Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/12/20

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
403 PM AKDT Thu Jun 11 2020 .SYNOPSIS... Isolated to scattered afternoon and evening showers and thunderstorm are expected across the Interior this evening as well as for the next several days. The best chances for storms today and Friday will be in areas east of Fairbanks. The northwest Arctic will see showers tonight thanks to an upper level low that is currently in place over Kotzebue Sound. This low and the associated showers will move north tonight and Friday. A warming trend in temperatures is expected for the Interior and the west coast over the next few days as a ridge builds over the area. && .DISCUSSION... The 12 UTC model suite generally initialized well when compared to the obs. The models all have the same general idea with the synoptic scale pattern out through early Saturday; however, by Saturday evening the models start to diverge. The GFS is much more aggressive than the NAM or with its handling of an easterly wave that will push across the Interior late Saturday into Sunday. For the afternoon forecast package, we will lean more on the NAM. Aloft, at 500 mb, a 543 dam low is currently in place over Kotzebue Sound, while the Interior and the eastern half of the North Slope is under a ridge. The low will move to the north tonight, allowing for the ridge to build to the west and strengthen. A shortwave will move from east to west along the south side of the ridge on Saturday. At this point, there are still some differences in how the models are handling this. Central and Eastern Interior: A stalled front associated with a low over Kotzebue Sound currently stretches along a line from Arctic Village to Northway. A weak easterly wave is currently moving over the southeastern Interior. The combination of the two is currently serving as a forcing mechanism for thunderstorms. We expect scatted thunderstorms along the line with some isolated thunderstorms elsewhere across the Interior. Temperatures tomorrow will be warmer than today for most locations with the typical afternoon showers and thunderstorms (with the best chances for thunderstorms east of Fairbanks). An easterly wave will move across the southern Interior on Saturday bringing showers and thunderstorms. The models differ on the timing and strength of this feature at the moment, which introduces some uncertainty into the temperature forecast for Saturday. North Slope and Brooks Range: Scattered thunderstorms are expected this evening along a stalled from that stretches over the eastern Brooks Range and the eastern half of the Arctic Plain. As the upper low moves to the north on Friday, expect scattered showers over the Brooks Range along with some isolated thunderstorms. Some high resolution guidance, such as the HRRR is suggesting that thunderstorms could make it as far north as the coast on Friday. West Coast and Western Interior: Showers along with a few isolated thunderstorms will continue under an upper low that is currently over Kotzebue Sound. The best chances for showers tonight will be in the Kobuk and Noatak Valleys. The low will slowly drift to the north tonight and Friday. Low stratus and fog will persist tonight for the Bering Strait and for St. Lawrence Island. A gradual warmup moves in on Saturday as interior ridging builds inland from the east. Coastal Hazard Potential Days 3 and 4...None. && .FIRE WEATHER... Scatted thunderstorms will develop this evening along a stalled front in the eastern Interior, mainly along a line from Northway to Arctic Village. Widely scattered thunderstorms are expected for the Fortymile Country on Friday. Easterly flow aloft will help ignite more active afternoon thunderstorms across the Alaska Range north to the White Mountains and Tanana Valley on Saturday. Otherwise, the warmest and driest conditions through the weekend are expected over the Yukon Flats, where temperatures will rise into the 80s. && .HYDROLOGY...No major concerns at the moment. It is possible that if a individual thunderstorm cell remains stationary for a while it may produce enough precipitation to cause a rapid rise in a small stream. This would be most likely in areas of steep terrain, such as the Alaska Range. && .AFG WATCHES/WARNINGS/ADVISORIES... None. && $$ JUN 20
National Weather Service Albany NY
1035 PM EDT Thu Jun 11 2020 .SYNOPSIS... A cold front will continue to move east of New England, as a much drier airmass will be ushered in tonight. Another cold front will move across the region Friday afternoon and evening bringing in a cooler airmass for the upcoming weekend. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... As of 1033 pm EDT...Some isolated to scattered showers will continue to until about midnight for the southern Taconics and Litchfield County, as the cold front and dewpoint boundary is slowly pressing south/southeast into the mid Hudson Valley, southern Taconics and northwest CT. The last few runs of the 3-km HRRR were a bit faster moving these showers out. We have not observed any thunder, but a localized half an inch to a inch of rain is possible based on the latest MRMS pcpn data. Dewpts continue to fall into the 50s to lower 60s in the wake of the boundary (some upper 40s in the Adirondacks). Overall, dry wx is expected for the rest of the region for the overnight period with subsidence in the wake of the boundary. The skies have become clear or mostly clear north and west of the Capital Region. The air mass is much drier with the 00Z KALY sounding having a PWAT of 0.86" compared to the 2.07" from this morning. We did add some patchy fog across southern VT especially east of the southern Green Mtns. Overnight lows will be 10 to 15+ degrees cooler than last night with some upper 40s over the southern Adirondacks and mainly 50s across the rest of the region. The winds will go light to calm as high pressure ridges in from the OH Valley. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... The region will remain under a trough which will deepen as short wave energy dives in out of central Canada. A secondary reinforcing cold front will cross the region Friday afternoon and evening. The airmass in place will be quite dry so just some isolated showers are possible. What will be notable is the cooler airmass which is ushered in with its passage for the weekend. Mainly fair weather is expected on Saturday but with trough over the region and short waves moves through have slight chance pops for showers. Dew points are expected to drop down in the 40s to lower 50s on Friday making for more comfortable conditions. Expecting highs in the lower/mid 80s in the Hudson Valley from the Poughkeepsie area into the Capital District with 60s across the southern Adirondacks and highest terrain of the eastern Catskills and southern Greens with 70s elsewhere. Highs Saturday are expected to be 10 degrees cooler. Lows are expected to be in the 40s to lower 50s both Friday and Saturday nights with some cooler upper 30s across the southern Adirondacks Friday night. && .LONG TERM /SUNDAY THROUGH THURSDAY/... Global models continue to trend drier through the long term period, though, forecast confidence remains low. At upper levels, two low pressure systems embedded in the upper level trough are progged to split, with one ejecting to the northeast on Sunday, and the other getting pushed to our south. The second low is expected to become cut off across the southeast CONUS with upper ridging building into the region. This would result in mainly dry weather through much of the work week as ridging strengthens. The main question is how far south the closed low tracks as pieces of energy could ride overtop the closed low and spark showers at times throughout the week. With both the GFS/ECMWF trending drier, have lowered PoPs from the ER model blend. There is more confidence in temperatures gradually warming into the mid and upper 80s by the end of the week but sky cover is also in question depending on the position of the low. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... A cold front will move across New England early this evening. High pressure will ridge in from the Ohio Valley and West Virginia overnight. A secondary cold front will approach from the St Lawrence River Valley with some some clouds, but very little low-level moisture with it, as the best chance of an isolated shower will be west of the Hudson River Valley. VFR conditions are expected most of the next 24 hrs ending 00Z/SAT for KGFL/KALB/KPOU/KPSF. The skies are clearing in the wake of the cold front early this evening, except near KPOU where the front should move through between 01Z-03Z. Some recent wet ground from the showers, light to calm winds and clearing skies may allow for some patchy ground fog to form at KPSF between 08Z-12Z/FRI. We placed some MVFR mist in. KGFL has a chance for some patchy radiational mist overnight too, but we left out of the TAFs for now. The skies will clear at KPOU- KALB-KGFL with the winds becoming light and variable at 4 kts or less. In the late morning into the afternoon, expect some sct-bkn diurnal cumulus to form and possibly some mid level clouds ahead of the front. The cloud bases will be around 5 kft AGL. The clouds should thin in the late afternoon with the frontal passage. The winds will be increasing from the south to southwest at 5-10 kts in the late morning, and then veer to west to southwest at 8-14 kts in the afternoon with some gusts around 20 kts at KALB/KGFL/KPSF. Outlook... Friday Night: No Operational Impact. NO SIG WX. Saturday: No Operational Impact. NO SIG WX. Saturday Night: Low Operational Impact. Slight Chance of SHRA. Sunday: Moderate Operational Impact. Chance of SHRA. Sunday Night: Low Operational Impact. Slight Chance of SHRA. Monday: Moderate Operational Impact. Chance of SHRA. Monday Night: Low Operational Impact. NO SIG WX. Tuesday: Low Operational Impact. Slight Chance of SHRA. && .FIRE WEATHER... A much drier airmass will be ushered in tonight. Another cold front will move across the region Friday afternoon and evening ushering in a cooler airmass for the weekend. Minimum RH values are expected to be 35 to 45 percent Friday afternoon and in the upper 30s to upper 40s Saturday afternoon. && .HYDROLOGY... The rainfall was much needed across the area. Rainfall totals ranged from a quarter of an inch up to almost 2 inches. A Public Information Statement was issued and a map of the rainfall was posted and tweeted on social media. Mainly fair weather is expected over the next several days. There could some isolated to scattered with any QPF being minimal. 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...IAA/Wasula NEAR TERM...Wasula SHORT TERM...IAA LONG TERM...JLV AVIATION...Wasula FIRE WEATHER...IAA HYDROLOGY...IAA
Area Forecast Discussion
National Weather Service Columbia SC
