Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/30/22

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
841 PM CDT Sun May 29 2022 .UPDATE... Issued at 835 PM CDT Sun May 29 2022 Overall the forecast is panning out okay. Did make a few changes to pops, but nothing significant. Latest HRRR has backed off on convection chances in the east this evening. ABR sounding did possess a bit of a cap around H7. The convection over Nebraska is what will likely develop northeast along an instability gradient through the overnight hours, likely getting into NE SD very late tnt. Latest HRRR keeps convection looking pretty beefy as it moves into the eastern CWA, so a few severe storms still look possible despite a pretty weak to non-existent LLJ. Temperatures look okay. && .SHORT TERM...(This Evening through Monday Night) Issued at 415 PM CDT Sun May 29 2022 A complex forecast continues to take shape for our CWA in this forecast period. First off, we`ll focus on the remainder of today into tonight. A nearly stationary frontal boundary or sfc trough remains draped from north to south across the Dakotas/Minnesota border area. Visible satl shows deepening CU field invof this sfc boundary from the Red River Valley southward into parts of west central MN and northeast SD. MLCAPE values of 2000-2500 J/KG are concentrated across our northeast corner with deep layer shear values of about 30-35 kts. Some of the CAMS depict convection firing across our northeast late in the afternoon/early evening before shifting north out of our area. The primary threats would be large hail and gusty winds from any supercells that would happen to develop. Overall, through the mid evening hours, most of our CWA should remain quiet. We will then turn our eyes southward as the next in a series of mid level impulses shifts northeastward into our region late tonight and early Monday morning. Another cluster of storms with embedded supercells is expected to develop across NE and southern-southeastern SD and track north northeastward overnight. This activity looks to reach our eastern zones closer to midnight at the earliest but more so after that time frame through the overnight into the pre-dawn hours of Monday. All severe weather threats will be possible with this, especially damaging winds and large hail. This convection could continue to be leftover across parts of our eastern zones perhaps closer to or just beyond sunrise. The final phase of the multifaceted storm system will move into our region and CWA during the day on Monday. A very potent sfc low pressure system with associated strong mid lvl low pressure is progged to track into SD through the daytime hours. The sfc low will run up and along the sfc frontal boundary which will help to and aid in new convection developing during the heating of the day. MLCAPE values Monday afternoon reach 2500-3500 J/KG across northeast SD and west central MN with more than adequate effective shear values in excess of 50-70 kts. The presence of a 30-40 kt low level jet across our far eastern/southeast zones will lead to favorable low level shear values that will be conducive to strong tornadic activity. Numerous supercells are anticipated in this environment across eastern SD and western MN during the afternoon and lingering into the early evening hours. All severe threats remain on the table with very large hail and strong tornadoes the primary threats. This favorable environment looks to shift fairly quickly out of our CWA by the early evening hours. So, anticipate the strong to severe threat will diminish in our CWA at that point. SPC has highlighted our eastern areas with an enhanced to moderate risk for severe weather. The other concern for Monday will be the potential for heavy rainfall. We`ll have to see how tonight`s/overnight`s convection plays out and what areas that rainfall occurs. If we get some type of training cells situation, some scattered flash flooding could be possible. .LONG TERM...(Tuesday through Sunday) Issued at 415 PM CDT Sun May 29 2022 The strong surface low pressure system responsible for Monday`s severe weather looks to be in the vicinity of northern MN by 12Z Tuesday. Rather cool airmass overhead as this system departs, with 850mb temps in the single digits C. Highs on Tuesday only look to reach the upper 50s to lower 60s with a stiff northwest breeze. Will also have to contend with wrap around showers that several models still indicate. Conditions then appear to quiet down Wednesday and Thursday before perhaps more energy crosses the northern plains towards the end of the week/weekend, bringing additional chances for showers and thunderstorms. As mentioned earlier, temperatures start off rather cool Tuesday, and even into Wednesday somewhat. Moderating temps occur by Thursday and Friday, but overall, the entire extended period looks to be characterized by below normal temperatures. && .AVIATION...(For the 00Z TAFS through 00Z Monday Evening) Issued at 613 PM CDT Sun May 29 2022 Terminals KABR,KATY,KPIR,KMBG VFR skies/vsbys are expected through most of tonight. However, as showers and storms proliferate late tnt and Monday, lower MVFR and even IFR cigs are possible, along with lowered vsbys during any storms. && .ABR WATCHES/WARNINGS/ADVISORIES... SD...None. MN...None. && $$ UPDATE...TDK SHORT TERM...Vipond LONG TERM...TMT AVIATION...TDK
Area Forecast Discussion
National Weather Service Boston/Norton MA
1010 PM EDT Sun May 29 2022 .SYNOPSIS... High pressure builds south of the region today and Memorial Day. This will bring summer temperatures for the rest of the holiday weekend. Slightly more humid on Memorial Day, but tolerable. A backdoor cold front brings cooler temperatures to the coast Tuesday, then to the rest of the region Wednesday. Unsettled weather returns late Wednesday/Wed night and again Friday in the form of scattered showers and thunderstorms. Temperatures then will average near to slightly cooler than normal. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... 10 PM Update... The forecast remains largely on track this evening with the exception of the pesky stratus deck to our southeast. Water vapor imagery suggests that any hint of moisture associated with that cloud deck has moved significantly south and east of the benchmark. The nighttime microphysics and IR channels from GOES support that notion. Given this evidence, vsbys and cloud heights were changed to reflect clear conditions through about 06Z. Should the stratus deck redevelop overnight it is possible that conditions deteriorate across Nantucket and the south coast however, there is a strong possibility that the deck does not redevelop/engulf the Islands overnight given a lack of strong southerly flow. While stratus appears to be less of an issue at this time, radiation fog is still on the table, and has been added to the forecast for the Connecticut River Valley and isolated pockets of central and western MA; where winds are most likely to go calm overnight. Congruent with the previous thinking, winds will stay just breezy enough, around 5 kt, across much of eastern MA and RI for widespread patchy fog to develop, but open fields and radiation prone areas across the eastern half of the CWA could see isolated patchy fog by daybreak. 