOB sampled a very moist boundary-layer with dewpoints in the upper 60s and a mean mixing ratio of 14.6 g/kg that was advecting northward. South of the quasi-stationary front, a plume of dewpoints ranging from the lower 60s across the Caprock and into the middle-upper 60s in the Rolling Plains is present with temperatures in the upper 80s to lower 90s, contributing to strong-extreme thermal instability as MLCAPE nears 3,000 J/kg on the latest RAP analysis. Confidence in this prognostication with respect to the magnitude of MLCAPE across the moist sector is high based off the observed morning sounding from WFO MAF. Effective bulk wind differences (EBWDs) are modest as the CWA remains beneath the glancing influence of the mid- and high-level jet streaks to the north, with EBWDs near 40 kt in addition to the 850-500 mb wind vectors remaining boundary-parallel. Isolated to widely-scattered thunderstorms are forecast to form across the South Plains with mean storm movement governed by advection, with storms quickly becoming severe as the large, upward-directed accelerations accentuated by wide updrafts offsets the modest shear. Significant/2"+ diameter hail is expected to occur in addition to severe-caliber gusts as cells move east-northeastward. Across the extreme southeastern Texas Panhandle and into the northern Rolling Plains, scattered convection is expected to develop mid-to-late afternoon as low-level convergence maximizes while quickly becoming severe. Precipitable water content is anomalously high, as per 12Z MAF RAOB and recent GOES-East Total Blended Precipitable Water imagery. Initial storm characteristics are expected to be multi- and supercellular, with weak storm-relative flow throughout the LCL-EL layer which will enhance precipitation-loading within the wide updrafts. Severe to potentially significant-severe/65+ kt gusts are expected as convection morphs into a Mesoscale Convective System (MCS) with embedded mesocyclones. MCS movement will be slow, and dictated largely by the combination of intense cold pools and the isolated to widely-scattered cells to the southwest merging with it which will augment the possibility of a forward-propagating MCS. A short-lived tornado risk will accompany any storm merger or within any mesoscale convective vortex that develops; however, the strong/cold downdrafts and potential steeply-sloped outflow boundaries will eventually undercut surface-based inflow parcel trajectories, ultimately resulting in the demise of the MCS as theta-e advection weakens and diabatic stabilization occurs. Severe convection should wane/exit the northeastern zones altogether near 01/06Z. The low-level jet will strengthen overnight with the stalled front remaining positioned in vicinity of the TX PH and South/Rolling Plains region, though the exact position of the front may be affected by convective outflows from the decaying MCS. The airmass is forecast to be in a similar state tomorrow ahead/south of the front, with the center of the sub-tropical ridge retrograding over Mexico along with a shortwave trough pivoting across the central Great Plains, causing mid- and high-level flow to veer. The stalled front will begin to transition into a cold front and move southward across the CWA by the mid-afternoon hours, with scattered, severe convection expected to develop with a few supercells possible across the South Plains before cold pools merge as frontogenetical forcing increases. Localized flash flooding will once again be possible, in addition to the potential for severe-caliber hail (possibly 2"+) and wind events. Sincavage LONG TERM... Precipitation chances will continue through the rest of the week after Wednesday afternoon with additional heavy rain and severe thunderstorm chances. The cold front will continue to push through the rest of the area Wednesday evening with expected widespread convection ongoing through the evening hours. The weather pattern will look slightly different for the rest of the week after that. Zonal flow will be overhead on Thursday with weak short wave ridging moving over the area. Southeasterly low level upslope flow will dominate the lower levels in the post frontal air mass. Furthermore, a weak short wave moving through the flow with the above conditions will promote higher terrain convection in eastern New Mexico. However, convection may struggle to reach far into West Texas. Better lift for convection will exist from the Permian Basin into Far West Texas and the Big Bend as a stronger upper level jet streak noses into that area. Additionally, instability will mostly be elevated on Thursday with cool and cloudy conditions. Severe chances may be better on Friday with upper flow slightly more backed. Much better instability will be available with better low level moisture and warmer surface temperatures. Additionally, another weak short wave may be moving through the flow aloft initiating thunderstorms again on the higher terrain of eastern New Mexico. However, this convection would stand a better chance at progressing farther across the South Plains for the aforementioned reasons. CIPS analog guidance highlights Friday as a higher probability day for severe weather over Thursday. A sloshing dryline will return this weekend but convective chances are doubtful at the moment with temperatures rising back well above seasonal averages. && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 51/99/99