1020 PM EDT Thu Jun 11 2020 .SYNOPSIS... A cold front will remain over the forecast area tonight and near the I-95 corridor through the weekend. The chance for showers and thunderstorms will continue with the highest chance across the eastern Midlands. Unsettled weather is expected through the middle of next week as an upper low stall over the eastern states. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... A line of thunderstorms near the NC/SC state line is expected to drift slowly southward overnight. The HRRR has been persistent over the past several runs that the thunderstorms will diminish overnight. Though perhaps not before entering the northern- most counties in the county warning area (CWA). Heavy rain from these slow moving storms will still be possible in Chesterfield and Lancaster counties and supports continuing the Flash Flood Watch. Any showers and thunderstorms that linger into early Friday morning should be isolated and generally in the eastern CWA. Low temperatures tonight will range from the mid 60s west to lower 70s east. Widespread fog potential is low due to mixing. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/... Friday and Friday Night: The cold front will become nearly stationary along the I-95 corridor on Friday and linger through Friday night. Precipitable water values will remain high, around 1.75 to 2.00 inches, near the front, but drop off considerably closer to 1 inch across the western portion of the forecast area as drier air advects in within a northeasterly flow. Given the large gradient in moisture across the area, expect a corresponding gradient in precipitation coverage. The forecast will indicate isolated showers and thunderstorms north/west of I-20, scattered coverage farther south/east, with numerous coverage near the I-95 corridor, where locally heavy rainfall is possible. Cloud cover and the cooler northeast flow will keep temperatures down a bit, with highs in the mid 80s most areas. Nighttime lows will be in the mid to upper 60s. Saturday and Saturday Night: The nearly stationary front will shift a bit closer to the coast on Saturday, with a drier northeast flow in place across much of the area. Isolated to scattered showers and thunderstorms are possible, but the greatest coverage should be across the eastern Midlands in closer proximity to the front. Despite the northeast flow, more sunshine should result in warmer temperatures, with highs in the mid to upper 80s. && .LONG TERM /SUNDAY THROUGH THURSDAY/... A closed upper level low will drop southeast out of the Ohio Valley late in the weekend, with the stalled front retreating inland as a warm front, moving across the area late Sunday and Sunday night. This will result in scattered showers and thunderstorms on Sunday with numerous showers and thunderstorms possible Sunday night across the northern Midlands with enhanced convergence along the front. The closed upper low will settle over the southern Appalachians and Carolinas through the middle of next week, resulting in unsettled conditions and cooler than normal temperatures during that time. The upper low finally begins to lift northward late in the week, with drier conditions expected. && .AVIATION /02Z FRIDAY THROUGH TUESDAY/... Front remains stalled out across the region, and it will remain into Friday. Local radar showing much of the shower/storm activity that had been across the eastern Midlands has diminished significantly. Will keep all sites dry at this point overnight, but will monitor for any redevelopment later. Convective models do hint at some activity moving in from the north late tonight, possibly impacting Midlands sites of cae/cub/ogb, but confidence in that scenario remains low. Plenty of cloud cover across the eastern Midlands associated with prior rainfall. High pwat values remain across the extreme eastern Midlands/CSRA, while drier air resides across the western Midlands and CSRA. This will affect cloud conditions and potential overnight. Higher confidence in lower mvfr/ifr ceilings late tonight at ogb due to previous rainfall and higher moisture content. Lower confidence at other taf locations due to model inconsistencies and lower moisture. Can not rule out a period of mvfr ceilings at all other locations towards morning. Stratus remains preferred over fog due to a 20 knot low level jet after 06Z. Winds will become southeasterly tonight and northeasterly by 12Z Friday morning, remaining northeasterly through the day. Another round of showers/storms possible across the eastern Midlands again late Friday morning into the afternoon. EXTENDED AVIATION OUTLOOK...A stalled front will remain in the area into the weekend. Early morning ceilings and visibility restrictions will be possible with mainly diurnal convection. && .EQUIPMENT... The Columbia SC (KCAE) WSR-88D Weather Radar will be out of service from June 12th to June 19th, 2020. This is due to necessary generator upgrades and other maintenance as part of the Service Life Extension Program (SLEP). During this outage, data is available from adjacent WSR-88D radars at Greenville- Spartanburg SC (KGSP), Charleston SC (KCLX), Wilmington NC (KLTX) and Warner-Robbins AFB GA (KJGX). For additional details, see our web page at && .CAE WATCHES/WARNINGS/ADVISORIES... GA...None. SC...Flash Flood Watch until 6 AM EDT Friday for SCZ016-116. && $$
Area Forecast Discussion
National Weather Service Quad Cities IA IL
