Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/10/17


Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1200 AM EDT Tue Oct 10 2017 .AVIATION... Quiet weather over southeastern Michigan with weak surface ridging in place and virtually zero thermal advections to speak of. Upper level confluence will strengthen by morning as the entrance region to the upper level jet axis will snap into place directly over the Great Lakes. Uncertainty exists as to the likelihood of fog overnight. Rap soundings have been bouncing around a fair amount in not only saturation but also with the surface inversion structure. RAP forecast soundings remain not nearly as bullish in amount of near surface saturation but given a couple of obs with Haze concerns, lack of mixing will lead to some br/fg. Will continue a MVFR fog mention. For DTW...Expecting some fog to develop late Tonight, just not sure how dense it will become with the shallow moisture. Otherwise, could see MVFR stratus track in from the north Tuesday morning. //DTW THRESHOLD PROBABILITIES... * Low for cigs at or below 5000 ft late tonight into Tuesday morning. * Very low for cigs/vis aob 200 ft and/or 1/2SM from 10-13z. && .PREV DISCUSSION... Issued at 348 PM EDT Mon Oct 9 2017 DISCUSSION... An outstanding fall day is unfolding around SE Michigan this afternoon. Under plenty of sunshine, highs are solidly in the mid to upper 70s which are 10 to 15 degrees above normal for early October but well short of records in the mid to upper 80s. A cold front over the northern Great Lakes will then move through the region tonight and bring quite a change for Tuesday. The front remains too lean on moisture for rain but will bring clouds and cooler air after fully exiting into Ohio Tuesday morning. Observations indicate just some fragile bands of low clouds within the frontal zone over the northern Great Lakes today, along and north of the surface wind shift and are modeled to remain in a similar relative position in the frontal zone during the night. This is important for potential fog development overnight as there is also a lack of high clouds upstream which will allow some radiational cooling of the relatively moist boundary layer over SE Michigan. Timing the frontal passage shortly after midnight in the Tri Cities and northern Thumb regions will likely prevent fog coverage there in favor of low clouds. A later wind shift farther south will bring the greatest coverage of fog along and south of the I-69 corridor and especially through the Detroit metro area to the Ohio border. The wind shift to the northeast will then scour out remaining surface moisture by mid Tuesday morning leaving varying amounts of low cloud coverage within the frontal inversion for the rest of the day. Expect these clouds will have greater coverage near the Ohio border while mid and high clouds associated with both the front and the next upper wave cover points north through the afternoon. Prefer guidance temperatures in the 60s considering the cooler northeast flow that will be in place along with the clouds. As the front settles toward the Ohio valley, the stage will be set for it to interact with the next low pressure system and produce a generous rainfall event Tuesday night through Wednesday. The upper wave is observed moving through the central Rockies today and is already producing significant lee side surface cyclogenesis over the southern Plains. There is good model agreement to then bring the system into the mid Mississippi valley during Tuesday while tapping deep moisture from the Gulf region that will supply a pattern of isentropic ascent over lower Michigan Tuesday night. The upper wave is then projected to move directly over the region early Wednesday with a surface low track south of the Ohio border through the day. There is some variation in solutions on the surface low track and character while agreement is solid in the formation of a mid level theta-e trowal axis over SE Michigan as a sign of the dynamic support within the wave. Model QPF offering 12 hr totals around 1 inch then look reasonable ending Wednesday afternoon. The potential for excessive rainfall will be limited by a northward push of the dry slot and the fast movement of the system. Upper-level ridging aloft and surface high pressure will influence the Great Lakes Thursday into Friday which will bring dry conditions and will allow temperatures to slowly ramp up through the weekend. Wind direction will shift from the northeast to the southwest Thursday into Friday, which will allow warmer air to push daytime highs into the lower 70s Friday afternoon. WAA will continue to ramp up Friday into Saturday, as noted in the 850 mb thermal maps, where temperatures averaging 6C Friday morning increases to 15C Saturday morning. An increase in warmer air and a chance to see periods of extended sunshine will allow daytime highs to peak in the mid to upper 70s, and even the lower 80s across Metro Detroit Saturday afternoon. For reference, normal daytime high temperatures reside in the lower 60s across SE Michigan for mid-October. The next likely chance for rain and thunderstorms will come to Michigan Saturday into Sunday, however, confidence regarding timing and intensity remain low as discrepancies between long range models are prevalent. The GFS pushes the warm front and an associated LLJ across Central Michigan which produces precipitation across the Tri- Cities to thumb. As low pressure pushes northeast from northern Illinois into Central Michigan, rain chances eventually spread across the Metro Detroit region, with PoPs continuing through early Sunday as a cold front sweeps through the state. The ECMWF model produces rain chances from the warm front early Sunday. The center of the low pressure center is north compared to the GFS run, pushing northeast from southern WI into northern lower Michigan, which drags the associated cold front through the state early Monday morning. Cool and dry air will filter in behind the cold front Monday into Tuesday, which is expected to return temperatures back to seasonal values. MARINE... A cold front dropping south through the region will bring an increase in north-northwest winds across lake Huron Tonight. Winds will be topping out between 20 to 25 knots over the open waters of Lake Huron by Tuesday morning. This trajectory will build wave heights to 4 feet over greater over southern lake Huron, which should impact the nearshore waters as well. Winds will then ease a bit late Tuesday and Tuesday night, while shifting to north. However, easterly winds on Wednesday will increase back into the 20 to 25 knot ranges, as low pressure tracks through the Ohio Valley. Additional small craft advisories will likely be needed. HYDROLOGY... Widespread rainfall is expected Tuesday night into Wednesday as a low pressure system tracks through the Ohio Valley. Rainfall totals around 1 inch appear likely, but the rainfall will occur over a longer duration, roughly 12 or more hours. Thus, no flooding is anticipated, but standing water on the area roadways and in the flood-prone low lying areas and area roadways should be expected. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...Small Craft Advisory until 2 PM EDT Tuesday for LHZ421-441-442. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....CB DISCUSSION...BT/AM MARINE.......SF HYDROLOGY....SF You can obtain your latest National Weather Service forecasts online at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Quad Cities IA IL
610 PM CDT Mon Oct 9 2017 ...00z AVIATION UPDATE... .SYNOPSIS... Issued at 320 PM CDT Mon Oct 9 2017 A front extended across Missouri into northern Illinois during the afternoon. Near and south of the front, temperatures reached the low 80s around Macomb. North of the front, readings were in the upper 60s near Independence. Clouds increased during the afternoon, along and east of the Mississippi River, while eastern Iowa was mostly clear. && .SHORT TERM...(This Evening through Tuesday) ISSUED AT 320 PM CDT Mon Oct 9 2017 The main forecast issues in the short term period are rainfall amounts and coverage, and potential for isolated severe weather and flash flooding. In the near term, the NamNest and HRRR have hinted at a few showers developing in the enhanced CU field over the far southeast counties during the late afternoon. Have opted to keep forecast dry for now and monitor short-term trends. Later this evening, expect an increasing N/NE wind as surface low pressure approaches the region. Have held off any showers until after midnight, per consensus model timing. Areas along and south of I-80 would be favored for rain through 12z. Tuesday morning, showers and scattered storms forecast to increase in coverage from south to north. There are some variations in the main surface low track, with the ECMWF still the farthest northwest. The 500mb low tracks are similar. The ECMWF continues to be very consistent with track and bullish QPF output. WPC has the forecast area in the day 2 marginal risk area for excessive rainfall. Am thinking most areas can take a good amount of rain with no issues, but will have to monitor urban areas affected by very high rainfall rates. Regarding severe weather potential, there are a number of factors that raise some red flags. This will be another unseasonably moist airmass, with PWAT values above 1.5 inches. A potent negatively tilted 500mb wave is concerning. The key may be if enough MUCAPE develops, to complement the large level shear/helicity and favorable 0-3km shear vectors. CAMS are indicating at the very least, some strong storms will be an issue Tuesday morning and again during the afternoon. Straight line winds and brief HSLC tornadoes would be the main threats with this potentially volatile set-up. The farther NW ECMWF solution would mean more of the southeast counties exposed to this risk. Confidence in these scenarios is typically low a day in advance, but we will be monitoring closely. .LONG TERM...(Tuesday Night through Monday) ISSUED AT 320 PM CDT Mon Oct 9 2017 The next storm system moves through Tuesday night and exits the area Wednesday morning. A general rain across the area is expected with some embedded thunderstorms early Tuesday evening. The best chances for rain look to be Tuesday evening with rain slowly ending from southwest to northeast late Tuesday night into Wednesday morning. Dry conditions are expected Wednesday afternoon through Thursday as high pressure builds into the Midwest. The models are suggesting the potential for a layer of moisture becoming trapped which, if correct, suggests plenty of low clouds Wednesday night and Thursday. Thursday night on... Thursday night/Friday the model consensus has dry conditions for the area as high pressure moves into the eastern Great Lakes. Temperatures will average above normal. Starting Friday night and continuing through Sunday a period of unsettled weather looks to be in store for the area. The models bring another front into the area that stalls. While the front is stalled, another storm system will ride up along the front bringing another widespread rain event for the area. There are timing differences on when the storm system will move up along the stalled front. The ECMWF suggests Saturday night/Sunday while the GFS suggests Saturday/Saturday night. There are also questions regarding moisture availability when the front initially arrives in the area Friday night. The arriving storm system will bring a slug of moisture with it so rain chances would be higher when it moves through the area. As a result of the timing differences, the model consensus has chance pops Friday night, likely to categorical pops Saturday/Saturday night, and chance pops on Sunday. Sunday night/Monday the model consensus has dry conditions for the area as high pressure moves through the Midwest. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) ISSUED AT 603 PM CDT Mon Oct 9 2017 VFR conditions expected tonight with gusty northerly winds developing in strengthening pressure gradient post frontal. Tuesday into Tuesday evening expect deteriorating conditions to MVFR in low clouds and bouts of rain/showers, as a storm system approaches from the Southern Plains. Some bouts of IFR is possible at times, mainly for visibility in the showers. There is a low risk of isolated storms near KBRL, but risk too low for mention at this time. Best storm chances appear to be southeast of the terminals from eastern MO into central IL. Winds on Tue-Tue evening will remain gusty at 15-25 kts. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...NONE. IL...NONE. MO...NONE. && $$ SYNOPSIS...RP Kinney SHORT TERM...RP Kinney LONG TERM...08 AVIATION...McClure
