Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/20/23


Area Forecast Discussion
National Weather Service Billings MT
315 PM MDT Fri May 19 2023 .DISCUSSION... Tonight through Sunday night... N to NW flow aloft will persist tonight through Sunday. This will continue to bring patchy smoke into the forecast area from wildfires in Alberta and Saskatchewan, and the RAP model supported this idea. Smoke could be seen in visible satellite imagery this afternoon, as well as on the webcams. KLVM reported visibility of 5SM at 19Z. An AQA was in effect for the forecast area in MT for moderate air quality. Will issue another SPS for air quality/smoke for Sheridan County, WY. Otherwise, upper ridging will bring dry conditions to the forecast area tonight with mild weather. A shortwave, seen on water vapor imagery over central Alberta this afternoon, will move SE through NE MT Saturday afternoon and evening. The wave will push a weak cold front S through the area in the afternoon. GFS and SREF showed CAPES of 500-1000 j/kg with little shear. PWAT`s increase to around 0.75 inches. Focus of convection will be from KBIL W and over the NE Bighorns with PoPs of 20-40%. Kept convection chances going through 03Z Sat. night based on deterministic models, and spread 20 PoPs SE through Big Horn County E into Powder River County. Convection will dissipate late in the evening with lack of lift and insolation. SW flow aloft increases over the area Sunday and Sun. night ahead of Pacific NW system. CAPE and shear on Sunday will be similar to the values on Saturday with PWAT`s 0.50-0.75 inches. Chances for convection will be confined to over and near the mountains mainly in the afternoon. It will be warm both days with highs in the 80s which was 15-20 degrees above normal for this time of year. Records were mostly in the 90s, so not looking at record heat. Arthur Monday through Friday... The main focus points over the long term will be ridging keeping our temperatures above to much above average and prolonged southwest flow next week bringing multiple precipitation chances. Monday will be hot with widespread temperatures in the high 80s to low 90s before a cold front passes through and the ridge axis moves further east. We will still have anomalously high heights the rest of the week with temperatures generally in the 70s to low 80s. Monday will see a Pacific trough located to the west of us bringing southwest flow favorable for precipitation chances. Winds will also be southerly throughout the plains allowing Gulf moisture to be advected into the region bringing high PWAT values. There will be some instability Monday and Tuesday with poor shear. There may be some isolated showers and thunderstorms if anything is able to form. Tuesday night through the rest of the week, better moisture moves in to create a more moist boundary layer bringing the better chances for precipitation. The shear profile may become more favorable but instability looks to remain along the border with the Dakotas making severe storms uncertain. Regardless, repeated precipitation chances next week gives most locations around a 50% chance for 0.25 inches according to NBM. This pattern change will bring about our best chance at getting rid of the smoke early next week. Torgerson && .AVIATION... Another push of heavier smoke is expected tomorrow morning bringing about reduced visibilities tomorrow, slant-wise visibility will be especially impacted. Winds look to remain light and skies remain clear until the possibility of some mid to high level cloud tomorrow afternoon. Torgerson && .PRELIMINARY POINT TEMP/POPS... Sat Sun Mon Tue Wed Thu Fri ----------------------------------------------------------- BIL 050/084 054/085 056/088 056/078 055/072 053/076 055/079 02/T 20/K 02/T 31/B 24/T 45/T 45/T LVM 049/081 050/083 052/083 049/077 048/069 048/074 049/076 02/K 22/T 14/T 32/T 25/T 46/T 56/T HDN 045/085 051/085 051/089 055/080 055/075 053/077 054/082 01/K 20/K 02/T 31/B 34/T 45/T 45/T MLS 044/084 053/085 056/090 060/080 056/075 055/074 055/079 01/K 10/K 00/U 31/U 23/T 43/T 43/T 4BQ 045/082 052/084 054/089 057/080 056/077 055/075 054/081 00/K 10/K 00/U 21/U 23/T 34/T 34/T BHK 041/080 050/083 052/087 056/080 053/074 053/074 051/079 00/K 10/K 00/U 22/W 23/T 34/T 33/W SHR 044/080 049/080 049/084 051/075 051/074 049/074 050/078 00/K 11/K 01/U 23/T 35/T 45/T 45/T && .BYZ WATCHES/WARNINGS/ADVISORIES... MT...None. WY...None. && $$ weather.gov/billings
Area Forecast Discussion
National Weather Service Glasgow MT
857 PM MDT Fri May 19 2023 .DISCUSSION... Evening Update: Smoke and haze mainly out to the west and east of the Glasgow area. Late this afternoon, smoke from the Crooked Creek RX fire from Petroleum County was visible on satellite imagery. For this reason, I included an broad area of haze for the CWA. Aside from that, the remainder of the forecast below remains valid. -Enriquez Previous Discussion: Today through Sunday night: The haze and smoke are temporarily holding off in central MT through tonight, before another wave of smoke is expected to move down into northeast MT from Alberta and western Saskatchewan by early Saturday evening. This will promote air quality issues, with low visibilities (as low as 1/2 mile at times) being a detector of how dense the smoke will be. So far, the RAP model gives confidence of smoke being over northeast MT through at least Sunday night. It is possible for smoke to continue on to later periods. With the frontal passage tomorrow morning, a slight chance of showers and thunderstorms is possible in far northeast MT near the ND border. Monday through Monday night: There is moderate confidence (50 percent) of scattered thunderstorms moving through with a shortwave trough passage. However, uncertainty remains in the timing and location of these storms. The warmest day of the season is possible ahead of this wave, so lapse rates will likely be steep (7.5 to 9 C/km). Current guidance from the NAM, GFS, and NBM agree on dewpoints being in the mid 40s on this day, with high DCAPE possible. Overall, this guidance suggests a few stray severe wind gusts across northeast MT in the afternoon hours. Tuesday into Wednesday: There is low confidence (30 percent) in thunderstorms occurring on Tuesday afternoon, with little agreement on a solution for storm mode. Wednesday night onward: A shortwave trough is showing up in model trends such as the GFS ensemble, but the question remains of whether or not this push will reach northeast MT to bring precipitation to the region. -Stoinskers && .AVIATION... LAST UPDATE: 0300Z FLIGHT CAT: VFR until 21Z, then down to MVFR to IFR in areas of smoke afterward DISCUSSION: Any areas of haze are lifted to at least 10 SM for the terminals. The line for haze continues to thin out, and will remain this way until Saturday afternoon. A push of smoke from Saskatchewan is expected by early Saturday evening, bringing visibility down to 1/2 to 1 mile. SFC WIND: Southeast at 10 to 15 knots decreasing to 5 to 10 knots. After 18Z, becoming northwest 5 to 10 knots. -Stoinskers/Enriquez && .GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE. && $$ weather.gov/glasgow
Area Forecast Discussion
National Weather Service Goodland KS
