Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/26/21

Area Forecast Discussion
National Weather Service La Crosse WI
1103 PM CDT Tue May 25 2021 .UPDATE... Issued at 148 PM CDT Tue May 25 2021 ** Re: storm potential this afternoon and eve ** This afternoon convective initiation continues to be somewhat murky. Latest trends in the 18-19Z GOES satellite Day Cloud Distinction show an area of very weak cumulus development in southeast MN and wc WI near KONA /Winona/ and northeast. This is along the building SW- NE CAPE pool of ~1500 J/KG all well out ahead of the surface dryline/cold front in MN. Cumulus was building and partially glaciating trying to initiate, but has trended down in the last 30 mins. This matches well with a weaker but steady- state deeper but broad moisture convergence region extending from the ongoing convective echo east of Medford, WI, to Winona MN to Mason City per SPC mesoa page. Day Cloud Distinction also showing growing cumulus along several frontal/near frontal boundaries across NW WI and eastern MN...roughly I-35 in MN KAEL- KMSP-KDLH. Wind shear across the area has increased with 0-6km bulk shear ~40kts or more north of I-90 per RAP and GOES derived cloud motion winds. Thus, supercell modes will be favored, and with storm motion 45-90 degs to front, should see discrete cells for a period after initiation. With aforementioned deeper weak convergence north and just west of La Crosse, would think lower-end storms could occur as capping is minimal, but thinking is that this area would have a lower threat of severe storms due to less sustained convergence. The cold front, now located further west along the growing cumulus fine lines near I-35 will continue east and provide a late afternoon severe storm threat in western WI, far southeastern MN /matches western edge of SPC SLGT risk well/. Would think the frontal convergence and dewpoint gradient will sharpen a bit in the coming hours, a bit steeper lapse rates and more large scale lift with shortwave trough energy will shift in. Overall, the frontal convergence is not super impressive with broad rounded trough at the surface. This will impact storm coverage. Parameters marking the I-90 and north area well for large hail and wind potential. Large hail parms suggest 2" hail possible there. Hodographs per current 88Ds at KMPX/KARX are straight line from 0- 2km and RAP hodos still carry small curvature in the 0-1/0-3km layer. SPC Mesoa Sig Tor Parameter ~1 north of I-90 which confirms a lower, entry level tornado risk currently. This may grow to ~2 with a bit of backing, should it occur, which is more likely north of I- 94 later. Thus, hail and wind threats seem on target for our messaging. Further south of I-90 the shear decreases but is still favorable for severe storms - just marginal supercellular - multicellular more favored...early eve timing. .SHORT TERM...(Wednesday and Friday) Issued at 215 PM CDT Tue May 25 2021 WET THU/THU NIGHT: Another shortwave is progged to move due east from the PAC NW tonight, spinning across the upper mississippi river valley thu/thu night. Some ripples in the flow could kick out of the trough over the desert SW, preceding the NW shortwave across the region. 30-40 kt 850 mb jet to feed the system. The mix of lift/moisture should lead to a broad expanse of rain. Little if any instability to work with, so thunder threat looks limited at this time. In addition, while the low level moisture transport noses into the region, warm cloud depths only peak around 3500 m while sfc pws top out around 1 1/4". Should see decent rainfall with 1/2 to 1" or so, but potential for more than a good soaker (ie, flooding concerns) looks low. TEMPS: with the passage of the dry line/cold front tonight, colder air starts to filter in from the north, with the main push of cold air coming in Thu/Fri. Widespread rain/clouds will also work to keep temps unseasonably cool. Highs still looking like they will struggle into the 50s both those days - a marked contrast from recent days when lows bottomed out in the 60s. .LONG TERM...(Saturday through Tuesday) Issued at 215 PM CDT Tue May 25 2021 The GFS and EC both favor shortwave upper level ridging come Friday, quickly sliding east/flattening that ridge out with west-east running shortwave across southern Canada. Uncertain whether that shortwave will sparking any pcpn sat night/early sun. Not much qpf in the models, and still have an exiting sfc high to contend with. A better shot for rain could come on Memorial day with some agreement between the GFS and EC with a piece of upper level energy dropping out of southern Canada and across the region. The GFS doubles up with advancing more shortwave energy into the area, out of a trough over the desert SW. Likely a lingering sfc front will come into play too. The EC leans more on a split flow type evolution, keeping more of its qpf across the north and south. The more robust GFS is widespread with its chances. Several of the EC ensemble members mimic the GFS`s take though, with bulk of the GEFS members also siding toward good chances to get wet. The cool temperatures will persist, although show some (meager) warming as we push into the new work week. Could see a return to at or above normal temps by the following weekend. && .SHORT TERM...(Wednesday and Friday) Issued at 215 PM CDT Tue May 25 2021 WET THU/THU NIGHT: Another shortwave is progged to move due east from the PAC NW tonight, spinning across the upper mississippi river valley thu/thu night. Some ripples in the flow could kick out of the trough over the desert SW, preceding the NW shortwave across the region. 30-40 kt 850 mb jet to feed the system. The mix of lift/moisture should lead to a broad expanse of rain. Little if any instability to work with, so thunder threat looks limited at this time. In addition, while the low level moisture transport noses into the region, warm cloud depths only peak around 3500 m while sfc pws top out around 1 1/4". Should see decent rainfall with 1/2 to 1" or so, but potential for more than a good soaker (ie, flooding concerns) looks low. TEMPS: with the passage of the dry line/cold front tonight, colder air starts to filter in from the north, with the main push of cold air coming in Thu/Fri. Widespread rain/clouds will also work to keep temps unseasonably cool. Highs still looking like they will struggle into the 50s both those days - a marked contrast from recent days when lows bottomed out in the 60s. .LONG TERM...(Saturday through Tuesday) Issued at 215 PM CDT Tue May 25 2021 The GFS and EC both favor shortwave upper level ridging come Friday, quickly sliding east/flattening that ridge out with west-east running shortwave across southern Canada. Uncertain whether that shortwave will sparking any pcpn sat night/early sun. Not much qpf in the models, and still have an exiting sfc high to contend with. A better shot for rain could come on Memorial day with some agreement between the GFS and EC with a piece of upper level energy dropping out of southern Canada and across the region. The GFS doubles up with advancing more shortwave energy into the area, out of a trough over the desert SW. Likely a lingering sfc front will come into play too. The EC leans more on a split flow type evolution, keeping more of its qpf across the north and south. The more robust GFS is widespread with its chances. Several of the EC ensemble members mimic the GFS`s take though, with bulk of the GEFS members also siding toward good chances to get wet. The cool temperatures will persist, although show some (meager) warming as we push into the new work week. Could see a return to at or above normal temps by the following weekend. && .AVIATION...(For the 06Z TAFS through 06Z Wednesday night) Issued at 1050 PM CDT Tue May 25 2021 Drier and cooler air is pushing into the region with northwest winds 9 to 15kts with some stronger gusts early on. Decreasing clouds overnight, however Wednesday morning should see clouds return to the area. MVFR ceilings are prevalent upstream, but there are hints that these will become more VFR through the morning, then decreasing during the afternoon. Northwest winds to gust 20 to 25kts after 12Z will a reinforcing cool front. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ UPDATE...Baumgardt SHORT TERM...Rieck LONG TERM....Rieck AVIATION...Zapotocny
Area Forecast Discussion
National Weather Service Bismarck ND
909 PM CDT Tue May 25 2021 .UPDATE... Issued at 907 PM CDT Tue May 25 2021 For this update, tweaked hourly temperatures and the sky cover forecast through early tomorrow afternoon. Clouds will continue to diminish across the southwest tonight with temperatures falling into the mid 30s. Therefore, some patchy frost isn`t out of the question across the southwest. However, the potential is not expected to be widespread enough to warrant headlines at the time. Otherwise, just blended in the latest observations to the forecast. UPDATE Issued at 641 PM CDT Tue May 25 2021 Will go ahead and cancel the Wind Advisory with this update. winds have fallen below criteria over the area. However, it will remain fairly breezy over the next few hours. Otherwise, just blended in the latest observations to the going forecast. A few showers will continue across portions of the south central and into the James River Valley over the next couple of hours, but will also diminish with the loss of daytime heating. && .SHORT TERM...(This evening through Wednesday) Issued at 333 PM CDT Tue May 25 2021 Winds diminishing this evening and a frost potential Wednesday morning highlights the short term forecast period. This afternoon, a potent mid-level circulation was evident on water vapor imagery tracking east across the International Border of North Dakota. Cold air advection at 850-700 mb has created weak instability, responsible for scattered showers across northern portions of the state. A tight pressure gradient and around 40 kts at 850mb have created windy conditions as well, with wind gusts reaching around 50 mph and sustained winds of 30 to near 40 mph. Tonight, the mid-level low will exit east and ridging with a building surface high will feature in the western portion of the state. 850mb temperatures will be seasonably cold, falling to the 10th percentile in the NAEFS climatological guidance. This cold air mass will create a threat of near freezing temperatures, with a frost or even freeze potential. However this should be generally mitigated by cloud cover, with RAP guidance depicting high relative humidity in the 925-850mb layer across the forecast area. The best opportunity for lows to approach freezing Wednesday morning may be in the western third of the state where the surface high will build, again highly dependent on cloud cover. No headlines will be issued at this time given high uncertainty but the potential may be there for those with sensitive vegetation to take precautions anyway. Ridging and a seasonably cool high pressure center will feature across western and central North Dakota Wednesday. Highs in the 50s can be expected and weaker winds than today, though the southwest will be breezy due to a deepening surface low ahead of the next shortwave trough. Chances for showers will develop in the southwest ahead of the trough during the day Wednesday, though best chances arrive Wednesday night. .LONG TERM...(Wednesday night through Tuesday) Issued at 333 PM CDT Tue May 25 2021 Good chances for rain across southern North Dakota Wednesday through Thursday and potentially near freezing temperatures Thursday morning and Friday morning highlight the long term forecast period. Aforementioned shortwave trough is expected to begin to cross the Dakotas Wednesday and track out of the region Thursday night. The placement of the lower level baroclinic zone is fairly consistent model to model favoring rain chances from the ND/SD border to the I-94 corridor, with the 12Z GEFS members still favoring a slightly further north solution than the ECMWF ensemble. This remains consistent with the previous forecast shift, with highest POPs along and south of I-94 and slight chances up to Highway 2. The warm sector and associated instability should be well to the south, with no severe weather in North Dakota expected. Freezing temperatures will be possible north of the precipitation shield Thursday morning and then again but more widespread Friday morning with the lingering cold lower level air mass. The northern extent of cloud cover Thursday morning will be in question for freeze potential, but NBM probabilities are at least highlighting the northern tier of counties as the most likely to fall below freezing. The strongest probabilities of below 32 F lows are lower on Friday morning, but the overall potential of frost is still more widespread with high pressure expected to build. Temperatures warm back up this weekend with overall mid-level heights on the rise. A quick moving trough and front will bring a chance of rain Friday night and Saturday but a notable cool down is not expected. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 641 PM CDT Tue May 25 2021 Scattered to broken cumulus and isolated showers will diminish as we approach sunset. However, MVFR ceilings will continue to push in from north to south tonight and through the overnight hours. Breezy northwest to north winds will also diminish around and after sunset. Ceilings will begin to improve into VFR categories Thursday afternoon, but chances of rain showers will be on the increase by the afternoon hours across the southwest, mostly likely impacting KDIK towards the end of the period. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...ZH SHORT TERM...AE LONG TERM...AE AVIATION...ZH