Area Forecast Discussion
National Weather Service New York NY
1101 PM EDT Tue May 31 2022 .SYNOPSIS... A backdoor cold front stalls across western New Jersey tonight. A wave of low pressure develops on the front Wednesday and moves back across the region Wednesday into Wednesday night. The front then stalls south of Long Island. A frontal wave along the stalled front will then pass to our south and east Thursday night into Friday. High pressure builds in thereafter through the weekend. Unsettled weather could return to the area by Monday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A few showers have developed with a weak shortwave rounding the ridge this evening. With decent DCAPE values, upwards of 1300 J/kg, a few stronger wind gusts are possible with any showers that do form. Added a slight chance for thunder through 6z, though this will be very limited. Widely scattered showers may persist though through much of the night, based on CAMS, maintained a slight chance for a shower region until 9z. Adjusted temps and dews to align better with current obs given the challenges of the backdoor cold front that continues to move inland, making its way through KEWR in the past half hour. Temperatures have been falling as much as 25 degrees with the passage of the front along with wind gusts up to 30 mph. Continued with the timing of the HRRR through tonight for the frontal passage. Rest of forecast remains on track. The backdoor cold front stalls to the west of the region, across western New Jersey, late tonight. Otherwise an upper ridge remains to the west of the region tonight. With the easterly flow overnight stratus will likely develop. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... A much cooler airmass will be in place for Wednesday as the stalled front to the west remains weak and moves eastward as a weak surface low develops on the boundary. The upper ridge does remain in place with a couple of weak shortwaves expected to move into and over the ridge during the day Wednesday. Initially the instability will be weak with little CAPE, and increase during the afternoon. The highest instability will be across the inland areas of northeastern New Jersey and the lower Hudson Valley. A few strong to locally severe thunderstorms will be possible, and the Storm Prediction Center has placed the area in a marginal risk. Leaned toward the cooler MAV and MET guidance for highs. The chance of showers will be ending Wednesday night as the weak frontal wave moves east by 12Z Thursday. Stratus likely remains in place Wednesday night. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Upper level ridge axis slides east of the area during the day on Thursday as a shortwave rotating around a closed upper level low approaches from the west. At the surface, a frontal wave will develop along a stalled front off to our west and track just south and east of the area. How much rain we see will depend on the exact track of this wave. This will continue to become more clear over the next 24 hours as the event enters the high-res CAM window. However, given the environment, there is potential for moderate to locally heavy downpours. The environment will be characterized by pwat values around 1.70 inches. Based on SPC`s Sounding Climatology Page, this is between the 90% moving average and the max moving average. There will also be deep layered lift with approaching shortwave energy, right rear quadrant of an upper level jet streak and nose of a lower level jet. Right now the thinking is that the best chance for heavy downpours is just south of the area where the greatest instability looks to be in place. High pressure builds in thereafter through the weekend resulting in dry weather. Unsettled weather could return early next week with a frontal system approaching from the west. Thursday looks to be the warmest day of the long term period with highs in the mid 70s to low 80s. Temperatures remain slightly above seasonable through the rest of the period. The NBM was mainly used for temperatures, with just minor adjustments. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... A backdoor cold front works west of the area tonight, while high pressure builds in from New England. Another frontal system approaches from the west on Wednesday and passes through the area Wednesday night. VFR to start with ceilings lowering to MVFR/IFR by daybreak. Some improvement on Wednesday with most locations improving to MVFR and possibly VFR, especially at the eastern terminals. There is some uncertainty overnight as to how quickly we moisten beneath a frontal inversion. This could occur later than currently forecast and there is a chance that ceilings never get down to IFR. Ceilings likely lower Wednesday evening with the chance of SHRA and a few TSRA, best chance after 00Z. Scattered showers with gusts up to 35 mph possible between 03Z and 09Z. Winds become E around 10 kt across the remainder of the terminals the next few hours. Brief gusts up to 25 kt possible immediately behind the cold front. E winds 5-10 kt on Wednesday veer to the SE. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... There is some uncertainty overnight as to how quickly we moisten beneath a frontal inversion. This could occur later than currently forecast and there is chance that ceilings never get down to IFR. Scattered showers with gusts up to 35 mph possible between 03Z and 09Z. .OUTLOOK FOR 03Z THURSDAY THROUGH SUNDAY... .Wednesday Night ...SHRA likely with a few TSRA the first half of the night. .Thursday...Becoming VFR. MVFR or lower SHRA/TSRA Thu eve/night. .Friday...AM MVFR or lower with SHRA, improving to VFR in the afternoon .Saturday and Sunday...VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/ && .MARINE... A backdoor cold front will continue to move westward this evening. Wind gusts with the frontal passage will generally be around 20 kt, with a few gusts approaching 25 kt. Otherwise winds and seas remain below SCA levels tonight through Wednesday night. With a relatively weak pressure gradient expected, winds and waves likely remain below SCA criteria through the beginning of next week. && .HYDROLOGY... Showers and embedded thunderstorm activity will likely move through the region Wednesday and Wednesday evening with the potential for brief heavy rainfall. There is a chance of poor drainage flooding. There is potential for moderate to locally heavy downpours Thursday night into Friday. The likely threat is for minor urban and poor drainage flooding. && .TIDES/COASTAL FLOODING... A moderate rip current forecast is expected for Wednesday for all ocean beaches as E winds veer to the SE. A low rip current forecast is expected for Thursday. && .CLIMATE... Vulnerable record highs for Tuesday May 31 (See RERs for records that were tied or set today.) EWR: 96/1987 new record set at 98 BDR: *91/2013 new record set at 94 NYC: *96/1939 LGA: 96/1987 JFK: 92/1988 new record set at 94 ISP: 92/1987 new record set at 93 *ALSO OCCURRED IN PREVIOUS YEARS && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS... NEAR TERM...DR SHORT TERM... LONG TERM... AVIATION...DW MARINE... HYDROLOGY... TIDES/COASTAL FLOODING... CLIMATE...
Area Forecast Discussion
National Weather Service Spokane WA
355 PM PDT Tue May 31 2022 .SYNOPSIS... The beginning of June will welcome 70 degree temperatures across the region with a few spots in the Columbia Basin getting into the low 80s by Thursday. Mountain showers will be possible on Wednesday, but most valley locations will be dry with increasing high level clouds. A showery pattern will return Thursday, and some thunderstorms late in the week into the weekend may be capable of locally heavy rain. && .DISCUSSION... Tonight through Wednesday night: Diurnally driven showers will persist into the early evening over the east slopes of the northern Cascades, Northeast Blue Mountains, and southern to central Idaho Panhandle Mountains. Some of these cells are expected to develop into thunderstorms. Storms this evening will be slow moving with brief heavy rain being the main impact of note. Issues with heavy rain really are only expected to be a concern if thunderstorms develop over a recent burn scar. These chances look low as thunderstorm coverage will be isolated in nature, but not completely out of the question. The RAP model is analyzing a weak vorticity maximum over the Northeast Blue Mountains that may help to give cumulus development there a little bit extra oomph into this evening. It`s quite possible that models may be under doing shower chances around Lewiston, Pullman/Moscow, and St. Maries do to this mesoscale feature that isn`t as well resolved. Showers and thunderstorms will quickly dissipate through the latter half of the evening as we lose our diurnal heating with the setting sun. Much of the boundary layer