Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/24/23

Area Forecast Discussion
National Weather Service La Crosse WI
1000 PM CDT Tue May 23 2023 .DISCUSSION...(This evening through Tuesday) Issued at 142 PM CDT Tue May 23 2023 Key Message: - Slightly cooler (for most) tomorrow and Thursday, otherwise warm and dry conditions continue. Tonight - Wednesday... There looks to be a small chance for some showers late tonight into Wednesday for areas generally north of Interstate 94. A cold front over northern Minnesota and Lake Superior this afternoon will slide south into the area. Some convection was developing along the front ahead of a short wave trough approaching from central Canada. This wave is expected to track across the Canadian Border and as the front pushes south it should eventually outrun this upper air support. As a result, some of the developing showers may survive into the norhtern parts of the area before they loose support and dissipate. Measurable rainfall amounts will be light and expected to be under a tenth of an inch. Looking ahead... The main forecast concern for later in the week continues to be very low relative humidity with the prolonged absence of moisture feeding into the region. Minimum relative humidity is forecast to fall into the low 20s on Thursday, Friday, and Saturday with the possibility of falling into the upper teens if mixing or temperatures exceed the current forecast. Another day of seasonable temperatures Thursday before warm air advection kicks back in causing gradual warming Friday through the weekend. High pressure dominates the synoptic environment into early next week. This will generally lead to clear skies, light winds, and dry conditions. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1000 PM CDT Tue May 23 2023 CIGS: high smoke will continue to keep milky skies across the region into Wed, but RAP model suggests thinning/improving as we move into Thu. Passing, backdoor cold front toward 12z Wed could bring in a few hours of a bkn mid level (VFR) deck. Will hold with SCT for now. WX/vsby: passage of cold front looks dry at this time. No impacts anticipated. WINDS: light south/southeast tonight, becoming more easterly by 12z Wed. Could see gusts into the upper teens Wed afternoon with tighter pressure gradient/daytime mixing. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...NONE. MN...NONE. IA...NONE. && $$ DISCUSSION...KAA/04 AVIATION.....Rieck
Area Forecast Discussion
National Weather Service Binghamton NY
941 PM EDT Tue May 23 2023 .SYNOPSIS... A weak disturbance will bring a chance for isolated showers and thunderstorms this afternoon, mainly over Central New York. More widespread showers and thunderstorms will arrive on Wednesday as a cold front passes through the region. Cooler and drier conditions will round out the week, with a risk of frost and localized freezing temperatures Wednesday and Thursday night. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... 940 PM Update... The showers never developed as what was indicated by most model guidance, though that was not surprising given the dry conditions. No changes were needed to PoPs as they were already too low to mention. The only changes that were needed with this update were the temperatures and dewpoints. These were touched up to better match obs. 600 PM Update... Skies continue to be shower-free this evening. Some of the CAMs and short-range model guidance continues to show showers for this evening, while others like the HRRR have very little. Soundings do hint at some mid-level moisture but near the surface, conditions are far too dry for anything to reach the ground. If this observational trend continues, it seems unlikely that anything will develop and if it does, it may not even reach the ground. Still, there is hesitation to completely remove PoPs given what some guidance is showing. PoPs were decreased even more but this update continues with the slight chance PoPs across CNY. The other main change to this forecast was to the dewpoints. With the drier conditions, the forecast was higher than what is being observed. A blend of short-range guidance got the forecast closer to observations. The rest of the forecast remains on track and needed little change. 250 PM Update... Smokey skies over the region again this today, giving the sky a milky white appearance. The smoke is reducing heating this afternoon, and this reduction is heating is likely why we are seeing less shower activity than previously forecast. With reduced instability, I have removed thunderstorms from the forecast this afternoon and have reduced PoPs to only slight chance. Any shower activity will dissipate after sunset. For tomorrow, a cold front with a strong upper level shortwave trough will push through the area. This will kick off a band of rain showers and thunderstorms. Instability will be limited again tomorrow with CAPE topping out near 500 J/kg, but 0-6 km bulk shear will be decent, approaching 40 knots so it is possible that a few stronger storms would produce gusty winds and small hail tomorrow afternoon. Front exits the region tomorrow evening with strong CAA behind it. Temperatures will drop into the low to mid 30s tomorrow night, but winds will likely prevent frost development. However, we may still need freeze headlines, as a few locations in the sheltered valleys of the Catskills and in Northern Oneida County may reach or drop below freezing. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... 230 PM Update... After a cold front moves through Wednesday, gusty northerly winds will keep temperatures on the chilly side for Thursday. Winds will calm down overnight Thursday, allowing for frost to occur across Central NY and along the Twin Tiers, with low temperatures in the mid- to high-30s. Temperatures will warm back up into the mid- to high-60s across the area on Friday. && .LONG TERM /SATURDAY THROUGH TUESDAY/... 230 PM Update... High pressure begins to build back over the area Saturday, and we`ll see an increasing temperature trend through Memorial Day. Model guidance disagrees quite a bit on the overall synoptic pattern heading into Memorial Day, with the ECMWF developing a separate low pressure system over Michigan, and the GFS propagating a shortwave off of a pre-existing system that is over North Carolina. The general consensus is a slight chance of showers on Sunday afternoon. On Memorial Day, temperatures are expected to warm up to the high-70s/low-80s, with a slight chance of thunderstorms and rain showers in the afternoon. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... VFR conditions are expected through Wednesday morning. By Wednesday afternoon, showers and possibly a few thunderstorms will pass through the region, which will bring at least MVFR restrictions at all Central NY terminals (KAVP likely remains VFR). Confidence is too low for thunder at this range, and therefore this was left out of the TAFs for now. This may be added with upcoming TAF issuances if confidence in thunderstorms increases. Gradual improvement is expected by late Wednesday afternoon/early Wednesday evening. Outlook... Wednesday night through Sunday...Mainly VFR. && .BGM WATCHES/WARNINGS/ADVISORIES... PA...None. NY...None. && $$ SYNOPSIS...MPK NEAR TERM...BTL/MPK SHORT TERM...KL LONG TERM...KL AVIATION...BJG
National Weather Service Bismarck ND