622 PM CDT Thu Jun 11 2020 ...AVIATION UPDATE... .SYNOPSIS... Issued at 214 PM CDT Thu Jun 11 2020 A gorgeous late Spring day was playing out across the Midwest after a busy past few days of dealing with tropical moisture remnants. 18z surface analysis showed sprawling surface high pressure centered from central Colorado to western Arkansas, with northwest flow in place across the Midwest. KDVN radar was mainly quiet, although some isolated rain showers were not too far away to the north near KARX, which were being driven by a weak upper level impulse moving across southeast Minnesota and southwest Wisconsin. Temperatures as of 2 Pm ranged from 76 in Freeport to 82 in Muscatine. && .SHORT TERM...(This Evening through Friday) ISSUED AT 214 PM CDT Thu Jun 11 2020 Key Message: 1) Other than a slight chance of an PM rain shower/sprinkle, dry condtions will prevail for the rest of the work week with near to below normal temperatures. Discussion. The aforementioned high pressure centered across the lower Mississippi River Valley will slowly progress towards the southwest portions of the Ohio River Valley over the next 24 hours, and will continue to be the primary influence on our weather. The majority of the period will see partly to mostly clear skies with some diurnally driven Cu. Temperatures will be seasonable, with lows tonight in the mid to upper 50s, and afternoon highs Friday in the upper 70s to low 80s. Like today, some guidance including the GFS, HRRR and NAMnest attempt to fire some scattered sprinkles/rain showers Friday afternoon over northwest Illinois as a shortwave rounding an upper level low moves across southeast Wisconsin. However, dry sounding profiles and best forcing remaining out of the area favors mainly dry conditions, hence only a slight chance for now. .LONG TERM...(Friday Night through Thursday) ISSUED AT 214 PM CDT Thu Jun 11 2020 Key Messages: 1) Beautiful weekend shaping up with comfortable condtions Saturday; slightly warmer Sunday. 2) Other than a slight chance of rain/storms Monday, mainly dry and very warm weather is forecast for the remainder of the long term period. Discussion. Friday Night through Saturday... High pressure building into the upper Mississippi River Valley will usher a backdoor cold front across the area from east to west Friday night, and will stall just to the west of the Mississippi River Saturday. Conditions should be mainly dry as it passes with little in the way of vertical moisture and forcing to work with. However, I can`t rule out a sprinkle or two, especially during the early morning. This front will set the stage for a picture-perfect start to the weekend as easterly flow advects surface dewpoints in the mid 40s/low 50s and 925-850 hPa temps around 5-10 C into the area. Afternoon highs ranging from near 70 in northwest Illinois, to the upper 70s in northeast Missouri are forecast Saturday with a mix of sun and clouds. Perfect to do just about anything outdoors or to even keep the window open! Sunday... High pressure remains in control with another great day expected. Temperatures will be slightly warmer as increasing southerly flow aloft begins advecting warmer temperatures back into the area. Currently have afternoon highs advertised in the mid to upper 70s. Dewpoints will remain comfortable in the low to mid 50s. Monday... Deterministic guidance trending towards an omega-like blocking pattern establishing itself from the southern Great Plains to the upper Mississippi River Valley to start the week. This will effectively push low and mid level ridging across the area, with 950- 850 hPa temps progged to climb back into the 20-25 C range by late in the day into the overnight. Surface temps will respond, with afternoon highs forecast to climb to near 80 to the lower 80s. With the arrival of the warm air will come a chance for showers/storms. GFS/ECMWF starting to agree on development of precipitation along an elevated warm front/LLJ across central and east central IA Monday morning, which may potentially linger into the early afternoon before diminishing with the passage of the front. Tuesday on... Blended guidance favors dry condtions for the remainder of the long term with very warm and humid conditions persisting underneath the ridging. Daily highs are progged in the upper 80s to lower 90s by Wednesday, with overnight lows in the upper 60s to near 70. && .AVIATION...(For the 00Z TAFS through 00Z Friday Evening) ISSUED AT 621 PM CDT Thu Jun 11 2020 VFR conditions will be the rule for all terminals over the next 24 hours. Winds will be generally under 10 kts, from the northwest. && .HYDROLOGY... Issued at 1118 AM CDT Thu Jun 11 2020 Quiet weather through next week means that routed flow will be the main concern in river forecasting. In the next day or so, we should have a much better idea of this routed flow and thus better forecasts for crests into next week. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...Speck SHORT TERM...Speck LONG TERM...Speck AVIATION...Ervin HYDROLOGY...Gibbs
National Weather Service Hastings NE