7:30 PM Update... As of this writing, dewpoints from observations were running as much as 4 degrees above the previous forecast. Normally, this wouldn`t spell trouble, but it is possible that this notable increase in moisture could generate patchy radiation fog across interior southern New England overnight; in areas where winds are able to decouple such as the CT river valley and our typical radiators in metro-west. This fog will likely be limited to radiation prone fields and valleys. The other consideration regarding this evening`s forecast is the low cloud deck currently centered to our southeast. Guidance is varied regarding how far northwest the deck will advance overnight, with the HRRR bringing vsbys down to virtually zero across ACK and the NAM keeping any sort of IFR conditions well offshore. To hint at the possibility of degraded vsbys across Nantucket and the Cape, fog was tucked into the forecast along the south coast, Nantucket sound, and Buzzards Bay. In the case of both the radiation fog potential and the low cloud deck that may impact the Islands, conditions are expected to rapidly improved after sunrise, as we mix quickly after sunrise with a westerly breeze. 4 PM update... Tonight... Tranquil/quiet weather with dry NW flow aloft. Weak high pressure south of New England will promote radiational cooling, and with dew pts in the 50s, most locations will experience lows in the 50s as well. A very comfortable night. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/... Highlights * Very warm Memorial Day with highs in the upper 80s & low 90s * Warm Monday night with WNW winds Memorial Day... Very warm airmass over the Great Lakes today begins to advect into southern New England tomorrow, with 850 mb temps increasing to +15C/+16C and 925 mb +22C/+23C. Model soundings indicate west winds increasing of 10-20 mph mixing down to the surface, providing some downslope adiabatic warming. These temps aloft combined with mixing to at least 850 mb along with downsloping winds, will yield highs from the upper 80s to lower 90s across much of the region, including the Greater Boston area. WSW winds will keep the south coastal beaches cooler with highs 75-80. NBM 75 percentile captured this best, thus derived highs tomorrow from this dataset. Modest west wind 10-20 mph will provide some relief to the very warm temperatures, but also the dew pts will be in the 50s much of the day, then increasing into the low 60s late. Thus, overall humidity will be tolerable. Monday night... NW flow aloft continues, providing dry weather. It will be warmer than tonight, given WNW surface winds and dew pts rising into the lower 60s. Lows only dropping off into the mid and upper 60s. && .LONG TERM /TUESDAY THROUGH SUNDAY/... * Strong backdoor cold front will cool off the coast on Tuesday, then rest of the region on Wednesday. * While Tuesday should remain mostly dry, there could be a few showers and even an isolated thunderstorm around. * Cloudy and cool on Wednesday with a few showers around. Thursday looks to be the pick of the work week. * Some showers around on Friday before a gorgeous weekend with near normal temps. Big picture... Overall, a cool pattern for much of the week with a Maritime high nearby. Best potential for above normal temps and 80s will be towards the CT valley where downsloping offsets the cooling onshore influence. Everyone will get their fair share of pleasant outdoor conditions but can`t completely discount the possibility for a few showers and non-severe thunderstorms, especially on Wednesday and Friday. Next weekend looks gorgeous with no real big heat. Details... Tuesday... Spent most of the time on Tuesday. Felt reasonably confident enough to deviate from the National Blend of Models (NBM) to provide more details about the strong backdoor cold front and impact on temperatures. While everywhere should be off to a warm start (see the short term discussion on overnight Monday), there will be quite an abrupt temperature drop and a noticeable wind shift as the backdoor cold front comes through. Places like Boston will likely see their daytime highs by mid morning before temp drops 15-20 degrees from near 80 to near 60 and then get stuck in the 60s because of cloud cover and onshore flow off ocean waters whose SSTs are still in the mid 50s. In addition, given the sharp temperature differential and mesoscale pressure rise- fall couplet, did increase the winds to the 90th percentile of the NBM guidance. The stronger winds will only likely last a couple of hours when the cold front comes through, but given the uncertainty in timing, opted to do a broad brush bump in the winds. For the temp forecast, blended in the MOS and a bit of the deterministic guidance (GFS, NAM) given that the NBM smoothes out the temp spread too much given the amplitude of the front. By Tuesday afternoon, there will likely be a 30-35 degree spread in observed temps, from 60s along the eastern MA coast to low to even mid 90s across the CT valley. In addition, given the strong forcing and instability in the warm sector, won`t be surprised to see a few showers and even an isolated non-severe thunderstorm develop across the western two-thirds of the CWA. So introduced slight to low chance PoPs with possibility for thunder for Tuesday afternoon. But most locations should remain dry, although there could be quite a bit of cloud cover for areas behind the frontal passage. Wednesday into Thursday... Still quite a bit of difference between the available deterministic guidance. While GFS shows a washout, the EC keeps the rain out of most of our CWA. Either way, it looks like a cool Wednesday for the entire region given the potential for multiple low pressure systems to be in the vicinity. Quite a bit of a chaotic pattern. In the upper levels, the maritime H5 trough that brought us the backdoor cold front will slide to our southeast, allowing for a H5 ridge to once again build towards New England. But the low levels are a different story. With a maritime high nearby, onshore flow off SSTs in the mid 50s will dominate for the remainder of the week, keeping daytime temps near to slightly below normal. From a synoptic standpoint, the backdoor cold front looks to stall just to our southwest. Then a low pressure system approaching from the Great Lakes merge and tries to push the stalled boundary back as a warm or occluded front. This will allow for increased chances for a few showers and thunderstorms especially across our western zones. This warm front is not likely to make much headway, however, given that the maritime high will hold its ground. In addition, a building upper ridge is not exactly ideal for widespread unsettled weather. Overall, did a blend of the NBM and Superblend given the uncertainty in how shower and thunderstorm chances would evolve. We are also at the time of the year whereby it is tough to get a prolonged stretch of clear blue skies so while there doesn`t seem to be much impactful weather to talk about, there also isn`t much hazardous weather to worry about. For those looking for a dry day to do outdoor activities, Thursday looks to be your best bet. In fact, Thursday could well turn out to be the pick of the work week. Friday into Sunday... A weak coastal low could lead to some showers and even a few non-severe thunderstorms on Friday along with below normal temps. But high pressure then builds in so the weekend looks gorgeous at this time with near normal temps. For reference, normal highs for early June are in the mid 70s. && .AVIATION /02Z MONDAY THROUGH FRIDAY/... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. 00z update... After 00z...moderate forecast confidence. Some uncertainty on MVFR/IFR conditions south of New England advecting northward and onshore overnight. Most likely scenario - VFR, dry conditions and light S-SE winds becoming SW overnight. Low risk on MVFR/IFR stratus and fog south of New England advecting northward overnight and coming onshore into coastal RI and nearby southeast MA. More likely to impact the Islands of ACK/MVY and BID. Monday... VFR with any cloud bases 050-060. WSW winds and dry weather. Monday night... VFR and dry. WSW winds becoming WNW overnight. KBOS TAF...High confidence in TAF. KBDL TAF...High confidence in TAF. Outlook /Tuesday through Friday/... Wednesday through Wednesday Night: Mainly MVFR, with areas VFR possible. Chance SHRA. Thursday: Mainly VFR, with areas MVFR possible. Slight chance SHRA. Thursday Night: MVFR. Chance SHRA, isolated TSRA. Friday: Mainly MVFR, with areas VFR possible. Chance SHRA, isolated TSRA. Friday Night: Mainly VFR, with areas MVFR possible. Chance SHRA. Saturday: Slight chance SHRA. && .MARINE... Low - less than 30 percent. Medium - 30 to 60 percent. High - greater than 60 percent. High forecast confidence thru Monday night... Tonight... S-SE winds this evening becoming SW late evening and overnight. Dry weather and good vsby prevail. Only wrinkle to the forecast is low clouds well south of New England. This low level moisture will return northward overnight, but expecting most of these low clouds and eventually fog to remain south of the waters, perhaps clipping the islands. Memorial Day... WSW winds 10-20 kt, highest wind near shore. Any patchy fog at sunrise quickly dissipates. Otherwise, dry weather and good vsby prevail. Monday night... Increasing winds aloft, but low level inversion precludes these winds from reaching the surface. Thus, light WSW winds and dry weather. Low risk of patchy fog as humid airmass overspreads the chilly ocean waters. Outlook /Tuesday through Friday/... Wednesday through Wednesday Night: Winds less than 25 kt. Chance of rain showers. Thursday: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers. Thursday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers, isolated thunderstorms. Friday: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers, isolated thunderstorms. Friday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Chance of rain showers. Saturday: Winds less than 25 kt. Areas of seas approaching 5 ft. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 6 AM to 8 PM EDT Tuesday for ANZ230>237-251-254. && $$ SYNOPSIS...Nocera/Chai NEAR TERM...Nocera/KS SHORT TERM...Nocera LONG TERM...Chai AVIATION...Nocera/Chai/KS MARINE...Nocera/Chai
Area Forecast Discussion
National Weather Service Duluth MN
644 PM CDT Sun May 29 2022 .DISCUSSION...(This evening through Saturday) Issued at 405 PM CDT Sun May 29 2022 Summary: Several rounds of thunderstorms are expected this afternoon through Tuesday morning. Some storms may be severe this afternoon through the overnight and again Monday afternoon through early Tuesday morning. In addition to the severe weather risk, heavy rainfall is likely over portions of central and north- central Minnesota which may lead to flash flooding. A quieter pattern emerges midweek through next weekend. Not much has changed in the forecast since this morning. Fog has lifted along the North Shore and is likely to return tonight, particularly for areas which received/will receive rainfall today/tonight. A Dense Fog Advisory may eventually be needed. However, low temporal and spatial confidence prevents me from issuing the headline with this forecast package. Would like to wait and see how the storms evolve and whether cloud cover interferes with fog formation. Showers and thunderstorms have been percolating in one form or another all day and were starting to see intensities and coverage increase over northwest into north-central Minnesota. A serpentine warm front stretched from near Grafton, ND (KGAF) to near Grand Rapids to near Moose Lake to near Hayward to western Lake Superior north of Ironwood. The undulation in the front is due in part to a persistent northeasterly lake breeze which has been persistent this afternoon. Cloud cover on either side of the warm front in central and north-central Minnesota has limited destabilization. SPC Mesoanalysis features an uncapped mixed layer over northwest Minnesota with 1000-2500 J/kg of MLCAPE. The CAPE gradient extends east into north-central Minnesota and roughly follows the contour of the warm front. MLCIN is on the order of 100-300 J/kg over my Minnesota zones suggesting the storms in Itasca County as of 2030Z are elevated. Look for the CIN to continue to erode this afternoon and evening allowing for additional convection to develop. Deep layer shear is limited in the wake of a meso-high from the morning convection over central Minnesota. Effective shear will increase to 40 to 55 knots over central Minnesota into the Arrowhead and northwest Wisconsin by 02Z. Storms are expected to increase in coverage through this evening. Supercells will be possible in the warm sector with large hail and damaging winds the main threats. A tornado or two cannot be ruled out if storms can become rooted in the boundary layer. Additional storms are expected to fire this afternoon and early evening along the cold front which stretched from the Dakotas/Minnesota border down to eastern Nebraska at 20Z. The storms should propagate eastward into central and north-central Minnesota this evening or tonight. Storms may be severe with large hail and damaging winds the main threat. There will also be a potential for training storms along the front which may lead to flash flooding. The Flash Flood Watch issued by the mid-shift was in good shape, so no changes needed. The cold front will stall over western Minnesota tonight and another area of low pressure will lift into the region for Monday. Storms may be ongoing at 12Z over northeast Minnesota and northwest Wisconsin. Any outflow boundaries which develop will likely provide forcing and enhanced wind shear for another round of storms Monday afternoon