955 PM MDT Fri May 19 2023 .UPDATE... Issued at 951 PM MDT Fri May 19 2023 Latest short term guidance is hinting at some isolated patchy fog to impact portions of northeast Colorado after 06z into sunrise. based on the latest surface analysis, this looks to occur along/ahead of the surface ridge axis, which is currently nosing into northeast Colorado. Will have to monitor in case guidance shows this potential to shift further east towards the Kansas border, but for now the best chances look to occur over isolated western portions of Kit Carson/Cheyenne counties. && .SHORT TERM...(This evening through Sunday Night) Issued at 242 PM MDT Fri May 19 2023 At the start of the short term period, the latest upper air RAP analysis displays an upper air low over northern WI and an upper air ridge over the western CONUS with a weak low embedded within the ridge over southern WY on Friday afternoon. Current surface observations report some reduced visibilities mainly in the western portions of the CWA due to Canadian wildfire smoke with the latest satellite imagery showing scattered to overcast clouds across the region. Models show this upper air pattern pretty much staying in place through the rest of Friday with a westerly upper air flow over the CWA. At the surface, a surface high looks to move south from the Northern Plains into NE overnight allowing for cloud cover to lessen as well as winds to become mostly light and variable. Dry conditions are expected for the remainder of the day as well. Models also show some reduced visibilities remaining in the southwestern quadrant going through the night due to the lingering smoke. Overnight lows expect to be in the lower to middle 40s. On Saturday, forecast guidance shows the upper air low residing over the CO/WY border with the CWA being barely underneath a subtropical upper air ridge in the morning. By the evening hours, models continue to give the CWA a westerly flow going into the night. Dry conditions are expected for the region throughout Saturday as the surface high slowly moves eastward during the day along with a surface trough in CO creating a southerly surface flow for the CWA. Precipitation chances look to stay south and west of the CWA, but will monitor in case this changes in future runs though there is low confidence in this happening at this time. Daytime highs on Saturday look to range between the lower and upper 70s while overnight lows are forecasted to be in the middle 40s to lower 50s range. Going into Sunday, models show the CWA underneath the area where a split flow joins together in the morning having an upper air low over the AZ/NM border and an upper air ridge over the northwestern CONUS that has an embedded weak low over northern CO in the morning. A shortwave disturbance then appears over the CWA by the late afternoon and evening hours. At the surface, chances for showers and thunderstorms are seen in the afternoon and evening hours particularly in the CO and KS counties. Best chances look to be south of I-70 in the evening. While there is a few hundred J/kg of CAPE seen in forecast model soundings, severe weather is not anticipated at this time as the environment looks to stay capped. Current QPF totals look to range between a trace to a few tenths with areas that see precipitation. Fire weather does not look to be a concern on Sunday as with the other days in the short term period due to minimum relative humidity values staying above criteria. Daytime highs on Sunday range between the lower 70s and lower 80s followed by overnight lows ranging between the upper 40s and lower 50s. .LONG TERM...(Monday through Friday) Issued at 201 PM MDT Fri May 19 2023 For this long-term forecast period, the overall weather pattern will begin shifting from a split-flow and upper level ridge centered over the High Plains to more of an amplified western United States trough. What this will mean for our region is that flow aloft will be from the southwest, allowing shortwave troughs to move through as they rotated around the primary longwave trough. This should mean a return to active weather, and with a dryline in place and return flow from the south, a return to potentially more substantial severe weather. For Monday and Tuesday, the High Plains will still be situated within a split-flow pattern. Typically, this does not bring us higher chances for precipitation. However, there should be a dryline situated somewhere along the Colorado border, serving as the surface mechanism for storms to form on. Instability will be on the rise with southeast flow bringing in warmer air and a return to the Gulf moisture. That being said, light winds aloft and the lack of substantial shortwave trough should mean generally quiet weather. A few storms can`t be totally ruled out, but significant severe weather or widespread storm coverage should not be anticipated given this setup. From Wednesday into Friday, the upper level pattern begins to change and the southern jet stream takes on a more amplified appearance. This happens as a trough of low pressure forms over the southwestern United States. As this happens, southeast flow should persist as a surface trough forms in lee of the Rockies. Moisture return becomes quite evident with surface dewpoints in the 50s and 60s forecast, and perhaps into the mid 60s by Friday. Precipitable water readings should also be on the rise, reaching the 1.3" mark for parts of the region Friday. Each day, instability will get a little higher with SB Cape climbing into the 2000-3000 j/kg range by late week. In addition, with the southern jet stream amplifying across the area, the wind field strengthens resulting in larger wind shear, with 0-6 km bulk shear eventually reaching 25-35 kts. With a dryline ebbing and flowing each day, anticipate thunderstorm development each afternoon and evening across the High Plains. Some storms could certainly be severe with the instability and wind shear anticipated, and with the amount of moisture present, we also can`t forget the potential for heavy rainfall and flash flooding. Keep an eye on the forecast towards the end of next week as it would not be surprising to see several days of severe weather. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 456 PM MDT Fri May 19 2023 For KGLD, mainly VFR conditions for the forecast period. There will be periods of patchy smoke through 13z Saturday, with a brief reduction to visibility to 6sm at times. Winds, northeast around 10kts through 03z Saturday, then light/variable. By 13z, south around 10kts, with gusts to 20kts from 17z onward. For KMCK, mainly VFR conditions for the forecast period. There will be periods of patchy smoke through 15z Saturday, with a brief reduction to visibility to 6sm at times. Winds, northeast 10-20kts through 02z Saturday, then light/variable. By 15z, south around 10kts. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ UPDATE...JN SHORT TERM...076 LONG TERM...RRH AVIATION...JN
Area Forecast Discussion
National Weather Service Grand Rapids MI
1059 PM EDT Fri May 19 2023 LATEST UPDATE... Update .UPDATE... Issued at 1059 PM EDT Fri May 19 2023 Surface visibilities are still being affected by haze from western fires even at this hour. Visibilities range from 9 miles along the lakeshore to 3-5 miles towards Lansing and Jackson. RAP model smoke progs show conditions improving through the night in the northwest flow behind the cold front. Vertically integrated smoke however will hang around into Saturday. Low clouds are seen off to our north and west at this hour and those clouds will advance into the forecast area through the night. We are expecting a dry rest of the night from this point as the frontal precipitation in the southeast is clearing out of the area. && .DISCUSSION...(This evening through next Friday) Issued at 217 PM EDT Fri May 19 2023 - Isolated thunderstorm risk this afternoon MU CAPE values from SPC`s Mesoscale Analysis page were under 250 J/kg across the area at this time. The values were climbing as this system draws in some moisture from the southwest. Projections through 21z suggest the values will increase to around 500 J/kg prior to the front pushing east of Jackson. Earlier there had been a few lightning strikes down in far southern Lake MI, but since then no storm have been observed. We will maintain a low risk for thunderstorms for a few more hours in the forecasts. - Warming trend early next week Mid level heights rise Sunday into Monday as ridging starts to move in. Down at 850 mb a southerly flow is shown to set up by Monday with temperatures at that level climbing to near 13 deg C. This will support temperatures reaching well into the 70`s with some 80 degree readings possible. A cold front is shown to drop down from the north Thursday into Friday but based on the latest trends that feature will likely stay up in Canada. The 850 mb temperatures are shown to climb to 14 to 15 deg C Memorial Day weekend which suggests many locations will see the 80s...supported by the ensemble max T`s from the ECMWF and CMC, but not by the GFS. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 832 PM EDT Fri May 19 2023 A cold front has swept to the south and east of the TAF sites as of 00z with a band of rain associated with it about to move east of JXN. The remainder of the night will focus on 1) haze reducing visibilities and 2) the formation of lower ceilings. As for the haze, it is associated with near surface smoke from Canadian forest fires per the RAP Smoke model. The haze is actually forecast to improve through the night a bit from 3-5SM to 6 or 6+ statute miles. Slightly improved conditions are expected on Saturday, but it will still be around to some extent. As for the low clouds, a surge of MVFR ceilings will invade the sky from the north overnight (after 04z). These ceilings will become widespread and reach maximum expanse between 13z and 15z Saturday morning. VFR conditions will then return for Saturday afternoon. Winds from the northwest at 5 to 15 mph will be common the next 24 hours. Wind gusts towards 20 knots will be possible on Saturday. && .MARINE... Issued at 217 PM EDT Fri May 19 2023 The combination of cold air advection and a tightening pressure gradient will lead to hazardous conditions for small craft developing for parts of the nearshore waters later tonight. The deeper mixing persists into Saturday afternoon...especially near and south of Muskegon. We will hoist a small craft advisory for that region. The winds and waves will decrease considerably by Sunday. Webcams show reduced visibilities around Grand Haven and South Haven. We added that risk to the hazardous weather outlook and included it in the grids. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory from 4 AM to 5 PM EDT Saturday for LMZ844>847. && $$ UPDATE...Duke DISCUSSION...MJS AVIATION...Duke MARINE...MJS
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
844 PM CDT Fri May 19 2023 .SYNOPSIS... Issued at 808 PM CDT Fri May 19 2023 Showers and a few thunderstorms will continue into the evening southeast of a Bloomington to Jacksonville line...before dry weather returns across the board overnight. Low temperatures will range from the middle 40s in the Illinois River Valley to the middle 50s south of I-70. && .UPDATE... Issued at 808 PM CDT Fri May 19 2023 Showers and patchy drizzle will persist in the vicinity of the cold front tonight, ending from north to south as the 500-mb trough axis sweeps across the region. Temperatures will be coldest north of I-72 where skies completely clear, radiating things down into the mid 40s. Otherwise, smoke ought to be with us again tomorrow as we remain in a northwest flow pattern aloft with deep boundary layer mixing. MJA && .SHORT TERM... (Through Late Saturday Night) Issued at 335 PM CDT Fri May 19 2023 20z/3pm surface analysis shows a cold front settling southward toward the I-70 corridor. Scattered thunderstorms have formed immediately along/ahead of the boundary from near Danville southwestward to Shelbyville. Meanwhile further northwest on the cool side of the boundary, a band of light to moderate showers has developed along a Bloomington to Jacksonville line. Based on radar trends and latest HRRR/RAP forecast, it appears precip chances will linger into the evening across the southeast two-thirds of the KILX CWA...with the primary threat for thunder shifting south of I-70. As the front drops further south toward the Ohio River, a few showers may linger past midnight along/south of a Robinson to Flora line...with dry weather expected everywhere before dawn Saturday. In addition to the showers, area obs/webcams have shown smoke from Canadian wildfires mixing to the surface behind the cold front. Visibilities have been reduced to 2-4 miles at times, so have included patchy smoke in the forecast late this afternoon into early this evening before it disperses and moves out of the area after dark. Lows tonight will be considerably cooler than last night...ranging from the middle 40s in the Illinois River Valley to the middle 50s south of I-70. Despite cloud cover departing, RAP data continues to suggest a high/thin overcast of smoke through the night into Saturday. Highs on Saturday will be below normal for this time of year in the lower 70s. Barnes .LONG TERM... (Sunday through Next Friday) Issued at 335 PM CDT Fri May 19 2023 Upper pattern dominated by western CONUS ridging and eastern troughing will break down early next week, resulting in a return to more zonal flow by Monday. With ample smoke upstream across ALberta/Saskatchewan and deep-layer northwesterly flow initially in place, think smoky skies will still be observed on Sunday. Despite the slight obscuration of the sunshine, rising upper heights will allow highs to climb into the middle to upper 70s. After that, the western upper ridge will build eastward. Models have been consistently showing a blocking pattern forming by the middle and end of the week...with ridging over the Great Lakes/Midwest and troughing across the Gulf Coast. This will ensure the continuation of warm/dry weather through the remainder of the extended. Temperatures will climb well into the 80s after Monday. Barnes && .AVIATION... (For the 00z TAFs through 00z Saturday Evening) Issued at 624 PM CDT Fri May 19 2023 Showers will continue to diminish this evening at CMI/DEC/SPI as a cold front sags further south across the state. Clouds will diminish overnight, though some residual smokiness may reduce visibility to between 5 and 10 SM through Saturday afternoon before dispersing. Surface winds will maintain a northerly component through this TAF period with sustained speeds between 5-10 kts. MJA && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$ WFO ILX
Area Forecast Discussion
National Weather Service New Orleans LA
904 PM CDT Fri May 19 2023 ...New UPDATE... .UPDATE... Issued at 851 PM CDT Fri May 19 2023 Overall, current forecast looks to be tracking well. We`ve had a few isolated showers flirting with the northeast corner of the CWA since sunset, with very limited areal coverage. Even those appear to be dissipating at this time. Can`t totally rule out additional isolated development later in the night, but probabilities well below the 15 percent threshold to carry in the ZFP. Winds, temperatures and dew points currently in line with forecast. An initial look at the 00z HRRR depicts a slightly earlier convective initiation Saturday afternoon than earlier runs, but not enough of a difference to shift the Saturday portion of the forecast at this time. Update that will be transmitted shortly is primarily to remove the today portion of the forecast. && .SHORT TERM... (This evening through Saturday night) Issued at 302 PM CDT Fri May 19 2023 Tonight through Sunday morning, high pressure will dominate the upper level pattern ahead of a weak frontal system that moves through Saturday night/early Sunday morning. Southerly surface winds will help to enhance warm air advection and moisture advection across the area, which will increase instability across the environment. Weak upper level divergence during the daytime hours Saturday will help to increase the buoyancy in the environment. As a result, scattered showers and storms will be possible Saturday, mainly during the afternoon hours ahead of the system. Generally, convection will form around the coastal areas more Saturday afternoon, especially along the MS and LA coastal areas associated with the weak frontal boundary. Then, scattered to numerous showers and storms will be possible Saturday night/early Sunday morning as the shortwave frontal system moves through the area. As a result of lower cloud cover chances as we move toward the weekend and generally light wind speeds, the temperatures will be quite warm again going into the weekend with highs in the low 90s and heat index values in the upper 90s. There is still some models indicating high cloud cover tomorrow (~60% or higher) due to higher rain chances and the system approaching, so NBM temperatures were left in the forecast for now for Saturday. People still need to remember to hydrate and wear loose fitting clothing as we progress toward Summer. MSW && .LONG TERM... (Sunday through Thursday night) Issued at 302 PM CDT Fri May 19 2023 Well definitely looks like we are fully in the process of moving into Summer to start the week off next week but that could quickly change. Warm humid conditions with daily rain chances pretty through