####018004870#### FXUS62 KGSP 120716 AFDGSP Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 316 AM EDT Sun May 12 2024 .SYNOPSIS... One more day of dry weather is expected today, before rain returns Monday afternoon. Rain and thunder are expected on Tuesday and Wednesday, followed by a brief stint of dry conditions on Thursday. Active conditions will resume for the weekend. && .NEAR TERM /THROUGH TONIGHT/... As of 310 AM: An upper ridge axis builds in through the period as a trough moves east of the area. At the surface, a lee trough sets up over the area today with the center of high pressure building in tonight. After some patchy mountain valley fog, mostly sunny skies expected with slowly increasing cirrus. Increasing thickness values and west to northwest flow will help highs rise to around normal. With a dry air mass remaining in place, RH values will approach 25 percent outside of the mountains. Winds will be relatively light outside of the mountains with low end gusts possible. Gusty winds expected across the mountains, but RH values remain above 25 percent. Moisture values should remain above critical levels keeping Fire Weather concerns low. Cirrus becomes thick and widespread tonight as upper level moisture move in ahead of the next weather system. Despite light winds and a dry air mass, the cirrus will help keep temps slightly elevated. Lows end up near to slightly below normal. && .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... As of 246 AM EDT Sunday: No major changes to the short term forecast. It still appears that Monday will be a transitional day, as profiles saturate from the top down. A shallow dry layer near the surface will hold precipitation at bay for a while, but overall guidance has sped up with bringing rainfall in Monday afternoon/evening. Categorical PoPs are warranted Monday night as isentropic ascent ramps up and a wedge-like pattern sets up. Lows will fall into the lower 60s outside the mountains. On Tuesday, deeper synoptic forcing will arrive as a cutoff low develops over the Ozarks and a weak upper jetlet sharpens over the Mississippi Valley...supportive of deep forcing over the Carolinas. Operational guidance is increasingly supportive of the wedge front, while initially south of the forecast area, gradually eroding through the afternoon in response to intense low-level WAA; this will allow some surface instability on the order of 500-1000 J/kg to develop over most of the forecast area by mid-afternoon. As a 500mb speed max rounds the base of the advancing upper low late Tuesday, deep layer shear values will surge to 40kts or more by evening and into the overnight. So, Tuesday, especially Tuesday night, is inreasingly looking like our next window for severe weather. Highs on Tuesday will be limited by the weak CAD configuration and widespread cloud cover, and will only climb into the lower 70s. Tuesday night, lows will again fall into the lower 60s. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... As of 304 AM EDT Sunday: By Wednesday, the western Carolinas will be ensconced in warm sector air ahead of an advancing surface low, which should carry a cold front across the area by late in the day. Operational guidance once again brings 1000+ J/kg into the Piedmont and Upstate during the afternoon hours, but shear looks to be notably weaker with diminishing 500mb flow...so severe risk may be muted compared to Tuesday. Ridging is still expected on Thursday, which should keep precipitation at bay. By Friday, another upper low drifting out of the central Great Plains will incite a lobe of upper forcing from the southern stream, and active weather will resume Friday and Saturday. At least diurnal convection is therefore likely Friday onward. && .AVIATION /07Z SUNDAY THROUGH THURSDAY/... At KCLT and elsewhere: Altocu moving out of the area with some ridgetop stratocu and mountain valley fog in place through the morning. Light west to light and variable wind, NNW at KAVL, through daybreak. Expect cirrus to slowly increase in coverage and thicken through the day into the evening. W to NW wind through the day, NNW with low end gusts at KAVL. Winds do turn WSW for the Upstate sites during the afternoon. Low end gusts can't be ruled out elsewhere. Winds diminish and turn NE during the evening. Outlook: Moisture returns late Monday with active weather and associated restrictions Tuesday and Wednesday. Brief drying expected Thursday. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...MPR NEAR TERM...RWH SHORT TERM...MPR LONG TERM...MPR AVIATION...RWH ####018008387#### FXUS63 KMQT 120717 AFDMQT Area Forecast Discussion National Weather Service Marquette MI 317 AM EDT Sun May 12 2024 .KEY MESSAGES... -Isolated pockets in the south central could (40% chance) see elevated fire conditions ahead of the showers and thunderstorms this afternoon. -Scattered thunderstorms develop this afternoon into early evening, especially south central. There is a marginal risk (5%) of large hail and/or damaging winds south central. -Dry weather returns late tonight, continuing through Wednesday afternoon. && .SHORT TERM /THROUGH TONIGHT/... Issued at 316 AM EDT Sun May 12 2024 As a shortwave over northern Manitoba heads into northern Ontario this morning, strong theta-e advection and a low-level jet at 35 to 45 knots is bringing some sprinkles across the area early this morning over the western U.P. As cloud cover and warm air advection increase over the area early this morning, we've seen temperatures across the area stabilize and slightly rise. Therefore, we've almost certainly hit our low temperatures already, ranging from the mid 30s over the interior east to the mid 50s over the far west. As the sprinkle activity moves into the eastern U.P. after dawn this morning, expect to see a little bit of clearing over the west and central. This will allow the sunlight to increase the temperatures at the surface while dewpoints remain generally steady, creating a strong inverted-v sounding near the surface. This is most pronounced over the south central, where RHs could fall down to around 30%. We could (40% chance) see a spot or two in the south central hit elevated fire weather conditions as the highs today look to get to around 80F and winds could gust up to as high as 20-25 mph from the southwest before a cold front moves through this afternoon. However, given the likelihood and possible coverage of the potential elevated fire weather conditions, no notification will be sent this morning. However, fire weather isn't the only concern over the south central today. With CAMs model soundings showing convection becoming surface- based over the south central this afternoon up to around 1200 J/kg and 0-6 km bulk shear vectors being around 35 to 45 knots perpendicular to a lake-breeze aided cold front moving through Upper Michigan this afternoon, we could see marginally severe wind and hail this afternoon into early this evening across the south central (5% chance). Hail chances are aided by the wetbulb zero heights being in the 7-9 kft range and severe wind chances are increased by the strong lapse rates and evaporation near the surface ahead of the cold front. Thinking the storms will remain fairly discrete this afternoon into this evening over the central and east, but they will mainly be restricted to the cold front as it passes through Upper Michigan. Therefore, we could see the storms congeal into a more linear state late this afternoon into early this evening. As the cold front continues to push south and east out of area this evening, expect the showers and thunderstorms to roll out of area with it. Therefore, the severe weather threat looks to end before midnight tonight, with skies clearing out behind the cold front. Due to the clear skies tonight, expect low temperatures to be around 40, save for around Menominee where lows look to be a few degrees warmer. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... Issued at 331 PM EDT Sat May 11 2024 A couple cold fronts will press through the Upper Great Lakes Sunday evening, allowing a cool to seasonable airmass to break into the region through at least mid-week. Ahead of the initial cold front on Sunday, afternoon shower and thunderstorm development may occur if we're able to destabilize enough following the Sunday morning isentropically/warm frontally forced showers. By 0z Sunday and the start of this forecast period, the cold front looks to be draped across the central UP with the aforementioned shower/thunderstorm region out ahead stretching from Menominee County northeastward into the eastern UP. The environment at this point should be less conducive for any new convective development given the quickly waning influence of the day's diurnal heating. However, if a strong or severe storm does develop earlier, guidance suggests enough deep layer shear could sustain updrafts into the evening hours. However, the window will be short lived given the cold front's fast eastward progression. By 3z, CAMS all suggest convective activity should be outside of the forecast area. Behind the