Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/10/18

Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
521 PM MDT Wed May 9 2018 .AVIATION... 00Z TAF CYCLE VFR conditions prevail and are forecast to persist. Isolated convection across northeast New Mexico will not impact TAF sites this evening. Winds will increase Thursday afternoon and get gusty. 11 && .PREV DISCUSSION...347 PM MDT Wed May 9 2018... .SYNOPSIS... Large high pressure over New Mexico will weaken slightly tonight and Thursday. A weak disturbance will move across southeast Colorado this evening, bringing slight chances for thunderstorms to far northeast New Mexico. Very warm air aloft will remain across the region Thursday, and near record high temperatures will be widespread. Breezy and unstable conditions combined with low humidity will create red flag conditions across the eastern plains and portions of west central New Mexico Thursday afternoon. Deep surface low pressure will form in southeast Colorado Friday, and west to southwest winds will become breezy to windy. Strong winds and low humidity Friday will spread red flag conditions across the entire area. Upper level low pressure will move into the northern Great Basin Saturday and remain nearly stationary Sunday. This system will bring slightly cooler air to the region this weekend, though high temperatures will still be well above normal. && .DISCUSSION... Models are indicating that a weak vorticity maximum will move across southeast CO late this afternoon and evening. There is limited low and mid level moisture in northeast NM this afternoon, and dewpoints are only in the upper 30`s to lower 40`s. The 19Z HRRR and 18Z NAM show a few hundredths of rain in far northeast NM this evening, as does the 12Z GFS. Included isolated thunderstorms in the forecast for far northeast portion of the state, before midnight. Otherwise, broken high clouds will move across NM tonight, and low temperatures will be well above normal. The ridge aloft will flatten out Thursday, as an upper low moves eastward across the Pacific Northwest. Winds aloft will increase Thursday, as a broad area of surface low pressure forms in eastern CO. The resultant increase in the surface pressure gradient across NM and strong daytime boundary layer mixing will produce breezy west to southwest winds Thursday afternoon. Despite the slight weakening of the ridge aloft, the core of very warm temperatures aloft will remain in place. Temperatures at 700 millibars Thursday afternoon will range from 14 to 16 degrees C. Near record highs are expected across all of northern and central NM Thursday with a few hundred degree readings likely in the east central and southeast plains. The upper low to the north will move into the northern Great Basin Tuesday. This will tighten the height gradient aloft across NM, and 700 millibar winds will increase to 30 to 35 knots by Thursday afternoon. West to southwest winds across the entire area Friday afternoon will range from 20 to 35 mph with gusts 40 to 50 mph. Slightly cooler air aloft Friday will cool surface temperatures 2 to 4 degrees F west of the central mountains, but downsloping winds east of the central mountains will keep high temperatures very warm and just a few degrees below record highs. The upper low over the northern Great Basin will remain nearly stationary Saturday and Sunday, keeping NM in dry southwest flow aloft. High temperatures will fall slightly Saturday and Sunday, as cooler air from the northwest slowly filters over NM. Highs will be slightly above normal in western NM Saturday and well above normal across central and eastern NM. Highs Sunday will still be well above normal east of the central mountains and slightly above normal to the west. Flow aloft will transition from southwest to west Monday through Wednesday with high temperatures remaining above normal. 28 && .FIRE WEATHER... ...CRITICAL FIRE WEATHER CONDITIONS EXPECTED THURSDAY THROUGH SATURDAY... Near record high temperatures, dry and unstable conditions will dominate through Saturday. Winds will begin to increase Thursday, then strengthen more area wide Friday into Saturday. Therefore, widespread critical fire weather conditions are likely for portions of the west and east Thursday and area wide Friday. Poor overnight humidity recoveries will dominate as well through the weekend, while some moisture sloshes back and forth over the east, leading to somewhat better, although not great, humidity recoveries near the Texas border. A few thunderstorms, possibly with little to no rain and gusty winds, could be triggered early this evening over far northeast NM. On Thursday southwest winds aloft will begin to strengthen over NM as an upper low forms over the Pac NW and surface low pressure over southeast CO deepens. High Haines and single digit humidities will combine to produce critical fire weather conditions over portions of the west, and over the Northeast Highlands and Northeast and East Central Plains. Five to 15 hours of single digit humidities are forecast from west of the Pecos Valley to the AZ border. Winds strengthen further Friday and will be combined with another day of unseasonably warm temperatures, ranging from over 10 to about 20 degrees above average and widespread single digit humidities as well as high Haines. The fire weather watch has been upgraded to a Red Flag warning area wide. Decided to hold off on a watch for Saturday at this time. Low to moderate Haines forecast with some cooler temperatures in the west, although Haines remains high in the east. Forecast models indicate winds may not be as strong as on Friday, and think models may change a bit in the next 24-48 hrs with the upper low/trough moving into the Great Basin and lingering. Models not too sure how the upper low/trough will evolve, whether it will eventually just stay put and weaken, if so, this would keep drier and breezy to windy conditions over the region into early next week with continued concern for critical fire weather conditions. Low level moisture may continue to try to migrate westward during the overnights, but mixes out during the day or is shoved back into TX. However, this could allow for a few thunderstorms to develop near the TX border. && .ABQ WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from 11 AM to 9 PM MDT Friday for the following zones... NMZ101>109. Red Flag Warning from 3 PM to 7 PM MDT Thursday for the following zones... NMZ103>105-108. && $$ 28