Tuesday, possibly Wednesday. That said there are some sizable differences in the main two medium range operational runs of the GFS and ECMWF with the evolution of the mid lvl pattern at the end of the work week. Each of these also have support from their respective ensemble means. In addition the Canadian is in its own camp as well but does lean towards the GFS and GEFS. The GFS side would suggest much cooler and maybe slightly better rain chances while the EC side is warmer and drier yet also below the NBM at this time. With that not going to make any major changes to the forecast from the NBM except to tweak down just to get closer to the EC temps at least until there is a better target to focus on. In addition this is at day 6/7/8 so there is time to see how things will evolve before jumping one way or the other and no real need to dig too deep yet. Beginning Sunday we will have a stalled weak boundary to deal with just off the coast from Saturdays activity. This obviously could lead to some coastal storms but just north of the coast along I-12 north and across the MS coast we should see drier conditions and even drier LL air leading to a fairly pleasant late May Sunday afternoon. H925 temps around 19-20C would translate to around lower mid 80s for much of the area and with dewpoints in the lower 60s to near 70 the apparent temps will not be a concern with Heat Index readings maybe just topping 90 in a few areas; not bad for late May on the weekend. Rain may not be completely out of the question though as there could be a small s/w that moves across the southern Plains and through the Lower MS Valley Sunday and could bring some showers and thunderstorms to far eastern zones, mainly east of I-55. This is associated with all of the energy currently over the Baja and western Mexico but whether or not it moves over this way could be the beginning of how we see things evolve next week. The ridge from the extreme western Gulf and stretching to the NNW into the southern Plains and how strong it is may give us our first clue about how the pattern will evolve. That piece of energy will be dictated by the strength of the ridge. A stronger ridge will slow it down, push it more north, or even block. A weaker one will allow it to slide through into the southern Plains and Lower MS Valley by late Saturday and through Sunday. To start the week the boundary will likely mix out/decay and likely a more zonal mid lvl flow regime initially however The development of a closed low over the sern CONUS or deep L/W trough along the Atlantic coast will begin to take shape by Tuesday and more so Wednesday. This should put the region into northwest flow aloft eventually or even N to NNE flow. Monday should initially be quite similar to Sunday but with a little moderation thus slightly warmer and more humid. Afternoon convection is more likely Monday and then on Tuesday just before mdls start to diverge we should be back into the upper 80s to lower 90s with scattered afternoon convection. By Wednesday and through the remainder of the week things are more p in the air but at the very least we should be cooler and could be below normal for temperatures, always a welcome site for late May and into the Summer. /CAB/ && .AVIATION... (00Z TAFS) Issued at 631 PM CDT Fri May 19 2023 Isolated SHRA have developed over the last hour just east of KMCB and over downtown New Orleans. Can`t rule out them impacting terminals entirely, but with sunset approaching, they are expected to dissipate in the next couple hours. At this time, don`t expect TSRA near KHBG to make it far enough south to impact local terminals before they dissipate. Overnight, expect some MVFR visibilities at KMCB around sunrise, and can`t rule out a brief period of IFR entirely. At remaining terminals, threat is pretty low for any significant restrictions. Any restrictions at KMCB should improve by 14-15z. Question then becomes the convective threat with the frontal boundary on Saturday. Northwestern terminals...KMCB/KBTR/KHDC could see scattered convection by mid-afternoon, with remaining terminals probably holding off until near or after 00z Sunday. Currently don`t expect areal coverage to merit any more than VCTS. && .MARINE... Issued at 302 PM CDT Fri May 19 2023 Generally, we will have good weather conditions going into the next week. Winds will be generally light to moderate (<15 kts) and southerly to westerly through Sunday morning. A weak frontal system will move through Saturday, so winds Sunday through Wednesday morning will be generally moderate (<15 knots) and northerly in direction. Wednesday through Thursday, winds will be stronger as the pressure gradient increases some. Currently, winds will be easterly and generally <15 kts, but conditions will be approaching exercise caution headlines (~15 kts). So, we will monitor for changes as we get closer. MSW && .PRELIMINARY POINT TEMPS/POPS... MCB 67 90 64 81 / 0 40 30 30 BTR 72 93 69 85 / 0 20 20 30 ASD 72 93 69 86 / 0 20 30 30 MSY 73 92 73 85 / 0 20 20 30 GPT 72 90 70 85 / 10 20 30 30 PQL 70 90 69 87 / 10 20 30 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...MSW LONG TERM....CAB AVIATION/UPDATE...RW MARINE...MSW
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
629 PM CDT Fri May 19 2023 .SHORT TERM... Issued at 250 PM CDT Fri May 19 2023 Through Saturday night... A weak surface cold frontal trough is currently moving across northeastern IL into northwestern IN. Areas along and ahead of this front (generally areas east of I-55) will continue to be the favored area for scattered showers and even a couple of thunderstorms for the next few hours this afternoon before the activity gradually sags southward out of the area with the front into early this evening. Elsewhere, including most of the Chicago metro and Rockford areas, the precipitation threat has ended. However, hazy conditions (with reduced visibilities) are expected to persist for a few hours this afternoon due to some of the Canadian wildfire smoke mixing down to the surface in the wake of the front. This is expected to only last for a few hours, with conditions improving from north to south into this evening. Otherwise, dry and seasonable weather is expected for Saturday, with inland highs topping out in the low 70s under mostly sunny skies. However, an onshore wind will make for cooler conditions (around 60) along the northeastern IL and northwestern IN Lake Michigan shores. KJB && .LONG TERM... Issued at 250 PM CDT Fri May 19 2023 Sunday through Friday... The upper-level flow pattern for the upcoming week will be characterized by a pronounced ridge that will slowly progress eastward across the central CONUS before a cut-off upper-level low becomes established over the Gulf Coast Thursday into Friday and sets up a Rex Block that appears likely to linger around through next weekend. At the surface, high pressure will be prevalent over the northeastern quadrant of the CONUS through much of this time period and will keep things mostly quiet weather-wise in this part of the country with most of any notable weather next week remaining confined to the Great Plains and Southeast. For the NWS Chicago CWA, this means that the Sunday through Friday time frame will likely feature little to no precipitation, plenty of sunshine, light winds, above normal temperature readings for this time of year, and comfortable humidity levels. Daily lake breezes can also be expected during this time, resulting in cooler temperatures near the lake each day. The lone "fly in the ointment" for next week, as the discussion from the preceding overnight shift put it, may be the continued influence of Canadian wildfire smoke as predominantly northwesterly flow downwind of the Canadian Rockies will likely shuttle additional smoke plumes towards the Great Lakes over the coming days. The latest RAP-Smoke output suggests that skies here on Sunday will likely be bereft of any smoke, though we may not be as lucky come Monday or Tuesday. Beyond that, the smoky sky outlook is less clear (no pun intended), but if the Canadian fires persist, then it`s not unreasonable to think that we may be seeing milky skies and filtered sunshine for much of next week, especially when considering