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
958 PM CDT Mon Oct 9 2017 .UPDATE... /REDUCED POPS SLIGHTLY...LOWERED MAX T SE TUES/ Cold front is seen on radar/satellite to have entered the CWA and appears to have increased forward speed to around 15 knots. This brings a few more areas into seeing the wind shift before midnight, so have adjusted the winds to shift earlier to reflect the latest rapid refresh data. Shower and thunderstorm activity is less robust then from earlier in the evening when some daytime heating ahead of the front was factored in; all the higher res models are trending down on QPF, and will follow suit on the forecast with less thunder/ QPF, and slightly lower PoPs across the board both tonight and Tuesday. Good mixing is still expected in the overnight hours and the front is still expected to clear all areas in time to prevent a mid-morning max temperature. Latest blended guidance has cooler maxes over southeast counties, and with deep frontal mixing and cloud cover expected nearly all day, will trim a degree or three off the highs SE of I-35 for Tuesday. && .PREV DISCUSSION... /ISSUED 701 PM CDT Mon Oct 9 2017/ UPDATE... 00Z Aviation Update Below. AVIATION... VFR conditions will prevail through the evening hours. A cold front will enter the northern Hill Country between 02Z-04Z and reach the AUS area roughly around 06Z and SAT/DRT around 07Z. Currently isolated TSRAs have developed along the front north of the region. Latest HRRR guidance indicates a few of these storms could approach AQO-BMQ and can`t rule out the possibility of a strong storm near this region. HRRR then suggests decreasing coverage after 04Z as front encounters increasing CIN after sunset and an inversion noted around H85-H8 by aircraft sounding data from AUS. The latest Texas Tech 4 KM WRF and HRRR overnight suggests convective activity primarily in the form of a quick shot of a scattered to broken line of SHRAs along and behind the front. Have therefore indicated primarily VCSH in the TAF sites overnight. Forecast soundings indicate MVFR deck developing behind the front and potentially lasting through at least midday on Tuesday, especially southern TAF sites of SAT and DRT. N winds will develop behind the front and strengthen to 13-20 kts, with gusts in excess of 25 kts, between 08Z-10Z at DRT and 11Z-13Z at AUS/SAT. The winds will gradually weaken mid to late afternoon. PREV DISCUSSION... /ISSUED 244 PM CDT Mon Oct 9 2017/ SHORT TERM (Tonight through Tuesday Night)... Mostly clear skies are prevailing across the area with temperatures already in the upper 80s to lower 90 degrees. Expect these values to warm a few more degrees this afternoon with highs reaching the lower to middle 90s. Some of the climate sites will likely be close to record values which are: Austin Mabry - 95 Austin Bergstrom - 93 San Antonio Intl - 94 Del Rio - 95. There is relief in sight as a cold front continues to push south across North Texas. The front currently lies along a line from near Midland to Abilene to Wichita Falls. The upper low associated with the cold front is currently in southern Colorado and will continue to push east into southern Kansas by tomorrow morning. Isolated to scattered showers and thunderstorms should develop along the boundary later this afternoon in Oklahoma and North Texas. The best dynamical forcing will be located in this region and therefore this is where the bulk of the activity will remain this afternoon and where storms should be strongest. There is a marginal risk for severe storms for North Texas and a slight risk closer to the OK/KS border where the upper low will track. For our CWA, the front will arrive to the northern counties around midnight and there should be a broken line of showers and storms along it. Any shower and storm activity will be primarily driven by frontogenetical forcing and should be a quick shot of rain with the FROPA. The environment overnight will have about 1000-1500 J/kg of CAPE but shear values of 15-30 knots will remain unsupportive for organized convection which is primarily due to the track of the upper low. With the expected instability values, a strong storm with gusty winds and/or small hail cant be ruled out in any multi-cellular cluster but not expecting much. The front will continue to progress southward overnight bringing much of the CWA a 40-60 percent chance of a quick shower or thunderstorm with it. The higher PoPs will be in the western counties where upper flow is a bit higher and there could be some weak upper lift to support a slightly higher coverage of activity. There could even be some scattered lingering activity as well through the morning hours in the western counties. Behind the front, cooler temperatures will quickly usher in. Night time lows will be dependent on where the exact frontal position will be in the morning. Upper 50s are possible in the Hill Country before the sun begins to bring surface heating in the morning. Highs tomorrow will be about 20-25 degrees cooler than today with highs in the upper 60s in the Hill Country and 70s elsewhere behind strong cold-air advection. North winds behind the front tomorrow will be breezy with speeds around 20 mph with higher gusts. For tomorrow night, lows will be in the 50s to near 60 degrees which should be a welcome change for most of us. LONG TERM (Wednesday through Monday)... The cooler weather will stick around Wednesday as the surface ridge remains in the region. Highs will be in the middle 70s to lower 80s. Lows Wednesday night will be back in the 50s/60s but just a few degrees warmer than Tuesday night. The warm-up will begin Thursday with highs expected to be in the middle to upper 80s and lows in the upper 60s to near 70 degrees. These temperatures will remain in the forecast through the Sunday. Medium-range guidance is somewhat consistent with the progging of another cold front Sunday night. The parent upper trough will be even farther north than the current front and therefore rain chances should be less. Will only show a 20 PoP Sunday and Monday to cover the low-end rain threat. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 62 73 57 78 62 / 40 20 - - - Austin Bergstrom Intl Airport 64 73 57 77 60 / 40 20 - - - New Braunfels Muni Airport 65 75 58 77 61 / 40 20 - - - Burnet Muni Airport 57 70 53 75 58 / 40 20 0 - - Del Rio Intl Airport 63 72 59 77 63 / 40 30 - - - Georgetown Muni Airport 60 72 55 77 59 / 40 20 0 - - Hondo Muni Airport 64 74 58 80 62 / 50 20 - 10 - San Marcos Muni Airport 64 74 57 77 60 / 40 20 - - - La Grange - Fayette Regional 67 74 59 79 62 / 30 20 - - 10 San Antonio Intl Airport 65 73 60 78 63 / 50 20 - 10 - Stinson Muni Airport 67 74 60 78 63 / 40 20 - 10 - && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Mesoscale/Aviation...Runyen Synoptic/Grids...Oaks Public Service/Data Collection...Treadway