628 PM CDT Thu Jun 11 2020 .SHORT TERM...(This evening through Friday) Issued at 257 PM CDT Thu Jun 11 2020 Clear skies and relatively light winds will continue this afternoon, and into tonight across the forecast area. A weak surface boundary stretches from near Dodge City up through far southern Nebraska. Winds are generally westerly north of this boundary and more southerly to the south of it, but otherwise isn`t impacting the weather in the local area. The HRRR shows some thunderstorms developing near this front this evening, but this should occur well south of our forecast area. Southeast winds start will increase a bit Saturday as surface high starts to shift east the pressure gradient tightens over the local area. That being said, we are talking about 15-25 MPH gusts, nowhere near the winds that we saw earlier this week. A warming trend will also start as an upper ridge amplifies overhead. Temperatures are forecast to be a couple degrees warmer than today in most spots with highs in the upper 80s and low 90s. .LONG TERM...(Friday night through Thursday) Issued at 257 PM CDT Thu Jun 11 2020 Hot and dry is the main story with this forecast. Most global deterministic models and ensembles are showing little (if any) precipitation through the next 7 days. The ridge axis will shift overhead Saturday into Sunday, pushing temperatures into the mid 90s to low 100s for most of the area. This will also be coupled with increasingly gusty southeasterly winds. Gusts to around 35 MPH are expected on Sunday. Chances for precipitation are very low during this period. The only opportunity for rain would be from High Plains convection moving in overnight, but locally dry air will make this very unlikely. This dry air will keep heat indices below heat advisory criteria through the weekend. The trough will be deamplified and pushed farther east Monday into Tuesday as troughing moves into the northwestern CONUS. This will lead way to more southwesterly winds at the surface, and highs are still forecast to reach the mid 90s and low 100s. There is a very small chance for isolated thunderstorms Monday as as a front tries to approach from the northwest. Even if these develop, the vast majority will still stay dry, so these chances remain far too low to include in the forecast. Next Wednesday is forecast to be the hottest day of the stretch, and most of the area will push into the upper 90s and make a run at 100 degrees. The passage of a front and increasingly zonal flow will then hopefully bring us some relief from in the form of rain chances and cooler temperatures next Thursday through the following weekend. && .AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Saturday) Issued at 626 PM CDT Thu Jun 11 2020 Skies are expected to be clear through the period. Light and somewhat variable winds are expected through the night and into Friday morning, before increasing from the east during the afternoon. && .GID WATCHES/WARNINGS/ADVISORIES... NE...NONE. KS...NONE. && $$ SHORT TERM...Mangels LONG TERM...Mangels AVIATION...JCB
Area Forecast Discussion
National Weather Service Goodland KS
535 PM MDT Thu Jun 11 2020 .SHORT TERM...(This afternoon through Friday Night) Issued at 1216 AM MDT Thu Jun 11 2020 18Z Water vapor imagery and RAP analysis indicated CWA on eastern portion of large H5 ridge centered over the northern Rockies. Large area of drying/subsidence was noted moving into the area. At the surface a trough was draped from southeast Colorado into central Nebraska. Not much of an airmass difference was noted across it in the Goodland CWA, although trough did mark the separation of strong southerly winds and much lighter conditions. For tonight...Any potential instability/thunderstorms will be to the south of the area where more intense heating and a narrow plume of higher dewpoints will be present. Given the northerly flow aloft, any storms that form here will not be heading towards the area. as a result expect clear skies and light winds to allow temperatures to drop into the low 50s at most locations and would not be shocked to see a few spots in the 40s in western zones. Friday-Friday Night...Upper level ridge will amplify and move to the east through the period, with strong subsidence and warming temperatures expected. Winds will shift to an easterly direction and increase in response to cyclogenesis over the Rockies. Some small potential for thunderstorms as instability axis will develop south of Interstate 70. Despite weakening CINH and instability, lack of persistent strong convergence and overall subsidence leads me to doubt that cap will be overcome and think continued dry forecast is warranted. Temps will return to the 90s on Friday and with increased winds may see conditions get close to Red Flag thresholds. For the time being it looks like conditions will not be met, but will have to keep an eye on it. .LONG TERM...(Saturday through Thursday) Issued at 154 PM MDT Thu Jun 11 2020 Through early next week, will see southwest flow aloft between a ridge axis to the east and an upper low over the northern Rockies. While thunderstorm chances will be low, cannot rule out an isolated afternoon or evening storm developing along persistent lee trough at the surface and synoptic forcing with any weak embedded shortwave aloft. The environment will be hot and dry, so storms will be high based with little precipitation reaching the ground, and potentially gusty winds. Starting Tuesday and through the end of the period, the upper ridge will retrograde/rebuild further west, though ECMWF weaker compared to the GFS. In fact, with the ridge further south, the ECMWF allows a weak cold front to slip into the area and a shortwave trough comes over the ridge with a chance of showers/thunderstorms on Thursday. No sign of this in the GFS, so will leave it dry for now. The other concern during this period will be fire weather. Fuels have dried enough in Kansas so that they are now considered susceptible to wild fires, in addition to Colorado. Relative humidity will drop to 15-20 percent every afternoon in the long term period with temperatures reaching the 90s to near 100. As a result, wind speeds will discriminate elevated from critical fire weather days. On Saturday winds will be marginal, on Sunday it appears critical conditions may be met with slightly higher wind speeds, on Monday and Tuesday winds are currently forecast to be light and only slightly higher on Wednesday and Thursday which appear marginal at best for critical. && .AVIATION...