Area Forecast Discussion
National Weather Service Denver/Boulder CO
908 PM MDT Tue May 25 2021 .UPDATE... Issued at 907 PM MDT Tue May 25 2021 Added low PoPs for the rest of the evening and into the early morning hours. A couple of showers and a weak storm have formed northeast of Denver. Warm air advection and the left exit region of the jet appear to be helping this form. HRRR model favor areas along the north of I-76. Based on satellite and current storm motion, this appears on track. UPDATE Issued at 834 PM MDT Tue May 25 2021 IR satellite imagery showing a large batch of high clouds over the Great Basin. These clouds will track east and over the region for Wednesday. Appears these high clouds will arrive prior to sunrise and unfortunately in time for the lunar eclipse. May be some breaks in the high clouds, or they may be thin enough to observe the eclipse. Adjusted sky cover grids to reflect this. Also increased south/southeast winds south and east of Denver where they should gust to 25 mph at times tonight. Because of this also increased temperatures a little as well. && .SHORT TERM...(This evening through Wednesday) Issued at 157 PM MDT Tue May 25 2021 Weak upper level shortwave ridging early tonight shifts east and gives way to a northern stream shortwave trough moving out of the Pacific NW and extending south into the Great Basin on Wednesday. Skies start off clear overnight with light east wind, turning more south as the surface high shifts east and in advance of the approaching shortwave. With low RH, clear skies, and light winds temps to radiate down to just above seasonal normals. All eyes turn to the skies toward morning when the lunar eclipse is scheduled. Cloud forecast for optimal viewing is tricky, and thinking is the urban I-25 corridor into Park County is the best, although not optimal. In that area there is still the risk for high cirrus, which could enhance visual impact if thin, or nearly obscure. Model soundings are not totally saturated above 400 mb, or roughly 15K feet, so hopefully will be some viewing opportunities. Further NW into North and Middle Park, closer to the approaching trough and upper jet should be more clouds. On the plains, returning moisture on south winds will likely generate lower clouds. There should be some breaks in the clouds on the plains, but not totally clear. For Wednesday return flow sets up on much of the plains, with gusty southerly winds increasing moisture. Precipitable water values near .90 inch in the northeast near the 90th percentile for this time of year. Over the metro area a weak Denver Cyclone sets up in the morning then dissipates with mixing later in the day. Max temps forecast upper 70s to upper 80s, with surface based capes increasing to over 2500 j/kg along an eastern Weld to Akron to Cheyenne Wells axis, shifting east during the afternoon. By the afternoon 0-3 km bulk shear gets to 20-30kts in northeast Colorado. Meanwhile a 60-70 kt 300 mb jet ahead of the approaching trough will move across the region. All this good for a slight risk for Wednesday afternoon in far NE Colorado, mainly Sedgwick & Phillips Counties. High resolution models showing storm initiation in the eastern Weld & Morgan County area 2-3 pm and move east through the afternoon. .LONG TERM...(Wednesday night through Tuesday) Issued at 157 PM MDT Tue May 25 2021 A few storms may linger into tomorrow evening across our far northeast. Severe potential would continue as these storms move off to the east into Nebraska/Kansas. Storm threat should end by about 9PM or so with the forecast area remaining dry for the overnight hours. Thursday will be mostly dry across the area with temperatures a few degrees cooler than Wednesday. Forecast guidance suggests some potential for thunderstorms across the southern Foothills/Front Range mountains but capping overhead should limit coverage. Maintained some slight chance/chance PoPs for these areas and into the Denver metro. Warmer temperatures are expected Friday with southwesterly flow aloft increasing and mid-level temperatures warming. Highs should reach the low 80s across the plains. The afternoon should remain dry with just a few showers or thunderstorms over the higher terrain. A more unsettled pattern will re-develop this weekend as a slow moving trough works its way across the desert southwest. Guidance remains in relatively good agreement in the overall setup, with weak upslope flow aloft above with near-surface moisture transport from the Gulf of Mexico. At least a few showers and storms are possible Friday, but the better moisture and upper level support comes Saturday through Monday. GFS/ECM both show CAPE > 1000 J/kg Saturday and Sunday afternoon with well above normal PWATs. Although there could be a weak capping inversion aloft, the current forecast is relatively unchanged from the previous forecast, with chance/likely PoPs over the Front Range and into the plains from Saturday through Monday. Additional details regarding burn area concerns detailed in the hydro section below. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 834 PM MDT Tue May 25 2021 VFR conditions to prevail through Wednesday. High clouds increase tonight with bkn-ovc skies for Wednesday. South to southeast winds are expected to persist through tonight and Wednesday morning. Gusts may be as high as 25 knots. Scattered showers and thunderstorms are expected to form east of the Denver area Wednesday afternoon. Outflow from this activity may produce a wind shift or two after 20Z Wednesday. && .FIRE WEATHER... Issued at 157 PM MDT Tue May 25 2021 Fire weather concerns elevated in the high parks and southern foothills Wednesday afternoon. Winds will become gusty on the plains and in the mountains as strong winds aloft mix to surface. While RH increases on the plains, mountains remain dry. Jackson/Grand/Summit/Park and southern Jefferson & western Douglas counties will see minimum RHs in the upper teens/low 20s, with wind gusts nearing 25 kts. Although below Red Flag criteria, any fire starts will still move quickly in this environment. Elevated fire danger will continue across the high parks Thursday and Friday with continued dry and windy conditions. && .HYDROLOGY... Issued at 157 PM MDT Tue May 25 2021 No burn area hydro concerns tonight and Wednesday, with no storms forecast. On the plains, any storms that form Wednesday afternoon will be heavy rainers in addition to the severe threat, however storms should keep moving with little flood threat. The main hydro concern in the forecast period will be this weekend as a slow moving system provides a few rounds of showers and storms over most of the forecast area. Storms are expected each afternoon as weak upslope flow develops Saturday and Sunday. There should be enough instability over the higher terrain both Saturday and Sunday for thunderstorms. Above normal moisture over the area would suggest potential for heavy rains in any thunderstorms that do develop. Precipitation continues into Monday, but cooler temperatures would limit thunderstorm potential. Hydro concerns will decrease Tuesday as the system departs the region. && .BOU WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...Meier SHORT TERM...Hanson LONG TERM...Hiris AVIATION...Meier FIRE WEATHER...Hanson/Hiris HYDROLOGY...Hanson/Hiris
Area Forecast Discussion
National Weather Service Quad Cities IA IL
632 PM CDT Tue May 25 2021 ...AVIATION UPDATE... We`re now watching two features which offer thunderstorm potential. First, a weak vorticity maxima moving through southern Iowa is increasing coverage of small/narrow updraft driven thunderstorms in southeast Iowa. These will likely zipper northeast along and south of a Washington to Maquoketa to Freeport line this evening. With the updrafts not strong and appearing to be narrow, they are not expected to become strong/severe. The cold front will approach late this evening, with another better forced, but less CAPE supported round of storms. We`ll have plenty of moisture, so heavy rains, though spotty, may be over 1 inch. These storms should end by 3-4 AM, and dry weather will move in for the morning. ERVIN .SYNOPSIS... Issued at 328 PM CDT Tue May 25 2021 Convection burgeoning across portions of southeast Iowa, northeast Missouri and west central Illinois attendant to a weak upper wave and divergence. This area has seen an earlier bout of showers, which coupled with cloudiness has resulted in cooler temperatures into the lower to mid 70s, overall limiting BL instability in an area of DCAPE minimum and weaker lapse rates per RAP mesoanalysis. Elsewhere, extent of convective development in the short term is a bit murky due to cloudiness limiting temperatures to near the convective temperature and lack of any coherent boundary, but there does appear to be a wave approaching from southwest Iowa. Thus, potential for additional scattered development north/west is possible rest of this afternoon. Otherwise, it`s been a breezy/windy day at times with 40 kts LLJ and deeper mixing leading to gusts 25-35 mph ahead of a surface cold front moving through far northwest Iowa. && .SHORT TERM...(This Evening through Wednesday) ISSUED AT 328 PM CDT Tue May 25 2021 Chance of showers and storms will persist tonight until the cold front passes 08z through 14z from northwest to southeast. A few of the storms could contain small hail, and also gusty winds as the BL remains mixed ahead of the cold front. In addition localized heavy rain is possible with PWATs approaching 1.7 inches. This activity looks to exit around daybreak or shortly thereafter across the far southeast on Wednesday with the front departing. In it`s wake, a very nice day is on tap Wednesday with much less humidity and a northerly breeze along with abundant sunshine. Highs should top out well into the 70s and lower 80s. .LONG TERM...(Wednesday Night through Tuesday) ISSUED AT 328 PM CDT Tue May 25 2021 Key messages: 1) Potential for MCS and heavy rain Thursday 2) Chilly to end the week, then a pleasant upcoming holiday weekend. Models remain in decent agreement on bringing an MCS across the area on Thursday. However, confidence is lower despite the good model agreement, as some of the old rules of thumb for genesis and track of MCS`s including 850 mb temperature gradient 19-24c would support a track well to our southwest/south if surface based and being in closer proximity to warm front. That said for now we`re in a marginal risk from SPC in our southern counties which if complex tracks further north couldn`t rule out some stronger storms south. The main concern though would be heavy rain with PWATs over 1.5 inches supporting 1-2 inch rain potential, but again this pending track/strength of system. Again if system tracks further south/southwest, then likely still inline for some rain Thursday with mid level wave and front, but potentially more stratiform rain and perhaps not quite as widespread or heavy though making for a nasty day and rather cool. Following this system, an anomalously strong high pressure system and cool airmass settles in for late week into the upcoming holiday weekend. Several models show 850 mb temperatures of 1 to 2C by 12z Friday! This will result in unseasonably cool conditions Friday into Saturday, with temperatures 15-25 degrees below normal with lows mainly in the 40s and highs in the 60s... though on Friday could see a few 30s for lows far north and highs staying in the 50s along the Hwy 20 corridor! Should be dry for much if not all of the holiday weekend, though have kept some small chances by late in the weekend and for Memorial Day west of the Mississippi but recent drying trends may see these go away in later forecasts. It would appear as though any rain chances would wait until return flow/warm advection commences heading past the Memorial Holiday into the middle of next week, with highs moderating back near normal. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening) ISSUED AT 621 PM CDT Tue May 25 2021 Brief MVFR cigs are possible this evening, in scattered showers and thunderstorms. A cold front will arrive overnight, resulting in winds changing to northwest, and dry air moving in for the early morning hours. Wednesday appears dry, with VFR conditions lasting through the day. Any storm tonight could bring a short period of gusty winds to 40 mph, and heavy downpours. They are enough of a threat for a temporary condition from 2-6Z or so, but will leave the IFR out of it for now, until locations can be better determined. ERVIN && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...05 SHORT TERM...05 LONG TERM...05 AVIATION...Ervin