the expected stagnant weather pattern here. Ogorek && .AVIATION... For the 00Z TAFs... Aviation Forecast Concerns: * Northeast winds shifting back to the north-northwest early this evening at ORD, and mid-late evening at MDW. * MVFR/low VFR visibility in smoke improving to VFR this evening. * Wind shift to northeast with another lake breeze Saturday by midday for ORD/MDW. Strong lake breeze push developed into ORD/MDW behind the earlier cold front, despite gusty north-northwest winds. MKE and ORD terminal Doppler radars show boundary has stalled northwest of ORD and was starting to shift back to the southeast, thus expect winds at ORD to shift back to 340-ish in the 01Z timeframe based on extrapolation of the boundary on radar. Should see a similar shift at MDW, though likely not until later this evening. Winds may continue to gust above 15 kts for a time before eventually settling down to around 10 kts late evening/overnight. Surface high pressure will drift into the region Saturday, with the weakening gradient again allowing a northeast wind shift behind the lake breeze. Could be slightly later, say 17-18Z for ORD, but with relatively low confidence at this time have maintained 16Z from previous forecast. Still seeing 5-6SM visibilities in smoke across the Chicago terminals, but RAP near-surface smoke forecasts suggests this should clear out this evening with winds turning northwest again. Otherwise, VFR conditions expected throughout the remainder of the TAF period. Ratzer && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...None. && $$ Visit us at weather.gov/chicago Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/NWSChicago www.twitter.com/NWSChicago www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1101 PM CDT Fri May 19 2023 .UPDATED for Aviation Discussion... Issued at 1059 PM CDT Fri May 19 2023 && .DISCUSSION...(This evening through Friday) Issued at 217 PM CDT Fri May 19 2023 KEY MESSAGES: - Brisk tonight into Saturday morning as lows drop into the low to mid 40s. - Pleasant stretch of late-Spring weather forecast through middle of next week. - A warming trend is expected from the weekend onward into next week. If you`ve been waiting for a nice stretch of Spring weather to enjoy before the Summer heat ramps up... this is it! There has been little change from the previous forecast update and in this case thats good news. Today`s weather has played out as expected as our stratus deck and cold air aloft have kept temperatures in check. Skies will clear out this evening into Saturday morning as a sprawling surface high pressure begins to settle in across the central CONUS. This allows our temperatures to plummet into the low to mid 40s by Saturday AM. Temperatures rebound quickly by Saturday afternoon with highs into the lower 70s on Saturday and mid to upper 70s on Sunday. RAP guidance does highlight the potential for another round of dense elevated wildfire smoke late Saturday and will stick around for Sunday. Our warming trend continues into next week as upper-level ridging builds east from the PAC NW into the Canadian Prairies and Northern Plains by mid next week. NBM has highs in the low to mid 80s for a majority of the CWA Tuesday through the end of the period as southwesterly flow will advect warm air into the Upper Midwest throughout the period. An impressive dry signal is present in both the EPS and GEFS through next Wednesday as ridging limits any threat of convection or precipitation. Our next potential system will begin to suppress the ridging across the Northern Plains, but there is a wide spread in with timing and intensity differences. This is apparent as NBM PoPs edge higher for the end of period with slight chance/chance PoPs Friday. && .AVIATION...(For the 06Z TAFS through 06Z Saturday night) Issued at 1059 PM CDT Fri May 19 2023 VFR conditions throughout. Expect clear skies overnight and Saturday, with north/northwest winds becoming more southwest. KMSP... No weather-related aviation concerns. VFR conditions throughout. Expect clearing skies overnight, with north/northwest winds becoming more southwest on Saturday. /OUTLOOK FOR KMSP/ Sun...VFR. Wind SW backing to SE around 5 kts. Mon...VFR. Wind S 10G15kts. Tue...VFR. Wind S 10G20kts. Wed...VFR with -SHRA possible late. Wind S 10G15 kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BPH AVIATION...JRB
Area Forecast Discussion
National Weather Service Marquette MI
655 PM EDT Fri May 19 2023 .SHORT TERM...(Tonight) Issued at 358 PM EDT FRI MAY 19 2023 Water vapor imagery and RAP analysis shows a closed mid-level low circulation near Eagle River. Wraparound moisture and deep layer q- vector convergence associated with the low is supporting isolated to scattered showers mainly over Lake Superior and the western counties of the U.P at this time. There is some conditional instability associated with the cold core of the mid-level as noted on the fcst soundings as mid-level lapse rates are 7C/km over central and eastern Lake Superior. Biggest inhibiting factor for more organized convection is abundant cloud cover over the area so only showers expected into this evening and no thunder. Highs today under cloud cover have ranged from only the 40s west to mostly lower to mid 50s central and east. Tonight, models indicate the mid-level low will slide southeast of the U.P. later this evening as CAMs show the bulk of the shower activity shifting from Lake Superior and west into north central and eastern counties of the U.P. this evening before sliding se of the fcst late tonight with the exiting closed low. Clearing skies are expected from west to east behind the exiting closed low and min temps could get quite chilly, especially interior west where winds will become lightest under a building sfc ridge. Look for min temps ranging from the mid 30s interior west to the lower to mid 40s mainly east and south central. Could be some patchy frost interior west. .LONG TERM...(Saturday through Friday) Issued at 418 PM EDT FRI MAY 19 2023 By 12Z Saturday, the low that forced showers today will be departed and PoPs will be exiting the region. In its wake, broad midlevel ridging will be over the central CONUS, with 500mb height anomaly of around 10 dam upstream through Monday. This will lead to a northwesterly flow regime and quiet weather for the weekend and start of the next work week. Saturday will be the day of highest fire weather concern, with minimum RH`s dropping into the 20s with wind gusts around 15-20 mph. Sunday`s RH`s are not expected to fall much despite dueling 1020s mb high pressures over Ontario and the middle Mississippi Valley thanks to a dry cold front keeping temperatures especially near Lake Superior cooler. Monday will be another quiet day across the region as the GEFS shows a mean high pressure near 1030mb over the Ontario/Quebec line. Little to no fire weather concerns Monday as relaxed gradients under the high pressure will keep winds low and minimum RH`s only fall to the 30s. PoPs return to the forecast Tuesday with another cold front dropping south with a surface trough. Precipitation totals are not anticipated to be high as even outlier solutions within the NBM only have a few tenths of an inch of rain at SAW. NBM temperature spread is also vast going into the midweek, with Wednesday`s high at SAW being anywhere from 55 to 80, likely due to the models not having a good grasp of where the cold front and associated upper level features will be and at what strength. High model spread and uncertainty persist into the late week, with even higher ranges for temperatures and many low but nonzero precip chances. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 655 PM EDT FRI MAY 19 2023 Low clouds, patchy fog, and spotty showers will keep prevailing MVFR to occasional IFR restrictions going through this evening before drier air and clearing skies work in later tonight. IWD and KCMX should improve to VFR early evening and at KSAW late evening or around midnight. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 418 PM EDT FRI MAY 19 2023 Northerly wind gusts of 20 to 25 knots over the central portions of the lake will end tonight. Winds remain below 20 knots through Saturday afternoon when southwesterly gusts increase to 20 to 25 knots over the west half of the lake until Saturday night. Sunday morning, a cold front passing north to south over the lake will kick up northerly and northeasterly wind gusts of 20 to 25 knots over the west half of the lake. Monday, winds remain below 20 knots. Early Tuesday morning, ahead of another cold front, southerly winds increase to 20 to 25 knots before becoming westerly at around 20 knots Wednesday. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Voss LONG TERM...GS AVIATION...07 MARINE...GS