Area Forecast Discussion
National Weather Service Duluth MN
702 PM CDT Wed May 9 2018 .SHORT TERM...(This evening through Thursday) Issued at 309 PM CDT Wed May 9 2018 The last of the rain showers from the current system will move out of the eastern sections of the Northland this evening, leading to drier conditions and clearing skies overnight. The mid-level shortwave trough and associated surface low currently situated over southwestern Wisconsin will move out of the region this evening. Some of the high-resolution model guidance (e.g., HRRR and NAMNest) is progging a thin band of very light precipitation to follow the main surge of precipitation along a weak baroclinic zone and cold front, which should only bring very small chances of a shower to the region, mainly over north-central Minnesota and perhaps over north-central Wisconsin. Much drier air will pour into the region behind this front, as indicated by plummeting values of theta-e. Dry conditions will continue through much of the day Thursday, with sunny skies, and light northerly winds as high pressure builds into the region. A low-amplitude shortwave trough will then eject from the Montana region, towards the southern sections of our forecast area by the afternoon. This should bring increasing clouds from the southwest. Any precipitation with this shortwave should remain to the south of the Northland through Thursday evening. .LONG TERM...(Thursday night through Wednesday) Issued at 345 PM CDT Wed May 9 2018 Thursday night through Friday night, a ridge of high pressure will slide across the Canadian border even as a low pressure system moves from eastern Colorado east across the plains to the lower Ohio River Valley. This system should bring some chance pops to our southern CWA on Friday, though the bulk of this system will be well to our south and depending on where the convection forms, may miss the forecast area altogether. With relatively clear skies and light winds expected across our north for both nights, have lowered min temps for the Arrowhead. We have been watching the development of an upper low that slides across the Rockies over the weekend. Previous runs of the models have been ejecting a shortwave across the MN/WI region on Saturday, but the latest runs have shunted that much farther south, and now we have a dry forecast for both Saturday and Sunday. With more sunshine and a drier airmass in place, expect minimum RH values of concern for fire weather both days, but winds should remain light both days with a surface ridge nearby to keep us out of critical fire weather conditions. Starting Monday, I have decreasing confidence in the forecast, with some fairly significant model differences appearing in their handling of the upper low that develops over the weekend and its phasing with the broader upper level flow. For now, we have near to above normal temperatures through early next week, with some slight chance to chance pops for Tuesday and Wednesday. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 701 PM CDT Wed May 9 2018 The low pressure system that has brought the low clouds, fog and rain to the Northland throughout the day will gradually move off to the east tonight. In the wake of this system, we will see increasing cloud bases, and eventually clearing skies. There will also be an abrupt end to the precipitation during the evening. IFR/MVFR conditions will give way to VFR from northwest to southeast. Those VFR conditions will continue on Thursday. && .PRELIMINARY POINT TEMPS/POPS... DLH 36 56 32 52 / 20 0 0 10 INL 30 54 27 62 / 0 0 0 0 BRD 37 57 36 58 / 20 0 10 20 HYR 40 60 33 55 / 40 0 10 30 ASX 39 54 29 51 / 70 0 0 10 && .DLH WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. LS...None. && $$ SHORT TERM...JTS LONG TERM...LE AVIATION...DAP
Area Forecast Discussion
National Weather Service Hastings NE
912 PM CDT Wed May 9 2018 .UPDATE... Issued at 905 PM CDT Wed May 9 2018 Updated the forecast to push thunderstorm chances further south. Thunderstorms will be rather isolated and primarily confined to our Kansas counties although we can not rule out an isolated thunderstorm this evening just north of the Kansas border. Thunderstorms will push even further to the south and out of our area after midnight if not sooner. && .SHORT TERM...(This evening through Thursday) Issued at 349 PM CDT Wed May 9 2018 Aloft: WV imagery and RAOB/aircraft data showed the flow was characterized by a modestly amplified Wrn USA ridge/Ern USA trof. A weak shortwave trof was near the WY/UT border. This trof will cont E and move thru this eve. The Wrn ridge will move E tonight as a trof reaches the W coast. The ridge will move over the Cntrl Plns tomorrow as the trof presses further inland. Surface: Weak high pres was over Neb/KS. A strong cool front was along the US-Can border. The high will depart to the SE tonight while the cool front presses S and deep into the CWA by 12Z/Thu. There is some model spread on its exact location...but believe it will drop into Nrn KS per the EC and SREF mean. Lee cyclogenesis will occur over CO tomorrow and this could force the front to lift back N a bit...but it will remain close to the Neb/KS border. Now thru sunset: P/cldy. TCU/CB are developing between AIA-TIF- LBF. The 19Z HRRR may be a bit too aggressive with its depiction ...but some of this activity could slide ESE into the LXN/HDE/EAR vicinity thru early eve. Coord with LBF to introduce some low pops. Radar has been changed to VCP21/precip mode. Diurnal CU will