and evening. The severe weather potential will include all modes, including flash flooding. The greatest tornado risk appears to be focused over western Minnesota and may extend as far north as the Brainerd Lakes and Aitkin during the late afternoon and evening. Very large hail to baseball size and damaging wind gusts of 70 to 80 mph will be possible in addition to the tornado threat. NAM mid-level lapse rates at BRD during the afternoon will be 7 to 7.5 C/km, for example with plenty of hail growth zone CAPE. The largest hail and strongest winds will be possible during the late afternoon into the evening over central to north-central Minnesota, and will eventually transition a wind threat overnight. Provided we can scour out the clouds from the overnight/morning convection, portions of northwest Wisconsin and the I-35 corridor may make a run at 90 degrees with warm but not as warm temps farther northeast across the remainder of my Minnesota zones. A few showers and storms may linger into Tuesday, but the severe weather potential will shift east of our area. A quieter period is expected for the remainder of the forecast through next weekend. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 644 PM CDT Sun May 29 2022 An unsettled period is expected as multiple rounds of thunderstorms work across the region. Favored the HRRR with this update and used that to refine the timing of convection for the overnight hours with storms not expected to develop until later this evening. Storms will bring periods of MVFR or lower VSBYs and CIGs will be variable at times with MVFR/IFR conditions possible, especially at DLH with onshore flow. Fog may once again redevelop across the area, but with winds not subsiding overnight, chances for this are reduced. Any storms passing over a terminal will have the potential for small hail and erratic winds. Some areas of LLWS will be possible overnight as a low-level jet works across the area, but the effects look patchy in nature. Additional rounds of storms will be possible on Monday and future updates will better time those threats out. && .MARINE... Issued at 1257 PM CDT Sun May 29 2022 Visibility improved this morning near the Twin Ports and along the shoreline areas. The Duluth and Two Harbors webcams still show fog farther out onto the lake. Extended the Dense Fog Advisory from Two Harbors to Grand Portage until 10 AM tomorrow while letting the portion from Two Harbors to Duluth to Port Wing expire at 1 PM. Storms will come through the area this afternoon and tonight, with large hail, damaging winds, and cloud-to-water lightning as the primary threats. Winds today along the North Shore are expected to reach up to 25 kts, which will cause waves for the North Shore and portions of the South Shore to increase up to 5 ft this afternoon and evening. Small Craft Advisories have been issued. Fog is expected to return tonight and may become widespread, requiring an expansion of the Dense Fog Advisory. Several rounds of storms are possible Monday through Tuesday morning. A few storms may be severe with hail larger than penny- size, wind gusts of 30 to 40 knots, and frequent cloud-to-water lightning. Gusty winds of 15 to 25 knots are forecast for Tuesday and another Small Craft Advisory may be needed. && .PRELIMINARY POINT TEMPS/POPS... DLH 56 78 58 66 / 70 50 90 50 INL 58 80 54 63 / 70 70 90 80 BRD 63 83 57 64 / 70 80 90 50 HYR 65 87 62 75 / 50 40 80 40 ASX 63 86 63 75 / 50 40 70 40 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...Flood Watch through Tuesday morning for MNZ010-011-018-025-026- 033>035. LS...Small Craft Advisory until 1 AM CDT Monday for LSZ140>146-150. Dense Fog Advisory until 10 AM CDT Monday for LSZ140>143. && $$ DISCUSSION...Huyck AVIATION...BJH MARINE...Huyck
Area Forecast Discussion
National Weather Service Quad Cities IA IL
625 PM CDT Sun May 29 2022 ...AVIATION UPDATE... .SYNOPSIS... Issued at 153 PM CDT Sun May 29 2022 Our CWA has spent the day under partial cloud cover from debris of the morning showers and thunderstorms that moved across central Iowa. Except for the northwest corner counties, this has resulted in less wind than forecast, and it appears we`ll be dealing with that cloud cover through the rest of the afternoon. Meanwhile, our northwest is seeing the collapse of the mesohigh related to the showers earlier, and winds are near 45 mph at times there. We`re handling this with a SPS. && .SHORT TERM...(This Evening through Monday) ISSUED AT 153 PM CDT Sun May 29 2022 Outside of the shower dissipation process in the northwest, winds are generally well under advisory, and am not planning on issuing anything beyond the SPS this afternoon/evening. Temperatures are in the lower to mid 80s (a few upper 80s) as of 2 PM, and this should be maintained into the early evening as we`re well mixed and far away from the surface boundaries. This fully established warm sector will remain over the area through Monday, with little reason for any elevated activity to move overhead as well. Thus, despite the active thunderstorm night and day ahead to our west / north, it should be warm, windy, and dry here (though dewpoints will certainly be increasingly uncomfortable). Monday we`re again going to see winds near advisory, but it looks rather low confidence for seeing widespread conditions, just like today has been. Thus, a hot day with winds reaching the 35 to 45 range is likely, but most spots hourly max should be under 45 mph. Dewpoints will be a few degrees warmer, with mid 60s widespread Monday. With the wind, heat index should be a minimal impact, but reading will certainly be hovering around 90 through the afternoon. The cold front will remain west of the CWA through 00z Tuesday, and any convergence for storms will be near if not somewhat post frontal, thus a dry forecast is in place through Monday afternoon. .LONG TERM...(Monday Night through Sunday) ISSUED AT 153 PM CDT Sun May 29 2022 Key messages: 1. Showers and thunderstorms expected Monday night/early Tuesday. Coverage and longevity of this activity will help determine storm threat and subsequent severe risk Tuesday afternoon and evening. 