moisture that was trapped in the valleys of northeast Washington into the Idaho Panhandle will have mixed out this afternoon and will result in lower chances for redevelopment of fog compared to earlier this morning. Shortwave ridging of high pressure off of the eastern Pacific will shift in over the region on Wednesday. Temperatures aloft will increase with higher heights building in and have an overall stabilizing effect on the atmosphere. Even so, models still indicate enough shallow surface based CAPE for cumulus development over the higher terrain for Wednesday afternoon. Modeled sounding profiles indicate equilibrium levels up to about 16,000 to 18,000 ft MSL, which would be enough for shower development but less likely for thunderstorms; although, a one-hit wonder can`t be completely ruled out. Temperatures will warm around 5 degrees over today with highs topping out in the 70s regionwide. These temperatures may feel warm (if not quite pleasant) but running right around what is expected for the first day of June. A weak shortwave disturbance will run up the backside of the ridge for through the course of Wednesday afternoon/evening. This will bring increasing moisture. The atmosphere will take some time to moisten from the top down with mostly higher level clouds increasing on Wednesday. Better chances for precipitation will come later on in the week. /SVH Thursday and Friday: A large low pressure system sitting off the coast in the eastern Pacific will move closer to the coastline and send pieces of energy into the region. Precipitable water values will increase to 120-180% of average. All ingredients are there for shower and thunderstorm development in the afternoon; moisture, instability and a kicker. We will see good upslope flow into the Cascades in the morning for some light rain. Then by the afternoon heavier and stronger showers and thunderstorms will develop across much of Washington and the ID Panhandle. The main concern for stronger storms on Thursday will be the Cascades and then during the evening them moving off the Cascades and towards the Okanogan Valley and Highlands. Locally heavy rain will be a concern, and will be closely monitoring any burn scars that are of concern. Friday region wide thunderstorms will also be a concern. Precipitable water values remain high, but storms will be moving slightly faster than previous days. As of now, flooding is not as much of a concern. Temperatures will cool a couple of degrees due to the cloud cover, but the southwesterly flow will keep us in the 70s, with low 80s possible for parts of the Columbia Basin and LC Valley Thursday. Saturday and Sunday: The low will migrate north. We will continue to see high precipitable water values and waves of energy moving through. Think most areas will at least see some light rain, just pinpointing when over the weekend that will occur is a bit more tricky. Have increased chance of precip through the weekend, with the highest probabilities Sunday. Temps will cool down to the mid to upper 60s. Monday onward: The precip water tap finally leaves the area and widespread showers will come to an end. However showers Monday cannot be ruled out, especially in the mountains. The Columbia Basin will get shadowed out. Tuesday showers chances decrease further, but still a slight chance in the mountains. Temperatures will remain on the cool side. /Nisbet && .AVIATION... 00Z TAFS: A weak mesoscale disturbance over the Pullman/Moscow Airport and Lewiston Airport will generate showers in the vicinity through 04Z this evening. There may even be a few lightning strikes with embedded thunderstorms, but this possibility carries low confidence. Isolated showers and thunderstorms are expected into the east slopes of the Cascades and over the Okanogan Highlands as well. This convection may produce a brief shower near at airports from Wenatchee, Chelan, Winthrop, and Omak. Convection will dissipate through the evening. There will be increasing high level clouds late tonight into Thursday with VFR conditions and light winds prevailing. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 49 74 54 75 54 72 / 0 10 10 40 40 60 Coeur d`Alene 45 73 52 74 53 70 / 10 10 10 40 40 60 Pullman 46 72 52 75 54 71 / 10 10 10 30 30 50 Lewiston 51 78 55 81 59 77 / 10 10 10 40 40 60 Colville 44 76 54 75 51 71 / 0 10 10 40 40 60 Sandpoint 44 71 52 70 51 68 / 0 10 10 30 20 60 Kellogg 48 71 51 72 54 68 / 10 20 10 40 30 60 Moses Lake 49 79 58 82 54 78 / 0 0 10 30 30 30 Wenatchee 54 77 57 77 57 75 / 0 10 20 60 50 40 Omak 48 78 56 77 54 74 / 10 10 20 50 50 60 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. && $$
Area Forecast Discussion
National Weather Service Mount Holly NJ