Area Forecast Discussion...UPDATED
National Weather Service Fort Worth TX
930 PM CDT Mon Oct 9 2017 .UPDATE... An upper low can be seen on the latest water vapor satellite loop moving east into the Oklahoma and Texas Panhandles. Lift associated with this system is spreading east into North Texas, which is beginning to generate elevated convection across the northwestern third of the forecast area. This activity is well behind tonight`s cold front, which has made it through the Metroplex and was located near a Bonham-Hillsboro-Lampasas line during the past hour. Surface-based convection will remain possible along the front as it pushes east, but strong to severe storms are no longer expected due to the loss of surface instability. Meanwhile, elevated showers and occasional storms will also remain a possibility farther west, and we have extended POPs farther west during the overnight hours to account for this activity. Precipitation will come to an end during the morning hours as the front moves southeast of the forecast area and the upper low shifts east of the Plains. Much cooler weather and breezy conditions are expected behind the front, and the rest of the forecast is unchanged. 30 && .AVIATION... /Issued 706 PM CDT Mon Oct 9 2017/ A cold front stretching from GYI to DFW to MNZ will continue to work its way through the Metroplex during the next hour. DFW is just now indicating a wind shift at the airport and DAL should follow suit during he next hour, so all TAFs in the Metro area will begin with northwest winds. The front will take a few more hours to reach the Waco area, and have indicated FROPA at 10/0200Z for KACT. Convection has begun to develop west of the KACT area in a region of good instability and these cells are spreading east-northeast. Additional storms will remain possible along the front even though the better forcing will remain north of the region. The TEMPO group for thunder has therefore been removed from the TAFs due to the isolated nature of this evening`s convection, but will keep VCTS in the forecasts though 10/04Z in the Metroplex and through 10/07Z at KACT. It`s possible that elevated showers will continue into the overnight hours as slightly better lift arrives, so will keep an eye on that for future TAF issuances. Northwest winds are gusty immediately behind the front but should slacken around an hour after FROPA. Wind speeds will increase again later this evening as the main surge of cooler air arrives. A layer of stratocumulus is still progged to develop above the frontal layer later this evening, but pretty much all of the latest guidance keeps this cloud deck up in the VFR range. Clouds will scatter during the day Tuesday, and winds will finally drop below 10 KT after sunset Tuesday evening. 30 && .SHORT TERM... /Issued 322 PM CDT Mon Oct 9 2017/ /Through Tonight/ At this hour, a strong cold front extended from near a Bowie to Mineral Wells to Eastland line. This feature continues to outpace most model guidance, with the exception of NAM-WRF solutions. With that in mind, the short-term forecast will follow this suite of guidance closely. In terms of convective chances, the latest mesoanalysis indicates that a plume of 1,500-2,000 J/kg CAPE was located along the I-35 corridor with decreasing CIN. As the cold front slides southward and overtakes a subtle dryline/pre-frontal trough, it still seems probable that we will see convective initiation around the 2300 to 0100 UTC time frame. Short term guidance still indicates that there are a couple of areas favored for convective initiation. The first is for areas near and north of I-20, closer to the strong belt of mid-level flow and an increasingly more robust CU field was noted here.. The other area is down across Central TX, where guidance may be keying in on enhanced surface convergence as the cold front overtakes the pre- frontal trough/dryline. I`m a little hesitant to go any higher than 50 PoP given that the environment aloft is still somewhat hostile for widespread severe weather, so we will keep with the chance PoPs. The threat for strong to severe thunderstorms still appears possible, but the speed of the front may ultimately prove to be too much for a long duration severe weather episode with the mid level system deeper and lagging behind the front. The threat for strong to severe storms should be brief on the order of perhaps 1 to 3 hours. The primary hazards will remain damaging winds and hail. For a more detailed storm scale analysis, please see the previous mesoscale update discussion. Latest runs of the HRRR do indicate the potential for some post-frontal thunderstorms and should this occur, the main hazard would be hail up to the size of quarters with this activity. For now, this is something that will need to be addressed in later short term/mesoscale updates. The other big change will be the strong northwesterly flow in the wake of the front. Surface pressure rises will allow sustained winds of 20 to 25 MPH with gusts to 35 MPH not out of the realm of possibility. We will hold off on a wind advisory as observations upstream are a little on the marginal side and for now, I`ll defer to later shifts. Overnight low temperatures will fall into the 50s and 60s. 24-Bain && .LONG TERM... /Issued 322 PM CDT Mon Oct 9 2017/ /Tuesday Through Next Weekend/ The strong early Fall cold front will be surging through East Texas and the Upper