914 PM CDT Tue May 23 2023 .UPDATE... Issued at 858 PM CDT Tue May 23 2023 Occasional storms continue along a boundary from Hettinger to near Courtenay north of Jamestown (with the greatest coverage over northern Stutsman County and eastern Adams County), though a few storms are starting to develop along a northward moving outflow over Bismarck to the north of Steele. Plenty of instability remains in place, but deep layer shear is lacking. With that said, the storms have been very slow moving, which has actually led to some minor flooding over northeastern Stutsman County. Expect the threat for heavy rainfall to continue for a few more hours given the slow storm motion and even back building occurring, combined with plenty of moisture available. UPDATE Issued at 647 PM CDT Tue May 23 2023 Main area of thunderstorms at this time stretch from the tail of Sioux County east-northeastward to the north of Jamestown, though occasional additional activity over the west has been noted. The storms have been slow moving, possibly bringing some heavy rain. Another concern, along with small hail given the instability, is gusty winds which have been reported just to the east of our area, which is supported by the latest forecast Jamestown soundings. Not thinking severe at this point, but still something to note. UPDATE Issued at 500 PM CDT Tue May 23 2023 A quick update has been sent out to expand precipitation chances through northwest and south central North Dakota as some showers and thunderstorms are starting to develop. && .SHORT TERM...(This Evening through Wednesday) Issued at 320 PM CDT Tue May 23 2023 A chance for showers and thunderstorms this evening and tonight, highest in the south central and James River Valley, is the focus of the short term forecast. This afternoon, a double barrel upper low was located over the Pacific Northwest into the southern Canadian Prairies, with a ridge axis centered over the central CONUS. At the surface, the center of a low was analyzed over west central South Dakota, while a strong high pressure sat over northern Manitoba and Ontario. A back door cold front has been sliding south through the day, meeting a weak warm front that has been drifting north from South Dakota. This intersection is where CAMs continue to initiate convection late this afternoon and into the evening, in a southwest-northeast oriented line from the Grant/Sioux County area to the Stutsman County area. Daytime satellite imagery shows some cu beginning to develop from Stutsman back into Logan and Kidder Counties, but as of 2000 UTC it`s still quite shallow. The 12Z HREF advertises a ribbon of 1000-2000 J/kg of CAPE oriented around the frontal boundary, but 0-6km shear is very weak, only around 10-15 knots. This is also seen in HRRR forecast soundings, where shear is around 10 knots and hodographs are basically an overlapping circle. With how weak the shear is, our thought is that pulsing thunderstorms are the most likely outcome with the present instability and strong lapse rates. Would not be surprised if the strongest storm or two end up with nickel to quarter sized hail, but this would be more likely with initial storms before convection gets clustered and consequently weaker. The other main concern with any strong showers or thunderstorms is the potential for heavy rainfall. Abnormally high PWATs combined with slow storm motion means there is potential for locally heavy rainfall, which could lead to minor flooding, especially in urban areas. As the combined frontal boundary washes out overnight, chances for showers and thunderstorms drift north and lessen, tapering off Wednesday morning. We do have a slight chance for showers and thunderstorms across parts of western North Dakota on Wednesday afternoon, but the bulk of precipitation looks to stay on the Montana side of the state line. Behind the cold front, breezy east-northeast winds will expand south through the entire forecast area, continuing through the day Wednesday. RAP smoke forecasts are showing near-surface smoke to be slowly diminishing from central to west through tonight and into the morning. Smoke aloft will persist, so expect hazy skies to continue. Overnight lows tonight will be in the 50s. Highs on Wednesday will be in the mid 70s to mid 80s. .LONG TERM...(Wednesday Night through Tuesday) Issued at 320 PM CDT Tue May 23 2023 Above average temperatures and on and off chances for showers and thunderstorms highlight the extended forecast. The synoptic pattern during the extended period is characterized by weak but broad ridging over the central and eastern Canadian Prairies and troughing over the western CONUS, leading to southwest flow aloft across the forecast area, as well as southerly low level flow and warmer than normal temperatures. Although flow aloft is weak and diffuse, surface flow is expected to be moderately strong, as a surface low coming off the lee of the Rockies is expected to deepen on Thursday. A modest surface pressure gradient and strong low-level winds will lead to continued breezy winds across the entire area through Thursday and Friday, diminishing some but still staying a bit breezy central and east through most of the holiday weekend. Chances of showers and thunderstorms are persistent through the end of the week and into next week, as multiple shortwaves move through the southwest flow aloft. As is typical this time of year, there is relatively low predictability in specific timing and location of any precipitation. No single day looks like a washout but there could be scattered convection each day, so something to be aware of, especially through the holiday weekend. Additionally, deterministic guidance continues to advertise weak shear through this time, which is not surprising given the diffuse pattern aloft. This would keep the severe thunderstorm potential relatively low, although with warmer temperatures and some instability present, there could certainly be a few stronger storms. This sentiment is echoed in both CIPs Severe Analogs and CSU machine learning probabilities. Temperatures look to stay similar through the extended period, with NBM 25/75th percentiles consistently in the upper 70s to upper 80s from Thursday through Tuesday. CPC outlooks also highlight above average temperatures favored to start the month of June, so this pattern is expected to continue through next week. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 647 PM CDT Tue May 23 2023 Isolated to scattered thunderstorms expected through tonight over western and central North Dakota. Gusty winds possibly by any storm, along with the threat of some small hail. In addition, easterly winds may become gusty this evening over northern areas. Drier weather expected over most locations through the day on Wednesday, but gusty southeast winds will develop. && .BIS WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...JJS SHORT TERM...Jones LONG TERM...Jones AVIATION...JJS
Area Forecast Discussion
National Weather Service Caribou ME
946 PM EDT Tue May 23 2023 .SYNOPSIS... High pressure will exit the area to the east tonight. A cold front will cross the area late Wednesday. An upper low meanders over the region from Wednesday night into Friday. Meanwhile, high pressure builds in at the surface into the weekend, then slides offshore early next week. && .NEAR TERM /THROUGH WEDNESDAY/... 930pm update...Ongoing forecast continues to look good with the coldest temps tonight Downeast. Winds will be fairly steady in northern zones ahead of the approaching front and prevent a radiation inversion. As a result, temperatures in northern zones remain above 60F at this hour. An inversion will develop due to strong warm air advection above the boundary layer tonight. High clouds gradually increase from the north tonight. Smoke has entered the area at this time as detailed in the previous discussion. Previous discussion... High pressure will drift east of Nova Scotia this evening as a cold front approaches from Quebec. Mainly clear skies intially expected across the state with some clouds over the terrain of the Longfellow Mtns. Visible satellite shows an area of Canadian Wildfire smoke pushing southeast over Quebec. RAP Vertically Integrated Smoke model is showing this arriving between 7pm-9pm across our western skies. RAP Model shows this becoming a very thick layer lasting into tomorrow likely. Tonight, again mainly clear skies but clouds will also increase after midnight from the west over the North Woods. Given the southerly flow expecting a warmer night with temperatures falling back into the 40s but with winds relaxing some across the Downeast and Bangor region expect the coolest lows to be there. Tomorrow, expecting a very hazy (smoke) sunrise across much of the area with clouds increasing along the Quebec border. Showers will be developing in Quebec early on in response to the surface lift. There still remains some slight timing differences between the Globals and Hi-Res CAMs. Made some minor tweaks to slow the arrival time of increasing POPs to mid morning across the northern and northwestern zones. Mostly sunny south with skies becoming overcast across the north. As the front pushes southeast expect showers to increase in coverage with some areas becoming steady rain especially as the 500mb trough tilts neutral and begins to close off over Northern Maine. This will ensure precip turns stratiform especially over northern areas. Cannot rule out some isolated thunderstorms where some daytime heating can generate some SBCAPE over mainly the Moosehead Region. A strong 850mb inversion will develop late afternoon likely shutting down any convection so mainly expecting just rain. Strong ascent especially over the mountains into Northeast Aroostook will enhance rainfall totals with 0.5-1 inch likely in many locations along this stretch. Expect highs to be held down across the North Woods due to clouds and rain with low to mid 60s. Southerly flow will keep the Downeast coast in the 50s to around 60F. Bangor Region into Northeast Aroostook can expect mid to upper 60s with a few 70F. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... A closed low slowly meanders across far SW Quebec and Northern New England from Wednesday night into Friday. Anafrontal rain will cover the area Wednesday night behind a departing cold front in response to the upper low. The precipitation will become gradually more showery and more likely concentrated across the north Thursday and Thursday night. For now it appears showers should tapper of from SW to NE on Friday as the upper low begins to exit into the Maritimes. There is the potential for a total of .5 to 1.5 inches of rain mainly across the North with this system through Thursday afternoon. Generally expecting at this time less than a half and inch of rain. Give it has been relatively dry over the past few months and this rain will be spread out over 24 hours, no significant hydrologic impact is expected. Lows Wednesday night should be near to slightly below normal, ranging from the mid 30s across far NW portions to the lower 40s across Downeast Maine. Highs Thursday should be around 10 degrees below normal, mainly in the 50s. Lows Thursday night should be around 5 degrees below normal and highs on Friday should be a few degrees below normal. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... Split flow sets up over the eastern US from late this week into early next week, with northern stream ridging over a southeastern closed low. Other than possibly some lingering showers Friday evening as the first closed low continues to depart, it should be dry. It should be noted, that there is still quite a bit of uncertainty with this pattern, with some clusters showing different placements of the upper ridge and low. So the confidence in the forecast Friday night-Tuesday is not all that high. After near normal temperatures Friday night, temperatures should be above normal Saturday-Tuesday. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... NEAR TERM: VFR conditions expected through Wed AM. Cigs will lower tomorrow with showers developing by midday into the afternoon. Steady precip likely across the N terms. Mostly dry during the day at BHB. S winds tonight 10-15kts with gusts 20-25kts across the N terms this evening. LLWS likely at FVE, CAR & PQI tonight. S winds 10-15kts tomorrow will shift late day NW. .SHORT TERM: Wednesday night...IFR or lower probable from KBGR on north, with MVFR or lower possible at KBHB.N-NE winds G15-20KT possible. Thursday-Thursday night...MVFR or lower possible, with best chance at northern terminals. N-NW winds G15-25KT possible. Friday...Becoming VFR from SW to NE. NW-WNW winds G15-20KT possible. Friday night-Sunday...VFR. W-WNW winds G15-25KT possible Sunday. && .MARINE... NEAR TERM: Southerly winds and seas remain below SCA through tomorrow. Chance of showers tomorrow afternoon across the waters. Waves generally 2-3ft with a period of 7-8sec. SHORT TERM: Conditions should be just below SCA levels Wednesday night into Thursday night, then well below SCA levels Friday- Sunday. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...MCW/Sinko Short Term...Maloit Long Term...Maloit Aviation...MCW/Sinko/Maloit Marine...MCW/Sinko/Maloit
Area Forecast Discussion
National Weather Service Cleveland OH
908 PM EDT Tue May 23 2023 .SYNOPSIS... A cold front plunges south across the area on Wednesday. High pressure builds in behind the cold front Wednesday night and remains in control of the weather through the holiday weekend. && .NEAR TERM /THROUGH WEDNESDAY NIGHT/... Minimal impact weather through the near-term, though a rather strong cold front will plunge out of Canada and slide through the area from north to south on Wednesday. This front may pop a few showers or thundershowers across our far southern / eastern counties early Wednesday afternoon before quickly exiting to the south. Otherwise, it will bring a surge of somewhat gusty northerly winds behind it Wednesday afternoon to go along with a notable airmass change by Wednesday evening. In terms of some specifics...after a careful deliberation, elected to remove the small slight chance shower mention across parts of Northeast OH for late this afternoon. A nice cumulus field has developed along and just south of a well-defined lake breeze, but cloud top temperatures on IR imagery have struggled to cool below 0C. Forecast soundings show a warm nose at around 700mb near the freezing level, and it seems the cumulus are having a hard time punching through that given a lack of any amount of forcing outside of the lake breeze boundary. In addition, dew points have lowered just a bit this afternoon due to slightly deeper mixing, somewhat more in-line with the HRRR and RAP models (which do not develop any showers) than the NAM (which does try to develop a few showers). Will all of this in mind, will optimistically go with a rain-free forecast this evening. High pressure surface and aloft should then provide for a tranquil night with half decent radiational cooling conditions. Some of the nooks and crannies in our inland/eastern zones will cool into the low-mid 50s, with upper 50s/lower 60s more common farther west and closer to the lake. Boosted temperatures just a bit ahead of the cold front on Wednesday given a fairly warm start and dry low-levels that will be ripe for quick mixing, though temperatures will level off if not drop a bit behind the front on Wednesday, especially closer to the lake. The bulk of the forcing with the shortwave trough forcing the front across our area will remain to our north/northeast, though enough skinny CAPE is projected to develop by the time the front clears our southeast/eastern counties to warrant a slight chance or low chance mention of showers, with a rumble of thunder not entirely ruled out. Northwest OH and locations closer to the lake farther east will likely observe a dry frontal passage, though the wind shift will be sharp and coincide with a noticeable increase in wind speed. A much cooler/drier airmass will allow temperatures to dip into the 40s beneath mainly clear skies Wednesday night. Parts of interior Northeast OH and especially inland Northwest PA may dip into the 30s, but a fairly strong pressure gradient and some continued cold air advection is expected to keep winds from decoupling, which should preclude frost formation. Enough elevated smoke from Canadian wildfires will remain ahead of the cold front to keep skies quite milky/hazy so opted for at least partly cloudy wording ahead of the front...the smoke is projected to get swept out behind the front, which should allow for much clearer skies to return later Wednesday and beyond. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... The post-cold frontal environment for Thursday will be quite dry both at the surface and aloft. Surface high pressure spanning the Great Lakes and eastern Canada will be in control with cooler northeasterly flows across the region. While likely not representative in real life, the NAM takes the CLE dewpoints around the 850mb level down below -60C according to BUFKIT forecast soundings. Whether that value is exaggerated on the low end or not, expecting a very dry day with low relative humidity, and dropped dewpoints manually from guidance numbers during the heating hours Thursday. Friday will have similar issues with very dry air mixing to the surface, but will be slightly less pronounced. All in all, expecting fire weather risks to increase with fuels likely continuing to dry out and again, the low RH values. Winds northeasterly 15-20mph over the western third of the CWA, 10-15mph further east each day. Again, this is a cooler airmass, and will be below average Thursday, but will have slow airmass modification with good insolation into Friday, and will see max temperatures 8-12 degrees and 3-7 degrees below normal respectively. && .LONG TERM /SATURDAY THROUGH TUESDAY/... Upper level system moves in late weekend, but will largely continue to be moisture starved in the low/mid levels resulting in low POPs only Sunday into Monday. Details to emerge on how much instability there is and can it ultimately find enough layer moisture for cumulus cloud growth. It is likely that most locations remain dry or experience only brief passing showers. Thunder chances are low but still non-zero for the southeastern CWA. Continuing to warm each day and should be above normal by Monday. && .AVIATION /00Z Wednesday THROUGH Sunday/... Generally VFR conditions expected through the TAF period. A cold front moves south across the area late Wednesday morning into the early afternoon. Isolated rain showers and some scattered cloud cover is possible with the frontal passage, with brief, MVFR ceilings possible in Northwest Pennsylvania. Mostly clear skies expected by Wednesday evening. Light winds overnight become northerly with the frontal passage, strengthening to 10-15 knots with gusts in the 20-25 knot range. Outlook...Non-VFR is possible with isolated rain showers Sunday afternoon. && .MARINE... The light, onshore northeasterly flow this afternoon gives way to southerly flow tonight ahead of a cold front dropping in from the north that will track across Lake Erie Wednesday morning. With the pressure gradient tightening behind the cold front, expect northerly/northeasterly winds to increase Wednesday into Wednesday night and early Thursday to 15-25kts. This will result in building wave heights to the 4-6ft range in the near shore zones. Winds will persist out of the northeast from later Thursday through Sunday with winds diminishing to 5-15kts and wave heights down to the 1-3ft range. && .CLE WATCHES/WARNINGS/ADVISORIES... OH...None. PA...None. MARINE...Small Craft Advisory from 4 PM Wednesday to 4 AM EDT Thursday for LEZ142-143. Small Craft Advisory from 10 PM Wednesday to 8 PM EDT Thursday for LEZ144>147. Small Craft Advisory from midnight Wednesday night to 11 AM EDT Thursday for LEZ148-149. && $$ SYNOPSIS...Sullivan NEAR TERM...Saunders/Sullivan SHORT TERM...26 LONG TERM...26 AVIATION...Saunders MARINE...26
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
622 PM CDT Tue May 23 2023 ...New AVIATION... .SHORT TERM... (Tonight through Wednesday night) Issued at 249 PM CDT Tue May 23 2023 The short term forecast is a challenging one as the region remains under northwest flow aloft with an upper ridge sitting near the TX/NM border. This afternoon into tonight: Thunderstorms are expected to develop across portions of west TX, mainly across the Panhandle, along/near a surface trough and dryline. These storms are expected to cluster and move southeastward through the evening and overnight hours as an MCS/MCV. The tricky part of the forecast is how far southeast will the storms maintain severe intensity, and how far southeast will they go before they diminish entirely. The HRRR seems to be the most aggressive solution at this time, especially for north and eastern portions of the CWA, but other CAMs also depict the line of storms reaching the I-35 corridor during the early morning hours tomorrow. While the storms will likely produce gusty winds until they completely diminish, the greatest severe threat should stay to the north and west across the Hill Country as depicted by the current SPC Day 1 Outlook. Despite what the CAMs are showing, we cannot rule out storms entirely dissipating before reaching the I-35 corridor due to the increasing convective inhibition overnight, and the forecast PoPs are fairly conservative to account for this possibility. Tomorrow and tomorrow night: There may be some lingering showers through the morning hours tomorrow behind the decaying MCS/MCV, but this activity should be isolated at best. Additionally, there is potential for areas of low ceilings and patchy fog to redevelop in the morning as well, mainly across the Coastal Plains and I-35 corridor, though the convective evolution overnight could play a role in this (e.g. storm outflow). Wednesday afternoon-night will see a similar setup as today with storms once again firing across west Texas and then potentially drifting into the area during the early morning hours Thursday, though there is even less confidence in the Day 2 activity than Day 1 at this time. && .LONG TERM... (Thursday through Tuesday) Issued at 249 PM CDT Tue May 23 2023 Northwest flow aloft will remain firmly in place across south central Texas through Saturday. Timing of mid-level shortwaves embedded in this flow aloft will be the main forecast challenge with regard to timing and location of precipitation chances. For Thursday through Saturday, the medium range models keep mid-level shortwave activity to our north and east. Based on this, we will keep the forecast dry for the mentioned period. However, we may need to add some low rain chances across the I-35 corridor, Hill Country and southern Edwards Plateau pending future model data. The flow aloft trends to a more southwest to westerly direction Sunday through Tuesday as the subtropical ridge axis to our west weakens while moving eastward. Rain chances will be favored over the Rio Grande plains Sunday, with perhaps some isolated activity moving into the Hill country and I-35 corridor on Monday and Tuesday. As far as temperatures through the period, MOS guidance continues to remain very steady in day to day trends. We will keep highs generally in the mid 80s to mid 90s with lows in the mid 60s to lower 70s. && .AVIATION... (00Z TAFS) Issued at 622 PM CDT Tue May 23 2023 A bit of a complicated TAF forecast with the potential for early morning thunderstorms at I-35 sites and possible MVFR ceilings tomorrow morning. Isolated storms near AUS are slow moving to the southeast and expected to weaken by 02-03Z. The other complex of storms may move across I-35 sites by 11-12Z Wednesday, with model trends favoring AUS and less certain of impacts at SSF/SAT. MVFR ceilings are also possible at DRT and San Antonio sites tomorrow, but storms will have a big impact on what actually happens. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 90 69 88 68 / 10 30 30 10 Austin Bergstrom Intl Airport 89 67 87 67 / 10 20 20 0 New Braunfels Muni Airport 89 67 89 66 / 10 10 20 0 Burnet Muni Airport 88 66 85 66 / 10 30 30 10 Del Rio Intl Airport 93 72 93 72 / 0 10 10 10 Georgetown Muni Airport 89 66 86 66 / 10 30 30 10 Hondo Muni Airport 89 66 90 67 / 0 10 10 0 San Marcos Muni Airport 89 67 87 66 / 10 20 20 0 La Grange - Fayette Regional 87 69 86 65 / 10 10 20 10 San Antonio Intl Airport 89 68 89 68 / 0 10 10 0 Stinson Muni Airport 90 69 90 69 / 0 10 10 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...Gale Long-Term...Platt Aviation...27
Area Forecast Discussion
National Weather Service Goodland KS