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
920 PM CDT Tue May 25 2021 .UPDATE... Convective activity to the west of the CWA, across the Big Bend and Trans Pecos, has been waning. The 00Z DRT sounding shows a cap in place at 850mb and SPC mesoanalysis indicates increasing CIN along the Rio Grande. Latest HRRR runs continue to show no convection reaching the western CWA. We have elected to remove precip out west tonight. Elsewhere, a few stray showers are possible through midnight near the I-35 corridor, as noted by recent but brief activity in Williamson County. && .PREV DISCUSSION... /ISSUED 653 PM CDT Tue May 25 2021/ AVIATION (00Z TAFs)... VFR conditions currently prevail across South Central Texas. A few isolated SHRAs are possible through sunset near and east of the I-35 corridor. We are watching closely convection across West Texas and the Big Bend. At this time confidence in it reaching DRT is too low to include in the TAF. Stratus is expected to develop west to east late evening through the overnight, with mainly MVFR ceilings. A few pockets of IFR ceilings are possible near and northwest of SAT. PREV DISCUSSION... /ISSUED 607 PM CDT Tue May 25 2021/ UPDATE... We have cancelled the Flash Flood Watch for the southeastern counties. A few isolated showers are still possible through sunset, but there is no longer a threat for heavy rainfall across this area. Confidence is decreasing on convection west of the CWA making it into Val Verde County based on current radar trends and storm motions. Latest HRRR runs are not indicating convection makes it. For now will keep a low 20 PoP in the forecast this evening out west and reassess after sunset. PREV DISCUSSION... /ISSUED 204 PM CDT Tue May 25 2021/ SHORT TERM (Tonight through Wednesday Night)... Robust showers and a few storms moving up the Coastal Prairies will send an outflow boundary northward to collide with the weakening MCS over Central TX this afternoon. High PoPs and heavy downpours of 1-3 inches are possible with the counties in the watch still the most likely to see flooding due to the rains of the past 3 days. Differential heating west of the rain areas should send a brief wave NW toward the SAT area, but otherwise the rain chances on the lower part of the I-35 corridor are on their way down. HREF members are all painting some dry-line convection over W TX moving east into our western counties in the evening, but with poor agreement on the extent of influence into our areas. Will show mainly 20-30 PoPs for Val Verde county and show the activity dissipating just after midnight over the southern Hill Country. Little of the eastern activity is expected to last much past sundown, so the FFA should be allowed to expire by 00Z. The clouds should remain abundant overnight with muggy morning lows for Wednesday. Then for daytime Wednesday shortwave ridging over TX should allow the clouds to mix out with western and central counties returning back to near normal high temps. Farther east lingering higher pwat values and ground moisture will keep Max Temps just below normal and generate a few afternoon pockets of convection. Humidity and clouds will return another warm low for Thursday morning, and it looks like the mild overnight lows seen in much of the spring aren`t coming back anytime soon. LONG TERM (Thursday through Tuesday)... Thursday will be a good day for our eastern counties to start to recover from the multiple rounds of rain over the past several days. Mid to upper ridging will continue building and helping to dry out and warm up the area. Thursday`s highs will stay seasonal in the upper 80s to low 90s. Similar conditions expected for Friday afternoon, but with a deepening trough to our north, low POPs for the Hill Country come back to the forecast friday evening and Saturday. The trough and associated cold front approach the area Saturday with varying solutions of frontal placement. The front placement will be the focus for lift for convection and confidence remains low. The current forecast will maintain the 20-30 percent chances for showers and storms for that timeframe. Sunday into next week to remain mostly dry with near normal temperatures. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 71 86 71 87 72 / 10 10 0 - - Austin Bergstrom Intl Airport 71 86 70 87 72 / 10 20 0 - - New Braunfels Muni Airport 72 88 72 90 73 / 10 10 0 0 - Burnet Muni Airport 70 85 70 86 72 / 10 10 0 0 - Del Rio Intl Airport 75 93 74 95 75 / 10 0 0 0 10 Georgetown Muni Airport 70 85 70 86 72 / 10 10 0 0 - Hondo Muni Airport 71 89 71 90 72 / 10 - 0 0 - San Marcos Muni Airport 70 87 71 88 72 / 10 20 0 0 - La Grange - Fayette Regional 73 88 73 88 74 / 10 30 0 - 0 San Antonio Intl Airport 72 88 72 88 73 / 10 10 0 0 - Stinson Muni Airport 73 89 73 90 74 / 10 10 0 0 0 && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Short-Term/Aviation...Runyen Long-Term...Morris
Area Forecast Discussion...CORRECTED
National Weather Service Grand Rapids MI
1051 PM EDT Tue May 25 2021 LATEST UPDATE... Update/Marine Corrected section times .SYNOPSIS... Issued at 329 PM EDT Tue May 25 2021 - Showers and Thunderstorms tonight into early Wednesday - Dry Wednesday afternoon into late Thursday - Rain, chilly and breezy Friday - Cool by Dry Memorial Day Weekend && .UPDATE... Issued at 1051 PM EDT Tue May 25 2021 Cold front is still forecast to bend into the CWA from the west late tonight and Wednesday morning. A band of rain will push in associated with the front, but from some left over showers and storms in the warm sector as well. Most areas will see rainfall tonight, with totals likely ranging from a quarter to half inch. Locally heavier swaths of half to three quarters of an inch are possible as well. With regard to thunderstorms, the prospects are not great given the fact that we appreciably lose CAPE as we progress through the night. There is still more than adequate moisture in place and a front will be advancing into it, but not expecting much more than some embedded thunderstorms. Thinking likely rain showers with scattered thunderstorms is the way to go tonight. Threat of severe storms is pretty much nil, but if we were going to see anything strong it would be up towards Big and Little Sable Points in the midnight to 500am time frame. Marginally gusty winds would be the main threat. && .DISCUSSION...(This evening through next Tuesday) Issued at 329 PM EDT Tue May 25 2021 - Showers and Thunderstorms tonight into early Wednesday- We are expecting an area of showers and thunderstorms to track into Southwest Michigan around midnight, then weaken as they move east through the I-69 area by sunrise. Expect locally heavy rainfall near and west of US-131, mostly near and north of I-96. There is some suggestion the I-69 area may get locally heavy rain as there is better coupling of the upper divergence with the surface wind convergence. The upper low that was stalled over the Southwest CONUS this past weekend is shearing out over the top of the eastern CONUS upper ridge tonight. This puts southwest Michigan in the jet entrance region of a 125 knot jet core. Typically this would mean strong to severe storms however as it turns out the low level jet core will be ahead of the convection tonight. On the other hand the deep layered shear is between 30 and 40 knots tonight. The precipitable water is around 1.5 inches. The most unstable cape will be near 1000 j/kg as the storms move into Southwest Michigan late this evening but that falls quickly to below 500 j/kg by 3-4 am. In fact the MU cape really never gets over 300 j/kg south and east of Grand Rapids overnight. Putting this together, and the HRRR for every run since at least 06z continues to show this as does the HREF, an area of showers and thunderstorms will move into lake shore, north of Muskegon by midnight. That will be when the storms are the strongest. As the storms move on shore they will weaken. The as the line moves south and east the part of the line west of US-131 will stay strongest but even that will be weakening over time. It may well be locations south and east of Grand Rapids will not even see thunderstorms. Most of the area should get at least some rain. Isolated locations may get more than an inch of rain tonight but most areas should get at least a tenth of an inch. The instability increases once the sun comes back up Wednesday but by then the storms should be east of here. The bottom line is the most impactful storms are expected to be near and west of US-131, north of I-96. There gusty winds, frequent cloud to ground lighting and locally heavy rain are the most likely impacts. - Dry Wednesday afternoon into late Thursday- Once the cold front comes through, we get on the anticyclonic side of the upper jet. Tandem with that, surface high pressure moves in to the area. The center of the high is over central Canada but the ridge axis of the surface high crosses Michigan on Thursday. This will be bring in much cooler and drier air too. Highs will be in the 70s tomorrow and only the 60s Thursday. Patchy frost is possible up north Thursday morning. - Rain , chilly and breezy Friday- Upstream we have another shearing out upper low. We have had many of these this year and so far nearly all of them have brought rainfall (snowfall when it was cold enough) south of this area. However, this time it is looking a little better for the rain to be farther north and actually impacting this area. This will help mitigate some of the drought impacts too. There is good model consensus for this area to get between .25 and a half inch of rain. With the surface low tracking south of here Friday will be chilly and breezy day. It may well be if we really get this rain all day, temperatures will mostly be in the 40s! The rain should come to an end by mid evening Friday. - Cool by Dry Memorial Day Weekend- Once that system moves out we get a shortwave ridge for Saturday into Sunday. A system tracks well north of here Sunday into Monday but at point it looks dry into Monday. There is a significant threat for frost Saturday morning and Sunday morning. Areas near and north of route 20 and east of US-131 may even have a freeze for a few hours both nights. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 809 PM EDT Tue May 25 2021 A cold front will sag southeast through the TAF sites tonight into Wednesday morning. A band of rain will move through the TAF sites along and ahead of the front moving through our area between midnight and noon EDT. Some embedded thunderstorms are possible, but instability will be waning and fairly low overall as we head through the night. An area of MVFR ceilings will develop overnight and persist into Wednesday morning. The MVFR conditions will show up at MKG around 07z and exit the southeast at JXN around 17z. Visibilities should not dip much below MVFR as the showers move through. VFR conditions are expected Wednesday afternoon. Winds will shift from the southwest tonight to west Wednesday midday and eventually northwest Wednesday afternoon and evening. && .MARINE... Issued at 1051 PM EDT Tue May 25 2021 Considered dropping the entire Small Craft Advisory as the warm air advection winds are having a hard time mixing to the lake surface. We did drop out the southern 3 zones as the winds and waves are just not meeting criteria. The Ludington buoy has been showing 4 footers for a time, so decided to leave the SCA going for the northern three zones. Even here though, it may be confined to the far north, north of Little Sable Point. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...None. LM...Small Craft Advisory until 8 AM EDT Wednesday for LMZ847>849. && $$ UPDATE...DUKE SYNOPSIS...WDM DISCUSSION...WDM AVIATION...DUKE MARINE...DUKE
Area Forecast Discussion
National Weather Service Wichita KS