(For the 00Z TAFS through 00Z Friday evening) Issued at 535 PM MDT Thu Jun 11 2020 VFR conditions will present for both terminals during the forecast period. For winds, KGLD will see northerly winds around 10kts thru 03z-04z Friday, then light/variable. By 16z, SE 10-20kts. For KMCK, NNE around 10kts thru 04z Friday, then light/variable. By 16z, ESE 10-15kts. && .GLD WATCHES/WARNINGS/ADVISORIES... KS...NONE. CO...NONE. NE...NONE. && $$ SHORT TERM...JRM LONG TERM...024 AVIATION...JN
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1023 PM EDT Thu Jun 11 2020 .SYNOPSIS... Drier air will filter in behind a cold front and seasonably pleasant weather will be in store for Friday and Saturday. The front moves back west on Sunday as a wave of low pressure forms along it then stalls. Unsettled weather sets up shop in our area for the first half of next week. && .NEAR TERM /THROUGH FRIDAY/... As of 1010 PM: A weak frontal boundary is stretched out just south of I-85 across the CWA, and this will settle slowly southward thru the remainder of the area this evening. Convective activity has continued to congeal across central NC, building westward to the Stanly/Cabarrus border in the last hour. This band is beginning to push into Union NC, with combined front/outflow boundary extending west to eastern York Co. TCLT returns indicate the outflow is starting to edge out from under the precip core, and trends in recent HRRR runs suggest that will be the beginning of the end of that activity. Nevertheless, torrential rain is expected in the next hr or two over much of Union County, where we have a seemingly expertly placed Flash Flood Watch (props to the previous shift). Still could see a bit more back-building into the eastern Upstate or far southern Meck in the same timeframe. Large DCAPE exceeding 1000 J/kg implies some risk of a damaging microburst with the more vigorous activity, in addition to the heavy rain threat. Meanwhile, a 500 mb trough axis will continue to sharpen up along or just west of the southern Appalachians tonight through Friday. This may further slow the eastward progress of the frontal zone. The Flash Flood Watch may be cancelled prior to its expiration at 6 AM. Between light easterly upslope flow behind the front, and upper DPVA from the west, increasing cloud cover is expected, and a stray shower can`t be totally ruled out. Northeasterly flow should finally bring better boundary layer drying in the early morning, lasting through Friday. Max temps will run 1 to 2 categories cooler on Friday afternoon, and dewpoints may advect/mix into the 50s in many locations, with plenty of high mountain 40s expected. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/... As of 225 PM EDT Thursday: The short-term fcst picks up at 00z on Saturday with heights falling across the fcst area as broad upper trofing digs down over the Eastern CONUS. The upper trof deepens thru the period as a series of shortwaves rotate thru the larger trof. At the sfc, a stalled-out frontal boundary will still be lingering to our east and south with very broad Canadian high pressure centered well to our NW. The high will gradually shift SE thru the period, keeping NLY to NELY low-lvl flow over the area thru most of the period. By the end of the period late Sunday, the models try to develop a weak wedge east of the Appalachians, but it is not expected to become very well-defined. Overall, Saturday has been trending drier with just a slight chance for convection over our NE zones. With deeper moisture spreading over the area on Sunday, the chances for sct to widespread showers and thunderstorms increase considerably, especially over the NE zones. Saturday temps will likely be just below climatology and Sunday temps will be a few degrees cooler than Saturday. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... As of 215 PM EDT Thursday: The extended fcst picks up at 00z on Monday with an upper low closing off over the Ohio Valley while steep upper ridging persists over the Central CONUS. The long range guidance continues to keep this upper low nearly stationary just to our north thru at least mid-week. The latest GFS tries to open the low back up by late Wednesday as it drifts over the Atlantic Coast, but then stalls the system again over the coast. The ECMWF keeps the low closed and farther west thru the end of the period. At the sfc, broad Canadian high pressure will be in place well to our north as the period begins. The ECMWF has another wave of low pressure develop on the stalled frontal bndy and keeps it nearly stationary allowing a moist ELY flow with widespread precip over the area thru most of the period. The GFS, on the other hand, moves the low NE on Tues and Wed with little in the way of widespread precip on both days. As for the sensible fcst, I continue to use a model blend which gives solid chance to likely PoP over our eastern zones and slight to solid chance over our western zones. Temps have been trending a bit cooler for much of the period, with values below normal thru Wednesday and near-normal temps by the end of the period. && .AVIATION /03Z FRIDAY THROUGH TUESDAY/... At KCLT and elsewhere: Front will settle past KAND later this evening, leaving northerly flow at all sites for the period. This flow will veer into NE quadrant late tonight or Friday. Patchy VFR clouds persist across the area, and development of easterly midlevel flow north of the front will lead to cig development around 035-060. Dissipating clouds in the morning with the few bases that remain being at VFR level. Outlook: Expect dry/VFR weather to continue through Saturday. Then, moisture slowly returns with chances of mainly diurnal convection Sunday through early next week. Confidence Table... 