949 PM EDT Tue May 31 2022 .SYNOPSIS... A backdoor cold front will slide into our region from the northeast tonight into Wednesday and lingers over the area through Thursday becoming the focal point for several rounds of showers and thunderstorms before a stronger cold front moves through the region Thursday night. High pressure builds into our region Friday and Saturday before gradually shifting to our east Sunday and Monday. Another surface low may move towards the region from the Midwest into the early part of next week. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... Mid-level ridging was seen on water vapor this evening with a potent closed mid and upper level low near the Canadian maritimes. In association with the strong low near the Canadian maritimes, a backdoor cold front is currently heading west across Long Island, NY. After LGA reached 93 degrees Tuesday afternoon, temperatures have fallen into the upper 60s behind the front. Meanwhile, a weak wave is traversing the top of the mid-level anti-cyclone with some showers forming near Watkins Glen, NY. These multiple weak features has made for an extremely difficult forecast this evening. The overall idea, is for the weak showers and isolated thunderstorms to slide southeast mainly across northern NJ and northeastern PA. This also happens to be where the best saturation is forecast ahead of the backdoor cold front. Severe weather is not expected with this initial batch of showers and an isolated rumbles of thunder. Across the eastern zones this evening it appears that the surface cold front will indeed head west and progress inland. The biggest question at this time is how far west does the cold front make it. The NAM is by far the strongest with the front, pushing it all the way to the Lehigh Valley. The GFS pushes the front to about the I-95 corridor. The high res is a mix of these solutions (the HRRR bringing the front to the Lehigh Valley while the ARW pushes the front just west of the I-95 corridor and the FV3 follows the GFS). The answer looks like it will be a blend of the two pieces of guidance. The latest runs of the NAM appears to be to bold with the QPF overnight from the convection (up to around 0.75" of QPF near DE and northern NJ). This likely is having the affect of reinforcing the cold front slightly to far west. The current thinking is to have the backdoor front make it to potentially the Lehigh Valley early Wednesday morning only to retreat slightly east. Just west of the backdoor cold front, forecast soundings quickly destabilize with around 1500 - 2000 J/kg of MLCAPE. As this occurs, a mid-level wave will be approaching from the west likely causing CI across central NY. The width of the warm sector is modest Wednesday with the best shear being just north and east of the CWA. Given that, there still exists 30/ 35 kts of deep layer shear which is sufficient for some rotating updrafts. Some clustering of storms to a few discrete cells will be possible with damaging wind gusts being the primary threat, and hail being a secondary threat. Confidence is high that storms will form over central NY Wednesday afternoon and head south and east. The main conditionality to the threat across NJ and PA tomorrow will be the placement of the cold front. As convection crosses over to the cool side of the boundary it will likely slowly start to decay. The highest threat area for our region Wednesday will be towards Carbon/ Monroe counties or closer to the boundary and warm sector. High temperatures will also be extremely variable Wednesday with mid to upper 60s forecast near Sandy Hook, NJ and upper 80s forecast over the DELMARVA. Wednesday evening the convection will push southeast and slowly weaken. Convection will then come to an end late Wednesday night into early Thursday morning. Expect low temperatures mostly in the mid 60s Wednesday night. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... ...Slight Risk of Severe Thunderstorms Wednesday evening and again Thursday afternoon and evening... Showers and storms look to move into into portions of our eastern PA and NW NJ zones Wednesday evening as shortwave energy ripples along the baroclinic zone over the area. At this time a warm front should be over eastern PA oriented NW to SE with a trailing cold front extending back over western PA into Ohio. ML CAPE looks to be upwards of 1000-1500 j/kg over the area with deep layer shear around 40 knots. For this reason, the potential for severe weather exists with the highest threat being over NE PA into far NW NJ. The greatest threat looks to be damaging winds followed by large hail. The main threat should be through the evening with storms moving out overnight. For Thursday, the first portion of the day looks fairly quiet ahead of the second shortwave trough as it works