Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/14/17

Area Forecast Discussion
National Weather Service Albany NY
1018 PM EDT Sat May 13 2017 .SYNOPSIS... An area of low pressure located along the mid Atlantic coast will strengthen and track northeast along the east coast to eastern New England through Sunday. This coastal storm will bring a widespread rainfall to the region over the weekend, along with cool temperatures. Showery, cool and breezy conditions will continue on Monday as low pressure only slowly pulls away from the eastern New England coast. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... As of 1018 PM EDT...KENX radar imagery shows steady rainfall over all of eastern New York and western New England. According to surface observations, rainfall is falling not quite as hard as radar would suggest, and this is probably due to some bright banding within the radar data, as the higher echos on radar are occurring where dual-pol variables suggest that melting layer is located. Surface observations are showing rain rates of a quarter to a third of an inch per hour over western New England. Light to occasionally moderate rainfall is ongoing over the area, as a wave of low pressure slowly lifts northeast off the Jersey shore and starts heading northeast towards southern New England. 3km HRRR suggest that the heaviest/steadiest rainfall will be this evening, and radar will be slowly ending from southwest to northeast through the overnight hours. By daybreak Sunday the coverage of rain should decrease as far east as perhaps to the Hudson Valley with the steadier rain persisting in western New England. The rain and clouds should prevent temperatures from falling much through the night but with some ageostrophic flow from the east where there is some drier low level air, some diabatic wet bulb temperature effects could allow temperatures to fall into the mid 40s but lower 40s northern areas. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/... Upper energy in Canada will merge with the upper energy currently over our region creating a larger scale upper cut off low. There will be quite a cold pool aloft tracking through our region Sunday with steep midlevel lapse rates. The upper dynamics and moisture over our region will support increasing coverage of showers and some isolated thunderstorms through the day. There could be some wet snow around the higher peaks in the mountains, and maybe some graupel or hail in some of the showers and thunderstorms in lower elevations. Any holes in the clouds Sunday morning should close as widespread convective cloud cover forms with the surface heating and the cold air aloft. Temperatures will reach the 50s to around 60. Any showers and isolated thunderstorms should end Sunday evening as the upper energy and cold pool aloft begins to exit. Clouds will still linger through much of Sunday night but some breaks in the clouds are possible toward daybreak in some areas. Boundary cold air advection spreads into our area toward daybreak and winds will rapidly increase as well. Upper energy will continue to exit Monday and the last lingering areas of the upper cold pool will also exit. Still, some shallow instability will contribute to widespread cloud cover forming through the daytime heating with some scattered showers. Best coverage of showers will once again be in higher terrain. Cold advection will spread over our region through the day and boundary layer winds will be quite strong. It will be quite windy Monday and some consideration for a wind advisory may be needed as we get closer to Monday. Highs Monday in the 50s to lower 60s. Better subsidence and clearing over our region Tuesday as high pressure builds in and boundary layer temperatures begin to warm. Winds will be lighter, too. Highs Tuesday in the lower to mid 70s but mid to upper 60s northern areas. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Much warmer air will be moving into the region for the long term period, finally allowing for an extended return to above normal temperatures. With an upper level ridge in place, 850 hpa temps will rise to +15 to +17 C by Wednesday. The high heights should help prevent much convection for forming on Wednesday, so it looks to be mainly dry across the area for Wednesday with a mostly to partly sunny sky with temps reaching into the 80s. Warm temps should continue into Thursday, but an approaching upper level shortwave over the Great Lakes could allow for some afternoon or evening showers and thunderstorms in some areas, especially for northern and western parts of the area. As the upper level shortwave slides across the area, there could be some additional scattered showers or thunderstorms on Friday. More clouds and cooler temps aloft may allow for temps to be a little cooler, but still above normal with highs into the 70s. Over the weekend, heights look to quickly rise once again as the shortwave departs off to the east, allowing for warm temperatures to move back into the region by Saturday. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... Steady light rainfall is occurring over the area with widespread MVFR conditions for both visibility and ceilings. With the heaviest rainfall south/east of the area, would expect the IFR conditions to stay away from the area as well, as conditions should primarily remain MVFR tonight. Cannot totally rule out a brief lowering to IFR from time to time, but flying conditions should mainly be MVFR overnight, with visibility in the 4-6 SM range and ceilings 1500-3500 ft. Steady rainfall should end towards daybreak Sunday, but cannot rule out some lingering showers at times into Sunday morning. Ceilings may be close to the borderline for VFR and high end MVFR at that time for all sites. Another period of steadier rain showers looks to occur on Sunday afternoon into Sunday evening, as the upper trough will be overhead. Flying conditions looks to be MVFR during that time as well for both visibility and ceilings. Light and variable winds overnight with gradually become N to NW by late in the day Sunday at 5-10 kts. Outlook... Sunday Night: Moderate Operational Impact. Windy With Gusts To 31.0 Chance of SHRA...TSRA. Monday: Moderate Operational Impact. Windy With Gusts To 36.0 Slight Chance of SHRA. Monday Night: Low Operational Impact. Breezy NO SIG WX. Tuesday: No Operational Impact. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: Moderate Operational Impact. Chance of SHRA...TSRA. && .FIRE WEATHER... An area of low pressure located along the mid Atlantic coast will strengthen and track northeast along the east coast to eastern New England through Sunday. This coastal storm will bring a widespread rainfall to the region over the weekend, along with cool temperatures. Showery, cool and breezy conditions will continue on Monday as low pressure only slowly pulls away from the eastern New England coast. Relative humidity values recover to 85 to 100 percent tonight with rain much of the night. RH values only drop to 55 to 75 percent on Sunday and recover to 80 to 100 percent Sunday night. Rh values drop to 50 to 70 percent Monday afternoon. Variable winds at 15 mph or less will shift to the northeast tonight at 5 to 10 mph and be from the northwest at 5 to 15 mph on Sunday. Winds will become north to northwest at 15 to 30 mph Monday. && .HYDROLOGY... A developing coastal storm will bring a widespread rainfall to our hydrologic service area through Sunday with generally three quarters of an inch of additional rain. Some higher amounts up to 1.5 inches area possible for areas well south and east of Albany into parts of eastern Dutchess, Berkshire and Litchfield counties. This amount of rainfall is forecast to result in within bank river rises around or short of action stage due to runoff, but flooding is not expected due to active vegetation reducing some runoff. The heaviest rain will likely fall well to the east towards coastal New England. Mainly lighter showers should linger into Monday, as the coastal storm will be slow to exit the eastern New England coast. Drier and warmer weather will finally build in towards the middle of next week. For details on specific area rivers and lakes, including observed and forecast river stages and lake elevations, please visit the Advanced Hydrologic Prediction Service /AHPS/ graphs on our website. && .ALY WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. MA...None. VT...None. && $$ SYNOPSIS...NAS NEAR TERM...Frugis/NAS SHORT TERM...NAS LONG TERM...Frugis AVIATION...Frugis FIRE WEATHER...NAS HYDROLOGY...NAS
Area Forecast Discussion
National Weather Service Bismarck ND
900 PM CDT Sat May 13 2017 .UPDATE... Issued at 858 PM CDT Sat May 13 2017 Scattered showers and a few thunderstorms moving into southwest North Dakota. So far do not anticipate severe weather but some gusty winds in an inverted V T-RH profile possible. Made some small changes to evening pops. UPDATE Issued at 527 PM CDT Sat May 13 2017 Current radar and satellite loops show thunderstorms forming off the western Black Hills of South Dakota and west into north central Wyoming. Current thinking continues to be the updraft helicity signal will support one or two strong updrafts late this evening in southwest North Dakota. Current radar and satellite support this trend. Current forecast looks good. && .SHORT TERM...(This evening through Sunday) Issued at 207 PM CDT Sat May 13 2017 The main concern in the short term period will be the chance of thunderstorms tonight. Short term and high resolution model solutions continue to show convection developing across eastern Montana, moving into western North Dakota later this evening. The Storm Prediction Center issued a marginal risk across mainly the southwest part of the state earlier, and HRRR runs continue to bring across a few isolated spots of higher 2-5km updraft helicity values during the late evening. Will continue with the current configuration in the Hazardous Weather Outlook which mentions an isolated severe storm in the southwest tonight. The best rain chances should be in the west initially, with thunderstorm chances spreading east overnight. A cold front moving across the region will continue its push east with the main chances of precipitation for Sunday shifting towards the Turtle Mountains and James River Valley. Fire weather will be something to monitor for Sunday, especially in the west where drier air will move in first. Minimum relative humidity values fall into the 20 to 25 percent range with westerly winds of 15 to 25 mph. A couple potentially limiting factors include the potential for rain tonight, and the current green up of fuels. .LONG TERM...(Sunday night through Saturday) Issued at 207 PM CDT Sat May 13 2017 The long term period will feature a large trough across the western United States through much of next week. This will eject shortwaves into the central and northern Plains with periodic chances for showers and a few thunderstorms. 12Z GEFS plumes show a large spread in QPF over the next week across western and central North Dakota with mean values in a broad 1 to 2 inch range. Overall the model blend captures expected trends and did not stray far from it`s output. It will also be cooler with highs 5 to 10 degrees below normal for Wednesday through Friday. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 652 PM CDT Sat May 13 2017 At 6 pm CDT a low pressure and associated cold front near the North Dakota and Montana borders will move east tonight. The cold front will be the focus for widely scattered thunderstorms near the KISN-KMOT-KDIK areas tonight and move east Sunday. VFR conditions will predominate through the 00Z TAF period. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...WAA SHORT TERM...CK LONG TERM...CK AVIATION...WAA
Area Forecast Discussion
National Weather Service Caribou ME
1010 PM EDT Sat May 13 2017 .SYNOPSIS... High pressure will move into eastern Canada overnight. Low pressure rides north along the east coast and will spread a soaking rain into the area Sunday morning and continue into Monday. && .NEAR TERM /THROUGH SUNDAY/... 1015 PM Update... CLouds continue to fill in w/some holes showing up across the nw and down to se sections of the CWA. Temps from the Bangor region down to the coast were in the mid to upper 40s while n of these areas, temps were in the low to mid 50s. The clouds will help to limit temps from dropping off too far overnight. Some fog developed right along the immediate coast and outer islands. Added areas of fog to the forecast overnight. The latest RAP and NAM12 soundings showed this potential w/the blyr layer moistening up. Radar loop showed the leading edge of the rain just beginning to show up along the ME/NH border. The latest RAP doing well w/this setup. Daycrew`s assessment of keeping the rain at bay til well after midnight for the ssw areas looks good. No changes made to the pops w/this update. Previous Discussion... Clouds will continue to increase and thicken this evening in advance of low pressure along the mid atlantic coast, while high pressure across the Canadian Maritimes continues to slide east. The low will track toward the northeast tonight. The air mass is still relatively dry, so it will take a while for atmosphere to moisten up, thus not expecting rain to spread downeast areas until after midnight. Concern is we could start to see some stratus and patchy drizzle developing later this evening along the downeast coast in the light southeast flow around the departing, high before the steadier rain moves in later tonight. Otherwise, the rain will slowly spread northeast across central areas by daybreak, but it will remain rain free overnight across far northern areas and the St. John Valley. Expect lows tonight to be generally in the low to mid 40s across the region. Sunday is shaping up as wet day, especially across central and down east areas, as low pressure tracks northeast toward the gulf of Maine. The rain may be locally heavy at times across downeast by afternoon, as abundant moisture gets transported ahead of the approaching low. However, across far northern Maine, especially the St. john Valley, the rain should hold off until afternoon. Rainfall amounts through Sunday afternoon are expected to range from around a tenth of an inch across far northern areas, to as much as an inch and one half across the downeast coast. East to northeast winds will keep high temperatures on Sunday well below normal for this time of year, with the warmest readings across far northern areas, where highs will range from the low to mid 50s. However, highs across downeast areas will generally be in the mid to upper 40s. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... Models cont to struggle with the Nrn cut-off of sig rnfl associated with low pres movg off the mid Atlc states to S of Nova Scotia...with every opnl 12z model run showing sig less QPF across the far N and a sharp grad of increasing QPF toward Downeast areas. Subsequently, we lowered fcst QPF across Nrn areas Sun Ngt into Mon compared to the last fcst. We did go literally with as low as this recent model run suggests attm for the far N, which is little or none, just in the event this is a spurious Srly bias model run, but it`s interesting to note that this run looks similar to what was advertised by the 6-10 day CPC outlook when this event was cntrd in pd earlier this week. Rn will taper to sct showers from N to S durg the day Mon as the upper low slowly move E to S of Nova Scotia and drier air llvl air from the N moves into the region. Sct shwrs may attms still may brush Ern and Nrn ptns of the region Mon ngt into Tue, otherwise, cldnss will be to decrease spcly ovr Swrn ptns of the Rgn. Temps will be coolest relative to avg for hi temps Mon with recovering hi temps on Tue. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... Models now indicate a pd of low and mid lvl warm advcn beginning late Tues ngt and contg right into Thu. A weak s/wv topping a building 500mb ridge could result in sct shwrs across the N and W Wed aftn into Wed ngt. Aftwrds, models now indicate a high chc that all of our region will enter the warm sector on Thu as the 500mb ridge crosses the Rgn. We raised hi temps sig upwards... but to be honest, if this scenario shown by the models were to hold as we get closer to real tm, we can see 80 deg+ hi temps Thu across all low trrn lctns N of the Downeast coast, with more sunshine then what we are advertised. For now, we show mid 70s N to lower 80s SW. We try to delay the Tmg of shwrs and possible tstms for the region til later Thu aftn into Thu eve from blended model guidance to better tm with the passage of a cold front ovrngt Thu. For now, Fri and Sat will be cooler with closer to seasonal norms for temps. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... NEAR TERM: Low pressure will track northeast from the mid atlantic region tonight through Sunday. Widespread rain will develop from southwest to northeast late tonight through Sunday, not reaching far northern Maine til after 16z Sunday. KFVE/KCAR/KPQI/KHUL...VFR tonight becoming MVFR after 16z Sunday in developing rain and decreasing ceilings. KBGR/KBHB...VFR this evening giving way to developing MVFR ceilings by 06z, with possible IFR ceilings developing in lower clouds vcnty BHB. Expect widespread IFR most of Sunday in rain and low ceilings SHORT TERM: IFR clg/vsby conditions in rn can be xpctd all TAF sites Sun ngt into Mon morn, with conditions improving to MVFR by Mon aftn and then VFR Mon ngt into Tue, with brief MVFR clgs with shwrs msly Nrn TAF sites. VFR conditions will then completely prevail Tue ngt thru Thu. && .MARINE... NEAR TERM: Winds/seas will remain below small craft levels tonight before increasing to strong small craft levels by Sunday afternoon. As low pressure intensifies and tracks toward the gulf of Maine later Sunday, a few wind gusts up to 35 kts will be possible. SHORT TERM: SCA winds and seas will cont Sun ngt into Mon aftn, then improve to below SCA conditions Mon ngt and cont so thru mid week. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...Small Craft Advisory from 8 AM Sunday to 1 PM EDT Monday for ANZ050>052. && $$ Near Term...Hewitt
Area Forecast Discussion
National Weather Service State College PA
1137 PM EDT Sat May 13 2017 .SYNOPSIS... Drier will overspread the region tonight. A pool of cold air aloft will pass over late tonight and Sunday. An anomalous upper ridge will migrate from the Mississippi Valley to the east coast next week. Much warmer temperatures will prevail for the later part of the week. && .NEAR TERM /UNTIL 8 AM SUNDAY MORNING/... All is well as the precip over the east has all but dried up and the convection from the NW is just now entering wrn PA. Things continue to break up as we lose heat, and 30-40 POPs at most will do fine for coverage. With the late clearing and rain up until that time, the light wind overnight could allow some fog to form if the air does not dry out over the east. Prev... Trapped in between the departing low to the east and the ridge to our west. The late day sunshine and residual moisture have combined to pop isold shra over the mountains. These should not last long past sunset as they are not supported by anything serious aloft. A more serious area of forcing associated with strong short wave trough crossing the lower lakes is making taller convection. HRRR pushes most of this convection over wrn PA and it takes a while to get into the Laurels/Alleghenies. Will hold just sct POPs for the night in the west. But, the cold pool and best forcing will be overhead by morning. While most of the convection will be to our N/E, POPs of likely or better seem on order for the nrn tier later tonight. Still a few strikes of ltg as it crosses the lake, where water temps are cooler than the ground. So, a bolt or two is not out of the question - but more so to the north of central PA. && .SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/... Upper low tracks over upstate NY on Sunday, while pool of cold air aloft combined with diurnal heating results in isolated to scattered mainly afternoon showers especially over the northern tier counties. Expect some gusty winds to mix to the surface by Bufkit soundings support frequent gusts in the 25-30kt range. Partly sunny skies and deeper mixing will result in a milder Sunday, but max temps should still fall several degrees short of climo. && .LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/... A deep upper level low will drop southeast on Sunday across the northeast on Sunday. Gusty winds will likely prevail into Monday, given the dynamics of the system. Did extend the showers into Sunday evening, given the cold air aloft, even with the low dewpoints. General thunder fcst further north. Did lower temperatures a tad Sunday Night and Monday Night, but did up a degree higher or so for Monday. Main change was to take out showers and storms for Tuesday and Wednesday, given the EC is dry, and strong height rises occur, as an anomalous upper ridge builds over the eastern states. Above normal temperatures for several days. Model consensus drops a dying cold front into the area on Friday. Slightly cooler weather to follow. There still could be a few showers or storms with the front trying to work back northward next weekend. 00Z EC show a hint of a QPF max across the southeast part of the CWA next Friday. Not seeing that on the 12Z EC run, but did not want to go with no weather at this point. The main thing is to get a few warm and dry days, so folks can get outside projects done, and area fields can dry out. Much wetter than last year across the north and west. && .AVIATION /02Z SUNDAY THROUGH THURSDAY/... The low has moved to the northeast as dry northwesterly flow has overtaken the region. For the most part skies have gone VFR. The last vestiges of low level moisture has brought MVFR to LNS and MDT with IFR to IPT. With low dewpoint depressions and light winds overnight, expect IFR and lower to continue at IPT until the winds can mix out tomorrow and the strong northwesterly winds to dry the lower levels. As temperatures drop tonight, MVFR to periods of IFR remain possible, especially after 09Z as a short wave trough will move through. Cigs and vsbys will improve between 13Z to 16Z. NW winds pick up to breezy/windy levels as we slip back into a more winter- like flow pattern with restrictions confined to the NW half of CWA. Scattered rain showers develop over NE 1/3 of CWA in the coldest air aloft. .OUTLOOK... Sun-Sun Night...Cig restrictions likely BFD/JST, and poss at times into the Central Mtns. Becoming windy. Mon...Breezy. No sig wx. Tue-Thu...No sig wx expected. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Dangelo NEAR TERM...Dangelo SHORT TERM...DeVoir/Fitzgerald LONG TERM...Martin AVIATION...DeVoir/Ceru
Area Forecast Discussion
National Weather Service Grand Forks ND
941 PM CDT Sat May 13 2017 .UPDATE... Issued at 939 PM CDT Sat May 13 2017 No changes to temperatures tonight as breezy winds will keep temps warm tonight, generally in the mid 50s. Did update sky as NW zones are seeing mid level cigs move across rgn...and populated with 12Z Canadian which has a reasonable handle on sky for tonight while hi-res models are too clear. UPDATE Issued at 640 PM CDT Sat May 13 2017 Several changes to Tomorrow period made on early evening forecast. Inherited temps did not reflect recent cool trend in SuperBlend and have bumped up Sunday temps across entire domain. Made adjustments to old sky grids with the latest RAP guidance and populated winds with latest time lagged CONSSHORT as wind shift tomorrow will impact aviation grids. No changes to POPs at this time but they may be a bit too aggressive on timing into western zones. Will see how 00Z runs look before adjusting. && .SHORT TERM...(This evening through Sunday) Issued at 252 PM CDT Sat May 13 2017 Expect fair skies and seasonably mild and dry conditions through the remainder of the afternoon and evening. Gusty southeast winds, warm temperatures, and low humidity levels will keep the threat for wildfires somewhat elevated until early evening. Overnight... a low pressure system will deepen into the western Dakotas late this evening and slowly edge eastward into the central Dakotas by mid morning. Along and ahead of this system expect to see increasing mid level cloudiness and scattered rain showers developing... with an isolated thunderstorm or two possible. Low temperatures should settle into the upper 40s near the Canadian border and into the lower 50s nearer the South Dakota border. Scattered showers should spread into eastern ND on Sunday forenoon and spread across the Red River Valley by midday. This band of scattered showers and isolated thunderstorms should continue to edge eastward across northwest MN through the afternoon...with sunshine returning in the west. Rainfall accumulations should be spotty with a few hundredths to a tenth of an inch or so most likely... and mainly north of the I-94 corridor. Otherwise patchy and warm sunshine should be evident as well... with high temperatures ranging from the upper 60s near the Lake of the Woods to the lower 80s in the southern Red River Valley. .LONG TERM...(Sunday night through Saturday) Issued at 252 PM CDT Sat May 13 2017 Sunday night through Saturday... An active pattern is still on tap for the upcoming week with multiple opportunities for precipitation. The main upper ridge that dominated the central portion of the country throughout the weekend will finally begin to slide off to the east by Sunday night. Southwest flow aloft then sets up which will contribute to the upcoming active pattern. A weak wave following on the heels of the upper ridge will allow some minor precipitation chances to linger Sunday night and into early Monday. A small area of high pressure looks to quickly pass through between stronger waves with the possibility of a brief break in precipitation chances later on Monday. The main precipitation producer for the week continues to be the system(s) arriving late Monday and lingering into Wednesday. The first of two surface low pressure systems set to impact the area during this time frame quickly pulls out of the eastern Rockies and deepens as it propagates off to the north and east. Respectable instability parameters and shear profiles suggest a decent chance for thunderstorms (especially across the south, at least with the current surface low track) for Tuesday afternoon and evening. A secondary low looks to develop on the heels of the first in the Tuesday night and Wednesday time frame, bringing additional precipitation chances. Models runs currently depict the track of the second low to pass further south and east than the first which will be a factor in who sees the best storm chances. Regardless, between the two systems, a fairly widespread area of an inch or more of rainfall is likely with higher amounts in any convection. Thursday looks to be the driest day of the week as upper ridging briefly builds back into the area. Yet another system is progged to push through the region to end the work week and start the weekend. Monday will bring one last day of above normal temperatures in the 70s or low 80s. Tuesday will bring slightly cooler temperatures before more cooler air is ushered into the area by Wednesday with highs struggling to reach out of the 50s or 60s for the remainder of the week. However, lows should remain relatively mild with plenty of clouds and moisture sticking around. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 640 PM CDT Sat May 13 2017 VFR. A cool front will bring a band of showers and possibly a TS across region tomorrow, but not enough confidence on timing to mention in sites east of DVL at this time. Expect associated cigs to be in the low VFR range...with wind shift being primary aviation issue. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...None. MN...None. && $$ UPDATE...Speicher SHORT TERM...Gust LONG TERM...Lee AVIATION...Speicher
Area Forecast Discussion
National Weather Service Green Bay WI
1037 PM CDT Sat May 13 2017 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Sunday Issued at 239 PM CDT Sat May 13 2017 A NW-SE orientated band of weak radar returns persist across the forecast area late this afternoon. This benign activity is in association with LFQ of upper jet and associated weak shortwave impulse moving southeast across the area within a region of rather steep low-level lapse rates. However, as indicated by the 12UTC GRB sounding this morning, atmosphere below 700 mb quite dry thus any precipitation is struggling to reach the surface. HRRR and NAM-Nest are in agreement that weak upper-level forcing and associated weak surface low currently exiting eastern Wisconsin, will continue to move southeast away from the forecast area, while surface high pressure begins to build in from the north overnight. Any light sprinkles should come to an end by sunset. Associated mid-level cloud deck over the forecast area actually extends northwest across the Minnesota Arrowhead back to Lake Winnipeg. These clouds are associated with some weak mid-level frontogenetic forcing and weak WAA along NW-SE orientated thermal gradient. Short-range guidance suggests these clouds will be a bit slower to depart but should gradually work their way east across the forecast area as the mid-level ridging continues to push east toward the area later tonight and Sunday. Did tweak min temps up a notch overnight given some mid-clouds, but pretty much stayed close to short-term model blend. On Sunday, upper ridge axis will continue to move toward the state with surface high pressure ridge axis drifting over Lake Michigan by around 18 UTC Sunday. In response, boundary layer southeasterly winds should become well established across most of the forecast area. This should result in somewhat cooler temperatures especially over eastern and eastcentral portions of the forecast area. Meanwhile further upstream, southerly flow will be on the increase upstream of an elongated area of low pressure over the northern and central Plains. This will result in a strengthening warm front extending from northern Illinois, far southwest Wisconsin to southcentral Minnesota. A few of the high resolution models are trying to even generate a few light showers or sprinkles near the frontal boundary well to our south Sunday afternoon. However, atmosphere is still initially dry so did not buy that signal. Overall, Sunday should be a fairly nice spring day with a notable temperatures contrast from southwest to northeast across the forecast area. Using blended model guidance gives highs ranging from around 75 in the southwest to the upper 50s along the lakeshore and bay where increasing gradient southeast winds will keep temperatures quite a bit cooler. .LONG TERM...Sunday Night Through Saturday Issued at 239 PM CDT Sat May 13 2017 Pattern change starts Sunday night as an upper ridge and surface high pressure region drifts east over the Great Lakes region. The departing upper ridge and developing southwest flow in its wake will bring a warmer and more active pattern to the region for the start of the new work week. Progs are already spilling some light precipitation into northwest Wisconsin over the ridge late Sunday night with the warm air return. Will continue the small chance of convection for north central Wisconsin after midnight. Upper ridge further weakens Monday across the northern Great Lakes region with the passage of a short wave trough. A developing frontal system Monday into Tuesday will slowly lift a surface warm and 850 warm front northward across the state. The warm front will be a primary location of convection Monday night and may linger across the north Tuesday. Convection may be on the increase again over the northwest half of the state as a surface boundary approaches. Progs then suggest a more significant short wave trough to track across the region Wednesday night as a cold front slides through. Quieter weather appears to be likely the rest of the week as a cold front drops south of the area and an upper ridge builds into the area. Another frontal system takes aim for the area toward the weekend for more showers and storms. && .AVIATION...for 06Z TAF Issuance Issued at 1036 PM CDT Sat May 13 2017 Quiet weather with good flight conditions will continue. Middle level clouds that were streaming across the area should gradually shift off to the east. Winds will be relatively light tonight, then pick a little from the east/southeast tomorrow. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....ESB LONG TERM......TDH AVIATION.......Skowronski
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
707 PM CDT Sat May 13 2017 .SHORT TERM...(This evening through Sunday) Issued at 313 PM CDT Sat May 13 2017 The HRRR was the basis for the thunderstorm forecast tonight. A blend of the GFS...NAM...GEM and SREF produced no rain chance so that forecast strategy was discarded in favor of a more aggressive soln. Steep mid level lapse rates are in place across the Panhandle with accas showing on visible satellite. The HRRR suggests the Cheyenne and Palmer divides and Pine Ridge will be the genesis for isolated thunderstorm development late this afternoon and this evening. The air across Ncntl Nebraska is forecast to remain quite stable and capped at around 12C at h700mb tonight. This should confine any storm development to Wrn Neb. Any strong storms which develop could produce gusty winds with cloud bases around 750mb. The RAP model suggests the best instability will be across Swrn Neb with favorable shear. An isolated severe storm with hail and wind could develop. The blended guidance plus bias correction suggests highs in the 70s to lower 80s Sunday. Deep vertical mixing is expected with north winds. Any rain chance should be south of the front across ern Neb and KS. .LONG TERM...(Sunday night through Saturday) Issued at 313 PM CDT Sat May 13 2017 The NAM and GFS generate a MCS Sunday night while the GEM and ECM are dry. The post-frontal upslope theta-e advection is too much for the american models and they generate convection. The model blend suggests a 30-40 POP Sunday night. Storms should form in Ern WY late in the afternoon and move into the Panhandle in the evening. The storm mode would be sfc based in the early evening becoming elevated after dark. The mixed layer and elevated instability is weak in the GFS and modest in the NAM. Shear calculations are complicated by the upslope easterlies beneath strengthening southwest winds aloft. SPC suggested just a general thunderstorm outlook with a conditional severe weather threat. The question is whether or not the upslope winds in the models are too moist. Just isolated thunderstorm chances are in place Monday night with the NAM...ECM and GEM dry and the GFS developing storms across Scntl Neb and SD. A fairly significant thunderstorm chance develops late Tuesday and Tuesday night. The better severe weather chances (high CAPE and shear) are over ern Neb. The GEM...GFS and ECM are in reasonable agreement except for slower evolution in the GEM and ECM which continue the convection throughout the day Wednesday. The blended soln or model consensus suggested a 30 to 40 POP Tuesday through Wednesday. Chance to likely POPs are in place Thursday for the big upper level low forecast to affect Wrn and Ncntl Neb through Friday. The best rain chance is late Thursday and severe weather is likely across KS. Nebraska may be post-frontal and this would limit sfc based instability and reduce the overall threat for organized severe thunderstorm development. && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 701 PM CDT Sat May 13 2017 Main aviation concerns will be isolated thunderstorms in the northwest Nebraska Panhandle and strong southerly winds decreasing tonight and low level wind shear developing. Thunderstorms in the Panhandle will dissipate after sunset and should only pose a marginal threat for strong gusty winds before then. Strong southerly winds will diminish through sunset but will not completely decouple. Low level southerly jet developing around 850mb will create wind shear over western Nebraska tonight. A cool front will push through from the northwest on Sunday with winds swithching to the northwest at 15 to 25 mph with higher gusts. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...CDC AVIATION...Power
Updated for 00Z Aviation Forecast Discussion below.

&& .PREV DISCUSSION... /issued 227 PM CDT Sat May 13 2017/ DISCUSSION...Surface analysis places a ridge of high pressure centered over Southwest Missouri this afternoon. This has resulted in sunny skies across the Mid-South with clearing occurring across extreme Northeast Mississippi and temperatures as of 2 PM CDT in the 70s at most locations. Surface and upper level ridging will continue to build across the Mid-South tonight through Tuesday. This will bring rain free weather along with pleasant temperatures with lows tonight in the 50s and highs on Sunday rising back into the lower 80s. A gradual warming trend is expected into next week. Latest long term model trends indicate the upper level ridge will begin to move east for mid to late next week. This will allow for the Lower Mississippi to be positioned on the western periphery of the upper level ridge axis along with a return of isolated to scattered showers and thunderstorms, especially along and west of the Mississippi River into next weekend as a series of mid-level shortwaves move across the region within southwest flow aloft. CJC && .AVIATION... 00Z TAFs Relatively dry surface high pressure will settle over the Midsouth overnight. 22Z HRRR suggest some patchy fog possible near JBR, with the pressure ridge centered along and west of the MS River at 12Z. Otherwise, VFR will prevail areawide through the next 24 hours. PWB && .MEG WATCHES/WARNINGS/ADVISORIES... AR...None. MO...None. MS...None. TN...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service Miami FL
835 PM EDT Sat May 13 2017 .UPDATE... Miami tied a record high today of 93 degrees, last reached on this date in 1985. The line of showers and thunderstorms associated with the weak cold front has mostly dissipated over most of Central Florida this evening, except for some showers and a few thunderstorms near Venice, FL. The weak cold front will continue to move southward tonight and should be around Lake Okeechobee region by early Sunday morning before moving through South Florida on Sunday. The latest HRRR and MET models are now showing not much activity over South Florida tonight, except for some showers and a few thunderstorms along the western areas late tonight as the front approaches South Florida. The HRRR and MET models are also showing less activity over South Florida on Sunday, as the deeper moisture is now forecast to be over the Atlantic waters. Therefore, the pops have been lowered for tonight and on Sunday over South Florida. The thunder wording has been removed for the eastern areas for tonight and lowered to a slight chance for the western areas for late tonight. The threat of thunder has also been lowered to a slight chance across South Florida on Sunday. Rest of the forecast looks good at this time and no other changes are planned. .AVIATION... The winds will be southwest tonight into Sunday over all of South Florida taf sites. The speeds will be around 15 knots until 02Z tonight before decreasing to around 5 mph for rest of tonight. The speeds will then increase to around 10 mph on sunday at all of the taf sites. The weather should remain dry over the east coast taf sites tonight with VCSH at KAPF taf site after 06Z tonight. On Sunday, showers will be around but the coverage of thunderstorms will be few and far between. Therefore, VCSH will be in the taf sites for Sunday and will keep out thunderstorm conditions at this time. The ceiling and vis should remain in VFR conditions through Sunday, but could fall down into MVFR conditions with any passage of shower or thunderstorm activity. && UPDATE...54/BNB AVIATION...54/BNB .PREV DISCUSSION... /issued 345 PM EDT Sat May 13 2017/ DISCUSSION... In the near term, moderate southwest winds this afternoon have held the Atlantic sea breeze up near the I-95 corridor. Just enough moisture is in place for isolated to scattered showers to develop along the sea breeze particularly in the area of strongest convergence over metro Palm Beach and Broward Counties. Any showers should dissipate or move offshore around sunset. Radar and satellite data at mid afternoon showed an area of rain and thunderstorms near the Interstate 4 corridor in Central Florida extending back into the central Gulf of Mexico. This activity was out ahead of a front extending from central Georgia into the central Gulf. This evening and tonight, expect this activity to continue slowly sinking southward toward the area, but should not enter the Lake Okeechobee region until late tonight as the front finally approaches. Along with numerous showers ahead of the front, a plume of deep moisture entrained in the deep southwesterlies ahead of the front, along with sufficient instability as indicated by forecast soundings, should allow for isolated to scattered embedded thunderstorms. Sunday, the front begins to wash out as it moves through the area. The remnant trough will continue to push slowly southward, promoting numerous showers and embedded thunderstorms along and ahead of it during the morning. Models are in good agreement the trough should be approaching the southern tip of the Florida peninsula by mid afternoon, limiting the best chances for rain to that part of the region late in the day. Behind the trough, however, sufficient moisture may remain for additional isolated showers at peak afternoon heating Sunday. Over the coming work week, a mostly quiet and dry weather pattern will be in place as a deep ridge of high pressure settles over the southeast states. Monday winds should be dominated by the Gulf and Atlantic sea breezes, but as the high develops the region will see gradually increasing and deepening easterly flow. Just enough low level moisture will be in place for isolated to scattered passing showers from time to time, but no strong forcing showing up for organized rain or thunderstorm activity. MARINE... Moderate southwesterly winds this evening and overnight ahead of an approaching front. The front will wash out into a trough as it moves across the area late tonight and Sunday, bringing numerous showers and a few thunderstorms. Winds will slacken Sunday but may be locally gusty near any thunderstorms. Mostly light winds over the area waters Monday, but a ridge of high pressure will build north of the region through the week, with easterly winds steadily increasing to moderate to fresh levels by the end of the week. AVIATION... Expect all east coast sites except KTMB to go SSE or SE by 19Z at 10-13kts with seabreeze. KAPF and KTMB remain SSW 10-12kts. All sites may see gusts to 20kts through sunset. Isold TSRA/SHRA with late afternoon seabreeze collision along east coast, with best chances near KPBI where have added VCSH 22Z-00Z. Winds diminish and become SSW 5-8kts after 00Z. Front approaches late tonight, with VCSH for KAPF after 14/09Z, and for KPBI-KFXE- KFLL after 14/15Z. TSRA threat too low to mention at time, but may need to be added later as front approaches. FIRE WEATHER... Although relative humidity values are staying above 40 percent this afternoon, gusty southwest winds are promoting very good to excellent dispersion. Winds will slacken overnight and there will be a good chance of showers developing as a weakening front moves into the area. Embedded thunderstorms late tonight into Sunday morning may bring a few lightning strikes and gusty/erratic winds. As the front washes out south of the area Sunday afternoon, slightly lower humidity and 20 ft westerly winds around 10 mph will filter into the Lake Okeechobee region. If drier air moves in faster than expected or a break in the clouds can boost temperatures more than expected, critical conditions may develop for a few hours Sunday afternoon particularly around Glades County. Over the work week, minimum relative humidity values over the interior will be near 40 percent each afternoon. Wind speeds generally under 10 mph early in the week will get a bit stronger later in the week as a ridge of high pressure builds north of the area. Depending on how much rainfall this area receives this weekend and later coordination with forestry officials on the status of fuels, borderline critical conditions may be a concern any afternoon over interior sections. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 72 90 70 90 / 20 50 20 20 Fort Lauderdale 75 88 74 90 / 10 50 10 20 Miami 74 90 73 91 / 10 50 20 30 Naples 74 87 71 87 / 40 40 10 10 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && UPDATE...54/BNB DISCUSSION...22/KS MARINE...22/KS AVIATION...54/BNB FIRE WEATHER...22/KS
Area Forecast Discussion
National Weather Service Pueblo CO
305 PM MDT Sat May 13 2017 .SHORT TERM...(This evening through Sunday) Issued at 304 PM MDT Sat May 13 2017 Dry and breezy to windy conditions expected over the next couple days as persistent upper trof remains in place along the west coast. Weak shortwave lifting out across CO this afternoon is progged by short range models to initiate thunderstorms along a dry line across the southeast plains in both the hrrr and 4km NAM. Overall not much CAPE to work with...and inverted V soundings suggest gusty winds up to 45 mph and lightning will be the primary storm threats. Other high based -SHRA/-TSRA will be possible over the mountains but these should remain pretty isolated in coverage. All activity winds down during the evening with a mild night in store as lee troffing keeps min temps in the upper 40s lower 50s across the lower elevations with a mix of 30s and 40s for the high country. Sunday should be a few degrees warmer still with south to southwest winds mixing down again during the afternoon. Appears to be even less moisture to work with tomorrow. Will have to watch the far east plains for potential thunderstorm development along an advancing dry line...but for now it appears best chance will be over the border in KS. Otherwise another day for highs in the 80s, even pushing 90 across the far southeast plains. -KT .LONG TERM...(Sunday night through Saturday) Issued at 304 PM MDT Sat May 13 2017 Sunday night through Tuesday...Southwest flow will continue across the region as the upper low pressure trough sits over the West Coast...pushing limited moisture into the state. An upper shortwave is forecast to cross the Great Basin Tue morning, and Colorado Tue aftn and eve. Therefore, warm sw flow and limited moisture with isolated dryline convection along the KS border will be the case for Mon, then more cloud cover and increasing pcpn chances over the mts as the shortwave crosses on Tue. Winds will become gusty at times both Mon and Tue afternoons, but do not believe that fuels are at the point to being receptive to carrying fire, so no fire wx highlights at this time. Look for high temps in the 70s for the high valleys and 80s to near 90F for the plains on Mon, then 60s for the high valleys and 70s to mid 80s for the plains on Tue. Wednesday through Saturday...A strong upper low pressure system drops southeast across ID on Wed, then sits over UT and CO on Thu and Fri before ejecting off to the northeast across NE on Sat. Current model runs indicate that the majority of the dynamics and activity associated with this system will remain north of the forecast area, but it should still remain somewhat active with scattered showers and thunderstorms over the higher terrain through Fri, and isolated activity over the plains. As the system exits the region on Sat, pcpn potential will drop off dramatically. As for temps, expect max temps in the 60s for the high valleys and upper 60s to near 80F for the plains on Wed. As the low nears then passes overhead, temps will be cooler and only climb into the 50s and 60s for most areas, and into the lower 70s near the KS border, for Thu through Sat. Moore && .AVIATION...(For the 00Z TAFS through 00Z Sunday evening) Issued at 304 PM MDT Sat May 13 2017 Main concern for TAF sites over the next 24 hours will be timing of gusty south to southwest winds. Winds will gust up to 25-30 kts at all three terminals until 02-03z this evening before decoupling with speeds under 8 kts. A weak front back doors into northern portions of the southeast plains late tonight and could bring a brief window of southeast winds under 10 kts to KCOS and KPUB Sunday morning. But as the front lifts back to the north...gusty south to southwest winds will mix back down into KCOS by 18z...and into KPUB by 20-21z. KALS will see winds increase from the south around 18z on Sunday. All three taf sites could see gusts in the 25-30 kt range Sunday afternoon. Otherwise VFR conditions expected. -KT && .PUB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...KT LONG TERM...MOORE AVIATION...KT
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
525 PM MDT Sat May 13 2017 .DISCUSSION...(This Evening Through Saturday) Issued at 213 PM MDT Sat May 13 2017 Latest water vapor imagery shows an upper ridge centered over western South Dakota with an upper low moving onshore over the Pacific Northwest. There is a long wave trough extending southward from the Pacific northwest low down to the Baja Peninsula. At the surface, there is an area of low pressure just north of the Black Hills with a cold front extending through central Wyoming and a warm front along the North/South Dakota border. 19Z radar imagery is showing the surface low in southern Meade County, just north of Ellsworth, with the cold front and wind shift just northwest of Rapid City. It is also showing the convergence boundary along the eastern foothills where convection is anticipated to develop this afternoon. For this afternoon and evening, low level instability combined with convergence along and the cold front and eastern foothills will allow some showers and storms to develop. Models indicate cap this afternoon first erodes over northeastern Wyoming and in the central/southern Black Hills with MLCAPE around 1000 J/KG. RAP model shows some energy at 700mb in the downstream convergence zone of the Black Hills, but water vapor imagery indicates the main bulk of the energy will be associated with the shortwave currently over northern Wyoming that moves through southeastern Montana and southwestern North Dakota overnight. Isolated strong to severe storms will be possible with activity moving off the Black Hills and Bighorn Mountains spreading into northeastern Wyoming and northwestern South Dakota this evening. Given deeply mixed, but drier boundary layer, the main threat will be gusty winds and marginally severe hail. The cold front should move through most of the forecast area overnight. On Sunday, models indicate the front will extend through central South Dakota during the morning before moving well east by Sunday evening. Temperatures will remain above normal behind the front, but will be about 10 cooler than Saturday. Will see gusty northwest winds behind the front continuing into the early afternoon hours, especially across the western South Dakota plains. A weak shortwave moves through Sunday night, with 250 J/KG of MUCAPE available. This should allow a few showers/isolated thunderstorms to develop, especially over southwestern and south central South Dakota. Southwest flow aloft will bring an active and unsettled pattern for the upcoming week. For Monday through Wednesday, several upper level shortwaves will move through the flow combining with the weak diurnal instability to bring daily chances of showers and thunderstorms. For Thursday and Friday, models continue to be in good agreement bringing the upper low from the Rockies into the northern Plains. Current track of the low would indicate the forecast area would see beneficial precipitation with this system. Temperatures over the higher Black Hills and Bear Lodge Mountains indicate the possibility of snow. Will continue to watch this closely. Overall, temperatures will be chilly for May by the end of the week. && .AVIATION...(For the 00Z TAFS Through 00Z Sunday Evening) Issued At 520 PM MDT Sat May 13 2017 Scattered showers and thunderstorms will continue through the evening hours across northeast WY and the Black Hills area. IFR conditions are possible in and near any heavier showers. A cold front will move east across the rest of the area tonight and bring areas of MVFR cigs overnight, especially across northeast WY, the Black Hills, and far northwest SD. Gusty northwest winds of 20 to 30 knots can be expected for a few hours after the frontal passage overnight. VFR conditions should return to most locations by Sunday morning after 14Z. && .UNR WATCHES/WARNINGS/ADVISORIES... SD...None. WY...None. && $$ DISCUSSION...MLS AVIATION...15