853 PM CDT Tue May 25 2021 ...Evening Mesoscale Discussion... .MESOSCALE DISCUSSION... Issued at 851 PM CDT Tue May 25 2021 BOTTOM LINE UP FRONT: We continue to monitor south-central Kansas for possible thunderstorm development this evening, but the potential appears more conditional. If storms do, indeed, manage to develop, severe weather would be possible. DISCUSSION As of 01z/8pm, satellite and surface observations pointed towards a weak surface low near Dodge City. A stationary frontal boundary extends southwest into the OK/TX Panhandles. To the north, a cold front stretches from the western Great Lakes southwest into central KS, where it intersects the above-mentioned SFC low. There also appears to be a weak surface boundary that stretches NW to SE from KS into central OK (perhaps a feature leftover from earlier day convection?). Scattered convection continues ahead of the Great Lakes to KS cold front, with the southern end of that convection showing a weakening trend recently on radar (south of Salina). Meanwhile, the last of the visible satellite images reveal some towering CU/convective attempts where convergence is maximized near the SFC low. More robust convection is ongoing further southwest across the TX/OK Panhandles. Recent RAP analysis suggests inhibition is still fairly weak across southwest/south-central KS, but a lack of stronger low- level convergence/large-scale forcing appears to be limiting storms from getting going near the SFC low. We`ll continue to monitor this area as a weak LLJ develops north from the TX Panhandle into SW KS. Short term guidance hints at some continued risk of storms near/just east of the SW KS SFC low, but this potential seems more conditional given the above-mentioned lack of lift. If storms can develop, and be sustained through tonight, severe weather would be possible. But, again, this threat appears very conditional. Martin && .SHORT TERM...(This evening through Thursday night) Issued at 312 PM CDT Tue May 25 2021 The main forecast concern is the potential for severe weather later Wednesday night and especially Thursday. Will maintain scattered thunderstorms in the forecast for tonight with the surface-850 trough axis moving slowly southeastward across eastern/southern Kansas. For Wednesday, south-southeasterly return flow will occur across the central Plains as an upstream shortwave trough progresses from the Great Basin/Northern Intermountain region into the Rockies. Mid- level shortwave ridging and associated weak subsidence should act as a suppressor to convection in the forecast area. Moist upslope flow and quasi-geostrophic forcing associated with the approaching shortwave trough will allow convection to develop over the northern/central High Plains Wednesday afternoon/evening. Any convection further southward along the dryline would likely be isolated with warmer mid-level temperatures. As a 50 knot southerly low-level jet develops Wednesday evening, the severe storms coming off the northern/central High Plains should grow upscale into MCS clusters which will propagate east-southeastward across Nebraska and especially northern Kansas. Will have likely storm chances roughly along/north of Interstate 70, tapering probabilities further south to 30%. These storms could contain strong-severe wind gusts and locally heavy rainfall. Thursday-Thursday night: This period looks to have the highest severe weather potential in the forecast area. The shortwave trough will continue moving east across the northern Plains, allowing a slow-moving cold front to work southeastward across eastern/southern Kansas. There is also a decent chance that an outflow boundary from overnight MCS activity could be located somewhere across eastern Kansas which could become a wildcard factor depending on how far south it makes it. Highs in the mid-upper 80s and dewpoints of 65-70 degrees will be in place ahead of the front around peak heating. Very strong to extreme instability is progged with moderate deep-layer shear. Surface-based storms should develop by early-mid afternoon from central Kansas southwestward into south- central Kansas. A combination of multi-cell and supercell structures is likely during the afternoon hours, with very large hail possible and damaging winds. A tornado or two cannot be ruled out near any effective residual outflow boundary, and along the northeast-southwest oriented cold front given the extreme instability and respectable low-level CAPE. A transition to a linear MCS storm mode is expected across southeastern Kansas Thursday evening as the cold front moves through. As a result, the threats should evolve to primarily damaging winds, isolated large hail, and locally very heavy rainfall. .LONG TERM...(Friday through Tuesday) Issued at 312 PM CDT Tue May 25 2021 Cooler than normal and drier air will infiltrate Kansas from Friday into this weekend as the cold front pushes southward to the Gulf. Pleasant weather is expected this weekend in the forecast area, with any convection chances confined to the High Plains. Chances for thunderstorms may re-enter the forecast picture early next week as a positively-tilted upper trough approaches the central Plains from the western CONUS. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 651 PM CDT Tue May 25 2021 * Isolated TSRA and low CIGs possible through tonight A couple of surface boundaries moving slowly through the area may continue to be a focus for isolated to scattered TSRA over the next 12 hours or so, but confidence is too low to for any TEMPO, or prevailing, TSRA groups in the TAFs. We`ll continue to closely monitor this potential, though. Where TSRA do occur, gusty/erratic winds and hail will be possible. On Wednesday, another surface boundary/warm front is forecast to move north through Kansas. This boundary may be accompanied by low CIGs and possibly some SHRA/TSRA. EXTENDED PLANNING OUTLOOK: TSRA will continue to be a potential impact Wednesday night through Thursday, some of which will likely be severe. Martin && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 64 84 69 85 / 30 10 40 70 Hutchinson 61 85 68 85 / 30 10 40 50 Newton 62 83 68 83 / 30 10 40 70 ElDorado 63 83 68 84 / 30 10 40 80 Winfield-KWLD 64 84 69 85 / 20 10 30 80 Russell 58 84 63 82 / 20 10 60 30 Great Bend 59 84 66 83 / 30 10 50 30 Salina 60 86 67 84 / 30 10 60 50 McPherson 60 84 67 83 / 30 10 50 60 Coffeyville 65 82 69 84 / 40 10 30 80 Chanute 65 82 69 83 / 30 10 30 90 Iola 65 82 68 82 / 30 10 30 90 Parsons-KPPF 65 82 69 83 / 40 10 30 90 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ MESOSCALE...RM SHORT TERM...JMC LONG TERM...JMC AVIATION...RM
Area Forecast Discussion
National Weather Service Lincoln IL
804 PM CDT Tue May 25 2021 .SYNOPSIS... Issued at 134 PM CDT Tue May 25 2021 Scattered showers and thunderstorms will increase in coverage late tonight as a cold front approaches from the northwest. Then, after a dry day for most on Wednesday, another chance for widespread showers and storms arrives Thursday afternoon and into Thursday night, bringing the potential for strong to severe storms and torrential rain. Conditions turn cooler and drier for the holiday weekend. && .UPDATE... Issued at 804 PM CDT Tue May 25 2021 Not a lot of lightning thus far in our forecast area, though we did have some strikes earlier around Decatur/Champaign, and some recent stronger showers have started to form along an outflow boundary between Decatur and Bloomington. Elsewhere, light showers have been affecting the Illinois River valley, though with ceilings pretty high up, not much of substance reaching the surface. Additional showers are moving northeast out of Missouri and will affect much of the forecast area later this evening. Latest surface obs show the main cold front from southwest to northeast across Iowa, accompanied by clusters of showers and storms. 6 pm HRRR run brings the front into the Galesburg area around 4 am and Springfield toward 7-8 am. While the highest PoP`s will be east of I-55 with the rain currently in Missouri, will have 40-50% rain chances across the northwest CWA overnight with the front`s arrival. Latest zones/grids have been sent. && .SHORT TERM...(This evening through Wednesday) ISSUED AT 134 PM CDT Tue May 25 2021 Afternoon GOES WV imagery depicts a closed upper-level low spinning over southern Manitoba. This feature will help drive a surface cold front through the upper Midwest tonight into Wednesday. Scattered light showers have developed west of the Illinois River this afternoon in response to subtle shortwave energy rippling through the mid-level flow. Skinny CAPE and poor shear profiles have limited convective activity up until this point, and that trend will likely continue through early this evening as quite a bit of dry air remains in the lowest few kilometers of the troposphere, further hindering updrafts. Latest CAMs are suggesting scattered showers staying west of I-55 through this evening, with a mostly dry forecast for locations east of I-55 given the drier air. However, as the nocturnal LLJ begins to strengthen and veer into southern Illinois late tonight ahead of the cold front, more widespread showers and thunderstorms are anticipated and locations east of I-55 will no longer be spared. When it`s all said and done, QPF will range between a couple tenths across most locations and one inch wherever convection becomes focused overnight, namely south of I-72. The current placement of the front extends from Minneapolis, MN to Sioux City, IA to Grand Island, NE. The latest hi-res trends suggest frontal passage occurs at Peoria by 13z/8am, at Lincoln by 15z/10am, and at Mattoon by 17z/12pm. In its wake, a drier and slightly less humid air mass will settle into central Illinois for Wednesday afternoon. Temperatures will still warm into the lower to middle 80s beneath plenty of sunshine while overnight lows cool to near 60 degrees. && .LONG TERM...(Thursday through Tuesday) ISSUED AT 134 PM CDT Tue May 25 2021 The attention quickly shifts to Thursday as a frontal system rides roughly parallel to the I-70 corridor. By late Thursday afternoon, portions of southern and central Illinois will be positioned in a warm sector with a boundary layer characterized by surface dewpoints in the mid 60s, MLCAPE values between 500-1500 J/kg, and deep layer shear around 40 kts. As the system warm front slowly lifts northward across the region, backed surface winds will likely enhance low-level turning and support organized updrafts. There is still some uncertainty on whether storms will be surface-based or elevated. The latest BUFKIT soundings reveal a capping inversion through much of the day, and a potential decaying MCS earlier that morning may limit solar insolation. Nevertheless, strong potential instability and mid-level flow will favor organized storms Thursday evening. Another concern for Thursday evening will be the potential for flash flooding. With anomalously high PWATs (progged in the 95th percentile of climatology) and storm motion roughly parallel to the frontal boundary, repeated rounds of heavy thunderstorms will be possible across portions of central Illinois. Latest QPF guidance from WPC offers 0.75"-1.50" across our outlook region, but the potential for localized 3.00"+ is certainly a possibility. Friday through early next week continues to look like a dry stretch across the Great Lakes and Midwest with mild temperatures beneath an expansive area of cooler surface high pressure. Daily temperatures through the holiday weekend will yield afternoon temperatures in the upper 60s to lower 70s with overnight lows in the upper 40s to mid 50s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 621 PM CDT Tue May 25 2021 Scattered storms passed near KDEC/KCMI earlier, but much of the early evening rain activity in central Illinois is devoid of lightning. Think this will last for a few hours, before showers/storms move northeast out of Missouri, and have concentrated the VCTS mention beginning around 03Z, from southwest to northeast. As a cold front moves into the area overnight, a period of MVFR ceilings, potentially below 2,000 feet, is expected for about 5-8 hours. VFR conditions should return by midday as skies clear behind the front. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SYNOPSIS...MJA SHORT TERM...MJA LONG TERM...MJA AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Indianapolis IN