dissipate...but cirrostratus will remain. IR satellite shows quite a bit of it with the approaching trof. Highs in the 80s. Tonight: Skies will be m/cldy ahead of the trof then decreasing clds behind it...away from spotty tstm activity. Mixing should be deep enough to initiate spotty high-based tstms over NW KS late this afternoon. The forcing associated with the trof and/or the low-lvl jet will probably keep this activity transversing E thru KS thru the night. MUCAPE will be no more than 750 J/kg. At worst...maybe some gusts to 43 kt and hail up to the size of nickels. Can`t rule out a couple small tstms develop over S-cntrl Neb S of I-80...but most of S-cntrl Neb will remain dry. Cooled lows a little below the 4 AM fcst due to a bit drier air and light/calm winds expected. Thu: M/sunny. There will be a few CU/altocu around. Can`t completely rule out an isolated tstm N and E of the Tri-Cities ...late AM thru midday...but the CWA will be basically dry. High temps are below normal confidence due to the location of the front. Areas N of I-80 could be a little cooler than we`re advertising and N-cntrl KS could be a little hotter. Increased winds a little above guidance in the tightly-packed isobars N of the front. Probably could`ve gone a little higher... but held off due to uncertainty on exact location of the front. .LONG TERM...(Thursday night through Wednesday) Issued at 319 PM CDT Wed May 9 2018 Aloft: Split flow will develop over N America tomorrow as a cut- off low forms and settles over the Wrn USA. The flow will remain split thru the rest of the fcst with the polar jet remaining far to the N. This will mean multiple days of SW flow. Weak/subtle vort maxima will rotate around the low and cross the rgn from time-to-time...but they have little to no predictability beyond 1 or 2 days. The low is fcst to weaken Tue and then possibly head E into the rgn Wed-Thu. But given the weak flow fcst...this scenario may change. Surface: The front referenced above will remain quasi-stationary from SW-NE across KS thru Sun. At least 3 lows will form over SE CO and eject NE along the front...filling while they do so. By Mon the front may begin to lose its definition and dissipate. Temps: Returning to near normal N of the front Fri...but remaining warmer than normal S of it. Sat will be much cooler than normal N of the front as it looks like extensive stratus will be in place. S of the front temps should return to near normal. Near normal Sun...then it`s probably back to warmer than normal Mon- Wed. Precip: It`s unfortunate...but if multiple days of model runs are to be believed...precip chances are not looking very good despite the persistent presence of this front. A lot of dry air from the Desert SW will be wrapping around the low. Thu upslope flow into the high plns will trigger spotty tstms over Ern WY 19-21Z. Present indications are that these storms will form a common cold pool and head E into Neb. Forcing in the RRQ of as strengthening jet streak should maintain these storms into the night. Based on ensemble QPF probs and multi-model QPF clustering... it appears the best chance of storms will be N of I-80. If some of these storms affect the CWA...they will move thru during the nighttime hrs in the form of a squall line. The means the primary threat will be isolated damaging winds...but 1-1.5" hail can`t be rule out. Fri is uncertain. It will be dry most locations. The SPC outlook may be overdone as a significant cap will be in place. Sat left a mention of thunder...but again it is extremely doubtful. GFS/NAM soundings have more of a drzl signal. Elevated CAPE remains but there is currently nothing envisioned to release it. Was very tempted to withdraw mention of tstms and replace it with drzl. Predictability is too low to mention any other precip potential beyond saying some spotty tstm activity will be possible...but most locations will remain dry. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Thursday) Issued at 905 PM CDT Wed May 9 2018 The wind will be light and variable tonight and then easterly during the day on Thursday. A frontal boundary will be located in the general vicinity and if it pushes north of our TAF sites we could see the wind take on a more southeasterly component. Expect only mid to high clouds and dry weather through Thursday afternoon. && .GID WATCHES/WARNINGS/ADVISORIES... NE...None. KS...None. && $$ UPDATE...Wesely SHORT TERM...Kelley LONG TERM...Kelley AVIATION...Wesely
Area Forecast Discussion
National Weather Service Wilmington OH
1009 PM EDT Wed May 9 2018 .SYNOPSIS... An upper level disturbance will move through this evening with an additional disturbance moving through overnight into the day on Thursday. A warm front will lift north Thursday night into Friday. Unsettled weather will be present for the weekend and into the next week as a frontal boundary remains in the vicinity. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... A line of showers and thunderstorms is currently moving through Indiana this evening and is expected to slowly weaken as it moves into Ohio. This is supported by CAPE values slowly decreasing as the storms head east as well as how the storms have pushed ahead of the surface cold front. Latest HRRR run (as well as the HRRRTL) has the line collapsing as it moves into our CWA and have advertised this in the grids. New zones already out. Prev Discussion-> Showers and thunderstorms are across the central portion of the forecast area. These storms will continue to move to the east this afternoon. An upper level disturbance will approach this evening allowing for additional showers and thunderstorms. Widespread severe weather is not expected. Cannot rule out an isolated strong to severe storm with damaging and large hail. Instability will be weakening tonight and therefore expect a decrease in thunder later overnight. An additional disturbance will be approaching by the end of the near term keeping precipitation across the region. With cloud cover overnight temperatures will only drop into the 60s. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/... Showers and thunderstorms will generally be limited to eastern portions of the forecast area as an upper level disturbance pushes to the east. Additional precipitation will be possible Thursday night as a warm front begins to push northward. Went close to guidance for temperatures with highs in the 70s to low 80s and lows in the 50s to around 60. && .LONG TERM /FRIDAY THROUGH WEDNESDAY/... A warm front will lift north across the area through the day on Friday. This will allow for some lower chance pops through the day, with the best chance across our north, closest to the front. As we get into the warm sector, high temperatures will range from the upper 70s across the far north to the mid 80s in the south. The boundary will stall out across northern Ohio Friday night into Saturday. With our area in the warm sector, lows Friday night will remain in the mid to upper 60s with highs on Saturday well into the 80s. There is some uncertainty to just how far north the boundary will make it so will hang on to chance pops for thunderstorms across mainly our northern areas through Saturday. Th boundary will begin to sag back down south across our area Saturday night through Monday. The 12Z ECMWF still appears to be the fastest pushing the boundary south of our area with the GFS still the slowest, lingering the boundary across the Ohio Valley through much of the first part of next week. Will trend a bit toward the ECMWF and go ahead and allow for a better chance of showers and thunderstorms to push slowly south across our area Sunday through Monday. Given the uncertainty beyond that though, will just hang to some lower end pops into mid week. Temperatures Sunday into Monday will be dependent on just how fast the boundary pushes south. For the most part though, it looks like we will remain well above normal for temperatures through the long term period. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... Leftover thunderstorm anvil is currently approaching KILN with all TAF sites VFR. Southerly winds will continue to slowly veer from the southwest with a cold front moving through Illinois. Along the cold front a line of thunderstorms has developed and is pushing southeast. The general idea is for this line of showers and thunderstorms to slowly weaken as it heads east. This makes sense as instability weakens as the storms head east. Looking at forecast soundings reveals enough instability towards KDAY which will probably allow for thunder. By the time the storms reach KCMH the chance for thunder will have even further diminished. After the storms pass, some MVFR cigs will be possible with SREF probs highlighting mainly CMH/ LCK. The low level pressure gradient will stay elevated Thursday allowing for some more gusty winds. Momentum transfer on the GFS and NAM are indicating gusts of 20 to 25 kts possible. OUTLOOK...Thunderstorms possible Saturday through Monday. && .ILN WATCHES/WARNINGS/ADVISORIES... OH...None. KY...None. IN...None. && $$ SYNOPSIS...Haines/Novak NEAR TERM...Haines/Novak SHORT TERM...Novak LONG TERM...JGL AVIATION...Haines
National Weather Service Jackson KY
1044 PM EDT Wed May 9 2018 .UPDATE... Issued at 1044 PM EDT WED MAY 9 2018 The forecast has been in good shape overall. Based on current trends in the HRRR model and upstream radar loops, decided to wait a few hours later to bring precipitation into the area. Now expecting the best chance of rain overnight between 5 and 12Z. Thunderstorms should be gone by 10Z or so. The QPF and weather type forecast elements were updated to reflect the updated timing of the precip as it moves in our direction. The updated zone forecast text product has already been issued. UPDATE Issued at 728 PM EDT WED MAY 9 2018 The forecast is on track so far this evening. Ingested the latest obs into the forecast grids to establish new trends in the data. Will continue to monitor to see if any updates are needed later in the shift. && .SHORT TERM...(This evening through Thursday night) Issued at 336 PM EDT WED MAY 9 2018 Isolated to scattered thunderstorms over the western part of the forecast area will continue to move east through the late afternoon, with greatest coverage in the south. These will dissipate by early evening. A upper/mid level trough will approach from the west later tonight. At the surface low pressure will move across the northern Great Lakes into Canada as a weak cold front drops southeast through the OH valley. As a result shower and thunderstorm chances will increase again late tonight. On Thursday shower chances will linger in the southeast part of the forecast area, with thunderstorm chances in the far southeast Thursday afternoon. The cold front will stall and above normal temperatures will continue, with highs on Thursday in the low to middle 80s and lows Thursday night in the upper 50s to lower 60s. .LONG TERM...(Friday through Wednesday) Issued at 402 PM EDT WED MAY 9 2018 The extended period begins as an upper level trough has progressed east of Kentucky. At the surface, a cold front will move through Friday and then begin to lift to the northeast. This will result in rain/storm chances for the afternoon and into the evening on Friday. The overall upper level pattern will be fairly slow-paced through the rest of the long term. This means the surface low pressure system in the Plains region will progress very slowly eastward. A warm front associated with the surface low in the Plains will lift to the north of the OH Valley on Saturday, bringing in warm and moist air from the Gulf. However, there will generally be a lull in precipitation until the frontal boundary advances towards Kentucky Sunday, bringing increased chances for precipitation. This front will stagger over the Commonwealth as a stationary front through Tuesday. In addition, instability is highest during the weekend and into next week over eastern Kentucky. Due to both of these factors, periods of rain/storms will be possible during this time. However, even with the models in fairly decent agreement with the upper level pattern through the weekend, confidence lowers as they deviate for the start of the new work week. Temperatures will be in the mid to upper 80s through the weekend, but a slight cool down to low 80s is in store for the start of the work week. Low temperatures will generally be in the upper 60s. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) ISSUED AT 728 PM EDT WED MAY 9 2018 VFR conditions are expected through the forecast period, but a few thunderstorms will be possible across the area this evening and again late tonight into early Thursday. Thunderstorm chances remain low and will not include any mention in the TAFS for this evening, but will include a period of VCTS late tonight as chances increase as a cold front approaches from the northwest. It looks like the second round of showers/storms will begin around 9Z on Thursday. As a low level jet increases across the area tonight, LLWS should develop and this will be included at all TAF sites. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...AR SHORT TERM...SBH LONG TERM...CGAL AVIATION...AR
Area Forecast Discussion
National Weather Service Louisville KY
1028 PM EDT Wed May 9 2018 .Forecast Update... Issued at 1026 PM EDT Wed May 9 2018 The radar is fairly quiet across the forecast area this evening. A few storms have popped up in southern IN this evening, but the majority of the showers and storms is along the cold front stretching from southern IL into central and northern IN. The bulk of this activity should stay to the north of the area, but the latest runs of the HRRR have begun to bring a bit better coverage of showers and storms to southern IN and north central KY after 05Z or so. The forecast was updated to increase pops a bit overnight as the front moves through, but still have kept them isolated to scattered in coverage. A few storms could be strong with gusty winds and small hail, but this is looking less likely as instability is less the farther east the storms go. && .Short Term...(This evening through Thursday) Issued at 245 PM EDT Wed May 9 2018 Convective complex from last night is washing out across central Illinois and Indiana, with the MCV still somewhat evident just north of Indianapolis. We have had isolated convection develop near the Ohio River just NE of Louisville, and that will continue to brush the far NE corner of our CWA. Temps are quite warm, but dewpoints are still in the upper 50s and precipitable water values are above climo but still below the 75th percentile for early May. Mesoscale models are less bullish recently compared to previous runs, but it still appears we will have enough instability to fire isolated/widely scattered convection, mainly over southern Indiana, as we head into late afternoon and early evening. Believe that model dewpoints are too high, so their instability progs are a bit overdone, but with modest instability and marginal bulk shear, we could see a few strong storms with gusty winds, mainly over southern IN but perhaps as far south as the Western Kentucky and Bluegrass Parkways. Not expecting much organization, so SPC Marginal seems to cover it. However, convective potential will persist well into the night, shifting into east-central Kentucky toward morning. Thursday will be another warm day, but the effective boundary will be far enough to our south and east to limit storm chances to the periphery of our area, along the Tennessee line and up the Cumberland Escarpment. Severe potential is minimal by Thursday. .Long Term...(Thursday night through Wednesday) Issued at 257 PM EDT Wed May 9 2018 Thursday Night - Friday... An upper level wave is forecast to move over the East Coast Thursday evening, with subtle background height rises over the Ohio Valley. A warm front develops over the area Thursday night and pushes north into central IN/OH on Friday. The bulk of this time frame will be dry. But NW to SE oriented band of moisture sweeps northward early Friday. A modest increase in the SW LLJ could touch off a few showers Friday morning. Otherwise, Friday looks dry, breezy, and warm. Highs should reach the mid to upper 80s under partly sunny skies. Gusts to at least 25 mph look likely on Friday. Friday Night - Saturday Night... Main area of convection is forecast to stay well north of the forecast area during this time frame. We`ll see increasing subsidence aloft along with more warm southerly breezes. Low-level thicknesses continue to increase this weekend, and highs on Saturday should reach the upper 80s to around 90 degrees in most locations. Overnight lows will be quite mild, in the mid 60s to lower 70s. Sunday - Wednesday... Sunday into Monday, the quasi-stationary boundary to the north is forecast to be pulled southward. Rain and thunderstorm chances increase as early as late Sunday, but most places may actually stay dry until Monday. Mid 80s to around 90 will likely be common for Sunday afternoon highs. The weather turns more active during the early to middle portion of next week. Warm, humid weather along with a bit more in the way of forcing should result in isolated to scattered convection becoming more common (especially during afternoon and evening hours). && .Aviation...(00Z TAF Issuance) Issued at 714 PM EDT Wed May 9 2018 Mostly mid and high level clouds are streaming across the region this evening with a few high based cu. The challenge for the TAF forecast overnight is the potential for thunderstorms near the TAF sites as a cold front moves in. The latest guidance has backed off on coverage of storms and pushed the timing later in the night. Will continue to carry VCTS as HNB, SDF, and LEX, but tried to limit the mention to a shorter block of time and pushed back the start time a couple of hours. Confidence in storms affecting any of the terminals is on the lower side. After the front moves through, winds will shift to westerly and gust at times through the day tomorrow. Skies should be partly cloudy on Thursday. && .LMK WATCHES/WARNINGS/ADVISORIES... IN...None. KY...None. && $$ Update...EER Short Term...RAS Long Term...EBW Aviation...EER