its way across the Midwest into the Great Lakes. This second shortwave will be the stronger of the two with a more pronounced negative tilt with the parent closed 500 mb low over central Canada. After any lingering rain departs in the morning Thursday, we should see a little clearing in the late morning and early afternoon. However, the greater the clearing, the greater chances for widespread severe weather into Thursday evening. With stalled frontal boundary remaining situated over the region, there will likely be an appreciable temperature gradient once again with cooler highs in the upper 70s for the northern half of the region and upper 80s to near 90 south of the front. The front will attempt to move northward as a warm front ahead of the incoming shortwave trough and attendant surface low. The greatest risk for severe thunderstorms remains south of the front, which looks to be mostly south of the PA Turnpike and AC Expressway (Philadelphia suburbs southward). The Storm Prediction Center has a Slight Risk for Severe Weather south of Philadelphia Thursday. With CAPE values forecast to be in the 1000 to 2000 J/kg range (perhaps upwards of 3000 J/kg MUCAPE in areas that see enough sun to the south). The greatest threats look to be hail and damaging wind with deep CAPE well above the freezing level and some modest dry air aloft leading to forecast DCAPE values from 500 to 1000 J/kg. LL shear looks to be supportive of at least some supercells initially that will morph into a broken line or QLCS. && .LONG TERM /FRIDAY THROUGH TUESDAY/... Rain will gradually come to an end Friday as the cold front moves offshore and drier air filters into the region. The southeastern extent of a Canadian upper-level trough swings across the Northeast and northern Mid-Atlantic regions to start Friday. The mid-level flow is forecast to become more zonal as the aforementioned Canadian trough becomes more elongated. Weak high pressure should build in later Friday and Saturday, although some clouds may be tossed our way as additional shortwaves track across the Great Lakes region. By Sunday, the high moves directly overhead. It is forecast to be less humid with surface dew points into the 50s, and high temperatures each day get into the mid to upper 70s Friday and the upper 70s and low 80s Saturday and Sunday. The forecast becomes a little less certain into early next week as a shortwave and developing surface low move across the Midwest and towards the Great Lakes. On the other hand, some of the guidance is trying to hint at another surface low forming over the Atlantic off the Carolina Coast, but should remain south of our region. How far north this reaches by Tuesday and Wednesday remains highly uncertain, but could end up blocking the incoming shortwave if it ends up taking a northern trek near Bermuda as the EC has favored. Highs Monday and Tuesday look to reach into the upper 70s and low 80s. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...Mainly VFR. However, MVFR ceilings are forecast to push into our region from the northeast and east late tonight. The MVFR ceilings are expected to reach KTTN, KPNE, and KACY. There is less confidence that the MVFR ceilings will reach KPHL, KMIV, KILG, KABE and KRDG although the potential exists. West to northwest wind 8 knots or less, becoming northeast to east. Medium confidence. Wednesday...IFR to start most likely north and east, transitioning to VFR southwest. High uncertainty on extent of IFR cigs in the morning. Most areas see cigs return to VFR in the afternoon. The greatest chance for showers/thunder is late in the day and at night. Winds will depend on the location of a backdoor cold front. Low confidence. Wednesday night... A return to VFR with lower cigs in any showers and thunderstorms. Low confidence. Outlook... Thursday...MVFR and/or IFR conditions possible with several rounds of showers and thunderstorms, especially from the Philly terminals north then spreading south through the rest of the terminals through the night. Winds mostly from the west in the early morning 5 to 10 knots then turning to the northwest through the day from 10 to 15 knots. Low confidence. Friday...Sub-VFR conditions possible in the morning as rain and thunderstorms move off to the east. VFR returning into the afternoon. Northwest winds from 10 to 15 knots. Moderate confidence. Saturday...VFR. Winds from west-northwest from 5 to 10 knots. Moderate confidence. Saturday night...VFR. Winds from the north 5 knots or less. Moderate confidence. && .MARINE... A southwest to south wind of 10 to 15 knots late today is forecast to shift to the northeast and east tonight with the arrival of a cold front from the northeast. Waves on our ocean waters will likely be 2 to 3 feet. They