Area Forecast Discussion
National Weather Service San Francisco CA
559 PM PDT Fri May 19 2023 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 109 PM PDT Fri May 19 2023 Morning clouds and cool temperatures will prevail along the coast with a robust marine layer. High pressure will bring warm temperatures to inland areas through mid week, with slight cooling expected thereafter. Breezy winds at times for the coastal waters and along the coastal interface. && .SHORT TERM... (This evening through Saturday) Issued at 109 PM PDT Fri May 19 2023 Another May day, another visible satellite image depicting stratus along the coast. This afternoon, stratus has lingered longer over the SF Bay, so places such as the SF Peninsula are still in the soup of low clouds. This will likely be the story for the remainder of the afternoon with a decent onshore gradient push continuing through the evening in addition to a persistent, robust marine layer. Today, sunny skies prevail inland and temperatures will feel similar compared to yesterday with highs in the mid to upper 60s near the coast and mid 70s to mid 80s further inland. On the broad scale, weather pattern will not change in the short term with ridge high pressure residing over western CONUS and an upper level low over the Gulf of Alaska. This means similar weather is to be expected tonight into tomorrow with stratus making its way inland, bringing patchy fog and cloudy skies through the late morning Saturday. && .LONG TERM... (Saturday night through next Thursday) Issued at 109 PM PDT Fri May 19 2023 Sunday will see a slight warmup in temperatures (a few degrees) with high pressure lingering. However, won`t be very noticeable along the coastline with marine influence. On Sunday, expect inland regions to be in the upper 70s to mid 80s. A pattern shift is expected beginning Sunday night as trough moves into the Pacific NW from the Gulf of Alaska, which will start to break down the ridge. Both deterministic and ensemble models show this pattern shift starting early next week. However, there are still different solutions on the strength/amplitude of this trough as deepens into our area midweek. As trough settles in, amplified ridge will set up over the eastern Pacific, tightening the onshore pressure gradient. With this, expecting stronger northwest winds midweek. Strongest winds expected to stay confined over the waters, but will still be breezier during the afternoons on Tuesday through Thurs. Another change in sensible weather will be the cool down that will take place as a result beginning on Tuesday lasting through the work week. Otherwise, rain chances continue to look slim but could see some light precip/drizzle midweek. && .AVIATION... (00Z TAFS) Issued at 559 PM PDT Fri May 19 2023 The marine layer depth varies only slightly from north to south this afternoon, 1500 feet Bodega Bay to 1600 feet Fort Ord per latest profiler data. Little change in the depth of the marine layer is forecast during the 00z taf cycle, coastal stratus and fog /LIFR-IFR/ moving back inland tonight and Saturday morning on onshore winds. Stratus and fog mixing out to the coastline by late Saturday morning and afternoon. Vicinity of SFO...Low confidence VFR holds through the evening since stratus is along the coast and there`s a robust onshore pressure gradient and wind; recently peak gusts to the upper 20 knots range. Model output from RAP and HREF leaning a little earlier with stratus /IFR/ intrusion than currently forecast (07z), forecasting between 03z and 05z. Will continue to monitor and coordinate with the CWSU for potential amendments to forecast. The HAF-SFO pressure gradient is 1.5 mb, SFO-SAC gradient is 4.0 mb. IFR ceiling tonight and Saturday morning, low confidence stratus mixing even as late as 19z per latest HREF output showing stratus holding through early afternoon. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...VFR, then stratus /IFR/ moving inland through the evening, a mix of stratus and fog /LIFR-IFR/ tonight and Saturday morning. Patchy light drizzle developing overnight. Stratus and fog mixing out by early afternoon, though may be slow to mix out per recent HREF output showing stratus and fog /IFR/ quickly returning inland Saturday evening. && .MARINE... (Tonight through next Wednesday) Issued at 443 PM PDT Fri May 19 2023 Breezy northwest winds continue across the coastal waters with favored coastal jet regions getting occasional gale force gusts during the afternoon today. Winds expected to increase over the northern outer waters starting Sunday lasting into midweek next week with gale force gusts likely, primarily north of Point Reyes. These strong winds will lead to steepened wind wave heights. Additionally, a long period southerly swell 3 to 5 feet at 15 to 16 seconds continues through the waters and will slowly decay into the weekend. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 PM to 9 PM PDT Saturday for PZZ530. Small Craft Advisory until 9 PM PDT this evening for PZZ535. Small Craft Advisory from 9 AM to 9 PM PDT Saturday for PZZ535. Small Craft Advisory until 9 AM PDT Sunday for PZZ540-565-575. Small Craft Advisory until 3 AM PDT Sunday for PZZ545-570. Small Craft Advisory until 9 PM PDT Saturday for PZZ560. Gale Watch from late Saturday night through late Sunday night for PZZ570. && $$ SHORT TERM...McCorkle LONG TERM....McCorkle AVIATION...Canepa MARINE...McCorkle Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea
Area Forecast Discussion
National Weather Service Salt Lake City UT
403 PM MDT Fri May 19 2023 .SYNOPSIS...Above normal temperatures will continue across the region through the next seven days. Moisture remains in place and will continue to lead to the development of showers and thunderstorms each day, especially over the high terrain and adjacent valleys. && .SHORT TERM (Through 12Z Sunday)...Afternoon satellite and H5 analysis show the shortwave trough overhead pinching off, with mid-level flow beginning to shift more northerly and eventually northeasterly as the weak disturbance is advected east of the forecast area through the evening. With that, seeing storm motions slow over southern Utah and begin to train off of terrain, though a decreasingly favorable environment will limit convective potential and the ability for storms to organize. Thus, likely to see continued shower and thunderstorm activity through the evening, but concern regarding hydro or wind impacts is minimal at this time. Smoke continues to sit over the region, advected in on the northerly flow from southern Canada and smaller fires in the PacNW and Intermountain West. Still thin enough to have little impact on high temperatures for the day, though enough seems to be present in the lower levels to have some visibility and air quality reductions across the region. RAP forecasts suggest the smoke will stay in place over northern Utah through at least Saturday afternoon, thinning and perhaps clearing out for central and southern portions of the forecast area overnight tonight. With the evolution of the pattern through the weekend, there is likely to be periodic improvement in the smoke before the next trough returns the area to northwest flow stretching back into southwestern Canada again by Monday. With split flow solidly in place for Saturday, will see continued instability/thermally initiated showers and thunderstorms across southern Utah where moisture is available, though terrain-tied showers are possible through central and northern Utah as well. Generally expecting limited impacts as the last two days proved unproductive with more favorable environment, though will need to watch for better potential for