Area Forecast Discussion
National Weather Service Memphis TN
916 PM CDT Wed May 9 2018 .UPDATE... A shortwave trough is moving east across the Great Lakes this evening with the trough axis extending south through the Mississippi Valley. Showers and thunderstorms have developed along the attendant cold front, but this front doesn`t have much southward push and may slip into the northern portion of the CWA late tonight or early Thursday before stalling. A few storms continue across western KY at this time and may affect northwest TN over the next several hours, with another potential for early morning showers/storms toward sunrise. The general forecast remains intact for tonight/tomorrow, with only minor tweaks included in the short-term. Johnson && .PREV DISCUSSION... /issued 305 PM CDT Wed May 9 2018/ Upper level flow will transition to a pattern more typical of mid-summer through this weekend. A low amplitude upper ridge over northern Mexico will lift east and amplify over the lower/middle MS River valley, ahead of upstream closed low dropping into the Great Basin. By midday Sunday, a 589dm 500mb height ridge will center over Memphis. Under such a pattern, daytime temps will average around 10 degrees above mid-May normals, with little to no chance of measurable rainfall. In the interim, slight rain chances remain in the forecast, mainly from northeast AR through northwest TN. Early afternoon runs of the HRRR depict a forward-propagating convective complex entering eastern KS by late evening. This MCS would likely take an east/ southeast path along the 850-500mb thickness gradient through the Ozarks and possibly into northeast AR by sunrise Thursday - if it holds together. Too early to tell if an MCV would develop from this convection, but if so, a regeneration of storms might occur downstream over the TN River valley later in the day Thursday. By early Friday, the aforementioned ridge amplification begins, precluding any appreciable rain chances through the weekend. 12Z medium range models were in good agreement for the early next week periods. During this time, the western U.S. upper low will weaken and retrograde into Rex blocking pattern over the Pacific northwest. Downstream, the upper ridge over the Midsouth will deamplify, returning westerly flow to the region. Concurrently, a non-tropical upper low will lift up the western coast of Florida. The return of weak westerly flow early next week will combine with daytime instability to return low end rain chances to the Midsouth. A few nighttime storms also not out of the question downstream from late evening storms over the plains. Midsouth temperatures will moderate slightly from the weekend, but still average 5 to 10 degrees above normal. PWB && .AVIATION... 00Z TAF Set VFR conditions will prevail over the next 24 to 30 hours. Did add vicinity shower wording at KJBR as a dying thunderstorm complex will be approaching the TAF site after 9Z. Also switched winds around to the NW for a short time after 13Z as the HRRR shows a gust front from the thunderstorm complex going through KJBR. The gust front could make it as far south as KMEM, but for now have left wind shift out of KMEM TAF. Otherwise, SW winds will remain around 10 KTS this evening before decreasing during the overnight hours. Speeds will pick back up to around 10 KTS by 14-16Z. KRM && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Norman OK
1027 PM CDT Wed May 9 2018 .UPDATE... Increased PoPs across northern half of OK. See discussion below. && .DISCUSSION... An area of moist convection continues to increase in coverage over west central KS late this evening. In fact, a supercell was nearing Langdon around 0325 UTC. Expect this activity to continue to migrate SE with a shortwave trough, and maintain itself with LLJ instensification thru 09Z. The HRRR seems to have a good handle on this scenario. A few strong wind gusts could impact extreme northern OK overnight. All updated products have been sent. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 65 87 66 89 / 20 20 0 0 Hobart OK 66 92 67 93 / 20 10 0 0 Wichita Falls TX 64 89 66 91 / 0 0 0 0 Gage OK 67 92 68 98 / 20 10 0 0 Ponca City OK 65 88 68 89 / 60 20 10 10 Durant OK 63 85 65 88 / 0 0 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ 03/99
Area Forecast Discussion
National Weather Service Paducah KY
640 PM CDT Wed May 9 2018 .SHORT TERM...(Tonight through Friday night) Issued at 115 PM CDT Wed May 9 2018 The HRRR looks like it has a real nice grip on the real time pcpn. If so, chances are diminishing for our late pm/evening event. Cloud cover is certainly impeding instability, with the modeled HRRR MUCapes only running upwards to about 500 j/kg in the lowest 1 KM thru the mid evening hours. Differential heating where clouds break may change that, but drier air is incoming from the north/west that could counter-balance that. We`ll monitor closely and generally carry a slight chance, maybe a chance, for convection thru the mid evening hours, waning thereafter. Still have the marginal risk, mainly north, til passage. Not sure we buy the frontogenetical wrap back of pcpn that the medium range models produce tonight, given the poor identity of the front itself and the night-time occurrence. Winds of course will diminish from their LWA (pm) peaks this evening, so we`ll let that expire naturally. Otherwise, it`s going to be a relatively quiet and generally dry and warming short term forecast. Some peripheral shower/storm chances may persist til some capping aloft with ridging incoming occurs Friday. Highs will nudge upwards to the mid-upr 80s, with Lows doing the same to the mid-upr 60s...Hello summer like feel. .LONG TERM...