2. Dry and comfortable conditions to end the work week. Monday night-Tuesday night...strong closed low in SD will lift north into northern MN to begin the period with a strong mid level jet located over the western half of IA. Strong storms will fire in this area during the evening along a 850mb theta-e gradient and track east northeast. Another shortwave will ride along this boundary a few hours later generating more showers and thunderstorms initially in southwest IA and moving east through the early morning. These storms will likely bring a severe risk and the question becomes will these storms maintain their strength and reach eastern IA. Latest CAMs and the 15z RAP would suggest that they would not reach our west until after 07z Tuesday. CAPE begins to wane quickly at this time and should help storms weaken below severe levels, but some scattered showers and embedded thunder will still be possible. Cloud trends from morning rain Tuesday and location of the synoptic front will help determine area of severe risk in the afternoon and evening. Warm and noticeably humid conditions are forecast Tuesday with highs in the 80s (warmest in IL) and dewpoints in the 60s. Timing differences still continue with the fropa Tuesday with the 12z GFS now the fastest solution and the 12z NAM the slowest through the CWA. A slower progression would increase the severe threat and a faster one would limit the severe risk to our far southeast portions of the CWA. Taking a look at forecast soundings, SBCAPE values over 2400 J/Kg and 0-6km shear values near 40 kts are seen along the front in addition to very high PWs approaching 2", bringing a damaging wind, large hail, and heavy rain threat under the strongest cells. Current thinking for timing any severe risk would be from 2- 10pm Tuesday across eastern IA, northwest IL, and northeast MO. SPC has most of the area in a Day 3 slight risk for severe storms. Once the front passes any location, the severe risk will diminish and cooler temperatures and humidity will move in. Wednesday-Saturday...transition to northwest flow aloft with a 1017mb surface high moving overhead will bring dry and pleasant conditions. With 850mb temps remaining below 10C and dewpoints in the upper 40s/low 50s, highs in the 70s and lows in the 50s are forecast. This will be 4-7 degrees below normal for early June and you will be able to give your A/C a rest and enjoy some fresh air. && .AVIATION...(For the 00Z TAFS through 00Z Monday Evening) ISSUED AT 620 PM CDT Sun May 29 2022 Main impact to aviation tonight into early Monday AM will be low- level wind shear with 50-55 kt S to SSW winds at 2000 ft AGL. At the surface, gusty S to SSE winds will decrease slightly overnight before increasing once again Monday morning. Expect peak gusts around 35 kts from midday Monday through the evening. VFR will prevail through the period. && .HYDROLOGY... Issued at 1035 AM CDT Sun May 29 2022 Have issued a flood watch for LD 18 and Burlington on the Mississippi River with this morning forecast issuance. While confidence is still low in reaching flood stage, we are now a half a foot away from it at both sites. Slow rises are expected over the next 48 hours and will be monitored for possible upgrade to warning in later forecasts. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Ervin SHORT TERM...Ervin LONG TERM...Gross AVIATION...Uttech HYDROLOGY...Gross
Area Forecast Discussion
National Weather Service Marquette MI
1203 AM EDT Mon May 30 2022 .SHORT TERM...(Through Early Evening) Issued at 236 PM EDT SUN MAY 29 2022 Stabilizing influence of warmer, drier air aloft over Upper Mi as noted on fcst soundings is being evidenced this afternoon on MQT radar imagery as convection forming over northern WI weakens or dies out completely as it lifts north and east into the U.P. This trend should continue into the early evening hours. However, may need to keep a watch on the interface of land/marine boundaries into tonight as the forcing of warm, moist air over the marine layer could provide added lift to break through any mid-level capping and initiate isold tsra. This just happened off Grand Marais in the past hr. Temps should remain fairly steady or could rise a degree or two into the early evening hours under mostly cloudy skies. Generally, readings most locations this afternoon have been in the lower to mid 70s with some cooler low 60s readings near the Great Lakes central and east. .LONG TERM...(Tonight through Sunday) Issued at 317 PM EDT SUN MAY 29 2022 Heat, humidity and dangerous swimming conditions are expected in this forecast package, with reprieve from these conditions expected Tuesday night and Wednesday. GOES16 water vapor imagery and RAP analysis captures the pattern across CONUS well, with long wave trough/ridge pattern from west to east and southwest flow across the north-central Plains. Impacts from the few shortwaves currently embedded within this southwest flow should be behind us by late this evening. As these pass through this afternoon, the ridge axis over western Lake Superior will shift eastward into Ontario, setting up a period of southwest flow and warm and moist air advecting into the region. Within this flow, a surface low is expected to develop over the Central Plains by late Sunday night and then ride the flow north-northeastward into the Dakotas by late Monday, and northwest Ontario Tuesday. From there, the troughing currently over the western CONUS is expected to deamplify and allow the surface low to occlude and cut off a closed upper level low over northern Manitoba by Tuesday night. As this low spins nearly stationary through the remainder of the week, flow across our region looks to become largely zonal. In terms of sensible weather, the southwest flow will advect in a very warm and moist airmass into the region. Together, these muggy conditions will make some feel uncomfortable being outside. If folks are venturing out, they should take frequent breaks and stay hydrated. Overnight lows tonight and Monday night have a real chance of challenging the current record warm lows at our office in Negaunee Township. The best shot looks to be Monday night, where we`re expecting to stay in the 60s overnight. Both nights, the western portions of the region should see lows in the low to mid 60s and the east near 60F. As warm air and downsloping adiabatic warming occurs, expect much of the region Monday to climb into the 80s with some low 90s being possible in the interior west and portions of the Lake Superior shoreline, including Marquette. Expect the heat to stick around Tuesday, but guidance is suggesting a slightly cooler day, with most folks topping out in the 80s. If you`re looking for the coolest conditions, the lakeshores of the Bay of Green Bay and Lake Michigan will be the best spots, but don`t go swimming! A stout LLJ overhead will make for gusty southerly winds, creating large waves and dangerous swimming conditions for all Schoolcraft County beaches Memorial Day (Monday/tomorrow) and Tuesday. With that LLJ overhead, dinural mixing to even a few thousand feet will be able to mix gusty winds to the surface. While the core of the winds should remain within the inversion, I`m still expecting 30mph gusts to be possible in some locations. Greatest potential Monday and Monday night looks to be across the east half and terrain opportunistic areas like the Lake Superior lakeshore east of Marquette and the higher terrain of the Michigamme Highlands and Gogebic Range. There`s some uncertainty about rain and thunderstorm chances Memorial Day. CAMs are presenting mixed solutions regarding where convective initiation takes place over Minnesota and Wisconsin during the day. As is typically the case, much of this will depend on MCS evolution prior and where exactly any surface boundaries linger. Overall though, if showers or thunderstorms end up moving into