cold front, a dry airmass will press into the region while a secondary cold front moves through after midnight Sunday night. This, in addition to surface ridging building over the area, will sustain a dry couple of days for the forecast area. The daytime high temperature gradient Monday and Tuesday should stretch from near 50F by Lake Superior to the low-mid 60s across the south- central. On Wednesday, more widespread 60s are expected, with most areas outside of the immediate lakeshores and Keweenaw looking to climb into the low-mid 60s. Overnight lows should be mostly in the 30s, with chances for sub-freezing temperatures in the interior- central spots (20-30% chance). Fire weather concerns should be mitigated by the near to slightly cooler then normal conditions and light winds these days. But daytime mixing into a dry airmass aloft may support RH values nearing 30% for some interior central and west locations. Mid-level ridging shifts through the region on Wednesday followed by a shortwave pressing through Minnesota/western Ontario Wednesday night. Consensus among the 12z deterministic guidance suite has this pressing into our forecast area Thursday, supporting another round of showers through the day. This contrasts some with the GEFS, EC, and GEPS ensemble systems, where some members suggest precip could start Wednesday night. && .AVIATION /06Z TAFS THROUGH 06Z MONDAY/... Issued at 112 AM EDT Sun May 12 2024 VFR conditions will prevail thru this fcst period at IWD/CMX/SAW. As low pres drops into far northern Ontario tonight, a low-level jet will develop into Upper MI late tonight into Sun morning, resulting in 2-6hrs of LLWS at all terminals, lasting longest at IWD. The low- level jet will also generate sct showers, but confidence in a shower passing over any of the terminals is low. Not expecting conditions to drop out of VFR if a shower does occur. More showers/possible t-storm will develop Sun afternoon across central Upper MI, possibly affecting SAW before showers sag south in the evening. && .MARINE... Issued at 331 PM EDT Sat May 11 2024 Winds are mainly expected to remain below 20 kts through the entire forecast period, with some exceptions. A warm front will lift through the lake late tonight and early Sunday. Ahead of and behind the front, some isolated 20-25 kt wind gusts will be possible. The stronger pressure gradient will be Sunday across the east half and behind the warm front; however, the increasingly stable airmass over the lake should work against mixing the stronger southerly winds to the surface. Given the environment, higher reporting platforms would be more likely to observed these stronger winds than the surface buoys. A cold front will press from west to east through Lake Superior through the day as well. A shower or thunderstorm can't be ruled out by afternoon across the east half, but with the focus for convection being over Upper Michigan and not Minnesota, the probability is low (20-30%). Behind the front, high pressure will settle over the lake, supporting a few days of mostly 20kts or less over the lake through at least midweek. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... Small Craft Advisory from 2 PM this afternoon to 11 PM EDT this evening for LMZ248-250. && $$ SHORT TERM...TAP LONG TERM...JTP AVIATION...Voss MARINE...JTP ####018006296#### FXUS64 KEWX 120719 AFDEWX Area Forecast Discussion National Weather Service Austin/San Antonio TX 219 AM CDT Sun May 12 2024 ...New SHORT TERM, LONG TERM... .SHORT TERM... (Today through Monday) Issued at 207 AM CDT Sun May 12 2024 The latest GOES 16 IR imagery shows a 500mb closed low over southwestern Colorado. At the surface, easterly flow has resumed after a cooler and comfortable day by early to mid-May standards. Moisture should start to work back in, but dewpoints should start to rise once again overnight and get back into the 70s by midday Sunday. Mother's Day will be a muggy day, but on the cooler side over the eastern half of the region as cloud cover will be hard to break. Further west, highs should climb back into the mid to upper 80s and lower 90s once again along the Rio Grande as low clouds break towards the afternoon hours. The short term forecast is a messy one, as precip chances look difficult to predict through Sunday night. Confidence remains low on timing of any thunderstorms and where they ultimately develop. Light showers and occasional drizzle should continue through the morning hours as isentropic ascent is realized with east to southeasterly flow on the 300k surface. By