training/backbuilding storms as the overall steering flow looks to be weaker. .LONG TERM (After 12Z Sunday)...The extended forecast period looks to remain modestly active as we continue to move into a continually wet early spring. A progressive ridge overhead will keep weather consistent as it has been with warmer temperatures and nice sunny days with the chance for some isolated showers and thunderstorms. A PNW low developing during the first half of the upcoming work week will take a bit of the warmth away and bring back the potential for more widespread precipitation by midweek. The start of the extended on Sunday looks to be more of the same as the high pressure ridge continues to sit overhead the Great Basin region. Before it moves out it will continue to promote warmer temperatures with most of the CWA seeing 5-10F above climatology for this time of year. We expect there to be a decent amount of lingering moisture left from the departed closed low, particularly in the southwest/south central parts of Utah, which will keep the potential for lingering isolated to scattered showers and storms for the afternoon/evening on Sunday and Monday. Similar to the past several days, showers/thunderstorms are once again expected to develop over high terrain areas before migrating off of terrain and into adjacent valley areas before diminishing, due to the weakly sheared environment. The light steering flow and anomalously high PWATs will contribute to an elevated flash flood risk for normally dry washes, slick rock and slot canyons. Temperatures peak on Monday with highs reaching the mid to low 80s for many valley floors while areas near St. George creep into the 90s. Temperatures fall slightly after the ridge moves out but still expected to hold just above climatology. The evolution of the upstream trough feature centered over the PNW starts on Monday and it slowly begins to effect the CWA. As this trough deepens over the CA coast its amplitude will promote much more moisture supply from the southern US into Utah. Its strengthening low will enhance the baroclinic zone at its leading edge as well which will help develop better large scale forcing for storms to develop by midweek. The path of the low remains to be somewhat uncertain but with strong S/SW flow, ample forcing and moisture profiles over the northern half of the CWA leaves the door open to some moderate thunderstorm development. By late week, models depict continued column drying, suggesting a gradual decrease in shower/thunderstorm coverage. A persistent active and wet spring continues! && .AVIATION...KSLC...VFR conditions are expected through the TAF period at the KSLC. Diurnally driven winds under mostly clear and sunny skies will effect the terminal. Some lowering VIS cannot be ruled out with the presence of wildfire smoke. .REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected through the TAF period at all terminals in Utah and SW Wyoming. Diurnally driven winds under mostly clear and sunny skies will effect the terminal. Isolated showers and storms could break up clear skies and bring some lower criteria when present today and tomorrow afternoon for southern sites. Some lowering VIS cannot be ruled out with the presence of wildfire smoke for northern sites. && .FIRE WEATHER...Unsettled weather under weak high pressure in place over the region will continue through the weekend into early next week. Periodic moisture transport will keep shower and thunderstorm chances around each afternoon through evening, though with little upper-level support these will be generally limited to areas along and adjacent to high terrain. Areas south of I-70 can expect these storms to come with the potential of locally heavy rainfall, while further north the drier low levels will increase the chances of strong gusty winds in the vicinity of these showers and thunderstorms. By Monday, more widespread precipitation coverage is expected as an area of low pressure approaches from the northwest, increasing the chances of wetting rain statewide. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...Flood Watch through Thursday afternoon for UTZ107. WY...None. && $$ Wessler/Selbig For more information from NOAA`s National Weather Service visit... http://weather.gov/saltlakecity
Area Forecast Discussion
National Weather Service Tallahassee FL
1031 PM EDT Fri May 19 2023 ...New UPDATE... .UPDATE... Issued at 1030 PM EDT Fri May 19 2023 The forecast appears to be on track this evening, updates do not appear necessary. && .NEAR TERM... (Through Saturday) Issued at 319 PM EDT Fri May 19 2023 A backdoor front roughly bisecting the NE Gulf Coast has helped keep a lid on convection so far this afternoon. Satellite imagery shows a gradual erosion of an expansive low stratus deck that blanketed our skies since the morning hours. Meanwhile, we are caught between an upper trough sliding into the FL Peninsula and a building ridge from the SW Gulf. As a result, current instability is rather meager with even some CIN noted on SPC mesoanalysis north of the FL state line. There is still a window of opportunity for some isolated showers and thunderstorms to develop along the seabreeze, but prevailing northeasterly low-level flow should keep the activity confined closer to the coast, so little inland progression is expected. The 18Z HRRR showcases this evolution by favoring precipitation along the FL Panhandle south of I-10 from 20-3Z. For tonight, we are looking at warm and quiet conditions as temperatures merely fall into the mid 60s. Low stratus accompanied by some patchy fog likely redevelops, particularly over the western and eastern fringes of the service area. Tomorrow, convection may initiate earlier ahead of an approaching "cold" front from the northwest. Rain chances peak late in the afternoon, especially west of the Apalachicola River. The airmass will remain anomalously moist and instability should be moderate to support scattered showers and thunderstorms, some of which could become severe. We also cannot forget the seabreeze. The SPC maintains a Marginal Risk (level 1 of 5) roughly along/northwest of a Berrien-Seminole-Walton County line valid 12Z Sat-12Z Sun. Main threats are damaging wind gusts followed by hail. Although convective coverage does not look great, the environment is supportive of a low-end threat given some enhanced flow aloft ushered in by the front`s parent trough in addition to Inverted-V modeled soundings. Storms likely continue into the evening thanks to the upper level support offsetting lower instability after sunset. Outside of storms, warm weather prevails with high temperatures ranging from the mid 80s to around 90. && .SHORT TERM... (Saturday night through Sunday night) Issued at 319 PM EDT Fri May 19 2023 A cold front is forecast to approach the tri-state region Saturday night into Sunday. Rain chances are expected to increase for the weekend as the front approaches. There is a little uncertainty regarding the timing of the front, which will impact when the precip will arrive in our CWA, whether it`ll be late Saturday night, or more during the day on Sunday. PoPs for Sunday afternoon range from 30%-40% south of I-10 and along the coast, to 60%-70% north of I-10. The front is expected to stall in the region during the day Sunday. Forecast instability is elevated for Sunday (~1000-2000J/Kg of CAPE), along with high PWATs (approaching 2"), allowing for thunderstorms to develop with heavy rainfall being the main concern. Thusly, the WPC has highlighted our eastern GA counties in a Marginal Risk (1 of 4) for Excessive Rainfall for Sunday. Some storms may be strong with gusty winds and frequent lightning but, the SPC has not yet highlighted any areas within our CWA for risks regarding Sunday afternoon. Temperatures for Sunday will be in the upper 80s to around 90 degrees for the afternoon high. The overnight lows during this term will be around 70 degrees. && .LONG TERM... (Monday through Thursday) Issued at 319 PM EDT Fri May 19 2023 The front will still be making its way through the CWA for the start of the work week. Showers and thunderstorms are likely for both Monday and Tuesday afternoons with PoPs ranging from 60%-80%, with Monday having the highest