the region, the most probable locations appear to be the west half of Upper Michigan and Lake Superior. As the surface low lifts northeast Monday night, upstream convection is expected to drift into western Lake Superior. Timing suggests the loss of dinural influence, but with deep shear values near 45kts, I wouldn`t be surprised if a couple elevated thunderstorms hold together and move into western Upper Michigan. By Tuesday, two boundaries are expected to swing through the region as the low pulls away to our north. The first looks to be sometime in the morning, and could have some thunderstorms with it if upstream convection holds together. If it holds, a wave of decaying showers/thunderstorms Tuesday morning looks centered across the west and central. Soon after, a period of strong southwesterly winds is expected, especially west. Guidance is suggesting being able to mix wind gusts of 45mph down to the surface in some spots. The main boundary looks to progress through from west to east starting around midday and into the afternoon. With the warm and moist airmass out ahead of the boundary, expecting daytime destabilization to kick off thunderstorm activity ahead of the boundary, mainly in the central and east. Guidance is suggesting MLCAPE climbing above 1000 j/kg and 0-6km bulk sheer of 50 to 75kts. This could result in some strong or severe storms capable of supporting hail or strong winds. Behind the boundary, a cooler airmass will build in Tuesday night. This will trend temps back toward more seasonal for the remainder of the work week. && .AVIATION...(For the 06Z TAFS through 06Z Monday night) Issued at 1203 AM EDT MON MAY 30 2022 IMPACTS: -LLWS threat early this morning at all TAF sites -LLWS threat again Monday evening/night -Strong SE surface winds becoming SSW at 12 to 14 kts with gusts up to 26 kts -Thunderstorm threat Monday afternoon/evening DISCUSSION: VFR conditions are expected for the duration of the TAF period. But, a series of low level jets will create a LLWS threat at all TAF sites early this morning and again this evening/tonight. And, southerly winds will be strong with sustained speeds in the 12 to 14 kt range, gusting to 26 kts. Also to note, there is a chance for thunderstorms this afternoon/evening, but confidence is not high enough in timing to insert mention at this time. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 317 PM EDT SUN MAY 29 2022 The increasingly warm and moist airmass over the region, coupled with strong winds aloft, will support a period of around 25kts winds on Lake Superior until the main boundary swings through from west to east Tuesday. As is typical in these increasingly stable conditions, identifying the extent of stronger winds aloft mixing to the surface is a challenge. I suspect there will be periods of near gale conditions for high reporting platforms like Stannard Rock or Rock of Ages, but coincident with less mixing and thus lighter winds lower toward the surface. The exception would be just off shore of the Lake Superior lakeshore in downslope prone regions. The first wave of potentially stronger winds are expected tonight, across mainly north and east of the Keweenaw Peninsula. The second wave looks Monday night and Tuesday. The strongest winds aloft are expected at this time, but as this coincides with the most stable period in this event, I`m even more uncertain about winds mixing to the surface. Until the main low lifts out of the region and the cold front swings through Tuesday, periods of showers and thunderstorms are expected on Lake Superior. Recent CAMs guidance suggests the northeastward progression of upstream convection to move into the western and northern portions of the lake tonight, tomorrow, and Monday night. Tuesday activity looks more concentrated over the central and eastern portions. With the warm and moist airmass, and much cooler lake surface, any persistent rain will result in fog developing. Following the cold frontal passage, a period of 20kt or less winds is expected heading into next weekend. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Beach Hazards Statement from 6 AM EDT this morning through this evening for MIZ014. Lake Superior... Dense Fog Advisory until 11 AM EDT /10 AM CDT/ this morning for LSZ162. Lake Michigan... None. && $$ SHORT TERM...Voss LONG TERM...JTP AVIATION...TDUD MARINE...JTP
Area Forecast Discussion
National Weather Service Phoenix AZ
410 PM MST Sun May 29 2022 .UPDATE... Updated Aviation && .SYNOPSIS... A series of low pressure systems across the intermountain West will bring cooler and windy conditions to the Desert Southwest through Monday. High pressure will then build east of the region, resulting in seasonably dry conditions along with a warming trend. A return to above normal temperatures is expected Wednesday through next weekend. && .DISCUSSION... Latest water vapor imagery reveals several mid-level vortices embedded within a well-defined low pressure system near Salt Lake City. Convection has been concentrated well to our north across Utah and Colorado. No rainfall is expected across the lower deserts of Arizona, however anomalously high dewpoints in the 40s have been observed today across central Arizona. Main impact from this system will be slightly cooler temperatures along with periods of windy conditions through tomorrow. Winds earlier this morning were strong enough to result in widespread reduced visibilities due to dust channels and plumes of blowing dust/sand across portions of southeastern California. Visibilities have improved though the threat of blowing dust will be possible again as windy conditions redevelop this evening. Further east across Arizona, very high fire danger continues to be a concern across mainly far southeastern Gila County and a Red Flag Warning remains in effect through this evening. Observations indicate RHs have dropped below 15 percent, and the experimental NBM indicates winds will strengthen this afternoon ahead of the aforementioned low pressure system. Across the Phoenix area, latest ECMWF ensemble, HREF and CAMs have trended a bit weaker with the winds. Nevertheless, gusts up to 30 mph will be possible into this evening. Meanwhile, latest HRRR also indicates the westerly flow will be favorable for low concentrations of smoke from the Lost Lake fire in southeastern California to reach central Arizona this afternoon and overnight. The below normal temperatures across the Desert Southwest will persist into Monday as another reinforcing trough drops into the Great Basin. Widespread breeziness is again anticipated and gusts could still reach 30 mph across far eastern Gila County. Latest GEFS/ECMWF ensemble suites remain in good agreement depicting a general weakening of the persistent and anomalous western CONUS trough. Gradual height rises early this week will translate into a warming trend along with a continuation of the seasonably dry conditions. General model consensus also indicates a weak eastern Pacific ridge will consolidate