02-08Z 08-14Z 14-20Z 20-00Z KCLT High 100% High 100% High 100% High 100% KGSP High 100% High 100% High 100% High 100% KAVL High 100% High 100% High 100% High 100% KHKY High 100% High 100% High 100% High 100% KGMU High 100% High 100% High 100% High 100% KAND High 100% High 100% High 100% High 100% The percentage reflects the number of guidance members agreeing with the scheduled TAF issuance flight rule category. Complete hourly experimental aviation forecast consistency tables are available at the following link: && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...Flash Flood Watch until 6 AM EDT Friday for NCZ082. SC...None. && $$ SYNOPSIS...CAC NEAR TERM...HG/08 SHORT TERM...JPT LONG TERM...JPT AVIATION...08
Area Forecast Discussion
National Weather Service Paducah KY
647 PM CDT Thu Jun 11 2020 .SHORT TERM...(Tonight through Saturday night) Issued at 239 PM CDT Thu Jun 11 2020 Dry weather will continue through at least Saturday night. A mid- level ridge will build eastward into the area tonight and Friday, which will allow for a nice warm up to slightly above normal levels. Highs in the upper 80s will be common. After that, the upper pattern will amplify with the trough pushing the ridge back to our west. This will result in dry and cool surface high pressure reasserting itself over our region for the first half of the weekend. Highs Saturday will be a few degrees below normal and lows Saturday night will be 7 or 8 degrees below normal. .LONG TERM...(Sunday through Thursday) Issued at 239 PM CDT Thu Jun 11 2020 Models show a mid/upper level trof to our east and a mid/upper level ridge to our west from Sunday through mid week. The ridge makes very little progress east due to a cutoff low developing in this trof. The low will roam around over the east central and southeast U.S., or just off the east coast, through the week. This pattern keeps the PAH forecast area dry, and with northerly flow aloft, dry air will keeps skies clear to partly cloudy. At the surface, north to northeast flow will persist through Tuesday. This will only allow temperatures to moderate a few degrees, going from highs in the middle 70s to near 80 degrees Sunday, to seasonal readings in the middle 80s by Tuesday. Humidity levels will remain quite low, with dew points in the middle 40s to around 50 degrees on Sunday, moderating to the middle 50s by Tuesday. Overnight lows Sunday night will be 8 to 10 degrees below normal in the lower to middle 50s, with lows Monday night in the middle 50s. By Tuesday night into Wednesday, a surface low over the Central Plains and a surface high over the northeast U.S. will shift our winds back to the south to southwest. This warm southerly flow will push high temperatures into the upper 80s by Wednesday and the lower 90s by Thursday. Dew points will also gradually creep upwards, with readings in the lower 60s by Thursday. This is still pretty comfortable for mid June. Overnight lows will also be trending upward, will lows near normal by Wednesday night in the middle 60s. && .AVIATION... Issued at 646 PM CDT Thu Jun 11 2020 VFR forecast for the 00z Friday WFO PAH TAF issuance. Some question of whether parcel moisture will be sufficient for Few or Scattered cloud bases around 6-10kft AGL across most of the TAF sites. RH values at this level barely reach 60 percent during the day on Friday. Moisture trajectories at this point don`t support much in the way of lower cloud decks at this time. Good mixing and moisture transport may have taken away alot of boundary layer moisture yesterday and today. For now, have gone with cloud bases near cirrus level, this is in line with a majority of NWS offices. The NAM and RAP guidance do bring some moisture in the 2.5-3km AGL level toward the KCGI/KPAH TAF sites near 00z Saturday, but would like to see some continuity before introducing cloud bases again with the 06z Friday TAFs. && .PAH WATCHES/WARNINGS/ADVISORIES... IL...None. MO...None. IN...None. KY...None. && $$ SHORT TERM...DRS LONG TERM...RST AVIATION...Smith
Area Forecast Discussion
National Weather Service Blacksburg VA
740 PM EDT Thu Jun 11 2020 .SYNOPSIS... For the weekend, an upper level trough of Low pressure over eastern Canada will gradually move south through the Great Lakes and Ohio Valley, bringing a return of moisture to the region. This upper level trough is expected to cutoff over the eastern United States and become nearly stationary for early next week resulting in unsettled weather Sunday through Wednesday. && .NEAR TERM /THROUGH FRIDAY/... As of 720 PM EDT Thursday... Made some minor adjustments in pops and weather for this evening into tonight using the latest radar images and blended in the HRRR and NAMnest. Adjusted temperatures for this evening into tonight utilizing the surface obs,their trends and shaped towards NBM tonight. As of 210 PM EDT Thursday... A cold front is moving across the VA/NC piedmont with scattered showers and thunderstorms out ahead of it. Instabilities have been restricted by cloud cover, but modest CAPE and shear enough for a Marginal Risk for strong/severe capable of producing damaging winds this afternoon. The front and associated convection will move east into the coastal piedmont this evening. Behind the front, high pressure will bring cooler temperatures and lower humidities to the area that will linger into the day Friday. Today`s highs will top out in the 70s across the mountains to upper 80s east of the Blue Ridge. Same idea tomorrow but a few degrees cooler. The upper 60s to mid 70s dew points the past couple of days will drop into the 50s. && .SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/... As of 100 PM EDT Thursday... A narrow region of high pressure will continue over the area Friday night into early Saturday, providing for no precipitation, less humidity, and slightly cooler conditions. This will be short-lived. Our next cold front is expected to arrive Saturday evening. This front will bring isolated to scattered showers and storms to northern parts of the region by Saturday afternoon. Additional showers will continue into Saturday night, and increase in coverage. By Sunday, the front is expected to be to our south, but stalled west to east across the Carolinas. Additionally, we are expected to see the development of a closed area of low pressure over New York state and a shortwave trough over the western Great Lakes region. While the NY low is expected to head northeast and weaken, the western Great Lakes feature is expected to head southeast into the Ohio Valley, stall, close-off, and deepen. While the proximity of the stalled front to the south will play a role as a focus for convection on Sunday, the advancing upper low with its steepening lapse rates will also help in shower and storm development. Heading into Sunday night, models start to deviate on the exact path this closed low will take. However, all seem in agreement that it will be slow in heading in any one direction. This will help keep the potential for additional showers in the forecast Sunday night. Temperatures during this portion of the forecast will start near normal, but trend to readings slightly below normal. Confidence in the above section of the forecast is moderate to high. && .LONG TERM /MONDAY THROUGH THURSDAY/... As of 1100 AM EDT Thursday... During this portion of the forecast, guidance is offering a solution that places a closed upper level low pressure parked over either the mid-Atlantic or southeast U.S. region of the country. While this variability makes specific details tricky given the nature of just where this upper low, and its associated surface low will meander, a more generalized statement is probably the best way to go at this point. With the low parked/wobbling either over, or very near the area, there should be daily chances of showers and some storms thanks to both the relatively steep lapse rates that will be produced by the system`s relative cool core aloft, and jet dynamics and weaker shortwave troughs traversing through the cyclonic flow around the parent low. Add in some daytime heating, and this entire period of the forecast has the potential for daytime showers and storms, maximized during the peak heating of the day, and then waning heading through the evening and overnight hours. On a day to day basis, we`ll need to monitor where the heaviest rains occur, potentially setting up one area of the region over another as a candidate for localized flooding. With expected precipitation and enhanced cloud cover, temperatures during this portion of the forecast are expected to average a little below normal, but with a trend towards potentially milder numbers late in the period if the low can make some progress east of the area. Confidence in the above scenario is moderate. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... As of 740 PM EDT Thursday... A cold front continues to move east towards the Atlantic ocean tonight. Isolated showers and thunderstorms are possible for the next couple of hours in the southeast portion of the forecast area. VFR conditions will continue at the TAF sites this evening into tonight. Patchy fog is possible in the western river valleys especially the Greenbrier valley overnight into Friday morning. KLWB may drop to LIFR conditions Friday morning. Any fog or low clouds will lift quickly Friday morning. VFR conditions expected Friday afternoon. High confidence in ceilings,visibilities and winds during the taf period. Extended Aviation Discussion... Surface front is expected to remain stalled along the eastern seaboard with main impacts to aviation confined to the piedmont and tidewater areas into Friday night. A secondary front is expected to cross the area Saturday, possibly associated with showers and MVFR Cigs. For early next week, an upper level trough of low pressure over eastern Canada will gradually move south through the Great Lakes and Ohio Valley, bringing a return of moisture to the region. This upper level trough is expected to cutoff over the eastern United States and become nearly stationary through midweek resulting in unsettled weather Sunday through Wednesday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...RCS NEAR TERM...KK/RCS SHORT TERM...DS LONG TERM...DS AVIATION...KK/RCS