may build near 4 feet late tonight on our ocean waters north of Barnegat Inlet. Waves should remain at 2 feet or less on Delaware Bay. On Wednesday, winds will remain mostly easterly at 5-10 knots with 2-4 foot waves, highest on the ocean north of Barnegat Inlet. Outlook... Conditions are expected to be below Small Craft Advisory criteria, though showers and thunderstorms Thursday and Thursday night could lead to locally stronger wind gusts and wind shifts. Rip currents... A south to southwest wind is forecast to increase to 10 to 15 MPH today. Breaking waves should be around 1 foot with a short to medium period swell/wind wave varying from south to east. There is a LOW risk for the development of rip currents today along the coasts of Delaware and New Jersey. A northeast wind around 10 MPH on Wednesday is expected to veer to the east, then to the southeast. Breaking waves should range from 1 to 2 feet with a short to medium period swell/wind wave varying from south to northeast. We will keep the rip current risk at LOW for Wednesday with the waves remaining rather tame. However, the risk could approach moderate at times due to the onshore wind. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ Synopsis...Davis Near Term...Fitzsimmons/Haines/RCM Short Term...Davis/Fitzsimmons Long Term...Davis/Gorse Aviation...Davis/Haines/RCM Marine...Davis/RCM
Area Forecast Discussion
National Weather Service Pocatello ID
144 PM MDT Tue May 31 2022 .SHORT TERM...Tonight through Wednesday night. Expect lingering showers and isolated thunderstorms early this evening ending by midnight with dry conditions the rest of tonight. Low temperatures will be in the 30s and 40s. Expect dry conditions Wednesday with high temperatures in the 60s to lower 70s. Only area with a chance of showers and thunderstorms will be the Island Park area near the Montana border and Yellowstone. Wednesday night will be dry across the board with lows in the 30d mountains and 40s valleys. GK .LONG TERM...Thursday through Tuesday. Model cluster analysis shows very good agreement among members through Saturday. A ridge of will bring mostly dry weather to the area. An are of low pressure off the coast of Washington will try to send some moisture through the ridge Friday and Saturday. This will produce a slight chance for showers and thunderstorms over most of southeast Idaho with better chances for scattered coverage across the central mountains into the upper Snake highlands. Temperatures look slightly above normal with the 25th-75th percentile NBM supporting highs in the Snake Plain and Magic Valley in the 70s with the 75th percentile supporting near or low 80s. Ensemble members begin to lose cohesion on Sunday as the ridge slides east and a shortwave trough moves into the area. The main differences involve the strength of the trough. A stronger trough supports better rain chances as a whole, but also better chances further south into the southern highlands. This solution produces 0.50-0.75 inches for the high country and up to 0.25 inches for the Snake Plain and Magic Valley. A weaker trough indicates of little if any rain for the southern highlands into the Magic Valley/Snake Plain and only up to 0.25 inches for the high country. Currently, the NBM 4.0 50th percentile supporter the drier solution with less than a 25 percent chance of the wet solution verifying. Once this system passes on Monday, models differ greatly indicating a high degree of uncertainty amongst ensemble members and low forecast confidence. 13 && .AVIATION... A few showers and thunderstorms are developing over the terrain and may affect TAF sites for a few hours this afternoon and early this evening. Most likely locations are SUN, DIJ, and possibly IDA/PIH. Model consensus has skies clearing through the night with light winds. HRRR is picking up on some patchy fog over the Snake Plain, but confidence is low if it will affect any of the TAF sites. 13 && .FIRE WEATHER...Cold upper low finally sags southeast of the region through tonight. Will see lingering showers and thunderstorms early tonight ending by midnight. Expect dry conditions Wednesday with a solid warming trend. Showers and a few thunderstorms may return to northern regions Thursday as the ridge begins to breakdown ahead of the next system arriving by the weekend. DMH/GK && .HYDROLOGY...Ample rainfall and higher elevation snow from the past few days is expected to bring some minor rises to East Idaho waterways as temperatures warm through midweek. The main river of concern remains the Big Wood near Hailey. Gage still indicates river fluctuating through action stage, and expectations keep the river at this range for the next several days. Flood Advisory remains in effect while minor flooding/ponding remain a concern. DMH && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Springfield MO