Texas Coast by the time we hit daybreak Tuesday. Strong CAA will combine with good surface pressure rises for gusty northwest winds 15-25 mph, much cooler temperatures, and a few elevated showers across the southeast CWA for the morning hours. The vigorous mid level shortwave will move readily northeast toward the Mid Mississippi Valley by afternoon with continued dry air advection for clearing skies and afternoon highs recovering to between 65 and 70 degrees northwest, to the mid 70s southeast. Northwest wind speeds will also begin a slow decline late in the day and into the evening hours, as the pressure gradient slackens with the arrival of the surface high and decoupling of the dry airmass. One of the coolest mornings since last Spring will occur Wednesday morning with good radiational cooling and light winds expected. Lows will be in the 40s most locales across rural counties, with low 50s possible across immediate urban areas and our far southern counties. The upper ridge of the Southeast U.S. and Gulf Coast will begin expanding westward over North and Central Texas with a slow return to modest south-southeast winds for the end of the week Thursday and Friday. Temperatures and humidity values will remain comfortable with lows in the 50s Thursday morning and highs in the lower-mid 80s. The warmth and humidity will begin to return in earnest later Friday into next weekend, as a large upper trough deepens across the Rockies once again. This will help to intensify lee side cyclogenesis to the northwest and ahead of another frontal boundary with southerly low level flow helping to pull Gulf moisture back northward. Friday into Saturday will once again see lows in the 60s and lower 70s, with afternoon highs pushing 90 degrees once again. A vigorous shortwave will once again exit east across the Plains later in the weekend with a cold front moving into the area last Saturday Night and Sunday. There are the usual and obvious discrepancies between the GFS and European models with the former being further south and more aggressive with the frontal timing and convective chances. Meanwhile, the latter is further north with system as a whole and slower by 12-18 hours. For now, went with the more conservative and slower European model for low convective chances Sunday into Monday due to the GFS looking to dissipate the upper ridge over southern latitudes too quickly. Nevertheless, cooler Fall conditions will return once again early next week. 05/ && .PRELIMINARY POINT TEMPS/POPS... Dallas-Ft. Worth 54 70 49 75 57 / 40 10 0 0 0 Waco 56 73 50 78 56 / 40 10 0 0 0 Paris 56 70 46 74 52 / 50 10 0 0 0 Denton 52 68 45 75 54 / 30 10 0 0 0 McKinney 53 69 46 74 54 / 40 10 0 0 0 Dallas 56 71 51 76 58 / 50 10 0 0 0 Terrell 57 71 47 76 54 / 30 10 0 0 0 Corsicana 59 73 50 77 56 / 30 10 0 0 0 Temple 57 72 51 76 55 / 40 10 0 0 0 Mineral Wells 52 68 44 75 52 / 30 5 0 0 0 && .FWD WATCHES/WARNINGS/ADVISORIES... None. && $$ 30/82
Area Forecast Discussion
National Weather Service Green Bay WI
1012 PM CDT Mon Oct 9 2017 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Tuesday Issued at 219 PM CDT Mon Oct 9 2017 The latest RAP analysis and satellite/radar imagery show a dry cold front over southeast Wisconsin. A broken band of clouds exists behind the front over the southern Fox Valley and northeast WI. More widespread mid-level cloud cover resides upstream over northwest Wisconsin and Minnesota, behind a secondary cold front. Temps are currently in the 40s behind the secondary boundary, while mainly in the 60s ahead of it. As this front sags into the area late tonight, forecast concerns center mainly around temps. Tonight...The trailing cold front will slide across north-central Wisconsin. Area of mid clouds and a northwest wind will likely hold up temps for the evening, but then should see clearing skies and calming winds occur overnight. With the incoming cold airmass, temps are projected to fall into the low to mid 30s over north- central WI, so will issue a frost advisory. Over northeast WI, some clouds will likely persist into early this evening, before partially clearing arrives. Low temps falling into the mid to upper 40s over eastern WI. Tuesday...As a storm system moves across the central Plains, will see clouds on the increase from late morning through the afternoon after a mostly sunny/partly cloudy start. Dry air will erode precip as it tries to move northeast ahead of the system, but left a slight chance in the forecast from southern Wood to southern Winnebago counties. Cooler high temps in the mid 50s to near 60. .LONG TERM...Tuesday Night Through Monday Issued at 219 PM CDT Mon Oct 9 2017 The main forecast concerns will be precipitation chances for the middle of the week and next weekend. High pressure and a very dry air mass will reside over the northern Great Lakes on Tuesday night. Farther south, an upper level low is expected to track toward southern Lake Michigan, and gradually weaken as it approaches. A tight moisture gradient will reside across the region, with PWATS around 0.25 inch over far northern WI, but increasing to 1 inch over parts of central and east central WI. Models are still struggling with how far north to bring precipitation Tuesday night into Wednesday morning, but northeast winds should draw enough dry Canadian air into the region to confine any significant rain to our far southern counties. Across north central and far northeast WI, relatively clear skies, light winds and the very dry air mass will support cool temperatures, with lows in the middle 20s to lower 30s at the typical cold spots. Would expect another widespread frost or freeze there, but since frost/freeze headlines will be suspended over northern WI after tomorrow, this should be a low impact event with no headlines. Expect a period of quiet weather from Wednesday afternoon through Thursday night, along with near normal temperatures. Precipitation will return Friday into Friday night, as post-frontal rains develop in the wake of a cold frontal passage. The rain will be supported by upper divergence in the RRQ of a 160 knot jet. POPs have been increased significantly through this period. Models are exhibiting timing issues with the weekend system, with the GFS bringing the surface wave up the front Saturday into Saturday night, while the ECMWF is about 12 hours slower. Both models do agree that the system will track a bit farther southeast than they have shown the past couple days, which would focus the more significant rain over our southeast counties and push the main threat of thunderstorms south of the forecast area. Will stay close to the preferred model blend, at least until the models get a better handle on the timing and track of the surface low. This system has fairly potent dynamics and abundant moisture, so heavy rainfall remains possible, especially over our southeast counties. && .AVIATION...for 06Z TAF Issuance Issued at 1012 PM CDT Mon Oct 9 2017 VFR mid level clouds will continue to slide over the area overnight. A high pressure system over the Northern Plains building into northwest Wisconsin through Tuesday will decrease the mid level clouds over northern Wisconsin. Mid level clouds may be more persistent over central and east central Wisconsin tonight into Tuesday as a low pressure area tracks into Illinois Tuesday into Tuesday night. && .GRB WATCHES/WARNINGS/ADVISORIES... Frost Advisory until 8 AM CDT Tuesday for WIZ005-010>012-018-019. && $$ SHORT TERM.....MPC LONG TERM......Kieckbusch AVIATION.......TDH
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1046 PM EDT Mon Oct 9 2017 .SYNOPSIS... The remnants of Hurricane Nate will cross New England tonight, but will leave a trailing boundary draped across the region. This front will lift north as a moist warm front on Tuesday, producing more showers and thunderstorms. Slightly drier high pressure will try to work into the area by Thursday, but a back door cold front may keep moist conditions heading into the weekend. && .NEAR TERM /THROUGH TUESDAY/... As of 1040 PM EDT Monday: The latest HRRR continues to feature some measure of blossoming shower coverage for the overnight hours, and weak 500 mb shortwaves riding northeast in the deep layer southwesterly flow support this. However, limited instability should keep any thunder chances quite isolated in nature during the early morning hours. The bigger concern could well be fog and low clouds, but light mixing in passing showers should keep the fog from becoming dense in most areas, and stratus is generally favored over widespread dense fog development. Still expect soupy mins in the lower 70s most areas east of the mountains, with 60s in the high terrain. For Tuesday, deep southwesterly flow will prevail yet again - leading to another day of above normal PoPs as the aforementioned moisture axis lingers despite the upper ridge. A weak warm frontal boundary will steadily lift north of the area. Although not great by any means, chances for a strong storm or two on Tuesday cannot be ruled out as high dewpoints continue and sbCAPE improves in slightly better afternoon insolation. Expect well above normal temperatures once again in the southwesterly flow regime. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... As of 130 PM EDT Monday: An upper ridge will gradually retrogress from the Atlantic west to the central Gulf states Wednesday thru Thursday. Further west, a vigorous fast-moving upper low will eject out of the central Rockies and lift NE into the Upper Midwest. This low will eventually open up and dampen as it rides over the ridge. The associated low pressure system will track into the Great Lakes and drag a dying cold front across the Ohio Valley to the southern Appalachians. This front will wash out quickly, and leave the eastern half of the CWFA still under above climo PWATS thru Thursday. So unsettled, muggy conditions will continue. However, no real strong sources of forcing expected, so severe threat and excessive rainfall are not expected. Will go with high-end CHC PoPs on Wednesday, and mid-CHC on Thursday. Temps will continue to be well above normal. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 130 PM EDT Monday: the medium range will start out with an elongated upper high over the Southeast, with a broad positively tilted trough across the west. The western trough will gradually sharpen up and eject a series of shortwaves across the northern tier states and break down the ridge. By the end of the medium range, an upper trough will set up across the east. At the sfc, a fairly strong high will build into New England and may force a backdoor cold front all the way thru the area. Cold air damming will likely set up Friday, as 850 mb flow turns out of the SE with some upglide. Depending on how deep the wedge is and how much light QPF can fall, the wedge may hold on thru Saturday. The remnant CAD cold pool may linger into early Sunday, but should erode by early AFTN, resulting in a sunnier, pleasant day, as the parent high exits well off the East Coast. As the aforementioned upper trough begins to dig across the eastern states, a cold front will approach from the west and may cross the CWFA on Monday per the 12z GFS and 00z ECWMF. This should usher in a return to more typical fall conditions just beyond the medium range. Temps will remain above normal, especially the overnight lows, which will run 10-15 deg above normal. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... At KCLT and elsewhere: VFR conditions briefly improved throughout the region this evening despite the lingering light rain showers. Given the very moist atmosphere and light flow overnight, widespread low clouds and fog will develop, and a few locations are seeing lower stratus form quickly already this evening. The only question is whether conditions will be predominantly LIFR or VLIFR, as slight mixing remains possible with light showers as upper shortwaves pass up the mountain chain, so will lean LIFR most areas with SW to VRB winds. The convection-allowing models have some better and more robust convection overnight, but this seems unlikely given the lack of instability. Very slow improvement in conditions is expected through Tuesday morning as abundant moisture remains in place at low levels as ridging slowly builds aloft. Anticipate recovery to MVFR by early afternoon, with late day VFR punctuated by periods of MVFR in any showers or thunderstorms. Light SW surface winds will continue. Outlook: Moisture will persist over the area through most of the week, with a diurnal increase in showers and scattered thunderstorms, and overnight restrictions likely. Confidence Table... 02-08Z 08-14Z 14-20Z 20-00Z KCLT High 95% High 88% High 92% High 90% KGSP Low 46% Med 76% Med 73% High 100% KAVL Med 61% High 80% Med 68% High 98% KHKY Low 48% High 80% Med 73% Med 70% KGMU Med 70% Med 74% Med 66% High 100% KAND Low 48% Med 72% Med 70% 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 and ensemble forecasts are available at the following link: www.weather.gov/gsp/aviation && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...ARK NEAR TERM...HG SHORT TERM...ARK LONG TERM...ARK AVIATION...HG
Area Forecast Discussion
National Weather Service Houston/Galveston TX
953 PM CDT Mon Oct 9 2017 .DISCUSSION... A line of showers and isolated thunderstorms were well to the northwest of Burleson, Brazos, Madison, and Houston counties at 9:45 PM. Expect these will continue to slowly move toward the forecast area. The 01Z HRRR and the 18Z Texas Tech WRF keep the forecast area free of precipitation until after 4:00 AM. Could see isolated showers moving onshore into the coastal counties before anything arrives from the west and northwest. Tweaked the rain chances for the rest of the evening. 40 && .PREV DISCUSSION... /ISSUED 653 PM CDT Mon Oct 9 2017/ AVIATION.../00Z TAF/ Surface analysis and GOES 16 imagery show pre-frontal trough located through north Texas/DFW down towards the NW Hill Country with a line of convection. The actual cold front was located back from western Oklahoma into west Texas near Lubbock. Ahead of the front expect area terminals to expect a mix of MVFR/IFR conditions with low clouds and fog forming. Cold front will catch the pre- frontal trough tonight and push into the area during the morning hours. Front should reach KCLL/KUTS around 09-10Z, KIAH/KHOU/KSGR 13-15Z and then along the coast 16-17Z. Hi-res models show convection developing along the front as it approaches the coast so will keep VCTS for KLBX and KGLS. MVFR ceilings will be likely post frontal and could hold on through the late morning to afternoon hours. Ceilings will improve through the afternoon with gusty northerly winds. Overpeck PREV DISCUSSION... /ISSUED 350 PM CDT Mon Oct 9 2017/ DISCUSSION... Another very warm afternoon where Bush-Intercontinental Airport`s maximum temperature record of 94 F was achieved by 3 PM with Galveston not being far off...a degree from tying 2007`s Tmax record of 90 F. An approaching cold front will be making its way through the northwestern CWA shortly after midnight tomorrow...moving across metro shortly after sunrise and then be off the coast by 10 or 11 AM. Early morning (pre-dawn) patchy fog may develop just downstream of the approaching surface front. Not an overly-impressive cold nor dry backing air mass but...in relative terms...cool and dry enough to take us from summer heat to comfortably autumn warm in less than a day. A mostly overcast morning with scattered showers and thunderstorms in the vicinity of the lower level front as it encounters the higher pooling of downstream moisture over the southern half of the forecast area. Partially clearing through the day with afternoon ambient temperatures slowly warming into the middle 70s up north to lower 80s further south. Drier air to slide in on weakening northerlies early Wednesday with the mid-week (afternoon) mid-level dry air mix down equating to interior 50 F dew points/upper 30 to mid 40 min %RHs. Winds veer around the dial through Thursday and be back onshore by Friday midnight. Nothing extreme in the post-frontal T/Td field as mid-level temperatures remain in the upper teens. This will equate to subsequent day warming from the coolest days of Tuesday-Wednesday back into the late week average upper 80s. Slight maritime rain chances this weekend as weak central Gulf disturbances rotate in from the east under a westward expanding southeastern U.S. upper ridge. This 5H ridge is forecast to be unseasonably strong as mid-590dam heights clamp themselves down on the northern Gulf coast. There should be enough suppression to counter increasing lower level moisture. Very low weekend rain chances focused across the coastal counties to account for breeze activity as the upper 80s are met. The next cold front is slated for late Sunday or early Monday. 31 MARINE... The main marine hazard through tonight will remain elevated tides along the Upper Texas coast before a cold front sweeps off the upper Texas coast Tuesday. Tide levels are currently running about 1-1.5 feet above normal and this may result in levels peaking at or just above 3 feet at times of high tide tonight. Have held off on a coastal flood advisory as overall levels continue to decrease with time and wave periods are 8 seconds or less at both buoys, but minor wave run-up may result in isolated issues on Bolivar Peninsula. Tide issues will come to an end behind a cold front moving off the coast tomorrow morning as moderate offshore winds become established behind the front. A Small Craft Should Exercise Caution statement will likely be needed behind the front Tuesday afternoon through Wednesday morning. Winds are expected to decrease mid-week and gradually shift from the northeast/east to onshore by this weekend. Huffman && .PRELIMINARY POINT TEMPS/POPS... College Station (CLL) 64 76 58 80 61 / 30 10 0 10 10 Houston (IAH) 72 83 63 80 65 / 20 40 10 10 10 Galveston (GLS) 78 84 70 80 74 / 20 60 10 10 10 && .HGX WATCHES/WARNINGS/ADVISORIES... TX...NONE. GM...NONE. && $$ Discussion...40 Aviation/Marine...39
Area Forecast Discussion
National Weather Service Wilmington NC