548 PM MDT Tue May 23 2023 .SHORT TERM...(This evening through Friday) Issued at 255 PM MDT Tue May 23 2023 Pattern through the short term period will not change, with an upper trough stuck over the Great Basin and southwest flow aloft ahead of it over the Rockies and plains. Embedded shortwaves in the flow aloft will result in daily chances of showers and thunderstorms beginning tomorrow. Severe chances appear marginal at best, with only weak to moderate instability forecast and deep layer shear values of 20-30 kts, with the best parameters occurring on Thursday. At the surface a moist southeasterly flow will persist, yielding anomalously high precipitable water values, which combined with relatively slow storm motions may present a limited risk for heavy rain and/or flash flooding. So for this afternoon and tonight, seeing a few very light showers pop up over southeastern portions of the area, where CIN has eroded and MLCAPE values approach 1000 j/kg. HRRR seems to have the best handle and shows this activity probably already peaking and gradually weakening through this evening. Overnight, cannot completely rule out a few showers redeveloping, but should be isolated. Stratus and fog will develop over western areas after 09z and persist through about 15z Wednesday morning. In the afternoon, expecting showers and storms to develop along the Front Range by 21z and slowly make their way eastward. Due to slow storm motions, this activity may not arrive at the Kansas border until the 00-03z time frame. By then, there should be a fairly large cluster of showers and embedded thunderstorms moving through the western portion of the area with a low risk for damaging winds (DCAPE 500-1000 j/kg) and locally heavy rainfall, primarily in northeast Colorado. HREF mean shows some 6-hour rain amounts in the 1-2 inch range tomorrow evening. This area of rain will continue eastward overnight but weakening after 06z. The area of rain may persists into Thursday morning as it slowly moves into eastern portions of the area. Provided the environment can recover, storms should redevelop Thursday afternoon in western areas with the next shortwave trough. As previously mentioned, parameters may be slightly better for severe storms compared to previous days, particularly deep layer shear which is forecast to be closer to 30 kts, combined with MLCAPE values 1500-2000 j/kg. Storm motions remain slow, 10 kts or less, suggesting heavy rainfall/flash flooding will also be a potential hazard. Some decrease in activity can be expected overnight Thursday. Friday sees the same pattern continue. Severe parameters weaken slightly, with deep layer shear 20-25 kts and weak to moderate MLCAPE, highest in western areas. However, there is some increase in storm motion forecast, up to 20 kts, which may mitigate the risk for flash flooding. Temperatures change very little through the period, with highs in the 70s and lows in the 50s. .LONG TERM...(Saturday through Tuesday) Issued at 1241 PM MDT Tue May 23 2023 The long term forecast period begins with an upper level high pressure over the Great Lakes region while an upper level low remains centered over the southeastern CONUS. An upper level trough is moving into the western CONUS, and with us sandwiched between systems, ample moisture continues to be drawn into the region with a generally southerly flow. A surface low is situated over southeastern Colorado. Depending on its exact position, may make for some gusty southerly winds (approx. gusts of 25-30 mph) for portions of the Tri-State Area over the weekend. With PWAT values generally ranging from around 0.75 west to around/just over an inch to the east and shortwaves moving through the area, will continue to see chances for showers and storms to impact the Tri-State Area each day of the long term period. Looking at severe parameters, may have sufficient (but not overly impressive) instability and shear in the afternoons- evenings Saturday to Monday for portions of the area to see a risk of severe weather. Quite a bit of disagreement remains between models in this timeframe so will need to continue to monitor as it nears for details to become clearer. For now, given the expectation of continued showers and storms, excessive rainfall and flooding may remain the largest concern. High temperatures in the mid to upper 70s on Saturday will climb into the mid 70s to low 80s Sunday-Monday, then into the upper 70s to mid 80s. Overnight lows continue in the 50s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 544 PM MDT Tue May 23 2023 KGLD...VFR conditions begin the 00Z TAF period with south- southeasterly winds around 13 kts that decrease to around 9 kts by 02Z. At 06Z, IFR conditions begin at KGLD with clouds dropping to around 500 ft. By 11Z, visibilities at KGLD start to drop to around 1SM with LIFR ceilings at 300 ft. VFR conditions expect to return to KGLD at 16Z with visibilities increasing and clouds decreasing in coverage as well as rising. At 21Z, KGLD winds look to become more southeasterly at 13G18 kts. KMCK...VFR conditions also begin the 00Z TAF period for KMCK with south-southeasterly winds at 10G18 kts that slow to around 8 kts at 02Z. At 06Z, models show winds becoming variable around 6 kts at KMCK before becoming southeasterly around 10 kts at 14Z and then increasing to 13G20 kts at 21Z. Going to continue to watch future model runs for how low visibilities at KGLD will get due to potential as well as timing for when the lower clouds begin as there still is some model discrepancy. Will also monitor for signs of KMCK becoming sub-VFR though latest runs look to keep lower clouds to the west. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...024 LONG TERM...CC AVIATION...076
Area Forecast Discussion
National Weather Service Grand Rapids MI
1054 PM EDT Tue May 23 2023 LATEST UPDATE... Update .UPDATE... Issued at 1054 PM EDT Tue May 23 2023 Back door cold front timing is for an early Wednesday morning fropa and a stark change to the currently calm/mild conditions. Expecting a surge of cool northeast winds to sweep through around 12Z, with wind gusts to 30 mph at times on Wednesday behind the front and temps only in the 60s. (May even stay stuck in the 50s downwind of Saginaw Bay.) Precip chances are very low along the front given all the dry air, with low chc pops for light showers or sprinkles restricted to mainly just the Clare/Mt Pleasant areas. && .SHORT TERM...(This evening through Wednesday night) Issued at 237 PM EDT Tue May 23 2023 The high pressure that has dominated the last few days will shift westward as a upper level trough swings through. Though it will be mainly dry, there is a slightly chance of rain north of I 96. The front will drop temperatures below normal. It will also bring gusty winds. The front will move quickly through with temperatures behind the front in the mid to upper 30s. While patchy frost will be possible, especially along and north of US 10, easterly winds should remain strong enough and mixed Wednesday night into Thursday to preclude widespread frost development. However, area where winds go calm, frost could form. .LONG TERM...(Thursday through Tuesday) Issued at 230 PM EDT Tue May 23 2023 A mid level high pressure system remains over the region into the start of the holiday weekend. Models are in good agreement on this. The subsidence and associated drying of the the atmosphere will support keeping rain out of the forecast through then. With the 850 mb thermal trough in place Thursday, the temperatures will end up cooler than normal. The feature builds east Friday into Saturday...allowing for gradually warming 850 mb temperatures. That will translate to a warming trend with the surface temperatures each day with above normal values looking likely for Saturday as 850 mb temperatures approach 10 deg C. Ensemble max temperature plots from the models support a steady warmup over the weekend and into early next week, but the ECMWF does show a fair amount of spread Sunday into Monday. For Sunday and Monday, the ECMWF is showing a weak mid level low building in from the south while the GFS and Canadian keep this feature stronger and well through of the CWA. The ECWMF is dry even with this feature around so the main impact of it would be to hold back temperatures. PWAT values are progged to start climbing early next week, but overall instability and RH fields look too limited to support any rain. Very little qpf is seen in the ensemble forecasts, even early next week when several of the members start to show precipitation. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 750 PM EDT Tue May 23 2023 Smoke layer persists aloft otherwise VFR conditions continuing tonight with light and variable winds. A sfc cold front drops down from the north early Wednesday with a fairly abrupt wind increase and shift to the northeast. Gusts around 20 kts are expected at times for much of the day. A band of clouds will accompany the cold frontal passage but at this time mainly VFR cigs are expected with only a slight chance for a period of MVFR cigs. Some near sfc smoke cannot be ruled out Wednesday with the frontal passage but no vsbys restrictions below 6 miles are expected at this time. Any near sfc smoke as well as the smoke aloft will clear out of the area from north to south Wednesday afternoon/evening. && .MARINE... Issued at 1012 PM EDT Tue May 23 2023 Some modifications have been made to the small craft advisory, specifically south of Whitehall. While the stronger northerly flow behind the front will firmly impact Big and Little Sable Points on Wednesday, latest HiRes HRRR and NAMNest guidance does not show those stronger winds impacting areas south of Whitehall. (Keeps the stronger flow well offshore.) However, there is a signal for strong easterly flow developing Wednesday evening in these locations and gusting to 30 kts at times, so have simply delayed/extended the advisory south of Whitehall to be for the Wednesday night time frame. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory from 8 PM Wednesday to 8 AM EDT Thursday for LMZ844>847. Small Craft Advisory from 10 AM to 10 PM EDT Wednesday for LMZ848-849. && $$ UPDATE...Meade SHORT TERM...Ceru LONG TERM...MJS AVIATION...Meade MARINE...Meade
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1040 PM CDT Tue May 23 2023 .UPDATE... Issued at 548 PM CDT Tue May 23 2023 Scattered showers with a few thunderstorms are slowly oozing northwest in east-central Missouri at this hour in an unorganized line along some weak surface convergence. Thunderstorms that form quickly collapse with no deep shear to separate the updrafts and downdrafts. The cumulus field is dissipating in the vicinity of the convection as the sun begins to set, and this weakening trend will continue into the early evening when all convection will likely cease. MRB && .SHORT TERM... (Through Late Wednesday Afternoon) Issued at 220 PM CDT Tue May 23 2023 Light easterly flow across the area is producing orographic lift over the Ozarks this afternoon. RAP soundings show around 1500 J/Kg in that area this afternoon, and a decent Cu field has developed. So far there hasn`t been much showing up on RADAR, probably due to weak upper level ridging over the Mid Mississippi Valley producing broad scale subsidence. There are still several hours of daytime heating left, so the slight chance PoPs in the going forecast for the rest of the afternoon into early evening continue to look reasonable. 0- 6km shear is virtually non-existent, so any storms that form will go straight up, and straight back down. While there could be a brief heavy downpour, and perhaps some gusty winds with these storms, they are not expected to be severe. Convection should dissipate during the evening, but redevelop again on Wednesday, most likely over central Missouri in response to some weak low level moisture convergence along a dewpoint boundary. This boundary will be the first manifestation of an east-to-west moving cold front which will move through the Mid Mississippi Valley. The truly colder air won`t reach us until Thursday, but this first wave of drier air will move westward from the Mississippi River Wednesday morning into central Missouri by the afternoon and provide a focus for convection. CAPE values Wednesday afternoon are similar to today`s, as are the shear values. Storms may be a little more numerous with the boundary to focus on, but the storms are not expected to be severe. Carney .LONG TERM... (Wednesday Night through Next Tuesday) Issued at 220 PM CDT Tue May 23 2023 The deterministic GFS and ECMWF models are in good agreement from Thursday through at least Saturday, and the WPC LREF analysis is very similar to to these solutions, lending high confidence to the forecast into the weekend. A cool surface high drops into the Great Lakes Region and Ohio Valley and shoves the cold front through southwest Missouri into the plains by Thursday night. The Mid Mississippi Valley will then be under the influence of the surface ridge for the rest of the week into the weekend. Temperatures immediately behind the front will drop to near or a few degrees below normal in the 70s on Thursday and Friday, but the airmass will modify into the weekend bringing 80+ degree temperatures back for Saturday and Sunday. The pattern aloft becomes highly amplified and blocky with a strong ridge over the Great Plains and long wave troughs to either side. This omega block evolves into a rex block by the end of the week as the eastern long wave trough fractures and cuts off an upper level low over the Southeastern U.S. and the northern portion of the ridge gets pinched off to form a closed anticyclone that drifts east into the Upper Midwest and Great Lakes region. There are 3 clusters in the ensembles, all with very similar solutions at least through Friday. One cluster doesn`t develop the rex block in the Friday- Saturday time frame, and is overall less amplified and a little more progressive than the other two. Ultimately, one solution over another will probably only affect precipitation chances starting early next week. The going forecast has slight chance-low chance beginning late Sunday night into Monday and this still looks reasonable given the uncertainties with the progression of the pattern...or lack there of. Carney && .AVIATION... (For the 06z TAFs through 06z Wednesday Night) Issued at 1033 PM CDT Tue May 23 2023 Mostly VFR conditions are expected to persist through the 06Z TAF period with only a few possible exceptions. A couple of small, weak thunderstorms continue to percolate near St. Louis area terminals as of 330Z, but this activity does not appear likely to impact local terminals in the area. Instead, these cells are likely to diminish within an hour or so, and by the start of the 06Z period they will more than likely have diminished. Overnight, some patchy fog may develop in low lying areas, with some potential to reduce visibilities at mainly JEF, SUS and CPS. Confidence is low that terminals will be significantly impacted, but the increase in humidity and expected light winds overnight has increased confidence that at least patchy fog will develop in the area. Any fog that develops should diminish shortly after sunrise. Otherwise, a weak cold front will move through the area tomorrow, reinforcing east to northeast winds. A few showers and weak thunderstorms will again be possible in the vicinity of JEF and COU in the afternoon, but confidence is too low for mention in the TAF at this time. BRC && .PRELIMINARY POINT TEMPS/POPS... Saint Louis 64 86 60 79 / 20 5 0 0 Quincy 59 83 54 74 / 5 10 5 0 Columbia 61 82 58 81 / 5 20 0 5 Jefferson City 61 83 60 83 / 10 20 5 5 Salem 60 83 56 75 / 5 5 5 0 Farmington 58 81 57 79 / 20 5 0 0 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Midland/Odessa TX
553 PM CDT Tue May 23 2023 ...New AVIATION... .SHORT TERM... (This afternoon through Wednesday night) Issued at 114 PM CDT Tue May 23 2023 500mb RAP analysis shows subtle ridging across southern AZ/NM, providing northwest flow of around 25-30kts across our area. With prevalent low level moisture in place across the eastern zones (55- 65F dewpoints), this westerly flow helps sharpen up a dryline late this morning along the TX/NM state line, stretching southward through the Big Bend. The dryline mixes eastward towards the central Permian Basin through the early afternoon, pushing the 60F dewpoints into the far eastern zones. Efficient insolation this morning has sent temperatures well into the 80s already, pushing the low 90s in some spots. This and the good moisture combine into 1000-2000 J/kg of MLCAPE, with the better instability located east of the dryline. Between convective temperature being reached and localized lift along the dryline, convective initiation is expected around first across western Stockton Plateau 19-20z, followed by the plains around 20-21z. Ultimately, the placement of the dryline will be key to the location of CI in the plains. Storm coverage will not be as great as yesterday, but the focus for severe storms is across the northeastern Permian Basin and western Low Rolling Plains where the better CAPE is found. Environmental shear gradually increases from a measly 15-20kts to around 30kts by the early evening but convectively driven cold pools may locally enhance bulk shear to 40- 50kts. All modes of severe weather are possible with storms today with the primary threats being very large hail and damaging winds. If storms linger beyond 00z, SRH becomes enhanced by a strengthening