702 PM CDT Tue May 31 2022 ...00Z Aviation Discussion Update... Key Messages: 1.Thunderstorms will occur at times from this evening through early Thursday morning as a slow moving cold front moves into and through the area. A few storms may be severe with the main risks being large hail, damaging winds, and flooding especially this evening and tonight along and northwest of I-44. 2. Cooler weather is expected Wednesday and Thursday with a warming trend this weekend into early next week. .SHORT TERM...(This evening through Wednesday) Issued at 250 PM CDT Tue May 31 2022 Starting to see convection increase just a bit over west central MO where abundant low level moisture and moderate to strong instability are present along an old outflow boundary from earlier convection. Dewpoints in the low 70s and uncapped mlcape values 2000-3000 j/kg. HRRR has been okay guidance in showing a gradual uptick in storm coverage this afternoon and early this evening. Deep layer shear (0-6km bulk shear 30-40kts) over the northwest cwfa will be supportive of supercells. In general low level shear is weak in the vicinity of a diffuse sfc cold front and that will limit the overall tornado risk, but initially some weak backing of sfc winds might contribute to some uptick in low level helicity. Large hail/damaging winds are the main risks with stronger storms focus near the northwest border of the cwfa through 10 pm. Will see storms propagate southeast with time late this evening and overnight with an outflow modified frontal boundary. Weakening instability later in the night will start to limit the overall severe storm risk, but strong winds will still be possible with a reduced hail risk. Storms increasingly get undercut by outflow as well. Based on latest guidance from WPC and some high res models, will be adding some counties to the flood watch and will monitor short term trends for additional hydro watches/warnings. watch will be in effect until 10am. Will continue to see some shower/storm potential Wednesday as a shortwave moves into eastern KS/OK with storms possible in the afternoon/evening. Again, some storm organization with deep layer shear of 30-35kts could produce a wind/hail risk where stronger instability can develop, which looks to be more favorable along/south of I-44. .LONG TERM...(Thursday through Tuesday) Issued at 310 PM CDT Tue May 31 2022 Thursday-Friday: Front drops south of the area with weak sfc high moving into the region. Could see some shallow dense fog late Thursday night but it shouldn`t last too long this time of year. Lows around 50 deg F will be possible, and maybe some upper 40s in low lying areas. Saturday: Sfc high shifts off to the east. NBM is somewhat bullish on rain chances late in the day (mostly due to the GFS ensemble members). Guidance does move the first of a series of shortwaves into the area, and will see some uptick in shower/storm chances, late in the day and Saturday night. Low confidence on the timing at this point. Sunday-Tuesday: A fairly active zonal flow pattern looks to exist from the central Rockies to the Mid MS Vly late Sunday night/Monday is the next time period pinged by the NBM for a round of convection but some differences exist, mainly in the timing (more a question of when, not if). An additional wave looks possible Monday night-Tuesday. Blended guidance will tend to spread out rain chances in this type of zonal/fast flow aloft regime, but it does look like at least a couple of waves will move through during this period. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 702 PM CDT Tue May 31 2022 VFR ceilings will continue at the TAF sites through much of the evening, with SGF/JLN seeing mid-level stratocumulus. A cold front still located over eastern Kansas will slowly move into the area later this evening and tonight, with increasing thunderstorm chances as the front moves in. Highest thunderstorm chances will be between 05-12Z at JLN, 09-14Z at SGF, and 12-15Z at BBG. May see some stronger wind gusts with the storms at times, but exact timing of the strongest winds is still difficult right now. Expect a lull in thunderstorm activity most of tomorrow morning into early afternoon before additional thunderstorms develop during the mid afternoon. Winds will veer to the northwest behind the cold front as it slowly moves through the TAF sites during the later portion of the TAF period tomorrow. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...Flood Watch through Wednesday morning for MOZ055>058-066>071- 077>081-088>091-093>095. KS...Flood Watch through Wednesday morning for KSZ073-097-101. && $$ SHORT TERM...DSA LONG TERM...DSA AVIATION...Rothstein