the afternoon, as instability increases, some strong to severe storms will be possible. The latest day 1 outlook from the Storm Prediction Center places the Hill Country, I-35 Corridor, and Coastal Plains within a Level 1 of 5 Risk, while a small portion of the CWA from east of Austin to La Grange and northward is in a Level 2 of 5 Risk. All modes of severe weather are possible, but at this time, the greatest threat appears to be large hail. Any discrete storm that can tap into rich boundary layer moisture could also start rotating, with a tornado or two also possible. Ultimately, the greater severe threat for Sunday lies just to our east, but conditions should be monitored closely nonetheless. Monday brings a greater threat for widespread strong to severe storms as the associated 500mb trough starts to move eastward. On it's southern periphery, a potent shortwave will round its base and move through south Central Texas. A cold front will approach from the northwest and work through the entire CWA by sunset Monday. SPC places the eastern Hill Country, I-35/I-37 Corridor, and Coastal Plains within a Level 2 of 5 Risk on Monday. The primary concern looks to be large to very large hail along with damaging winds, but a tornado or two cannot be ruled out along the boundary early in the afternoon. The RRFS, HRRR, FV3, and NSSL WRF are all on board with afternoon convection. The real item up in the air is what happens before the lunch hour. Some members of the HREF develop early morning convection over the Hill Country and spread it eastward while others show little to no activity at this time. For now, focus will be on the afternoon storm chances as instability, shear, lift, and lapse rates will be highest within this time frame, but morning storm chances will have to be monitored as well. && .LONG TERM... (Monday night through Saturday) Issued at 207 AM CDT Sun May 12 2024 A cold front will be moving out of the area with possibly some showers or thunderstorms Monday night over the Coastal Plains before pushing east overnight. Dry conditions are then expected for Tuesday through Wednesday morning as upper ridging moves overhead. Above normal temperatures are expected Tuesday afternoon from the mid 80s in the northeastern portion of the area to the upper 90s and 100 degree mark in the west along the Rio Grande. A trough located just off the southern coast of California on Tuesday will move east towards the Plains Wednesday and Thursday. This will bring the next chances for precipitation to the area late Wednesday afternoon through Thursday night. There remains the potential for some severe thunderstorms and heavy rainfall with this activity. The current forecast places the heaviest rain potential over the northeastern portion of the CWA which is also where WPC has placed a level 2 of 4 risk for excessive rainfall. For now, the forecast remains on the dry side Friday through the weekend although there is decent spread in model guidance after the mid-week system. Some low precipitation chances may be introduced for next weekend in the coming forecasts. A warming trend is possible late week into next weekend. && .AVIATION... (06Z TAFS) Issued at 1212 AM CDT Sun May 12 2024 A rather messy forecast at area terminals over the next 24-30 hours. Confidence is low in timing of TS at terminals so opted for PROB30 groups at AUS, SAT, and SSF with the best forecast available right now. One thing we are confident about is the ceilings tanking to IFR and perhaps LIFR at all four sites by sunrise or shortly after it. Showers and vicinity showers are possible through about midday Sunday. VFR ceilings should move in by 20-22Z at SAT, SSF, and DRT, but confidence is low at AUS on whether VFR can be achieved before sunset. Overall, expect messy ceilings and reduced visby's through the morning followed by borderline MVFR for most of the day Sunday. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 80 72 87 67 / 50 40 60 10 Austin Bergstrom Intl Airport 80 71 87 65 / 50 40 60 10 New Braunfels Muni Airport 85 72 89 67 / 50 20 60 10 Burnet Muni Airport 77 70 85 63 / 50 30 30 0 Del Rio Intl Airport 94 74 101 70 / 20 20 10 0 Georgetown Muni Airport 77 70 86 64 / 50 40 60 0 Hondo Muni Airport 89 73 92 66 / 20 20 30 0 San Marcos Muni Airport 82 71 88 65 / 50 30 60 10 La Grange - Fayette Regional 80 73 86 67 / 50 40 60 20 San Antonio Intl Airport 88 73 90 68 / 40 20 40 10 Stinson Muni Airport 89 74 91 69 / 30 20 40 10 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term...MMM Long-Term...27 Aviation...MMM