coverage. Model soundings show decent instability with modest lapse rates around 6 C/Km in the mid-levels. The sounding profiles shows long, skinny CAPE which is a good indicator for heavy rainfall. Thunderstorms on Monday and Tuesday will be able to produce gusty winds but, the heavy rainfall will likely be the main concern. By Wednesday, the front will have completed its passage headed further into the peninsula. Afternoon showers and thunderstorms will still be possible but, drier air will have filtered in as a surface high settles through the week. This will decrease the PoPs for the remainder of the week (20%-30%). Temperatures for this term will be in the mid to upper 80s along the coast and low 80s inland. Overnight lows are expected start in the upper 60s and cool to the low-mid 60s by Friday. && .AVIATION... (00Z TAFS) Issued at 734 PM EDT Fri May 19 2023 Persistent MVFR cigs at ABY have stuck around all day and will likely continue through the evening hours. DHN just went VFR, but is on the edge of the extensive MVFR stratus deck. As time goes on tonight, expect the MVFR cigs to expand and then lower to IFR in the 07-09z timeframe. These cigs shouldn`t make it as far south as last night, however. After daybreak, gradual improvement in conditions should occur with VFR all sites by 16z. Confidence in any TSRA tomorrow are too low to include in this TAF cycle. && .MARINE... Issued at 319 PM EDT Fri May 19 2023 Tranquil boating conditions through Tuesday with winds generally around 10 knots or less and seas of 1 to 2 feet. The only exception will be near thunderstorms, especially with a stalled frontal boundary near the waters. As the front moves south of the waters by Tuesday Night into Wednesday, northeast winds will increase up to 15 knots and seas building to 3 feet. && .FIRE WEATHER... Issued at 319 PM EDT Fri May 19 2023 A persistently moist airmass and elevated rain chances precludes fire concerns the next few days outside of gusty/erratic winds from thunderstorms. Scattered convection ahead of an approaching cold front develops late tomorrow afternoon into the evening, for which some isolated severe weather is possible. Wetting rains appear likely Sunday and Monday when the front stalls across the Tri-state area. && .HYDROLOGY... Issued at 319 PM EDT Fri May 19 2023 While there will be rain chances each day through the period, the wettest days will be on Sunday evening through the day Monday as a frontal boundary stalls across the region. Most locations will see around 1 to 1.5 inches of rainfall over the next week. However, the stalled front combined with Precipitable Water values approaching 2 inches on Sunday and Monday will lead to locally higher amounts of heavy rainfall. This may result in flooding of urban and low-lying areas of poor drainage on Sunday and Monday, with localized flash flooding possible. The WPC has highlighted our eastern GA counties on their Day 3 outlook (Sunday) for a Marginal Risk (1 of 4) of Excessive Rainfall. On area rivers and streams, no flooding issues expected. && .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 67 89 70 89 / 10 30 0 50 Panama City 68 84 72 85 / 10 10 0 40 Dothan 64 85 69 85 / 0 40 30 60 Albany 64 86 69 87 / 0 30 20 70 Valdosta 66 86 69 88 / 0 20 10 60 Cross City 67 90 69 90 / 20 20 10 30 Apalachicola 71 84 73 84 / 10 10 0 20 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AL...None. GM...None. && $$ NEAR TERM...IG3 SHORT TERM...Montgomery LONG TERM....Montgomery AVIATION...Godsey MARINE...Montgomery FIRE WEATHER...IG3 HYDROLOGY...Montgomery
Area Forecast Discussion
National Weather Service Las Vegas NV
140 PM PDT Fri May 19 2023 .SYNOPSIS...Scattered showers and isolated thunderstorms are expected through the weekend, especially in the higher terrain of southern Nevada and northwest Arizona. Rainfall amounts will generally be light, but stronger storm cells may produce gusty winds and lightning. Shower and thunderstorm coverage is expected to shrink daily early to mid week. Above normal temperatures are expected to continue along with increasing southerly breezes next week. && .DISCUSSION...Tonight through the weekend. High pressure centered over western Nevada over the weekend will continue to provide a northeast to southwest steering flow where storms that initiate over the mountains move into a region of higher anomalous mid-level moisture over the deserts. This will increase chances for strong outflow winds from thunderstorms collapsing into a dry low-level environment. The HRRR continues to forecast a complex of showers and storms developing or moving into central and southern Mohave County late this afternoon that are forecast to move into the Colorado River Valley by early evening. Shower/storm coverage elsewhere is expected to be more isolated in the evening and on a decreasing trend overnight. The shower and storm coverage area is forecast to expand to include much of the forecast area on Saturday. Hires models have storms initiating over the mountains by noon Saturday, with coverage expanding throughout the afternoon, decreasing in the evening, and then decreasing or ending after midnight. Similar conditions and a similar story on Sunday. Overall, precipitation amounts are expected to be generally light with an exception across the eastern half of Mohave County where enhanced rainfall amounts are possible Saturday afternoon/evening. The wind environment off the HREF has much of the area under a 50% or higher chance of seeing wind gusts over 30 mph from storms on Saturday with a signal for gusts exceeding 50 mph in Death Valley prior to sunset. Winds not associated with thunderstorm activity are expected to be mostly light across the area through the weekend with high temperatures topping out around 5 degrees above normal each day. Monday through Friday... The weather pattern is forecast to change early next week as high pressure to our northwest breaks down as shortwave energy passes from the Pacific Northwest into the northern Rockies. Low pressure is forecast to become the dominant weather influencer as troughing develops over the west and the upper flow becomes increasingly southwest across our area. With the changing weather pattern, the area of anomalous moisture becomes focused across the Sierra and southcentral Nevada rather than the lower deserts as we are currently seeing. Shower and storm chances thus become focused in these area on Monday through Wednesday. Shower coverage decreases Tuesday and Wednesday as moisture finally gets swept out of the area. The forecast calls for typical dry conditions for May with increasing southerly winds. && .AVIATION...For Harry Reid...Easterly component at 10 kts or less expected through 22Z. After 22Z, forecast becomes challenging due to potential outflow boundaries from convection. Confidence not the highest regarding potential outflow winds coming from the west or north between 22Z and 01Z. Around 03Z this evening, there has been better model agreement (higher confidence) that outflow winds from the southeast will reach the valley. Those winds may peak between 20- 25 kts. After those outflow winds subside, the rest of the night into Saturday morning will have light winds under partly cloudy skies. Another round of afternoon and evening thunderstorms with strong, gusty outflow winds possible on Saturday. For the rest of southern Nevada, northwest Arizona and southeast California...Greatest impact from thunderstorms late this afternoon and evening will be across southern Mohave County and lower Colorado River Valley. Easterly wind gusts up to 35 kts expected to roll into the lower Colorado River Valley between 01Z and 03Z. That outflow could persist and impact the Las Vegas Valley with gusty southeast winds up to 25 kts(KHND, KVGT) after 03Z. Then reach KDAG around 05Z. Isolated light showers expected to last well into the night across parts of the region before skies become partly cloudy with light winds Saturday morning. Another round of afternoon and evening thunderstorms with strong, gusty outflow winds possible on Saturday. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...Salmen AVIATION...Pierce For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter