Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/27/17

Area Forecast Discussion
National Weather Service Albany NY
1025 PM EDT Mon Jun 26 2017 .SYNOPSIS... An upper level disturbance will move across the region this evening with mainly isolated to scattered showers and thunderstorms. An upper level low and a cold front will bring additional scattered showers and isolated thunderstorms on Tuesday, with cooler than normal temperatures. High pressure will build in from the Mid Atlantic Region by Wednesday, but temperatures will still run slightly below normal for late June. A warm front approaching from the southwest will bring more showers and possible thunderstorms for Thursday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... As of 1015 PM EDT, scattered convection continues with a couple line segments moving through mainly north of the mid-Hudson Valley. While expectations are this convection to slowly diminish through the late evening hours, H2O vapor loop reveals an enhanced mid level jet rounding the base of the upper low. Some showers have developed across eastern PA which per the HRRR may bring another round of showers just south of Albany overnight. For now, we will introduce a slight chance PoP and monitor trends. As for temperatures, where convection did occur these values did drop back rather quickly. Overnight lows look good per previous excellent forecast with no changes at this time with regard to overnight lows. Did add some patchy fog to the forecast/grids as well with moist lower level environment, especially where precip occurred. Prev Disc... Latest WV satellite imagery suggests one small upper level impulse tracking E/NE along the southern shore of Lake Ontario, with another tracking E/NE across Lake Erie. The combination of these two impulses will allow a continuation of isolated to scattered showers/isolated thunderstorms to linger well into this evening for areas mainly near and north of I-90, with much less coverage, if any, to the south, which will be farther from upper level dynamics and instability. Again, any taller convective elements will continue to have the potential to produce small hail/locally gusty winds this evening, especially if any cells merge into small line segments/clusters. Convection should diminish toward and especially after midnight, with partly cloudy skies continuing. Some patchy fog could form in any areas which receive appreciable showers this evening. It will be cool once again tonight, with lows mainly in the 50s. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY NIGHT/... Tuesday, the main upper level trough is expected to slowly translate east across the region during the late morning and afternoon hours. The combination of forcing ahead of this feature, and developing low/mid level instability with the cold pool aloft and any breaks of morning sunshine should once again contribute to scattered showers/isolated thunderstorm to develop in the late morning through early evening hours, with the greatest coverage once again expected mainly from the I-90 corridor and points north. Also, with low wet bulb zero heights and still relatively strong winds aloft/evaporational cooling potential, will continue mention of gusty winds/hail with thunderstorms. Forecast soundings suggests similar SB CAPE values to today, generally reaching 400-800 J/Kg, perhaps locally higher where dewpoint pooling occurs. Highs should reach the lower/mid 70s in valleys, with mainly 60s across higher terrain, however temperatures will likely fall into the 50s/lower 60s once the core of any showers/storms pass by. Tuesday night, any lingering convection should diminish fairly quickly after sunset, with some clearing expected. Once again, it will be cool, and some patchy fog will likely form in some areas where appreciable showers occur prior to any clearing. Lows mainly in the 50s, with some 40s possible, especially across higher terrain. Wednesday-Wednesday night, although the main upper level trough should finally move east of the region, lingering cold air aloft and possible weak disturbances rotating south/southeast on the west side of the departing trough could initiate isolated showers or perhaps a thunderstorm across portions of the southern Adirondacks, the Lake George region and southern VT in the late morning through afternoon hours. Otherwise, mainly sunny and a bit warmer, with highs reaching 75-80 in valleys, and upper 60s to lower/mid 70s across higher elevations. For Wednesday night, clear to partly cloudy, with clouds more likely to increase toward daybreak. Lows mainly in the 50s. Thursday-Thursday night, increasingly active weather expected once again, as a warm front approaches from the southwest. A strong low/mid level jet max, with H850 winds 40-50 KT, will impinge on western areas by late morning, and most central and northern areas by afternoon. There could be some form of an MCS spreading across central/northern areas late morning into the afternoon, possibly in a weakening form, although new convection could refire along its southern edge given the strong low level warm advection. Trends will have to be watched. For now, certainly expect showers and some embedded thunderstorms to develop from W to E across the region during the late morning through afternoon hours, with additional clusters of showers/thunderstorms potentially continuing well into Thursday night, especially for areas near and north of I-90 where the greatest forcing from warm advection should occur. Highs Thursday mainly in the 70s, although some southern areas could surge into the 80s late in the day depending on the placement of the warm front, with mainly 60s expected for lows Thursday night. && .LONG TERM /FRIDAY THROUGH MONDAY/... Active weather is anticipated through the duration of the long term period, with the potential for showers and/or thunderstorms each day. At the start of the long term period, our region will be situated within W-SW flow in the low to mid levels, allowing 850 hpa temps will have warmed up to about 16-18 degrees C. A flat ridge will be in place over the area, and some subtle disturbances at 500 hpa will be sliding through the fast flow aloft. Despite no nearby surface boundaries, daytime heating will allow for scattered showers and thunderstorms to develop on Friday, especially across the higher elevations, and then drifting into the valley areas. While not everywhere will see a shower or t-storm, there is the chance for a brief one to occur just about everywhere across the area, with temps rising into the 80s. It will also feel rather muggy with dewpoints well into the 60s to near 70 F. While the chance for showers/t-storms may slightly diminish on Friday night, there will be another good chance to see some showers and thunderstorms on Saturday, especially for northern areas, as a pre-frontal trough starts to approach the area from the west. With the warm and humid airmass in place, will need to watch for some locally strong to severe t-storms on Saturday afternoon, although this will ultimately depend on the exact amount of instability and shear in place. It looks to be another warm and muggy way with highs well into the 80s once again. As low pressure passes by to the north across southern Canada, a cold front will be passing through the area on Sunday. This will allow for some additional showers and thunderstorms. If the timing on the latest 12Z GFS is correct, the best chance would be early in the day, although this is certainly subject to change, as timing differences can be expected this far out. Behind the front, somewhat less humid air will start to work into the area. Still cannot totally rule out a stray shower thanks to a nearby upper level trough, but most places look dry behind the front on Monday with temperatures near seasonable levels. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... A quick update to the KALB-KGFL TAF`s. For KGFL, an area of clearing before the next potential round of clouds and showers have allowed for IFR conditions to quickly evolve. As for the line(s) of showers, the deeper convective elements appear to be tracking south of ALB yet we will place a TEMPO group for the next few hours to account for lightning activity that may evolve. Otherwise, a couple rounds of showers are possible north of KPOU through this evening. While VFR conditions should prevail through the TAF forecast cycle ending 00Z Wednesday, some exceptions could occur with patchy fog development overnight and shower potential through the daylight hours Tuesday with mainly lower CIGS. Winds diminish to less than 6 Kt tonight. Winds become south to southwest Tuesday morning at less than 10 Kt. Outlook... Tuesday Night: Isolated SHRA...TSRA. Wednesday: Low Operational Impact. Breezy NO SIG WX. Wednesday Night: No Operational Impact. NO SIG WX. Thursday: High Operational Impact. Likely SHRA...TSRA. Thursday Night: High Operational Impact. Likely SHRA...TSRA. Friday: Moderate Operational Impact. Chance of SHRA...TSRA. Friday Night: Moderate Operational Impact. Chance of SHRA...TSRA. Saturday: High Operational Impact. Likely SHRA...TSRA. && .FIRE WEATHER... An upper level disturbance will move across the region this evening with mainly isolated to scattered showers and thunderstorms. An upper level low and a cold front will bring additional scattered showers and isolated thunderstorms on Tuesday, with cooler than normal temperatures. High pressure will build in from the Mid Atlantic Region by Wednesday, but temperatures will still run slightly below normal for late June. A warm front approaching from the southwest will bring more showers and possible thunderstorms for Thursday. The RH values will recover to 85-100 percent overnight, dropping to values in Tuesday afternoon will be in the 35 to 60 percent range. The winds will from the southwest to west at 5 to 10 mph tonight. The winds will increase from the southwest to northwest at 5 to 15 mph Tuesday. Winds will be stronger, and variable in direction in and near any thunderstorms. && .HYDROLOGY... No widespread hydrological problems are anticipated over the next several days. Scattered showers and isolated to scattered thunderstorms are expected this evening through Tuesday, mainly during the afternoon and evening hours, as a series of disturbances impact the region with an upper low. Basin average rainfall amounts will generally be a tenth to a quarter of an inch in some locations. A brief period of mainly dry weather is expected most of Wednesday into Wednesday night with ridging from the south. An active pattern sets up Thursday into the weekend with showers and thunderstorms possible with increasing humidity levels. Rainfall amounts will vary based on where any convection occurs. The most widespread potential rainfall is expected Thursday and Saturday. 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...KL/Wasula NEAR TERM...KL/BGM SHORT TERM...KL LONG TERM...Frugis AVIATION...BGM/NAS FIRE WEATHER...KL/Wasula HYDROLOGY...KL/Wasula
Area Forecast Discussion
National Weather Service Dodge City KS
614 PM CDT Mon Jun 26 2017 ...Updated Aviation... .SHORT TERM...(This evening through Tuesday) Issued at 157 PM CDT Mon Jun 26 2017 Early this afternoon, northwest flow aloft was occurring across western Kansas. There was a jet streak within this flow aloft extending from South Dakota into northern Missouri, and this perturbation was pushing southeast. A weak frontal push at the surface could be identified in the observations at 18z, and GOES-16 visible satellite confirmed growing cumulus field along this boundary across southwest Nebraska. At 1830z, a small severe storm had developed in the Holdrege area, which was moving almost due south. For late today and tonight, will be carrying 20-30 POPs up along I-70 as this activity is expected to continue to expand a little bit in coverage where cumulus was forming west of this initial storm toward Holyoke, CO (and points southwest from there to the Palmer Divide). There is not the upper support farther west to warrant a prolonged cluster of severe convection. Numerous runs of the HRRR so far today show a general lackluster performance of convection from this region as it moves southeast through the late afternoon and by evening, dissolve convection all together just about everywhere by sunset. Also watching a mesoscale area of surface convergence across far southwest KS, but again the short-term convective allowing models (CAMs) just do not suggest much in the way of sustainability of any convection down in that area. Nevertheless, will maintain some 15-20 POPs across the rest of southwest KS as any little zone of convergence could initiate a storm that grows into something fairly strong, if not borderline severe, in the area south of the Arkansas River. Any longer lived storms up north could produce up to ping pong or even golfball size hail before weakening. Going into Tuesday, the flow pattern changes to more of a west- northwest pattern, but the surface flow pattern will be radically different as a substantial leeside trough takes shape. The increased pressure gradient will lead to 20 to 30 mph winds developing by late morning and continuing into the afternoon. Lee trough convergence will strengthen, and this will be the area of focus for any late day convection. This convergence zone will likely extend from far northeast Colorado down to northeastern New Mexico. The upper flow pattern favors more aggressive elevated mixed layer development/capping, so lee trough convection may have a difficult time becoming sustained the farther south one goes. .LONG TERM...(Tuesday night through Monday) Issued at 245 PM CDT Mon Jun 26 2017 Mid to late week looks to be fairly active as far as the large scale pattern is concerned as it relates to severe weather potential across the Central Plains. A largely zonal upper tropospheric pattern will be in place, with the global models showing an 80-90 knot 250mb jet translating east through the pattern late Wednesday into Thursday. A lead shortwave trough late Tuesday Night will push a front east and south into northern Kansas by Wednesday. The aforementioned jet streak moving into Colorado late in the day Wednesday should favor post-frontal upslope easterly flow into northeastern Colorado, which will be in the mid tropospheric baroclinic zone. We would be looking for severe convection to form back in the upslope area in addition to the front itself which should stall out somewhere from southwest into north central/northeast KS. The problem for southwest KS as far as widespread severe potential goes is the cap. There will most likely be a sharp southern cutoff to convective activity. Highest POPs Wednesday will be in the north as a result. The CAPE/Shear environment would favor supercell storms with good 850-500mb crossovers. The initial jet streak late Wednesday will push east, but it will be followed by another perturbation rippling through the pattern. Mid level temperatures across western KS should be cooler, and if the front does not push too far south into the warm temperatures aloft, another severe weather event will likely unfold across Kansas. The overall CAPE/Shear environment looks identical to, if not a bit better than Wednesday. These two days look the best for severe weather in our region (mainly eastern counties) during this Long Term range. On Friday, there is global model consensus that the surface front will push down into Oklahoma with the emphasis for severe storms down in that area. We should see quite a bit cooler temperatures Friday as a result. Saturday and Sunday are initially looking potentially wetter as post-frontal moist low level winds resume in a general west-northwesterly flow pattern aloft. It`s really too early to tell how the 4th of July will fare at this point, given the obvious model uncertainty in the D+8 to 10 range. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 535 PM CDT Mon Jun 26 2017 In the short term the biggest uncertainty is the isolated storms in portions of northwest and north central Kansas along with southeast Colorado. Latest forecast may have a VCTS around HYS through 02Z however it looks like GCK and DDC should be storm free. Looking ahead the winds will start to pick up for all the airports at around 18Z tomorrow with around 20 kts sustained out of the south and gusts up to 30 kts. && .PRELIMINARY POINT TEMPS/POPS... DDC 63 89 70 94 / 20 10 10 10 GCK 62 92 68 94 / 20 10 10 10 EHA 62 91 67 95 / 20 10 20 10 LBL 64 91 69 97 / 20 10 10 10 HYS 61 88 70 93 / 30 10 20 10 P28 64 89 71 96 / 20 10 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...Umscheid LONG TERM...Umscheid AVIATION...Tatro
Area Forecast Discussion
National Weather Service Lincoln IL
904 PM CDT Mon Jun 26 2017 .UPDATE... Issued at 900 PM CDT Mon Jun 26 2017 A brief re-intensification has occurred along a couple of outflow boundaries from earlier today, with some thunder development. Coverage should remain isolated in general, but have extended the mention of thunder for the next few hours of the evening, mainly for our southwest counties south of a line from Lincoln to Rushville. The HRRR and RAP output show showers lingering until midnight, but remaining weak and isolated. Have kept the PoPs in the slight chance to low chance categories the rest of the evening, and went dry after midnight. Patchy fog, some locally dense, is the other concern later tonight under light winds and generally clear skies. Boundary layer moisture appears sufficient for fog development based on our lowest dewpoints during peak heating this afternoon along with forecast low temps. Will add some patchy fog to the forecast, especially where HRRR shows some dense fog from Bloomington to Lincoln in the central part of our forecast area. Lows look on track for the low to mid 50s, but we can`t rule out a few upper 40s in traditional colder spots. Tomorrow looks to be a pleasant day, with sunny skies, light westerly winds, and slightly warmer high temps in the mid to upper 70s. Updated forecast info will be available shortly. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 315 PM CDT Mon Jun 26 2017 A weak front will continue to move south through the CWA this evening. The clearing that has occurred has allowed some heating and instability to occur/develop over parts of the area. Isolated to scattered showers and storms will remain possible late this afternoon through early this evening. The precip should wane around sunset leaving the remainder of the evening dry with skies becoming clear. Dry weather is expected then to build into the area late tonight and into tomorrow as high pressure builds into the region. Temps will remain on the cool side tonight and through tomorrow. .LONG TERM...(Tuesday night through Monday) ISSUED AT 315 PM CDT Mon Jun 26 2017 High pressure will continue to dominate the weather across the area Tue night as the pattern becomes more zonal. Then another weather system will quickly move into the area beginning Wed. As the front moves through the CWA it will become parallel with the flow by Thur and then sit somewhere over the area through the rest of the week. Models appear to be in fairly good agreement with the front draped across central IL through this period, which means showers and storms will remain possible. Models also look similar with timing of individual waves moving along the front so consensus forecast of likely pops somewhere in central IL Wed night through Fri looks like a good forecast at the moment. Into the weekend the front should get pushed out of the area to the southeast. However, additional chances of precip will return for later part of the weekend and into the beginning of next week as the pattern returns to a somewhat northwest flow with a upper level trough over the Great Lakes region. Temps will also get warmer again ahead of the next system and then remain that way through the week, evening with precip/clouds and the front somewhere across the area. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 649 PM CDT Mon Jun 26 2017 A line of showers will continue to drift south through central Illinois early this evening. There has been a steady weakening trend in the convection, and little to no additional lightning is expected during the first couple hours of the 00z TAF period. Have not included any thunder as a result, with just VCSH primarily as the diminishing showers linger through 02z. VFR conditions will prevail over the next 24 hours, with the lowest ceilings during any showers early this evening at or above 4K ft. High pressure will provide quiet aviation weather the remainder of the TAF period, with light and variable winds overnight and light westerly winds tomorrow. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Shimon SHORT TERM...Auten LONG TERM...Auten AVIATION...Shimon
National Weather Service Jackson KY
1045 PM EDT Mon Jun 26 2017 .UPDATE... Issued at 1045 PM EDT MON JUN 26 2017 Thicker clouds are slowly advancing from the northwest, with a few showers popping up near and north of the Ohio River. The latest HRRR has been showing more lighter returns making it into our area compared to some of the previous runs. As such, will maintain the slight to low chance POPs through the rest of the night. Did increase temperatures a bit in places, where thicker clouds are combatting the drier low level air. Updates have been sent. UPDATE Issued at 733 PM EDT MON JUN 26 2017 Freshened up the hourly temperatures and dew points through this evening. Thicker cloud cover moving in from the northwest should hold off long enough for a quick drop in the valleys through 06z, otherwise the forecast remains on track. && .SHORT TERM...(This evening through Tuesday night) Issued at 328 PM EDT MON JUN 26 2017 Another cool and dry summer afternoon remains in place across eastern Kentucky, with temperatures in the low-mid 70s and dewpoints comfortably sitting in the mid 40s-mid 50s. One band of mid-high clouds continues to move across southern to central Kentucky, while another subtle shortwave impulse is producing a second batch of these from the Midwest through the Ohio Valley. This latter wave, stretching from the Great Lakes to near St. Louis, will bring isolated to scattered showers through the Ohio Valley and into eastern Kentucky later this evening through tonight. Moisture will be very limited and confined to top-down moistening, as surface ridging moves south into the Tennessee Valley. Therefore, expecting rainfall amounts to remain below one tenth of an inch. Rain chances will continue into Tuesday afternoon as the axis of the mid level trough swings through eastern Kentucky. Given steepening lapse rates owing to lower heights with the base of the trough overhead, isolated thunder chances will be in the offing until a weak cool front pushes through by mid-late afternoon and shuts off any additional chances for precipitation. This potential for thunder will be rather limited as temperatures only warm into the mid 70s with dewpoints in the mid 50s. One more cool summer night will be in store Tuesday night into Wednesday morning as a ~1020 mb surface ridge slides across the Bluegrass. Temperatures will drop into the mid 50s on ridges and upper 40s to lower 50s in valleys, allowing for some areas of valley fog. .LONG TERM...(Wednesday through Monday) Issued at 3 PM EDT MON JUN 26 2017 There is good model agreement with the overall upper air pattern through the forecast period. The long wave trough over the eastern U.S. at the beginning of the period will be lifting out with more zonal flow becoming established across our area. A couple of short wave troughs will move through the mean flow during latter part of the week, with the most significant short wave moving across the Great Lakes this weekend. At the surface, high pressure will be moving off to our east on Wednesday. As a result temperatures will begin to warm and with return flow developing moisture will also be on the increase across the area through the latter part of the week. Wednesday will still have dewpoints in the 50s, but after that dewpoints will go back into the 60s, with mid and upper 60 dewpoints expected for the remainder of the forecast period. By Thursday afternoon a short wave passing by to our north may result in a few storms in the northern part of the area while moisture returning from the south will bring a slight chance of storms to the south. With a slow moving front to our north at the end of the week, and moisture continuing to increase, the storm threat will expand on Friday. However storm chances on Friday will remain relatively low. The best chance for showers and storms will occur on Saturday into Saturday night as a more significant short wave and associated surface low moving across the Great Lakes results in a southward push of the cold front. The front will stall in the OH valley and this will keep a chance of showers and thunderstorms in the forecast into next week. Temperatures will warm back into the mid 80s on Thursday, but the daily threat of showers and storms will keep maximums in the lower 80s for most days from the weekend into early next week. With the increase in dewpoints after Wednesday we`ll see our typical summer lows of muggy 60s from the end of the week into next week. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) ISSUED AT 733 PM EDT MON JUN 26 2017 VFR conditions look to hold on through the period. Clouds will thicken and lower to around 6k feet agl from northwest to southeast tonight, as a weak cold front approaches. A few showers will threaten from late tonight into Tuesday morning, before chances diminish into the afternoon as the cold front exits. Light and variable winds will turn more out of the northwest at around 5 kts once again into Tuesday. && .JKL WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...GEOGERIAN SHORT TERM...GUSEMAN LONG TERM...SBH AVIATION...GEOGERIAN
Area Forecast Discussion
National Weather Service Lake Charles LA
1020 PM CDT Mon Jun 26 2017 .DISCUSSION... Regional 88Ds show the bulk of the precipitation which developed earlier today has moved off into the Gulf with just a few showers now noted along the coast over swrn LA. Water vapor imagery shows drier air moving into the region from the north which is corroborated by regional 00z soundings as much lower PWAT/mean RH values are noted to our north. All of this spells a trend in overnight POPs of slim/none across most of the nrn half to small chances closer to the much higher over the coastal waters. As expected, this also agrees with latest short-term high-res runs as well. Elsewhere, just minor tweaks at most per latest obs/trends. Update out shortly. 25 && .PREV DISCUSSION... /issued 659 PM CDT Mon Jun 26 2017/ DISCUSSION... For 00z TAF issuance. AVIATION... Local 88Ds continue to show quite a bit of convection covering the srn 1/2 of the forecast area, possibly impacting the srn terminals...however as this activity is diurnal in nature, expect it to diminish over the next few hours with loss of heating. Forecast time-height sections not indicating much boundary layer moisture through the overnight hours so not expecting any fog at this time. Tomorrow appears to be a repeat of today with good moisture closer to the coast along with a weak shortwave or weakness aloft and daytime heating. 25 PREV DISCUSSION... /issued 326 PM CDT Mon Jun 26 2017/ DISCUSSION... Weather map showing weakening frontal boundary across SE TX/S LA this afternoon, likely along the I-10 corridor. Showers and thunderstorms have increased in coverage over the last couple of hours across SE TX/SW LA, with scattered coverage over the coastal waters. This was expected with continued consistence from the HRRR guidance this morning and afternoon. The convection expected to continue through sunset and diminish this evening after the loss of daytime heating. The front is expected to slowly dissipate with a predominate southeast flow resuming across the region by Tuesday, bringing with it increased Gulf moisture and higher chances of showers and thunderstorms. The best chances for showers and thunderstorms expected Wednesday through Friday as a weak shortwave aloft enhances lift within our region already saturated with moisture moving in from the Gulf. By Friday evening into the weekend, high pressure with slightly drier air aloft is expected to diminish shower and thunderstorm chances to near ~20% for the weekend. DML MARINE... High pressure settling east of the area will provide a more predominate east to southeast flow, with winds and seas increasing by the end of the week. This will bring increased Gulf moisture for increased chances of showers and thunderstorms through Friday. By Friday afternoon into the weekend, high pressure and drier air aloft is expected to limit shower and thunderstorm activity. DML && .PRELIMINARY POINT TEMPS/POPS... AEX 68 89 70 90 / 10 40 20 50 LCH 73 88 73 87 / 30 50 30 50 LFT 71 87 72 87 / 20 50 20 50 BPT 73 87 74 87 / 30 50 30 50 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...None. && $$
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
1016 PM CDT Mon Jun 26 2017 .UPDATE... Brought PoPs and weather grids in line with current trends along the immediate coast and near shore waters. Went with RUC13 model hourly PoPs which does show 90% or better where activity is currently, then a tight gradient to near 0% closer to the New Orleans metro area. There is some indication of potential convection forming overnight over Lake Pontchartrain which is plausible in this environment. This update mainly affects the web-based areal point-n-click forecasts, which may or may not be fully functional at this time. Major point forecast locations are unaffected aside from perhaps the Houma-Thibodaux area. Will not send a ZFP as the gradient across the lower parishes will grab the higher values and would be unrepresentative for some areas such as Upper Jefferson and the adjacent River Parishes. 24/RR .AVIATION... Most terminals should remain VFR despite large anvil blow-off from ongoing convection along the LA coast. KHUM has not reported an observation since 26/2347Z, and possibly may be transmitting with an incorrect date. Therefore will show NO AMDT SKED with the 06Z TAF issuance. 24/RR && .PREV DISCUSSION... /issued 738 PM CDT Mon Jun 26 2017/ SOUNDING DISCUSSION... The 00z sounding shows a dry and very stable airmass in place. Precipitable water values have continued to decline on the back of a persistent north-northeast flow in the low to mid-levels of the atmosphere. PW values dropped a quarter inch since the 12z sounding, and the mean mixing ratio fell from 13.2 to 11.2g/kg. This drying of the mid-level atmosphere has resulting in warmer temperatures between 850 and 700mb, and that warming has reduced overall instability. This is most evident by the very weak 5.6C/km lapse rate observed in the 850-500mb layer, lack of CAPE, and very high convective temperature of 100F. 32 && .PRELIMINARY POINT TEMPS/POPS... MCB 68 88 69 87 / 0 0 0 50 BTR 70 88 71 87 / 0 0 10 60 ASD 69 89 72 86 / 20 0 0 60 MSY 73 86 74 84 / 20 20 10 60 GPT 71 86 73 85 / 20 10 0 50 PQL 68 89 71 87 / 10 10 0 30 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
658 PM CDT Mon Jun 26 2017 .SHORT TERM... 203 PM CDT Through Tuesday... Showers and a few thunderstorms have increased across the I-80 corridor and southward ahead of a surface trough/cold front. MLCAPE per RAP mesoanalysis is about 250 J/kg, thus the widely scattered shower but generally isolated and brief thunder. This activity will continue to slide southeast along and ahead of the trough axis. A few showers are possible farther north, but the cu field here is flatter and we need to await the upper low in WI for a little better forcing later this afternoon. Instability is weaker near this low, and with the later arrival expect some isolated showers in far northeast IL late this afternoon. Compact upper low will quickly dig southeast of the area this evening, ending our lower precip chances fairly quickly in its wake. Surface high pressure will slide just to the southwest of the area tonight. With clearing skies in subsidence behind this wave, it will be another fairly chilly night with lows again in the upper 40s to mid 50s. We maintain a weak pressure gradient over the area which will keep things from getting too cool and limit any fog. The surface high will move from central Illinois east through the Ohio valley on Tuesday, while low pressure will develop across the high plains. With lower level winds shifting southwesterly in this pattern and plentiful sunshine, expect a nice rebound in temperatures back to near 80. A lake breeze may also form, but at this point it appears to remain confined to the near lakeshore areas. KMD && .LONG TERM... 233 PM CDT Tuesday night through Monday... A busier pattern sets up with multiple chances of showers and storms Wednesday through Friday, and then again early next week. Surface high pressure shifts east Tuesday night, and a surface low develops over the northern plains. The NAM and ECMWF still suggest a dying convective line/MCS may move into northern IL Wednesday morning while other models keep the convection over WI. Continued with a dry forecast Wednesday morning, but if a convective line or cloud shield move over the area, they could limit storm development in the afternoon. Showers and storms are expected ahead of the low Wednesday afternoon. The low`s warm front lifts through the region leading to highs in the low 80s. Expecting lift from an upper level shortwave, but forecast soundings feature very little CAPE. CAPE increases to around 500 J/kg by 00Z Thursday/7PM Friday. Shear on the other hand is strong at around 50 kt. Low level shear in particular looks strong and LCL`s are low. CAPE values are much higher over Iowa so thinking while we will see scattered thunderstorm development, the majority of severe storms will occur over Iowa. Thinking storms to the west will become linear and move through Wednesday evening/night. The other issue for Wednesday will be wind gusts. As the previous discussion mentioned, the potential exists for wind gusts to reach or exceed 35 MPH. However, unsure at how well we will mix due to cloud cover. The low continues over the northern Great Lakes Thursday, and its cold front stalls over north central IL. Heat and humidity build with highs in the mid 80s Thursday. Showers and storms are expected south of the boundary roughly south of I-88. Forecasted CAPE values vary from 1000-2000 J/kg, but shear values are much lower around 20 kt. Zonal flow aloft allows additional upper level disturbances to shift east overhead through Friday. In addition, a surface low is forecast to form over Iowa/Missouri Friday morning and shift northeast over the forecast area Friday. Cooler air aloft arrives Saturday and it looks like precip will stay to the north and east. High pressure moves over the region Saturday night and Sunday. Guidance on how the next upper level system will evolve early next week with the GFS featuring a stronger system than the ECMWF. Therefore left PoPs as is. JEE && .AVIATION... For the 00Z TAFs... Latest radar imagery showing a continued diminishing trend of the scattered showers and isolated thunderstorms just to the south of the terminals. Don`t anticipate any further development near or around the terminals tonight or through the remainder of the forecast period. Several outflow boundaries do remain around the terminals though, but do anticipate winds to stay in the north northwest direction for this evening. The exception is GYY, where winds have turned to the northeast. This direction will likely remain through mid/late this evening. VFR conditions will continue through the period, while winds gradually shift more west and then southwest tonight into Tuesday morning. Rodriguez && .MARINE... 233 PM CDT Northwest winds have increased to 20-25 kt across the nearshore waters. Winds will become even more northwest as a cold front moves through this evening. Winds diminish to where a small craft advisory will not be needed for the IL shore early this evening. However, waves in the Indiana nearshore waters will remain hazardous past midnight and slowly subside overnight. West winds become southerly Tuesday as the high pressure ridge moves over the lake. The next low forms over the northern plains Tuesday. The pressure gradient tightens over the lake Wednesday between the high over the central Atlantic Coast and the low over the northern plains. South winds may increase to gales Wednesday. The low weakens Thursday as it shifts east, and winds weaken and become west to northwest. Another, weaker low may move over the southern end of the lake Friday afternoon/evening. West winds are expected behind the low through Sunday. JEE && .LOT WATCHES/WARNINGS/ADVISORIES... IL...None. IN...Beach Hazards Statement...INZ001-INZ002 until 4 AM Tuesday. LM...Small Craft Advisory...IL nearshore waters until 7 PM Monday. Small Craft Advisory...IN nearshore waters until 4 AM Tuesday. && $$ VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE) FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT: WWW.FACEBOOK.COM/NWSCHICAGO WWW.TWITTER.COM/NWSCHICAGO WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion...UPDATED
National Weather Service Miami FL
1100 PM EDT Mon Jun 26 2017 .UPDATE... As of 1100 PM EDT...Quick late evening update to bump up PoPs across the Gulf Coast to account for cluster of thunderstorms that have developed over coastal Collier County, along with another area of storms over Lake Okeechobee. These storms have likely formed in response to convergence along outflow boundaries from earlier afternoon storms. This activity should continue for the next few hours, with frequent lightning and locally heavy rainfall the primary threats, and will continue to monitor potential flooding concerns in vulnerable areas in and around the Naples metro. Elsewhere across the region, mainly dry conditions persist, with a few isolated showers over the Atlantic waters. For the rest of tonight, the Gulf convection should begin to slowly wane and dissipate over the next few hours, similar to activity near Lake Okeechobee. A light land breeze is still expected to develop off the east coast, helping to focus additional isolated to scattered showers and storms through the remainder of the night, mainly over the Atlantic waters. Low temperatures will generally be in the 70s. && .PREV DISCUSSION... /issued 803 PM EDT Mon Jun 26 2017/ AVIATION... Isolated showers with a couple rumbles of thunder will continue to dwindle over the interior during the next few hours, leaving behind scattered low clouds with bases around 3000 ft msl. Wind will decrease to light and variable overnight. Aft around 27/1300Z, south east winds will again increase to near 10 KT. VCSH conds should begin to develop aft 27/1700Z or 18Z. Convection will occur closer to the east coast TAF sites on Tuesday afternoon, but still mainly concentrated in the interior. PREV DISCUSSION... /issued 715 PM EDT Mon Jun 26 2017/ UPDATE...Convection this afternoon has been a little sparser than expected despite the numerous boundary collisions. Current forecast updates are mainly to cut back rain chances into this evening, with ongoing boundaries keeping at least isolated convection going through late evening. Latest RAP analysis shows very light NE steering flow (less than 5kts), but this may be enough that new activity that gets going along collisions will trend towards the west side of the interior. Land convection dies by late evening with mesoscale models showing the overnight landbreeze leading to the development of showers and storms over the water late tonight. It remains warm and muggy, otherwise known as South Florida in late June, with lows in the 70s. PREV DISCUSSION... /issued 411 PM EDT Mon Jun 26 2017/ DISCUSSION... THIS AFTERNOON AND TONIGHT: Frontal boundary is draped across the north Central peninsula this afternoon, pushing the ridge axis further south into our region. With the axis overhead steering flow is very light, with a little more southerly component than the past few days. Scattered showers and storms are ongoing along both seabreezes as they move inland this afternoon. Boundary collisions, along with the collision of the seabreezes will continue to drive development into the evening hours. Given the light flow, storm movement will be minimal with heavy rain, gusty winds, and lightning the main concerns. While most activity will remain over the interior, outflow boundaries may drive a few storms into either coast. Convection dies late tonight with mesoscale models hinting at landbreeze development leading to the development of showers and storms over the water and adjacent land areas overnight. TUESDAY AND WEDNESDAY: Upper level trough moving across the eastern US erodes the northern side of the western Atlantic ridge through midweek. Low level front currently across North/Central Florida will slowly drop south through mid week, but as is usually the case this time of year, washes out before it reaches Lake Okeechobee. Prevailing flow will become more southwesterly, though fairly light at 10kts or less, with a modest increase in mid level moisture and slightly cooler temperatures aloft. All of the above will lead to a higher coverage of showers and storms as we head into mid week. We should see both seabreezes developing and moving inland, with the best coverage during the late afternoons and evenings over the interior with the seabreeze collision. THURSDAY THROUGH UPCOMING WEEKEND: Remnant frontal boundary across the FL peninsula washes out into late week across the state. Upper level trough will exit the northeastern US as the upper level extent of the Western Atlantic ridge rebuilds across Florida. The surface ridge behind the front across the Mid Atlantic will move offshore and reinforce the western Atlantic ridge, bringing a return of prevailing deep easterly flow. This drier, more subsident pattern will allow rain chances to drop closer to seasonal norms for this time of year with afternoon convection favoring interior and Gulf coast areas as the east coast seabreezes moves inland faster. MARINE...Frontal boundary across North/Central Florida will weaken the western Atlantic high, leaving light easterly flow in place through midweek. Both the Gulf and Atlantic seabreezes will develop and move inland each afternoon, bringing winds up to around 10kts near the coast. Best coverage of showers and thunderstorms will generally be inland, however outflow boundaries could enhance some convection over the waters. High pressure rebuilds to the north late week with east-southeast winds returning around 10-15kts into the upcoming weekend. && .PRELIMINARY POINT TEMPS/POPS... West Palm Beach 77 91 75 90 / 20 50 30 50 Fort Lauderdale 79 90 78 91 / 20 40 40 50 Miami 78 91 78 92 / 20 50 40 60 Naples 76 89 76 91 / 40 30 20 50 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && UPDATE...92/IRL DISCUSSION...88/ALM MARINE...88/ALM AVIATION...27/JT
Area Forecast Discussion
National Weather Service New York NY
1055 PM EDT Mon Jun 26 2017 .SYNOPSIS... Weak high pressure builds farther offshore tonight as a cold front approaches from the Great Lakes. The front moves through the area Tuesday evening. High pressure will then briefly follow for the middle of the week. Another frontal system approaches for the end of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A weak surface trough was across the region from the Hudson Valley into eastern Pennsylvania and into north central Maryland. This was the focus of a few light showers, along with a shortwave rotating through an upper trough. Put probabilities, slight chance, into the forecast for areas across the far western zones initially and then slowly east through the overnight. The HRRR was also supporting the chance of showers overnight, just a couple of hours too quick. Lower levels are dry and any precipitation reaching the ground is expected to be light. Anomalously strong upper trough across the Great Lakes and Ohio Valley states pivots eastward the next couple of days with gradual height falls and increasing daytime instability. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Airmass gradually destabilizes on Tuesday with height falls and approaching cold front over the Great Lakes. However, dry low- levels and lack of strong surface trigger will be limiting factors for the development of showers/thunderstorms. The best chance will be across the interior during the afternoon hours. Wind shear is also weak, limiting any organization. Cold front works across the area in Tuesday evening with high pressure to follow. Daytime highs will once again be near or just below seasonable levels. There is a moderate risk for the development of rip currents Tuesday. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... High pressure will be in control Wednesday through Thursday night, bringing dry conditions and near normal temperatures across the area. As high pressure moves offshore, warmer temperatures and increasing chances of showers and thunderstorms will develop Friday through Sunday. High pressure builds back on Monday, bringing more seasonable temperatures and dry conditions across the area. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... A weak trough of low pressure over the area will move east late tonight...followed by another one on Tuesday. VFR through the TAF period. An area of showers over SE PA may impact KSWF between 05z and 06z. Latest hi res guidance weakens this activity as it tracks NE next few will watch and amend as needed. Also a few showers have popped up in northern MD, but is not as much widespread as some of the earlier guidance was indicating. Thus, have decided to hold off on adding showers to other terminals for now. S-SW winds 5-10kt will become light and vrb outside of NYC terminals overnight. Winds will increase 10-15kt Tue aftn with gusts in the upper teens to lower 20s...becoming W-NW around 00z as the trough pushes through. Could be some isold showers/tstms Tue aftn associated with upper disturbance and sfc trough moving through. .OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY... .Tuesday Night-Wednesday...VFR. .Thursday...VFR. Chance of a late day shower/thunderstorm. .Friday and Saturday...Sub-VFR in showers and thunderstorms. && .MARINE... Winds and seas forecast on track. With an overall weak pressure gradient remaining across the region, winds and seas are expected to remain below small craft advisory criteria (25kt winds, 5 ft seas) through Tuesday. Below small craft advisory conditions expected Wednesday as High pressure moves south across the area waters. Winds and seas increase, and small craft advisory conditions are possible later Thursday and into Saturday. && .HYDROLOGY... No hydrologic impacts expected through the beginning of next week. && .TIDES/COASTAL FLOODING... Astronomical tides are still running high with a low chance of any minor coastal flooding across the south shore back bays of Nassau county with this evening high tide cycle, approximately between 10pm and 12am. The water levels would only be expected to touch the minor benchmarks few just a couple of gages so no statement has been issued. && .EQUIPMENT... Observations from KFRG (Farmingdale, NY) are not available. Observations from KHPN (White Plains NY) and KHVN (New Haven CT) are being disseminated through backup methods. All is due to an FAA communication line outage. Return to service time is unknown. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Fig/DW NEAR TERM...MET/DW SHORT TERM...DW LONG TERM...Fig AVIATION... MARINE...Fig/MET/DW HYDROLOGY...Fig/DW TIDES/COASTAL FLOODING... EQUIPMENT...
Area Forecast Discussion
National Weather Service Pittsburgh PA
932 PM EDT Mon Jun 26 2017 .SYNOPSIS... Upper low pressure will maintain cooler temperature and a periodic shower chance for the first half of the week. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A vigorous shortwave trough will approach tonight bringing another round of scattered showers. Showers will push east late this evening and dissipate upon arrival due to unfavorable timing in a stabilizing atmosphere. CONSShort (with a higher RAP weight) was utilized heavily for construction of overnight PoPs. While some elevated instability does remain overnight, will keep thunder out of the forecast as it should be very isolated. Overnight lows will again will run 10 degrees below normal. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Cold troughing will keep isolated showers in play through the morning but will diminish by the afternoon with the upper trough axis to the east. Temperatures will again be well below normal but by Wednesday temperatures will begin to moderate as flow aloft flattens/ridges in response to a trough digging across Western Canada. Warmth and humidity are forecast to enhance via southerly boundary layer flow as that trough progresses over the Northern Plains/Upper Midwest, and precip chances escalate as ejected energy slides over the Lakes and spawns convection by Thursday. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... The aforementioned trough/associated cold front is projected across the Great Lakes and Upper Ohio Regions next weekend. Precip is thus likely but temperature in the wake of the system is expected to remain near the seasonal averages given the lack of amplitude in the progged flow pattern. && .AVIATION /02Z TUESDAY THROUGH SATURDAY/... Will continue with prevailing VFR through most of the night across the region, as any showers with the overnight shortwave passage should be fairly brief overall. Have handled with VCSH for now. Do have a TEMPO mention for thunder at FKL/DUJ early on with lingering convection, but overnight activity should be more scattered and weaker overall. Towards sunrise, MVFR ceilings are still expected north of PIT, with lesser chances of such to the south. These ceilings will lift with mixing later in the morning. Isolated showers will remain possible through much of Tuesday, before a clearing trend takes hold by sunset. .OUTLOOK... Next chance for widespread restrictions comes with the approach of frontal boundary at the end of the week. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. && $$
Area Forecast Discussion
National Weather Service Pocatello ID
220 PM MDT Mon Jun 26 2017 .SHORT TERM...Tonight through Wednesday. Upper trough pushing over forecast area. Moisture working northeast toward the region. Favorable upper jet dynamics and instability in favor for development of convection starting this afternoon, shifting east ahead of surface cold front. HRRR still showing gusts near severe limits this evening as line of storms works northeast from south of BYI through the Snake Plain. DCAPE values support stronger convective gusts as well. PW values at or above 0.75 where convection expected to develop/move so wetting rains likely out of the storms. Initial shortwave shifts east through the night, and models all still paint weak convection lingering across the region past sundown, mainly higher elevation areas. Have kept precip going overnight. Second shortwave shifts across the region Tuesday, and could see another round of strong storms particularly in NE quadrant of fcst area. Breezier through the day as sfc gradient tightens behind tonight`s front. Upper trough axis slowly sags SE, with one more shortwave associated with base of trough passing through on Wednesday. Yes, one more round of convection, expected to be weaker, and mainly concentrated in areas along the WY border. DMH .LONG TERM...Wednesday night through Monday. Upper trough pushes into the Plains in the latter portions of the week, with northwest flow over ID and dry conditions. Next Pacific trough slips inland Saturday, and both GFS/ECMWF settling on increased chances for convection across the area. Have nudged PoP upward slightly for Saturday. This trough is fairly progressive, so models project another return to dry northwest flow Sunday and Monday. DMH && .AVIATION...Thunderstorms are expected to develop and move southwest to northeast across the area late this afternoon and tonight as an upper-level trough and attendant cold front slide across the area. Best thunderstorm chances through this evening appear to be at KBYI and KSUN...with lesser coverage expected near KPIH...KIDA...and KDIJ. Better chances will eventually shift east to KDIJ late tonight and tomorrow. Strong gusty winds will be possible with the storms...along with brief MVFR or lower conditions. Outside of any showers/storms...VFR conditions are anticipated. West/southwest winds will increase Tuesday morning behind the front with strongest winds expected at KPIH/KIDA/KBYI. KB && .FIRE WEATHER...Showers and thunderstorms will continue to develop this afternoon and evening ahead of an upper-level trough and cold front...and make their way southwest to northeast across the area late this afternoon through tonight. Some of the thunderstorms this afternoon and evening may produce strong gusty winds and little rainfall. The Central Mountains and South Central Highlands are favored to see the greater thunderstorm coverage through this evening. Better chances will become focused over the Central Mountains and Upper Snake Highlands late tonight...with the Upper Snake Highlands seeing the higher chances on Tuesday. Behind the cold front passage tonight...west/southwest winds will increase on Tuesday with the strongest winds expected in the Snake Plain and Eastern Magic Valley where gusts to around 35 mph will be common. Temperatures on Tuesday will cool 10-15 degrees from today in wake of the front...resulting in higher RH values (minimum RH values 20 percent or higher). Thus no critical fire weather conditions are anticipated despite the gusty winds. For the remainder of the week...near normal temperatures can be expected along with mainly dry conditions aside from some lingering showers and storms in the Upper Snake Highlands on Wednesday. KB && .PIH WATCHES/WARNINGS/ADVISORIES... None. && $$