1158 PM EDT Tue May 25 2021 ...Updated Aviation Discussion... .Forecast Update... Issued at 936 PM EDT Tue May 25 2021 Surface analysis this evening shows broad high pressure in place across the southeastern states. A cold front was found across NW Wisconsin...stretching southwest across Iowa. Water vapor imagery shows a plume of deep moisture streaming across Missouri into Illinois and NW Indiana. Skies across Indiana were partly cloudy...with clouds associated with this plume invading from the west. Warm and moist southerly surface flow was in place across Indiana with dew point temps in the 60s. Clouds will be expected to continue to invade overnight. This along with ongoing warm air advection will hamper cooling of temperature. Thus have stuck close to the NBM on lows...trending several degrees warmer than persistence. HRRR keeps precip east of the forecast area for the next several hours. However forecast soundings and time heights begins showing saturation aft 06Z. Thus have tried to keep to a dry forecast through 06Z...ramping up pops from west to east thereafter. && .Short Term...(This evening through Wednesday night) Issued at 336 PM EDT Tue May 25 2021 High pressure is moving off to the SE, over Florida, diminishing subsidence over the area. Isolated showers have already started to form across central Indiana. Currently these showers are pulsey afternoon showers from daytime heating but additional convection and thunderstorms will be possible later this afternoon. Precipitation coverage will then increase later this evening into Wednesday as the trough axis swings across the region. The surface low is continuing to make its way across Canada and as it tracks just south of the Hudson Bay tonight into tomorrow, the associated cold front extending SW into the central plains and Mississippi Valley will bring a line of isolated to scattered showers to the area. For tonight, some instability will be present but below 500 J/kg. Weak frontogenesis and upper lift with the decent amount of moisture will be enough to produce showers and isolated thunder throughout the night. Going into Wednesday morning, the front is then expected to slow down and briefly stall just to the east as the low lifts north. Models show instability increasing to above 1000 J/kg Wednesday morning into midday as well as low level lapse rates. This will then allow for a threat of some gusty winds and possibly evening some hail to be embedded within storms during the day as the airmass will still be fairly warm and unstable. At this time, the area with the best chance of some stronger storms will be across the SE half of the forecast area. Weak ridging will establish rather quickly in the wake of the frontal passage with noticeably drier air advecting in. Should see clearing skies by late day into the northwest half of the forecast area with all convection out of central Indiana by midnight with dry weather expected throughout Wednesday night. With rain and higher dew points tonight, overnight low temperatures will only get down to the mid to upper 60s. Above normal temperatures will continue into tomorrow, albeit slightly cooler than central Indiana has been seeing this past week. Behind the weak cold front, tomorrow night`s lows will drop back down to near 60. && .Long Term...(Thursday through Tuesday) Issued at 336 PM EDT Tue May 25 2021 A short wave trough will approach central Indiana on Thursday, leading to the main precipitation event for the long term. During the day on Thursday, weak flow in the low levels will limit moisture transport resulting in 20 degree dew point depressions. This will push the LFCs closer to the ML laps rates of less than 7.0 C/km, limiting the overall instability. However, by later that evening, the short wave trough will near, helping advect warm, moist air within SW flow. Stronger WAA will keep evening temperatures from falling, maintaining in the mid 70s with dew points in the upper 60s. The resulting low LCLs and broad isentropic lift should help initiate convection out ahead of the trough with likely rain and scattered thunderstorms after sundown. There will be a severe threat with this convection late Thursday evening into Thursday night. The moderate WAA will keep the thermodynamic environment fairly conducive for longer. CAPE values around 1000 J/kg are expected to maintain through around 04Z; , diurnal cooling will begin to take over, limiting any SBCAPE. Prior to this, the development of a nocturnal LLJ along with a deepening surface low will create a fairly conducive environment for isolated severe thunderstorms. Wind will be the primary threat as by the time the thunderstorms reach central Indiana they should be primarily linear. The strengthening LLJ and resulting speed shear should help induce some RIJs within linear segments. As diurnal cooling takes over, the thunderstorms will become elevating reducing the wind threat greatly. This is likely to occur shortly after the 04-06Z time period. The severe threat for the entire region will greatly depend on when the thunderstorms reach central Indiana. After this event passes through early Friday morning, the thunderstorm threat will drop to near zero, with isolated showers possible within wrap around moisture. High pressure will begin to build in the wake of the system helping clear out skies late on Friday. The resulting high will originate from the colder Canadian Plains, keeping temperatures much cooler this weekend. Expect highs in the low to mid 70s with dew points in the low 50s. The next rain event looks hold off until early next week as SW flow returns, replacing the high pressure from this weekend. && .Aviation...(06Z TAF Issuance) Issued at 1158 PM EDT Tue May 25 2021 IMPACTS: - VFR Conditions overnight. - MVFR CIGS with SHRA arriving near 12Z Wed. - A return to VFR aft 18Z-20Z Wed. DISCUSSION: High pressure was found over the southeastern states. A plume of tropical moisture was streaming clouds across Missouri to IL and southern MI. Radar shows areas of scattered showers beneath this plume to the west. GOES16 show SCT Cu and a few high clouds across Central Indiana. Showers over IL were making slow progress northeast. Given this...VFR conditions will be expected the next few hours as the plume of moisture to the west slowly advances...and sct precipitation arrives through the night along with a short wave aloft. Time heights and forecast soundings show deep saturation through the morning hours as the HRRR shows scattered showers drifting across the TAF sites. As the short wave departs on Wednesday afternoon forecast soundings and time sections dry out as subsidence begins. Thus a return to VFR. && .IND WATCHES/WARNINGS/ADVISORIES... None. && $$ Update...Puma Short Term...KH Long Term...Updike Aviation...JP
Area Forecast Discussion
National Weather Service New Orleans LA
937 PM CDT Tue May 25 2021 .EVENING UPDATE...All forecast parameters are on track with observed conditions and there will be no changes made to the forecast this evening. PG && .PREV DISCUSSION... /issued 635 PM CDT Tue May 25 2021/ AVIATION (00Z TAF DISCUSSION)...VFR condtions will remain in place at all of the terminals through around 08z. After 08z, weak boundary layer flow will allow for another night of patchy fog at some of the inland terminals. KMCB will be most prone to fog development and have a TEMPO group with LIFR visibility and ceiling conditions in place from 10z through 14z. IFR conditions are forecast with TEMPO groups at KHDC, KBTR, and KASD around 12z. By 15z, all of the terminals should return to VFR conditions as boundary layer mixing increases. PG PREV DISCUSSION... /issued 327 PM CDT Tue May 25 2021/ SHORT TERM (Today through Thursday)... Quick scan of the upper levels shows a broad ridge draped over the southeast CONUS and a trough dipping out of Canada into the upper Mississippi Valley. That trough will skirt the US/Canadian border as it tracks east Wednesday before heading towards the northern Atlantic Thursday. A shortwave will be following in the wake of this trough although a bit farther south latitude-wise. The track of those 2 troughs will cause the ridge over the southeast to suppress. This won`t do much in the way of dropping temps but might allow for some isolated to scattered storms to develop this afternoon and again on Wednesday. The NBM POP output looks great and basically mirrors the deterministic HRRR composite reflectivity. Thus, will be just going with the NBM for coverage forecast the next few days. Same for the temps, which is fluctuating above/below climo for this time of year. MEFFER LONG TERM (This Weekend)... The trailing shortwave will be absorbed by the trough in the northwestern Atlantic. The apex of these combined troughs will stretch southwest from the northeast CONUS down the Appalachian Mountains to almost the northern Gulf Coast on Saturday. In doing so, the ridge thats currently in place over the CWA will be completely squashed. A boundary associated with the trough will approach the local area from the north/northeast late in the day on Saturday. It does have somewhat a of a backdoor front `look`. GFS sounding at MCB does show modest CAPE. Shear values are quite weak however. Suspect there will be some potential for some strong and a few marginally severe storms with hail and gusty winds the main threats. Either way, this weekend will probably be fairly active with at least 50% coverage (or more) on Saturday. Sunday will possibly be just as active too. That is more dependent on if the boundary stalls or continues south into the open Gulf. MEFFER AVIATION... VFR to MVFR ceilings will persist through the forecast period. Visible satellite shows CU field has developed over the region. The height of decks should vary from high end MVFR to low end VFR. These clouds are diurnal and will fade as the sun set. MEFFER MARINE... Center of a surface ridge will generally remain east of the coastal waters throughout the week. This will keep onshore flow in place with gradual variances in wind direction. The same goes for wind speeds but should stay in the realm of 5-10 and 10-15kts. MEFFER && .PRELIMINARY POINT TEMPS/POPS... MCB 67 86 67 88 / 10 20 0 10 BTR 68 87 68 88 / 20 30 0 20 ASD 68 86 68 88 / 0 20 0 10 MSY 71 87 71 88 / 10 20 0 10 GPT 70 85 70 85 / 0 10 0 10 PQL 67 85 67 86 / 0 10 0 10 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
913 PM CDT Tue May 25 2021 .UPDATE... 912 PM CDT Numerous subtle mid-level perturbations pushing across the region within a moist and generally uncapped airmass have supported areas of showers and the occasional thunderstorm this evening. Think the thunder potential in the immediate near term here will remain low as we await the arrival of the next set of impulses, one across central Missouri, and then the main shortwave upstream which is presently pushing into western Wisconsin. With surface dewpoints in the upper 60s to near 70 degrees across northwest Illinois, convective inhibition is minimal even at this hour, and so the anticipation is for a gradual increase in shower and embedded thunderstorm activity ahead of an incoming cold front as better jet dynamics overspread our area with time tonight. With this in mind, we`re thinking the latest runs of the HRRR are a bit underdone with precipitation chances towards midnight and thereafter. The more substantial mid and upper-level flow is forecast to lag the main area of precipitation a bit, and so while we`ll start to slightly increase our 850-600 mb lapse rates with time, the potential for much storm organization seems pretty low. A rogue storm with a stronger wind gust or small hail can`t be ruled out, but the strong-severe threat continues to look pretty low. As 925-850 mb flow increases ahead of the incoming trough, there may be a brief window favoring some slow-moving/backbuilding convection before the low-level flow veers more appreciably late tonight. This window (<3 hours or so) seems too brief to cause any flooding concerns, especially considering how dry things have been of late, but some locally heavier rainfall can`t be ruled out across parts of northwest Illinois. Carlaw && .SHORT TERM... 245 PM CDT Through Wednesday night... Shower and thunderstorm trends/timing into tonight continue to be the primary focus for the short term period. The Gulf Moisture plume that has resided to our west-southwest over the past few days is now being steered east-northeastward into our area in advance of a robust storm system shifting eastward across southern Manitoba into western Ontario. The airmass within this moist plume moving into the area features precipitable water (PWAT) values in excess of 1.6" (1.65" measured on the 12 SGF RAOB). While the main storm system will remain well to our north in southern Canada, an associated cold front will shift southward towards the area tonight. The approaching front will set the stage for a period of showers and thunderstorms across much of the area tonight. Scattered showers are already ongoing across parts of the area early this afternoon. This activity is being driven by a smaller scale perturbation in the mid-level flow. Most of these showers have been void of lightning primarily due to poor lapse rates above a well-mixed boundary layer. While this looks to continue to be the case for the next couple of hours, we cannot rule out a few thunderstorms late this afternoon. The main threat from these showers will be some locally gusty winds up to 45 mph. More widespread showers and thunderstorms are likely over northern IL and northwestern IN tonight after 10 PM. These storms are expected to develop to our northwest late this afternoon in the vicinity of the aforementioned surface cold frontal boundary as it begins to interact with the higher theta-e pre-frontal airmass shifting into the region. Upscale growth into a southeastward moving line/cluster of storms is then likely this evening as moisture convergence increases along the elevated frontal boundary beneath the entrance region of a 90+ KT upper jet streak developing over the Upper Midwest and western Great Lakes. Gusty surface winds may accompany some of the stronger storms tonight, but the overall severe threat looks to remain low/isolated. However, some locally heavy rainfall will be likely with these storms given the high PWATs. Also, the northeastward movement of the individual storms could result