(Saturday through Wednesday) Issued at 243 PM CDT Wed May 9 2018 It looks rather tranquil but warm for the weekend. A quasi stationary boundary will be situated well to our north during this time frame. Deep southwesterly flow will continue during the period as well and an upper level ridge will build into the area over the weekend. This will help temperatures reach the upper 80s to around 90 degrees. It definitely looks like the record highs could be in jeopardy of being tied or even broken over the weekend. Toward the latter half of the weekend, we will also have dewpoints creeping into the upper 60s which will sure make it feel like summer is here. Therefore, low temperatures will be rather warm as well and settle into the upper 60s to lower 70s making for some muggy conditions. The forecast for early next week is not as certain and the weather pattern becomes much more diffuse and difficult to analyze. This makes forecasting day to day weather a challenge. Models are not handling the break down of the upper level ridge very well and the timing of any disturbances approaching differs between the data sets at this time. Overall, moisture does deepen with time and instability will be plentiful. Therefore, the threat for widely scattered to scattered showers and storms seems to be the way to go for early next week, as it does look like we will have either a surface trigger (the front to our north sagging south) or triggers aloft to help initiate convection. Timing of any convection becomes the problem. Temperatures will remain warm with highs continuing in the mid to upper 80s. Again, record highs for early next week may be close to being broken. && .AVIATION... Issued at 640 PM CDT Wed May 9 2018 Progressive trough currently moving through the WFO PAH TAF locations continues to kick off isolated convective activity at the time of this writing. Kept a mention of either a brief period of convection (e.g. KCGI) and a vicinity mention of convection closer to the higher shear associated with the trough (KEVV, KOWB). There is enough of wind discontinuity that a mention of LLWS was necessary for KOWB and KEVV. this evening, until the trough fully passes through and the ridge develops over the WFO PAH TAF sites. Overall, ceilings and visibilities will remain VFR through the forecast period, despite nearby convective activity this evening. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...Lake Wind Advisory until 7 PM CDT this evening for ILZ075>078- 080>094. MO...Lake Wind Advisory until 7 PM CDT this evening for MOZ076-086- 087-100-107>112-114. IN...Lake Wind Advisory until 7 PM CDT this evening for INZ081-082- 085>088. KY...Lake Wind Advisory until 7 PM CDT this evening for KYZ001>022. && $$ AVIATION...Smith
Area Forecast Discussion
National Weather Service Pueblo CO
322 PM MDT Wed May 9 2018 .SHORT TERM...(This evening through Thursday) Issued at 322 PM MDT Wed May 9 2018 Weak upper wave crossing the state today, producing rather thick mid/high level cloud shield over the area, but only a lone convective cell near the Raton Mesa as of 21z. For the remainder of the afternoon, HRRR and latest radar loop suggests area along the Raton Mesa/NM border has the best chance of an isolated tsra, with convergence and weak boundary along the Palmer Divide providing a focus for a storm or two as well. This evening, if storms can reach the higher CAPE air located near the KS border, a couple of briefly strong/severe storms will be possible, with gusty winds the main threat given high cloud bases and dry sub cloud layer. Activity will then shift eastward into KS by midnight, with clearing skies overnight as upper wave moves east. On Thursday, deep layered swly flow develops across the area as upper low drops into the nwrn U.S. Should see winds increase all locations, with gusts in the 20-30 kt range for a few hours in the afternoon. Overall, will keep current Red Flag Warning in place, though some concern that far eastern plains may stay too moist ahead of the surface trough, and portions of the Arkansas Valley may not be windy enough for the required three hrs. A few models hint at an isolated tsra over Baca county in the afternoon, where low level moisture lingers the longest, and will include some very low pops for a small sliver of the plains late in the day. Given deep mixing and rising mid level temps, max temps will reach their warmest levels of the season, with records forecast for many observation sites (ALS record 78 in 2009, forecast 81; COS record 85 in 1962, forecast 87; PUB record 92 in 2000, forecast 94). .LONG TERM...(Thursday night through Wednesday) Issued at 322 PM MDT Wed May 9 2018 Thursday night through Saturday...A closed upper low drops down out of the Pacific NW and into the Great Basin late Thu night, and is expected to remain in place through Sat. This will increase southwest flow across the Four Corners, and coupled with very warm and dry conditions will likely mean fire danger increasing to near critical levels. A front is forecast to drop south across the Palmer Divide late Fri night, and where it sets up across the plains on Sat will serve as a focal point for some isolated convection, as well as the line between very warm and dry air to the south compared to slightly cooler, more moist air to the north. Temp forecast for Sat will be tricky, as will the fire weather forecast as the southern foothills may see critical conditions again on Sat. As for pcpn chances, there should be some isolated convection over the central mts and Palmer Divide aftn and eve both days, though most of the forecast area should remain dry. Look for highs in the 70s for the high valleys both days, while the plains will see mid 80s to mid 90s Fri, and upper 70s to upper 80s for Sat. Sunday and Monday...The upper low over the Great Basin will weaken Sun and Mon and stretch out lengthwise, reaching from CA up into MT. Southwest flow will weaken somewhat, and though conditions will remain warm, fire danger will likely become borderline at best. Much of the pcpn potential will remain over the central mts and Palmer Divide, though the GFS is hinting at a weak cold front dropping south late Mon perhaps bringing a few showers to the eastern plains and mts for Mon night. Max temps will remain in the 70s for the high valleys, while the plains will warm into the mid 70s to mid 80s. Tuesday and Wednesday...Very low confidence in the forecast by Tue as models are all over the place with potential solutions. The models try to hint at an upper ridge crossing the region through midweek, which would mean continued warm with isolated mt convection each aftn and eve. Will stick with the extended procedure solution which is very broad-brushed at this time. High temps will stay steady, with 70s for the high valleys and mid 70s to mid 80s for the plains. Moore && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 322 PM MDT Wed May 9 2018 VFR at all taf sites tonight and Thursday. Very low threat of -tsra on the eastern plains this evening, though impact on the terminals will be limited to briefly gusty outflow winds at KPUB and KCOS. On Thu, W-SW winds will increase across the area, with gusts over 20 kts at all terminals after 18z. && .PUB WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from 11 AM to 9 PM MDT Thursday for COZ220>222- 225>237. Fire Weather Watch from Friday morning through Friday evening for COZ220>222-225>233-235-237. && $$ SHORT TERM...PETERSEN LONG TERM...MOORE AVIATION...PETERSEN
Area Forecast Discussion
National Weather Service Springfield MO
913 PM CDT Wed May 9 2018 ....MESOSCALE DISCUSSION... Issued at 851 PM CDT Wed May 9 2018 An area of showers and thunderstorms was developing across northwest Kansas as of mid/late evening. These storms were developing in response to the approach of shortwave energy from Wyoming and Colorado. IR imagery shows cooling cloud tops with these storms. A surface front was bisecting our CWA from Fort Leonard Wood to Pittsburg, KS and stretched back to the west from just south of Wichita into northwest Kansas. This boundary appears to be retreating to the north across Kansas per ICT WSR88D loops. MU capes were generally less than 2000j/kg along and south of the boundary. Much drier air was located across our northern counties with some upper 40 dewpoints. Upper 50s to Lower 60 dewpoints were common south of the boundary. A low level jet will begin to develop in earnest over the next 1-3 hours across north Texas into western Oklahoma and veer slightly into South Central Kansas. VWP from various sites in that area show 850mb winds are currently around 25kts. These should increase to near 45kts after midnight. This will aid in the continual development of showers and thunderstorms across Kansas as the llj impinges on the boundary. A upper level jet streak also moves overhead during the overnight hours therefore confidence is high that showers an thunderstorms will continue to develop overnight to our west and roll east. MU capes will slowly decrease overnight however with 30kts of effective shear, we cant rule out some small hail (less than 1.00in diameter). Areas across far SE Kansas and western Missouri has the best chance of seeing those storms before instability wanes further. Cloud to ground lightning will be the primary risk overnight along with light to moderate rainfall. Generally followed the HRRR for PoP trends since it has been consistent the last 3-5 runs. Therefore went with 50-80 pops across our west and tapered less the further east one goes. && .SHORT TERM...(This evening through Thursday) It was a warm and humid afternoon over extreme southeast Kansas and the Missouri Ozarks. Temperatures warmed well into the 80s, under a mix of sun and clouds. Thunderstorms shifted east of the region this morning associated with a passing shortwave trough axis. Tonight`s precipitation forecast was fairly difficult, as some of the CAMS models are bringing in a cluster of showers and thunderstorms, with a decent areal coverage with it. A speed max was noted across the High Plains, therefore, we increased precipitation chances for tonight. With 30 knots of deep layer shear, the cape/shear environment seems marginal for organized storms. This needs to be reassessed late this afternoon and evening. There should be some lingering showers and isolated thunderstorms early Thursday morning, before dissipating by late morning. Temperatures will warm back into the 80s Thursday afternoon with most locations remaining dry. .LONG TERM...(Thursday Night through Wednesday) A window of warm and dry weather will begin Thursday and continue through Sunday afternoon. Humidity levels will be on the increase with highs in the 80s on an afternoon basis. Overall it should be a good weekend for outdoor activities. Weak southwest flow evolves in the upper levels of the atmosphere, while a series of weak shortwave troughs migrate through this regime, increasing thunderstorm chances early next week. This is somewhat of a dirty ridge setup, that could bring heavy rain and severe weather to portions of the Ozarks. However, confidence in knowing where thunderstorms will develop under this pattern is difficult this far out. One thing is for sure, it will feel like summertime, with highs in the 80s and lows in the 60s. Will continue to monitor model trends for next week. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 615 PM CDT Wed May 9 2018 VFR conditions are expected for the first six hours of the taf period. We will need to watch for the development of thunderstorms across Kansas overnight that will slide into the area Overnight into early Thursday morning. These showers and thunderstorms would reduce flight conditions. Winds will start out from the west but turn more towards the south by morning. VFR conditions are expected for most of Thursday afternoon and evening behind the morning rain. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ MESOSCALE...Burchfield SHORT TERM...Cramer LONG TERM...Cramer AVIATION...Burchfield