LLJ which may aid in isolated tornado development across the far eastern zones. Depending on outflow boundary-based development, all storm activity should move out of the area by 06z tonight. Northwest flow persists through tomorrow as well, with the dryline having retreated up against the higher terrain tomorrow morning. Thanks to plenty of low level moisture in place scattered thunderstorms are possible initially off the higher terrain of the Davis Mountains and high New Mexico plains. From there, northwesterly flow could allow for upscale growth as storms move southeastward into the Permian Basin. Where storms initially develop in eastern New Mexico and available environmental instability and shear will determine where a potential MCS may move through tomorrow evening, whether it will hit the central/eastern Permian Basin, clip the eastern edge, or not develop at all remains to be seen. Any lingering boundaries from today`s convection may locally enhance storm development as well. As for temperatures, lows tonight and Wednesday night will be right around normal with highs tomorrow being a touch cooler than today across the northern/northeastern Permian Basin owing to any precipitation from today/tonight. -Munyan && .LONG TERM... (Thursday through Monday) Issued at 114 PM CDT Tue May 23 2023 Upper ridge over Mexico Thursday will extend northward across the region with a low over WA/OR and its trough extending southward to CA. This pattern will continue Friday and Saturday. A cut off low develops over CA Sunday moving down across the state Monday... wobbling over Srn CA Tuesday and into Nrn Mexico Wednesday. On Thursday upper ridge builds over the western half of the country. High temperatures mostly in the 80s Thursday through Sunday with 90s along the Pecos and Rio Grande. Temperatures warm early next week with 90s becoming more widespread. Lows mainly in the 60s with a few 50s for higher elevation and Nrn Lea Co. SE wind Thursday and Friday will help to keep moisture in place with dewpts in the 60s. Been active this week with thunderstorms around the area... this will continue Thursday with a Marginal Risk running N-S along the NM/TX border. Thunderstorms continue over the higher elevations and Nrn Permian Basin Friday through Sunday shifting more to the east Monday. && .AVIATION... (00Z TAFS) Issued at 546 PM CDT Tue May 23 2023 VFR conditions will prevail next 24 hours. Convective chances this evening look best KMAF/KHOB, but chances too low to include attm. NAM brings in a stratus deck overnight, w/cigs as low as IFR KMAF/KHOB, but this is an outlier, and we`ve left them out for now, as well. Otherwise, return flow persists, but on the light side. Forecast soundings develop a cu field late Wednesday morning KFST, spreading through other terminals by mid-afternoon, w/bases 6-11kft agl. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 62 86 62 85 / 30 20 30 30 Carlsbad 61 94 63 89 / 0 10 10 30 Dryden 67 93 68 90 / 30 20 10 10 Fort Stockton 66 95 65 89 / 10 20 10 30 Guadalupe Pass 63 88 62 84 / 0 0 0 20 Hobbs 59 88 61 85 / 10 10 30 30 Marfa 55 90 56 87 / 10 10 10 30 Midland Intl Airport 63 89 63 87 / 10 20 20 30 Odessa 64 90 65 88 / 10 20 20 30 Wink 64 95 66 90 / 0 10 20 30 && .MAF WATCHES/WARNINGS/ADVISORIES... TX...None. NM...None. && $$ SHORT TERM...16 LONG TERM....72 AVIATION...44
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1049 PM CDT Tue May 23 2023 .DISCUSSION...(This evening through Tuesday) Issued at 240 PM CDT Tue May 23 2023 KEY MESSAGES: - Seasonable temperatures on Wednesday. - Warm, above normal temperatures Thursday through early next week. - A slight chance of rain tonight into early Wednesday over central Minnesota. Otherwise, dry conditions persist for the next week or so. This Afternoon through Friday... Another warm day with temperatures in the 80s for most locations. Western MN has the warmest location as Madison (MN) hit 90 at 2 PM. The warm temepratures and stagnant surface pattern has led to an Air Quality Alert for most of the MPX forecast area that goes through this evening due to elevated surface ozone pollutants. The hazy skies have become a stable so far this month due to the Alberta wildfire smoke. The smoke will remain in place, but recent rainfall over the source region has limited additional smoke formation this week. So what will the smoke do over the next few days? Well an elevated layer will continue to linger over the next 2 days. The 15z RAP extension suggests we will see a gradual improvement into Thursday as elevated layer gradually thins and any surface smoke is pushed out overnight by the cold front. A cold front will slowly move through region overnight. This will lead to a brief period of chance PoPs tonight into early Wednesday, primarily across central MN where better forcing and moisture is available. The FROPA will bring cooler temperatures on Wednesday and an improvement in air quality. Highs will be in the 60s (WI) and 70s (MN) but locations southwest of the Minnesota river could see temperatures back into the low 80s as the cold front stalls/weakens along the river. High pressure will settle into the region with a return to mostly sunny skies on Thursday and Friday. This will set up a warming trend that continues into the weekend. Saturday through Tuesday... High pressure looks to stick with us both at the surface and aloft on Saturday and Sunday. Previous forecast was too quick with the departure of the ridging, but 12z guidance maintains the influence from the high pressure into Monday. Monday and Tuesday is less certain. 12z guidance is in surprisingly solid agreement now that we will end up on the western edge of the upper level ridge. So this should lead to additional hot and dry weather as long as the upper level ridge holds over the Upper Midwest. If we look just beyond the forecast period, the 12z ECMWF brings through a weak system next Thursday. This would be our next chance for any widespread precipitation over the next 7 to 10 days. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1044 PM CDT Tue May 23 2023 Cold front will just be moving into the northeast sections of the MPX area at 6z. The front is already slamming on the breaks it will slowly lumber across southern MN Wednesday, stalling out over western MN Wednesday night. Still not antipating any precip with this front, with even the cloud cover on a diminishing trend over most of MN for Wednesday. The only thing to watch is as the flow behind the front comes off of Lake Superior, it is bringing some MVFR/IFR cigs with it and there`s an outside chance some of these lower cigs could make into western WI Wednesday morning. Other than that, it`s VFR conditions with east winds this period. KMSP...No additional concerns. /OUTLOOK FOR KMSP/ THU...VFR. Winds SE at 10-15kts. FRI...VFR. Winds S at 10-15kts. SAT...VFR. Winds S at 10-15kts. && .MPX WATCHES/WARNINGS/ADVISORIES... MN...None. WI...None. && $$ DISCUSSION...BPH AVIATION...MPG
Area Forecast Discussion
National Weather Service Marquette MI