in a short period favorable for some training storms along the frontal boundary. While this could result in some isolated minor hydro concerns, the ongoing drought conditions and low river levels across much of far northern IL are likely to limit the threat for flooding outside of urban centers. The showers and thunderstorms will likely undergo a diurnal weakening trend overnight, so there is some uncertainty about the southern reach of these storms late tonight. Any lingering showers and storms should end from northwest to southeast late tonight. Quieter weather is on tap for Wednesday following the frontal passage. Expect highs on Wednesday to be in the lower 80s for inland areas, with a bit cooler temperatures expected near the lake due to the likelihood of an afternoon lake breeze. KJB/Ogorek && .LONG TERM... 245 PM CDT Thursday through Tuesday... Low pressure will track eastward across southern Iowa and into central IL Thursday and Thursday night. This should result in a pronounced east to northeast low level flow across the area which should suppress the associated warm frontal boundary well south of the lake and may hang the boundary up across our southern tier of counties. Rain chances will spread in from the west as the system approaches Thursday afternoon into the evening. Greatest thunder potential will be closer to the warm front over southern sections of the area. Will need to monitor the threat for severe thunderstorms near and south of the front and with SPC Day 3 Enhanced risk currently to the southwest. Latest thinking continues with the idea that most areas will see some rain with this system but there is always the chance that significant convection to the south robs some of our moisture flux or provides some level of subsidence to the local area. Highest amounts will be focused closer to the front with the better convection with lighter amounts to the north. Thursday will also see a large spread in highs from north to south and near Lake Michigan. Expect upper 50s near the lake with low to mid 60s for northern inland areas and mid or even upper 70s south of I-80. The surface low will be to the east on Friday but the associated upper level trough will cross the area bringing showers to the area and much cooler air. Northeast winds will be steady with highs only expected to be in the 50s for most areas, with lower 60s far south. High pressure will spread into the Great Lakes Saturday and be in place through the weekend. Temperatures will moderate overall, but persistent flow off Lake Michigan will keep areas near the lake cooler each day. Expect 60s Saturday then 70s thereafter inland of the lake. There are mixed signals for rain chances by Monday but with variability in guidance collaborated with neighboring offices to keep the forecast dry during the day with chances increasing Monday night. MDB && .AVIATION... For the 00Z TAFs... An area of -SHRA associated with a weak mid-level wave will cross the Chicago metro through 02Z. While TS had been observed upstream with this activity, the environment has become much less supportive of TS over the terminals. A lull in the precip is expected mid evening into the early overnight hours, though a few stray showers will remain possible. SW winds will continue to gust to 25kt during this time. Ongoing convection across central IA and central WI will likely connect into a broken line of TS through mid-evening. This line will propagate southeastward across northern IL and northwest IN during the overnight and pre-dawn hours and may contain wind gusts in excess of 30 knots. A narrow axis of MVFR ceilings, possibly as low as 1kft, will likely develop behind the convection through daybreak Wednesday before the arrival of much drier air behind a cold front around 12-13Z. VFR conditions are expected through the day Wednesday with WNW gusts over 20 knots. A lake-enhanced boundary will then shift winds NE at 10-15 knots early Wednesday evening at ORD/MDW. Kluber && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...None. LM...Small Craft Advisory...nearshore waters until 4 AM Wednesday. && $$ Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
946 PM CDT Tue May 25 2021 .UPDATE... Issued at 938 PM CDT Tue May 25 2021 The forecast looks generally on track for the rest of the night with scattered showers moving through east central and southeast Missouri into southwest/south central Illinois. Short range deterministic guidance shows low level moisture convergence over the region, and this looks like the primary forcing mechanism for these showers. This moisture convergence shifts east through the night ahead of an 850mb trough, and it`s through our eastern counties by around 12-15Z. The RAP is still showing a bit of MUCAPE over the region...maybe just enough to produce a thunderstorm or two, so I`ve left slight chance for thunder in the forecast for the rest of the night. Carney && .SHORT TERM... (Through Late Wednesday Night) Issued at 323 PM CDT Tue May 25 2021 Key Messages for the short term period: 1. An MCV system will move north-northeast into the CWA this afternoon and evening, producing widespread rain over the area. 2. Wednesday afternoon and overnight will be dry. Showers continue across central and northwest Missouri into west- central Illinois this afternoon, driven by low-level WAA. While a couple flashes of lightning have been observed across west-central and northeast Missouri this afternoon, forcing is too weak to tap into the 500-1000 J/kg of MUCAPE present across the forecast area. While spotty WAA showers are anticipated to continue across the CWA through the evening, the MCV in southeast Missouri is the main feature of note for this afternoon and evening. Driven by a shortwave aloft, this complex will move north-northeast into central Missouri by mid-afternoon and produce widespread showers and a few thunderstorms. Even though the forcing for this complex is more robust, the massive cold pool generated by the precipitation is cutting the system off from environmental instability. Given this, and that the system will move into the forecast area during the waning hours of the afternoon, nothing more than a rumble or two of thunder is expected amid the widespread rain. A weak baroclinic zone will drop southward through the Northern Plains and Upper Mississippi Valley during the day today, finally inching into our forecast area by early Wednesday morning. Showers and a few thunderstorms could generate along this boundary as it slides through the region Wednesday morning, enhanced by WAA along persistent low-level southwesterly flow. Thunderstorm development will be limited as the weak boundary slides out of the CWA by late morning, and lapse rates, instability, and shear will be poor. A deepening surface high over the Great Lakes region will help push the baroclinic zone through the forecast area tomorrow, providing a brief dry period Wednesday afternoon through the overnight hours. The weakness of the surface boundary will result in little change between today`s high temperatures and tomorrow`s. Today`s noon-time temperatures across eastern Nebraska and western Iowa, behind this feature, are in the upper 70s to low 80s. High temperatures forecasted across the CWA are in the mid 80s, accounting for the mostly sunny post-feature sky and slightly more southern latitude. Overnight temperatures tonight and Wednesday will be in the 60s, though slightly cooler Wednesday night as the mostly clear sky at the beginning of the night will produce more effective radiational cooling. MRM .LONG TERM... (Thursday through Next Tuesday) Issued at 323 PM CDT Tue May 25 2021 Key messages for the extended period: 1. There is a potential for strong to severe thunderstorms on Thursday. 2. Memorial Day weekend will be cool and largely dry. By early Thursday morning a mid-level trough will be pushing through the central Plains into the Mid-Mississippi Valley, guiding an MCS into the region. Operational models are in agreement with the formation and relative positioning of the mid-level trough and in the movement of the MCS through the CWA. However, guidance diverges in the timing and implications of the low-level disturbance and resulting MCS. One of two scenarios is possible as the MCS moves through the CWA: 1. the widespread cloud cover and robust cold pool reduce any chance for further thunderstorm development, or 2. the MCS produces a lingering boundary that will be the focus of thunderstorm development later in the day. At this point, it is still too early to diagnose which of these scenarios and their mesoscale features will occur. At the same time, the surface front from Wednesday will move northward back into the region as a warm front along persistent southerly surface flow Thursday morning. To the south of the front, warm, moist, unstable air will create a favorable environment for isentropic lift to generate showers and thunderstorms. Operational and SREF guidance indicates 1500-2000 J/kg of mean SBCAPE and 30-40 kts of 0-6 km shear will be available during the afternoon. Thunderstorm development and growth is most favorable across central, east-central, and southeast Missouri where the highest instability will occur. While an isentropically lifted thunderstorm could grow upscale to become strong to severe, if the MCS produces a boundary across our CWA the warm front could interact with the it to effectively force deep thunderstorm development. Thunderstorms that develop could become strong to severe, capable of producing damaging winds and a few tornadoes. Lapse rates around 6 C/km will limit any hail threat with thunderstorms that develop. By Thursday evening instability will diminish as will severe thunderstorm chances. Showers and thunderstorms will linger across the area into the evening Thursday and through the day Friday as a cold front is pulled through the region by the mid-level trough. A surface high will move into the region in the wake of this system, keeping the Memorial Day weekend largely dry. Northwesterly winds and CAA will pull temperatures down from their previous toasty values. High temperatures on Friday will be chilly in comparison, peaking in the low 60s across northeast Missouri and west-central Illinois to low 70s across southeast Missouri. Temperatures will rebound slightly over the weekend under mostly sunny skies with highs still below normal in the upper 60s to mid 70s. Beyond the weekend the WPC Cluster Analysis indicates that rain will once again return to the region, though there is some uncertainty in timing and location of features. Most of my attention has been paid to the short term and Thursday system, and I have largely let the National Blend of Models populate the extended period. MRM && .AVIATION... (For the 00z TAFs through 00z Wednesday Evening) Issued at 639 PM CDT Tue May 25 2021 VFR flight conditions with light rain is expected to prevail across much of the area this evening. There may be an embedded heavy rain shower or thunderstorm that could cause the visibility to briefly drop to IFR, but these look to be few and far between. The majority of model guidance shows ceilings dropping to low MVFR with a few spots of IFR after 06Z across most of the area as low level moisture pools ahead of a weak cold front. These low ceilings will persist for most of Wednesday morning, lifting and scattering after 16-17Z. Light west-southwest wind overnight will briefly shift to the northwest and then to the north Wednesday afternoon, but will likely turn back to the south by the end of the period. SPECIFICS FOR KSTL: VFR conditions are expected to prevail at Lambert this evening, with light rain showers moving in after 00Z. There`s a small chance that a heavier shower or thunderstorm could produce rain that is heavy enough to drop the visibility to MVFR or IFR this evening, but the probability is so low that I did not mention it in the TAF. Ceilings are expected to drop to MVFR late tonight between 06-08Z, and stay down until between 16-18Z ahead of a weak cold front. The front will briefly turn the wind around to the northwest and then north as it passes, but wind should be back around to the south by 00Z Thursday. Carney && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion...UPDATED
National Weather Service Lubbock TX