with the westward-building subtropical ridge Thursday/Friday east of the area, resulting in a return to above normal temperatures. However, probabilities are quite high that temperatures will remain well below daily records. Cluster analysis depicts a forecast characterized by relatively low variance into the weekend, with a high likelihood of at least somewhat cooler conditions. && .AVIATION...Updated at 2310Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Very minor wind issues should be the only weather concern through Monday evening under clear skies. Confidence is good that W/SW gusts 20-25kt will gradually decouple during the mid evening, then be more delayed than usual in switching to the nocturnal easterly direction. East winds should only persist for a short time frame Monday morning before reverting to a W/SW component by noon. Gusts may be less pronounced Monday afternoon. Otherwise, minor slantwise visibility issues could exist around sunset/sunrise due to lofted dust/smoke. Southeast California/Southwest Arizona including KIPL and KBLH: Some increased wind gusts will be the only weather issue through Monday evening under clear skies. W/SW gusts 20-25kt will be common this evening before gradually decoupling overnight. Wind trends suggest directions becoming more northerly Monday morning and early afternoon before backing to southwest with less gustiness. Otherwise, lofted dust around the region will keep skies hazy through tonight. && .FIRE WEATHER... Dry and windy conditions will predominate across the Desert Southwest today. Combined with near-record fuel dryness, this will result in very high to extreme fire danger, particularly east of Phoenix. Although cooler conditions are expected today, winds will be stronger across southern Gila County, where gusts could reach 35 mph. Drier conditions are anticipated Monday with widespread minimum RHs at or below 10 percent, however gusts as high as 30 mph will remain possible across southern Gila County. Seasonably dry conditions will linger through the week, though winds will be lighter as high pressure builds across the region. A return to above normal temperatures is also anticipated by midweek. Latest guidance also suggests increased probabilities of hot/dry/windy conditions late in the week ahead of a weak trough moving into the Great Basin. Another cooling trend is likely next weekend, though temperatures will remain slightly above normal. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...Red Flag Warning until 7 PM MST this evening for AZZ133. CA...Wind Advisory until 2 AM PDT Monday for CAZ562. && $$ Visit us on Facebook, Twitter, and at DISCUSSION...Hirsch AVIATION...18 FIRE WEATHER...Hirsch
Area Forecast Discussion
National Weather Service Pueblo CO
355 PM MDT Sun May 29 2022 .SHORT TERM...(This evening through Monday) Issued at 354 PM MDT Sun May 29 2022 Key Messages: 1) Strong winds and high fire danger expected Monday with Red Flag Warnings hoisted for most of the area. 2) Light snow tonight central mountains with isolated gusty wind producing thunderstorms this afternoon and evening. 3) Some high wind potential for the San Luis Valley and southern I- 25 corridor for Monday. Broad upper low over the northern Great Basin and Pacific Northwest will remain in place through the 24 hour period with waves of energy ejecting across northern portions of the area. First one has spread showers and thunderstorms into the Continental Divide and this will continue into the evening as the brunt of the forcing moves through. The higher areas of the central mountains will see some light snowfall accumulations above 11000 feet and given the steep lapse rates could see some localized heavy snow bursts, graupel or even small hail with the stronger embedded cells. Farther to the south and east, critically dry humidity values combined with gusty winds has brought critical fire weather conditions to most of southern CO. The front has been slower to recede across the plains this afternoon with KLAA still seeing east winds around 10 mph as of 3 PM. However high res models continue to push south to southwesterly winds into the area through the evening with the potential to meet the 3 hour duration of critical fire weather conditions. Red Flag Warnings will remain in place through 9 PM. As high based showers spread off the mountains into the adjacent lower elevations this evening, there is the potential for gusts in the 50 to 60 mph range mainly along and north of highway 50 in localized areas given the strong downdraft CAPE. High res models (HRRR and NAMNest) both depict a wind shift from the northwest with varying magnitudes with these across Pueblo and El Paso counties. The cold front will make another push into the southeast plains tonight before getting swept back out early Monday morning as strong downward forcing moves in behind the deepening/ejecting upper low across western NE. Getting mixed signals from the model blends and high res models concerning high wind potential across the San Luis Valley and southern I-25 corridor from Colorado City to Walsenburg. While 12z HRRR and NAMNest along with 18z HRRR suggest these areas could hit high wind criteria from mid morning through early afternoon, the 18z NAMNest has backed off on this scenario. Will bring wind gusts very close to high wind criteria with gusts up to 55 mph in the afternoon. Hopefully 00z runs will bring better clarity. Regardless, very windy conditions with gusts in the 50 to 60 mph range will bring a return of critical fire weather conditions to most of southern CO and have upgraded Fire Weather Watches to Red Flag Warnings. Have also included zone 223 for elevations below 9000 feet where RHs are below 15 percent. -KT .LONG TERM...(Monday night through Sunday) Issued at 354 PM MDT Sun May 29 2022 Key Messages: 1) Critical Fire Weather conditions across the SW Mtns and into the San Luis Valley Tuesday and Wednesday. 2) Cooler across the plains with the potential for widespread showers Tuesday night and Wednesday. 3) Warmer with potential for afternoon showers and storms for later in the work week and into next weekend. Monday night-Wednesday night...Latest models are coming into better agreement of a break in between weather systems in the Monday night and early Tuesday timeframe, as Monday`s system continues to translate north and east into the Northern High Plains Monday night, and secondary energy across the Intermountain West digs into the Great Basin. Passing system sends a weak cold front across the eastern plains Monday night, with breezy northerly winds into early Tuesday morning becoming breezy easterly across the plains Tuesday afternoon. Meanwhile, west to southwest flow aloft increases across the central Rockies, as the Great Basin system starts to translate north and east into eastern Utah through out the day, and remains progged to continue to move out across northern Colorado Tuesday night and Wednesday. The stronger southwest winds look to mix down across western portions of the area through the day Tuesday, leading to probable critical fire weather conditions across the San Luis Valley and the lower elevations of San Juan and La Gartia Mts, where Fire Weather Watches have been kept and added to from 11 am to 9 pm Tuesday. For the Tuesday night through Wednesday timeframe, models have also come into much better agreement of more widespread overunning precipitation developing across the eastern mountains and out across the southeast plains, with strong waa as moisture within the southwest flow aloft moves over the deep low level easterly flow. Models do differ on the amount qpf across the area, though can`t rule out some areas across the plains seeing upwards of 1/4 inch of liquid through the day Wednesday. With the expected easterly upslope, clouds, and precipitation, temperatures across the plains on Wednesday look to be well below seasonal levels mainly in the 60s, while further west across the high mountain valleys, highs look to warm into the 70s with continued breezy westerly winds leading to probable critical fire weather conditions once again. Thursday-Sunday...A warmer westerly flow pattern looks to develop across the northern Tier and into the Rockies, with occasional hard to time disturbances moving through the flow. This will allow for temperatures to warm back to early summertime levels by the end of the work week and into next weekend. The hard time disturbances would lead to chances of mainly afternoon showers and storms across the higher terrain, along with possible strong to severe storms across the eastern plains, especially on Friday, where models continue to indicate the potential for a developing dry line. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 354 PM MDT Sun May 29 2022 Gusty southwest winds will continue this evening with localized gusts to near 40-50 kts near any high based showers as they move off the mountains this evening. This is most likely to impact KPUB and KCOS through 02z. VCSH will be possible at KALS this evening with clearing after 06z. Winds will stay elevated from the northwest at 10-20 kts for both KCOS and KPUB. KALS will see light winds overnight with speeds under 15 kts. However winds will increase early Monday morning for all three terminals with west wind gusts to 50 kts possible at KALS during the late morning and afternoon. KPUB and KCOS will see gusts to 35 to 40 kts by late morning through the afternoon. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... Red Flag Warning until 9 PM MDT this evening for COZ222-224- 226>237. Red Flag Warning from 11 AM to 8 PM MDT Monday for COZ222>224- 226>237. Fire Weather Watch from Tuesday morning through Tuesday evening for COZ223-224. && $$ SHORT TERM...KT LONG TERM...MW AVIATION...KT
...Update to aviation forecast discussion...

.DISCUSSION... Issued at 256 PM CDT Sun May 29 2022 Key Points: - Warm and windy through tomorrow - Severe storms possible late afternoon through nighttime hours tomorrow - Additional rounds of storms Tuesday into Wednesday bring locally heavy rainfall and renewed flooding concerns Sfc trough extends from southeastern CO through western KS into central NE early this afternoon, which has resulted in a tight pressure gradient across the CWA. South winds have reached advisory criteria at a few locations and should slightly decrease this evening and overnight, though gusty winds are expected to continue into tomorrow. Wouldn`t rule out near-criteria conditions on a more isolated basis and will monitor trends, but no changes have been made to the advisory at this time. Have removed PoPs from north central KS this evening with the better forcing being well to our northwest and CAM guidance largely keeping convection out of the area. The only exception to this is overnight, closer to sunrise, with a few CAMs once again showing a weak signal for isolated elevated convection within the WAA regime as we`ve seen the last couple of mornings. Added slight chance PoPs for a brief period tomorrow morning near the KS/NE border, although that could extend further south if we trend more toward the latest HRRR run from 18Z. Most focus has been on the potential for severe storms tomorrow. What we do know at this point is the environment looks favorable for severe weather by the afternoon, especially along the dryline. Main question revolves around the coverage of storms, both around initiation time and into the evening. At this time, the favored scenario is for storms to develop along the dryline late in the afternoon, which is progged to be located in the Marysville- Manhattan-Abilene vicinity. The atmosphere would be very unstable with an eroded cap by this time with 2000-4000 J/kg SBCAPE and 50+ kt effective shear. Supercells look to develop initially before congealing into lines and/or clusters. Hodographs become more elongated into the early evening with the increase of the LLJ. This would favor large hail, damaging wind, and a few tornadoes all being possible. Later into the evening and overnight, the event should evolve into more of a hail and wind threat with the cold front catching up to the dryline and pushing southeast across the area. The higher probabilities are in the northern half of the CWA, but everyone should at least be prepared for severe weather potential - east central areas would see it later in the night if it holds together. The GFS has the frontal boundary south of the area by Tuesday afternoon, but the NAM continues to keep it a bit slower, so we continue to keep an eye on potential for redevelopment Tuesday afternoon mainly in east central areas. Even if the sfc boundary is further south, the 850mb front hangs around into Wednesday and with additional disturbances within the flow, chances for storms exist through mid-week. Good moisture transport along with Pwat of at least 1.5" should result in efficient rain producers, and areas that see repeated rounds of rain could see a return of flooding concerns with more saturated grounds. High pressure moves in for Thursday and Friday with cooler temperatures and highs in the 70s. Another chance for storms may arrive late in the week as another system moves through the area. && .AVIATION...(For the 00Z TAFS through 00Z Monday evening) Issued at 622 PM CDT Sun May 29 2022 LLWS is once again the main hazard especially over the first half of the period. Winds around FL015 increase to 60-65kts or possibly a bit stronger generally soon after sunset lasting an hour or two after sunrise. Surface winds relax but only slightly overnight and remain generally from the south. Can`t rule out a few isolated or scattered elevated showers or storms especially around KMHK by around sunrise. However, confidence is too low at this time for inclusion. Potential for severe weather increases by the end of the forecast period and into the next cycle. && .TOP WATCHES/WARNINGS/ADVISORIES... Wind Advisory until 8 PM CDT this evening for KSZ020>022-034>038- 054-055-058. && $$ DISCUSSION...Picha AVIATION...Drake