743 PM EDT Tue May 23 2023 .SHORT TERM...(This evening through Tonight) Issued at 243 PM EDT TUE MAY 23 2023 A cold front is dropping south across Lake Superior this afternoon with clouds and a few showers north of the boundary. There were a few elevated thunderstorms across the far northern lake this morning, but the only thunder this afternoon is well west/northwest of the lake. Am struggling with timing of the wind shift and precip chances this afternoon/evening since a band of light showers reached the tip of the Keweenaw by late morning and hasn`t moved for several hours since. Additionally, latest radar imagery shows a lake breeze knocking on the WFO doorstep as of 2 PM, but surface observations suggest the temperature gradient is fairly weak. An agitated Cu field is bubbling UP along this lake breeze and HREF guidance shows a non-zero chance of shower activity developing boundary this afternoon. The latest 17z RAP mesoanalysis shows a localized pocket of >250 J/kg CAPE southeast of Munising where HREF highlights some light QPF. At this time, thunder chances are too low to include in the grids. Much cooler temperatures spread across the area this evening as the reinforcing cold front moves through with a long fetch of NNE winds coming off the still cold lake water. Some light shower activity should accompany the FroPa, but measurable precip is tough to come by and is most likely across the east. Despite temps falling into the upper 30s by Wednesday morning, steady northeast winds and some cloud cover should prevent any frost formation (though tomorrow night is a different story). In fact, model soundings indicate the incoming air mass is cold enough to support a shallow ~2kft layer of lake-induced instability by tomorrow morning. Once low level clouds burn off, abundant sunshine is expected with the layer of smoke also blowing south and west of our area. .LONG TERM...(Wednesday through Tuesday) Issued at 249 PM EDT TUE MAY 23 2023 Upper air pattern consists of 500 mb troughs on the west and east coasts and a broad ridge over the northern and central plains 12z Wed. The pattern changes little through 00z Sat with the ridge building over the upper Great Lakes. In the extended, the GFS and ECMWF shows 500 mb troughs in the western and eastern U.S. and a ridge across the plains into the upper Great Lakes 12z Sat. The ridge remains over the upper Great Lakes into Tue. Temperatures look to be above normal for this forecast period. One problem with temperatures though will continue to be smoke from fires in western Canada and this could knock temperatures down a few degrees. Will continue dry for this forecast. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 742 PM EDT TUE MAY 23 2023 Cold front is current dropping s across Upper MI. Lagging the front is a band of -shra and lwr cigs. As this band sinks, expect VFR to fall to a period of MVFR at IWD late this evening and to a period of IFR at SAW late this evening where upsloping will be strongest under ne winds. At CMX, ne winds don`t have much of an upslope component, so VFR may be able to prevail thru the evening. NE winds thru the night should be gusty at times to around 20kt at all terminals. Much drier air arriving overnight will cause lwr clouds to clear out with all terminals returning to VFR, though upsloping may lead to IFR or low MVFR cigs persisting to around sunrise. VFR will then prevail for the remainder of the fcst period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 249 PM EDT TUE MAY 23 2023 Cold front will drop southward across Lake Superior early this evening. Significant pressure rises behind the front will yield gusty north and northeast winds as the front passes and behind it. The strongest winds will be over the western Lake where a favorable northeast wind direction will result in gusts up to 30 knots tonight through Wednesday afternoon. As surface ridge settles over the Upper Lakes Wednesday night and then to the lower and eastern Lakes late week through the weekend, winds will diminish and remain below 20 knots from Thursday through Memorial Day. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...EK LONG TERM...07 AVIATION...Rolfson MARINE...07
Area Forecast Discussion
National Weather Service Las Vegas NV
903 PM PDT Tue May 23 2023 .SYNOPSIS...Showers and thunderstorm chances will become more confined to central Nevada through the week. Breezy afternoons will be prevalent each afternoon through this week, otherwise, temperatures will drop a few degrees late-week before increasing back to above average once again through the weekend. && .UPDATE...Thunderstorms were persisting over central Nevada including Esmeralda County where training storms were occurring ahead of an upper level vort max rotating into the central/southern Sierra as it moves through the base of a broad quasi-stationary trough over the Pacific Northwest and California/Nevada. Scattered showers were lifting up through Lincoln County this evening, but little potential for lightning. The latest HRRR indicates thunderstorms may continue to develop between Silver Peak and Tonopah the next few hours before dissipating. Emseralda County will again be the focus for afternoon showers and thunderstorms Wednesday afternoon as it remains near the center of the southern branch of the aformentioned trough. This is reflected in the going forecast and no immediate changes are needed. -Adair && .PREV DISCUSSION... 1118 AM PDT Tue May 23 2023 .SHORT TERM...Today and Tomorrow. As of 17Z, GOES18 satellite showed thunderstorms developing just north of Lincoln county with increasing cumulus development over the high terrain areas north of the I-40 corridor. 12Z HREF and latest mesoanalysis depicted a very conditional convective setup for locations south of the HWY 95 corridor whereas areas north should see scattered thunderstorms this afternoon and early evening. Shortwave energy will put central Nevada in a favorable dynamically lifted environment, coinciding with better deep layer moisture than farther south where low level dry air is progged to filter in from the south and southeast, eroding almost all surface based instability south of the 95 corridor. That being said, marginal mid level moisture still exists enough to keep PWAT values above normal for the column, so can`t completely rule out convection for Clark, Inyo, and San Bern...but those areas will highly depend on high terrain to convect. Would expect these storms to orphan immediately after coming off the terrain, but not before dropping some impressive outflows if they can can maintain coherent updrafts above -50C. Ended up bumping up PoPs for Nye/Lincoln and left slight chance PoPs for high terrain locations farther south to account for this. For any storms that develop, again the main concern will be strong outflows and cloud to ground lightning. The 12Z HREF 35+mph thunderstorm wind fields paint a very reasonable picture for where the stronger gusts could occur with 30+% probabilities encompassing Ewill move fully into northern Nye County over the next hour or two then smeralda, Nye, and Lincoln, with lesser chances to the south. Moving into tomorrow, the shortwave from today should be re- enforced by another round of vorticity maxima in the same general area, but lesser overall moisture availability compared to today (per GEFS/EC mean PWAT). This should serve to further lessen convective potential across southern Nevada, perhaps staying just as cumulus across higher terrain with a very low end chance for a shower or storm south of the Highway 6 corridor. .LONG TERM...Thursday through the Weekend. Moving into the latter half of the week and weekend, the 500mb synoptic setup and moisture situation more or less remains unchanged in the 06Z GEFS/EC and this was seen in the 00Z clusters as well. This would increase confidence of southwest wind gusts each afternoon heading into the weekend but there is general agreement that this shortwave energy will shift off to the east, leaving generally weak southwest flow across the west. Marginal height increases will allow for temperatures to recover a few degrees, by the weekend, into the mid 90s for KLAS but long range NBM temperatures seem to plateau at that point for the next several days. CPC 6-10 day outlook from yesterday has a rather high probability of above average precip central CA and NV, but would expect this to shift farther north given the latest trends in the long range models. && .AVIATION...For Harry Reid...Expecting south to southwest winds to increase this afternoon with speeds between 15-25 knots, with some localized gusts up to 30 knots possible. There could be some isolated convection this afternoon over the Spring Mountains, but overall most of the thunderstorm activity will remain well north of the terminal. Any outflow winds are unlikely today. Winds to decrease by 04z-06z. For the rest of southern Nevada, northwest Arizona and southeast California...Winds will gradually shift to the south to southwest over most area by early afternoon with most locations seeing speeds between 15-25 knots with a few locations seeing gusts to 30 knots. Afternoon showers and storms look to largely remain north of terminals. There is about a 10% chance of storms at KBIH, but any storms should generally remain east over the White Mountains. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && $$ DISCUSSION...TB3 AVIATION...Gorelow For more forecast information...see us on our webpage: or follow us on Facebook and Twitter