831 PM CDT Tue May 25 2021 .UPDATE... Impressively rich moisture has made its way westward into the central South Plains with WTM observations showing dewpoints in the upper 60s and lower 70s as far west as the Littlefield and Smyer WTM sites. Despite the moisture and very strong instability, convection has failed to initiate on the retreating dryline across the South Plains, likely due to weak capping and a lack of upper support. On either side of the South Plains, deep convection did erupt over the Texas Panhandle as well as in the Permian Basin. The northern convection is now approaching Happy, though it is struggling of late. The more southern activity has made its way northeastward into the southern Rolling Plains. This convection is much more robust, as it ingests high theta-e supporting MLCAPEs around 4000 J/kg. Given the trends, we will likely be dropping the Severe Thunderstorm Watch for a good chunk of the CWA shortly, though not across the southeast zones (where robust convection continues) and across the north, where storms are still possible. && .PREV DISCUSSION... /issued 651 PM CDT Tue May 25 2021/ AVIATION... Biggest question mark is whether or not convection will affect the terminals this evening. Thus far storms have failed to develop along the dryline located just west of KLBB and KPVW, while storms have formed further north, to the west of KAMA, and south of Fluvanna. The ongoing storms will avoid the western terminals, but explosive storm development could still occur over the next hour or two in near proximity to KLBB and KPVW. Given this, we have maintained VCTS at the beginning of the TAFs. KCDS will have a chance of seeing storms in the area later this evening, around and after 03Z, but confidence isn`t high enough for more than a VCTS mention. Depending how things play out tonight, there will be a window for MVFR to IFR cigs Wednesday morning. Have hinted at this, but not included a broken deck explicitly. Another chance for thunderstorms will exist late Wednesday afternoon into the evening. PREV DISCUSSION... /issued 405 PM CDT Tue May 25 2021/ SHORT TERM... As of 2PM the predominant area of subsidence aloft was over the Rolling Plains and moving east with the overnight MCS currently over east Texas. The stratiform portion of the cumulus field is rapidly eroding with a prominent outflow boundary stretching from Vigo Park southeast into Matador to just north of Aspermont. Another outflow boundary earlier this morning that extended from Muleshoe to Silverton isn`t as clear on radar early this afternoon, but can still be seen in the surface observations. Both of these boundaries should be important through the remainder of the afternoon and evening wrt to convective initiation and evolution. As the dryline mixes east out of eastern New Mexico through the remainder of the afternoon, it will first interact with a robust theta e axis currently extending from Morton southeast to Lake Alan Henry. The most robust initiation indicated in multiple runs of the HRRR is expected along and just east of the dryline between 4pm-6pm just west of the I27 corridor. The earlier and more westward that initiation occurs will decide the extent of thunderstorm coverage on the Caprock and especially areas surrounding Lubbock County, where there were pockets of 1-2 inches of rainfall and localized flooding last night, especially around Buffalo Springs Lake and east Lubbock. Farther south along and southwest of the ThetaE axis, dewpoints are in the mid to upper 60s with pockets of CAPE over 4000J/K extending from the city of Lubbock down to Lake Alan Henry. With a robust CU field in place, steep mid level lapse rates exceeding 8.5 C/km and favorable hodographs the farther southeast you go, all severe hazards are possible where storms initiate and mature. Eventually storms are expected to be multi-cellular but any discrete initiation may be supercellular early in their life cycle and capable of producing very large hail and tornadoes, especially in the vicinity of the ThetaE axis, where as of 2pm the Post mesonet station is 81/69 with a light southeast wind. As convective mode eventually goes upscale later this evening, another MCS is expected to develop over the southern Rolling Plains into the I20 corridor by midnight. Strong wind gusts and large hail will still be a threat as the convection pushes east-southeast out of area by around midnight. We`ll see mild temperatures overnight with plenty of moisture in place and more favorable upper level dynamics for strong to severe thunderstorms again tomorrow afternoon, initiating along the dryline in vicinity of the NM/TX state line and moving northeast through the evening hours. Most of the forecast area is highlighted in a `Slight Risk` by the SPC for tomorrow, again with all severe hazards possible including tornadoes. LONG TERM... Active weather appears likely to stick around through the long term period as the upper level pattern remains transient and amplified. Early on Thursday, upper level flow will return to southwesterly as an upper trough sweeps across the Desert Southwest. With difluence aloft and an uptick in shear compared to past days, severe weather appears plausible as the dryline sets up across the western and central South Plains during the afternoon. On Friday, flow overhead becomes more zonal as an upper trough transits over Montana with another, deeper trough rotating through the Great Lakes. As this occurs, a surface low moving east over the Ohio Valley combined with the influence of a building ridge over the Upper Midwest will send a weak backdoor front into our area from the east on Friday. This setup bears watching, as the surface evolution combined with ample instability and continued low level moisture advection Friday may combine to produce a heavy rain and severe weather threat heading into the holiday weekend. Saturday, the upper level pattern looks to amplify yet again as another 500 mb trough moves ashore over Southern California. Guidance is in relatively good agreement that this trough will slow its eastward progression over the weekend, with both the GFS and ECMWF keeping the low lingering in the vicinity of the Four Corners throughout the weekend. If this turns out to be correct, southwesterly flow would be present aloft over our area for several days. With a persistent surface ridge locked in place to our east, southerly to southeasterly surface flow would continue to pump moisture into the CWA, with PWATs perhaps near the the percentile of climatological values. With the upper low lingering to our west, a sloshing dryline scenario appears plausible this weekend, leading to thunderstorm chances each afternoon and evening as the dryline pushes east into the area. Certain specifics of the setup remain uncertain, such as the magnitude of capping/inhibition and the effects of overturning from prior convection. However, instability and shear look to remain generally sufficient to support severe weather each day. Next week, guidance begins to differ on the evolution of the upper level pattern, however a decent signal exists which points to the possibility of southwesterly upper flow remaining in place, suggesting that thunderstorm chances continue into the middle of next week. In terms of practical weather, at this time it appears that this weekend has the potential to be quite active, with thunderstorm chances each day. While it is too early to nail down the precise evolution of how any rain and storms evolve, it does appear that severe weather, heavy rain, and localized flooding will make an appearance at some point during the holiday weekend. Stay tuned as the details evolve over the coming days. /DWK && .LUB WATCHES/WARNINGS/ADVISORIES... None. && $$ 23/30
Area Forecast Discussion
National Weather Service Midland/Odessa TX
141 PM CDT Tue May 25 2021 .DISCUSSION... Veered, albeit weak, 7h winds suggest the dryline will evetually move to near a Lamesa to Odessa to near Alpine line with a mstr rich and unstable condition e of the dryline with ML CAPEs 2500-3000 J/KG. Storm initiation has occurred in far e Jeff Davis Co and n Brewster, very close to HRRR forecast. These storms are forecast to move e and increase across Pecos Co where severe storms could develop between 20Z-21Z. Surface dewpoints are high at Sheffield early this afternoon 68. Between 00Z-03Z/Wed a second area of storms may develop across the cntrl and ern PB. Deep layer shear in general is 20-25kts, but instability is likely to make up for it and severe storms will certainly be possible. Wed 7h winds back to the s and dryline will remain much farther w where some of the hottest surface temps will be, mid to upper 90s SE NM- Upper Trans Pecos-wrn PB. A few strong storms will develop in those areas, but coverage will be limited with SB CINH stronger farther e. Deep layer shear will increase to 30-35kts on Thu as sw flow at 7h signals dryline will mix/move farther e. SB instability axis is likely to be focused along a narrow corridor from near Lamesa- Midland/Odessa-Crane- Bakersfield. Sustained se-s low-level flow will increase convergence along dryline. Initial development is certainly possible, if not favored, along and just n of a dryline bulge between Penwell and Saragosa. Using 30 degrees right of 7h wind for storm motion would bring strong/severe storms into the Midland/Odessa area early evening. However, storms could be strong right mover (following mstr axis) bringing higher end severe threat into srn PB and e Pecos Co.. Still coverage is minimized, however potential intensity of storms could make up for it? Another interesting day Fri with outflow/cold front e-w along I-20, dryline extending s from cntrl PB with model indications of a thermal low or mesolow across wrn PB. Boundaries will be good focus for tstm development, but where the boundaries will actually be is difficult to say, so for now suffice it to say slight chance to chance storms possible Fri afternoon-evening. There may be a few storms Sat, but the better potential will start Sun across the wrn areas and then expand e Mon ownward as a slow moving mid-level trof moves into the Desert SW. Sunday through mid week or so could be an active period with all severe wx threats possible, including flooding. Over the next few days temps will remain above normal by a few degrees, but by next week with mid- level trof to w and increased rain high temps are likely to cool back closer to normal or below. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 68 91 70 92 / 20 10 10 10 Carlsbad 63 96 65 97 / 0 10 20 10 Dryden 71 94 71 96 / 30 0 10 20 Fort Stockton 69 96 70 98 / 20 20 10 20 Guadalupe Pass 66 90 65 91 / 0 10 10 10 Hobbs 64 93 66 94 / 0 20 20 10 Marfa 57 92 58 95 / 10 20 10 10 Midland Intl Airport 68 93 70 94 / 20 10 10 20 Odessa 69 93 70 94 / 20 10 20 20 Wink 68 98 70 99 / 10 20 20 20 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...None. TX...None. && $$
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
940 PM EDT Tue May 25 2021 .SYNOPSIS... Offshore high pressure will extend over the area through late week as a weak trough of low pressure lingers inland. A more active weather pattern expected by the weekend as a cold front pushes through the area Saturday with waves of low pressure developing along it. High pressure will build over the area Monday and Tuesday. A fairly uniform and quite warm night upcoming with lows upper 60s well inland and low/mid 70s near the coast. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... As of 940 PM Tue...Shower activity over Duplin county has dissipated with all areas across eastern NC now dry. Stubborn mid-level cloud deck lingers along the US 70 corridor and may complicate overnight fog potential in recently saturated locales. For now will leave patchy fog mention in the forecast. Prev disc...Radar and satellite imagery showing thunderstorms along the sea breeze inland at mid-afternoon mainly west of Highway 17 in the Coastal Plains counties. Craven County, in particular, has had fairly widespread rain coverage this afternoon. Light mid- level flow has led to little movement of the precipitation, so a few areas getting beneficial rain this afternoon. Cirrus shield from the convection has spread back toward the coast as well. The precipitation should end with loss of heating at or before dark. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... As of 330 PM Tuesday...Despite some lowering in the mid-level height field on Wednesday, high-resolution models show minimal precipitation in our area as low-level flow becomes more SW/WSW. Surface forcing looks weak and will keep the forecast dry on Wednesday with model guidance support very warm high temperatures in the mid to upper 90s along and west of the Highway 17 corridor, upper 80s southern coast and mid 80s Outer Banks. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... As of 310 AM Tuesday...A hot and dry pattern will persist into late week with temps staying above climo for late May. Dominant ridge begins to break down by the weekend as a more active weather pattern emerges. Wednesday Night and Thursday...Winds shift more westerly Thursday, allowing for better downslope flow to keep temps inland around the mid 90s. Some guidance suggest a weak shortwave trough aloft will move through ENC Thursday afternoon, coincident with peak heating, which warrants an increase in PoPs to 20-25% most areas. Decent instability but weak shear and lack of moisture will result in isolated showers and thunderstorms with this weak feature aloft. Friday through Saturday...Upper level ridging pattern shifts south Fri in response to a trough aloft moving into the Ohio River Valley and into the Mid-Atlantic region by Saturday. The surface ridge shifts offshore Fri, followed by a modest cold front moving south-southeast into the region during the day on Saturday, presenting the next best chance for measurable precipitation through the long term forecast period. Afternoon highs drop into the low 90s Fri and low-mid 80s Sat. Sunday into Monday...the upper trough will slowly shift into New England Sunday into Monday, dragging the cold front offshore and well off the coast by late Mon. High temps will fall into the 70s Sun, then into the low 80s on Mon. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... SHORT TERM /through 00Z Thursday/... As of 730 PM Tue...VFR conditions prevail across the TAF sites this evening with SSE flow at 5-10 kt. Main sticking point in forecast tonight will be the potential for patchy fog at terminals that saw appreciable rainfall, mainly EWN and ISO. HRRR soundings show slightly more favorable low-level moisture profiles for at least some patchy instances relative to PGV/OAJ, and introduced vis restrictions to TAFs. Otherwise VFR overnight with only a few high clouds. VFR tomorrow with winds veering SW and increasing to 5-10 kt with gusts to 15 kt or so during the afternoon. Rain chances at the terminals are minimal. LONG TERM /Wednesday Night through Sunday/... As of 320 AM Tuesday...VFR conditions will prevail through the long term but cannot rule out patchy light fog during the late night/early morning hours. A cold front will move through Eastern NC on Saturday, producing showers and thunderstorms which will have the potential to reduce aviation conditions. && .MARINE... SHORT TERM /through tonight/... As of 345 PM Tuesday...Winds have largely veer to E/SE at late afternoon at 5-15 knots with seas 3-5 feet. All Small Craft Advisories have expired on area waters. High pressure will continue to build in from the NE tonight. Winds becoming S later tonight and SW 10-15 knots with 15-20 knots in the afternoon and a few occasional gusts to 25 knots are possible Wednesday afternoon. Seas will hover in the 3-5 foot range for most waters tonight and Wednesday. LONG TERM /Wednesday Night through Sunday/... As of 330 AM Tuesday...Winds shift more SW Wed night through Friday as an offshore high strengthens, with winds relaxing to 10-15 kts Thu and Fri. Seas drop to 2-4 ft Thu and Fri. Conditions deteriorate Saturday as a cold front moves from north to south through the ENC waters. Winds shift N/NE by Sat afternoon with seas beginning to build from north to south by Sat evening. Next round of SCAs expected by Saturday Night and could last into Memorial Day. && .CLIMATE... Record High temps for 5/26 (Wednesday) LOCATION TEMP/YEAR New Bern 100/1953 (KEWN ASOS) Cape Hatteras 88/1962 (KHSE ASOS) Greenville 99/1927 (COOP - Not KPGV AWOS) Morehead City 96/1953 (COOP - Not KMRH ASOS) Kinston 96/2011 (COOP - Not KISO AWOS) Jacksonville 96/2019 (KNCA ASOS) Record High temps for 5/27 (Thursday) LOCATION TEMP/YEAR New Bern 96/1989 (KEWN ASOS) Cape Hatteras 89/2019 (KHSE ASOS) Greenville 96/1972 (COOP - Not KPGV AWOS) Morehead City 88/2006 (COOP - Not KMRH ASOS) Kinston 98/2019 (COOP - Not KISO AWOS) Jacksonville 97/1989 (KNCA ASOS) Record High temps for 5/28 (Friday) LOCATION TEMP/YEAR New Bern 95/1941 (KEWN ASOS) Cape Hatteras 88/2019 (KHSE ASOS) Greenville 98/2019 (COOP - Not KPGV AWOS) Morehead City 94/2019 (COOP - Not KMRH ASOS) Kinston 93/2019 (COOP - Not KISO AWOS) Jacksonville 95/1967 (KNCA ASOS) && .MHX WATCHES/WARNINGS/ADVISORIES... NC...Beach Hazards Statement from 8 AM EDT Wednesday through Wednesday evening for NCZ196-203>205. MARINE...None. && $$ SYNOPSIS...MHX NEAR TERM...CTC/MS SHORT TERM...CTC LONG TERM...DAG AVIATION...DAG/MS MARINE...DAG/CTC/CQD CLIMATE...MHX
National Weather Service Raleigh NC
830 PM EDT Tue May 25 2021 .SYNOPSIS... A warm front will lift back northeast through central NC Wednesday morning. The hot air mass to the south will return to NC on Wednesday. A strong cold front will approach from the northwest late Friday. && .NEAR TERM /TONIGHT/... A main outflow boundary had curled to the ESE into far NW Forsyth County as of 830 PM. The northern portion of the outflow had surged NE into Stokes/Patrick VA. There is still an opportunity for scattered showers and isolated thunderstorms in the Triad, especially the Winston-Salem area into late evening. Another outflow boundary had entered the SW Piedmont from Charlotte to Wadesboro. It appears the best instability is located to the west, or near the old boundary. Therefore, only an isolated chance of a shower in the SW Piedmont for the next hour or so. It is becoming more stable in the east with loss of heating. The sea breeze had pushed to near Raleigh and Fayetteville with only a subtle wind shift noted. Previous discussion as of 604 PM this evening... A chance of a shower or storm in the far NW and the far SE through 1000 PM. Dry and pleasant elsewhere. The latest data analysis indicated mixed layer CAPES on the order of 1000 j/kg in the far NW Piedmont, with more stable conditions to the east out over the Piedmont. The low level boundary had "backdoored" westward into the eastern slopes of the Blue Ridge. Scattered slow moving thunderstorms have developed over the higher terrain around Boone, West Jefferson, and Glade Valley. Some of the storm have extended out over the Foothills nearing Wilkesboro and Mount Airy. The latest RAP indicated that the showers/storms should continue going for the next couple of hours before nightfall convective inhibition takes over. We will eliminate chances in the Winston-Salem and Greensboro areas through 700 PM, then carry a chance of showers and isolated storms between 700 and 1000 PM in that region (NW part of the Triad) before the convection dies off late evening. Elsewhere, the sea breeze has moved into the Coastal Plain. However, convergence and instability are on the wane there. There is still a a chance of a quick shower or storm in Sampson/Wayne/SE Johnston through mid-evening. Otherwise, partly cloudy skies are expected tonight with lows in the 63-68 range. Previous discussion issued as of 156 PM Tuesday... Latest analysis shows yesterday`s backdoor front has pushed well to our south and is currently stationary across central SC and extends across upstate SC then northward along the NC foothills. The airmass north of this boundary and over us remains moist and stable per latest mesoanalysis. This morning`s stratus is breaking up, so we`re finally seeing sfc temp readings beginning to climb into the low 80s. Farther east, the clouds broke up much earlier, and thus with better instability when coupled with the sea breeze, we`re seeing some showers near the coast. These showers may move wwd and eventually approach our ern-most zones; but farther west across our Piedmont zones, most of the recent CAMs suggest showers will have a difficult time developing given the aforementioned stability. Should any showers develop in our CWA, the would likely be near the edges of the earlier stratus shield, namely across our southern and western zones. Thus will carry slt chance PoPs this evening for those zones, but otherwise most of central NC should remain dry. Finally, should any cells develop, with PWAT around 1.5-1.8 inches and given weak deep layer flow, the isold spots that see such showers could see very localized heavy downpours. The risk for showers will quickly diminish after sunset, with partly to mostly cloudy skies lingering overnight. Lows in the 60s. && .SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/... As of 156 PM Tuesday... Look for fair and hot weather during the daytime hours Wednesday with highs temps climbing to the low to mid 90s (highest south). But during the evening and Wednesday night, a short wave trough will cross the Ohio Valley and eventually the Mid Atlantic region later at night, with a band of showers and tstms along and ahead of this feature. While guidance suggests most of this activity will remain to our north across VA, we can`t rule out the southern tail end of these showers to move across our zones north of Hwy 64 late Wednesday and Wednesday night. Will include a slight chance PoP across our northern zones during that time. Lows Wednesday night in the upper 60s to around 70. && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 156 PM Tuesday... Not much change in the guidance with respect to Thursday, as a weak shortwave trough will move through the area during the early part of the day. Ridging behind the trough to the west and the development of a weak coastal front to the east should allow for the development of isolated showers and thunderstorms east of I-95 during the afternoon. Given weak forcing and meager shear/instability, I`m not anticipating much in the way of a severe threat. Thursday will be another warm day with highs in the low to mid 90s. Lows bottoming out in the mid/upper 60s. Larger scale forcing for ascent will move in from the west during the afternoon on Friday with a a surface low forecast to move through Delmarva early Saturday morning. The associated surface cold front is expected to cross the mountains during the afternoon/early evening hours and most of the available deterministic guidance, as well as the majority of ensemble members, suggest measurable precip across a good portion of the area Friday evening. That being said, amounts don`t look terribly impressive (despite nearly 2" PW`s) and not nearly enough to eradicate the drought, but it`s rain nonetheless. Thermodynamic parameters appear to be supportive of a mention of thunder with at least a few hundred J/KG of MLCAPE to work with coincident with the frontal passage along with 30kts of deep layer shear. 00Z deterministic ECMWF is a big slower with FROPA and keeps things drier, but ECENS appears to be a bit on the wetter side and more in line with other solutions. Regardless, temps will warm into the low/mid 90s ahead of the front, dropping into the low to mid 60`s behind it. The upper air pattern on Saturday morning will feature a southwesterly flow across the Carolinas with a southeastward advancing shear axis moving across central and eastern NC during the morning and afternoon. A more prominent upper trough with a closed low across the southern Great Lakes on Saturday morning will drop southeast into the central Appalachians by Sunday morning. At the surface, a trough enhanced by convection on Friday/Friday night will be located across the eastern Carolinas with a much stronger but slow moving front crossing the mountains on Saturday morning and pushing south and east across the Carolinas through Saturday night. Guidance is suggesting that a weak surface wave may develop across the southern Carolinas slowing the southward progression of the front. Scattered showers and thunderstorms are expected on Saturday and Saturday night with the greatest coverage across the east and northeast in a region of deeper moisture and ahead of the initial shear axis. Highs on Saturday will be variable with the front moving across the area. Highs will only reach the lower 70s near the VA border but will reach the lower to possibly mid 80s near the SC border. Lows on Saturday night will range in the 50s. There remains some model uncertainty in the progression of the strong upper trough across the mid Atlantic with the operational EC moving the trough off the coast by midday Sunday with more recent GFS slower and moving the trough off the coast on Monday morning. May need to hold onto some low chance PoPs across the east into early Sunday. With morning low level thickness values in the 1340s and 1350s, it will be a cool day on Sunday with highs only in the lower 70s north to the upper 70s south. The upper trough should move offshore by Monday with a northwest to westerly flow aloft developing across the Carolinas into Tuesday as upper level ridging begins to develop across the Deep South for early next week. This should result in a period of generally fair and dry weather. Highs in the upper 70s to around 80 on Monday will moderate into the lower to mid 80s on Tuesday. -Blaes && && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... As of 750 PM Tuesday... Through 00Z Thursday: Generally VFR conditions to continue across central NC through the period. Isolated MVFR conditions with showers are possible near KINT through 03z/tonight. After 00Z Thursday: VFR conditions are expected late Wednesday and Thursday as any shower or storm chances will be minimal. Higher chances of showers are expected Friday PM and continue into the weekend. && .CLIMATE... High temperatures that could be broken this week: Raleigh: Wednesday, May 26: 94 set in 2019 Thursday, May 27: 96 set in 1916 Greensboro: Wednesday, May 26: 95 set in 1926 Fayetteville: Wednesday, May 26: 100 set in 1953 && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ NEAR TERM...Badgett/np SHORT LONG TERM...DL/NL/BLAES AVIATION...Badgett/np