943 PM EDT Mon Oct 9 2017 .SYNOPSIS... Unseasonably warm and humid weather will continue much of this week as high pressure well offshore maintains southerly winds. A cold front will reach the Carolinas Thursday or Friday bringing drier and slightly cooler air. A return to fall-like weather should come early next week with an arrival of a more substantial cold front. && .NEAR TERM /THROUGH TUESDAY/... As of 930 PM Monday...Earlier showers died completely away leaving just mid-level clouds around currently. A single convective shower up near Fayetteville shows we still have elevated instability present, and model soundings continue to show we`ll have potential for pop-up showers overnight. Several models are highlighting the area from I-95 east to Elizabethtown and Whiteville for the best potential of measurable rain overnight. Winds have decoupled in clear spots this evening which necessitated a couple of small downward revisions in forecast low temperature, mainly near Conway and Marion, SC. Otherwise changes with this update were minor. Discussion from 630 PM follows... In a weather pattern more reminiscent of July than October, we`ve got popcorn showers and thunderstorms firing in the Florence vicinity, with decaying showers across the Cape Fear area the result of earlier heavy rainfall over coastal South Carolina. Some of those rainfall amounts were impressive earlier: 2-4 inches was reported on a number of mesonet stations in Myrtle Beach and Surfside Beach, SC, with nearly 2 inches in Murrells Inlet. 300-500 mb high pressure is parked just off the coast, but tremendous low-level moisture and warm low-level temperatures exist for this late in the year. Shower/t-storm activity should diminish some this evening, however I believe the models when they show a resurgence of showers overnight as a weak convective cap around 800 mb dissipates and allows elevated convection to redevelop as one or two upper level disturbances approach from the west. PoPs have been increased substantially across Florence County for the next couple of hours, but elsewhere I have bumped up PoPs by another 10-20 percent to account for what should be scattered convection redeveloping. No significant changes have been made to low temperatures, which will again run very closer to all-time historic October warmth. Discussion from 300 PM follows... Sounding climatology shows that PW values continue to be all- time high values for the date. Impressive numbers around 2.4 inches show deep layer saturation. RAOBs from CHS and MHX also showing very weak lapse rates through most of the column also indicative of the truly tropical nature of this airmass. As such there has been a bit of randomness as to rainfall distribution, though the HRRR has had a fairly good day today. This model shows a decrease in rainfall coverage and intensity this evening, a seemingly plausible trend. Other major guidance shows that activity should linger overnight as some channeled vorticity streaks overhead just west of the offshore mid level ridge axis. Both the GFS and WRF seem to favor the coast for this activity but given how low LCLs remain did not add that detail to the forecast. High moisture content to once again limit overnight cooling with tonight`s lows not far from climatological high temperatures and areas that received rainfall may fog up some especially should clouds break sufficiently. Tomorrow largely a repeat of today in most aspects. && .SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 300 PM Monday...Period begins with elongated 5h ridge over the Southeast and Bermuda High off the coast. Deep tropical moisture remains in place with precipitable water hovering around 2 inches through the period. Despite the abundant moisture there is a lack of forcing and instability. Temperatures will be well above climo but abundant cloud cover will limit surface heating during the day while the ridging aloft tempers any mid-level support. Convection associated with low level convergence may carry over into the first part of Tue night before convection wanes. The combination of marginal heating and low level convergence will lead to another round of afternoon and evening showers and isolated thunderstorms in the vicinity of and west of the I-95 corridor. This activity may slowly move east-northeast, but it is likely to weaken and dissipate before reaching the coast late Wed evening or Wed night. High temperatures will continue well above climo with highs in the low to mid 80s. Lows Tue night and Wed night will run close to 20 degrees above climo with both cloud cover and mixing keeping lows in the low 70s.&& && .LONG TERM /THURSDAY THROUGH MONDAY/... As of 300 PM Monday...A shortwave will ride across the top of the ridge pushing a weak cold front through the area on Thurs. Initially it looked like the front would bring cooler weather but more recent model runs do not have this front modifying the air mass much. Front loses some of its identity as it moves over the mountains, but does look like it makes it into the I-95 corridor on Thurs. With such a moist air mass in place, looks like we should see a decent amount of shower and thunderstorm activity along and ahead of the front as it moves south. Once the front passes south, this should put an end to the deep tropical air mass, but overall, it looks like a several degree drop in dewpoints from the 70s into the 60s and diminished chc of pcp. The mid to upper ridge builds back up from the southwest with mainly dry mid to upper levels into the weekend but a tropical wave moves west from the Bahamas which helps to increase and turn the broad low level flow from NE post fropa on Thurs to a more easterly direction Fri and Sat. This will keep some low level moisture present and could mean some clouds and pcp around, especially as it looks like a coastal trough will become more enhanced. But, there will mainly be a brief break before next more substantial cold front comes through early next week with another round of more substantial shower activity ahead of it on Monday. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/... As of 00Z...Exceptionally moist air continues across the Carolinas. This should result in more MVFR to IFR ceilings developing overnight as the boundary layer cools and saturates this tropical moisture in place. Scattered showers and t-storms in the FLO area now should dissipate, but additional showers will develop across the area overnight into Tuesday. Extended Outlook...MVFR/IFR conditions are possible during the mornings Wednesday and Thursday from ceilings and/or reduced vsby from fog. In addition, pop-up showers each day could produce brief MVFR/IFR conditions. && .MARINE... NEAR TERM /THROUGH TUESDAY/... As of 930 PM Monday...Latest sea heights measured at the buoys range from 4 feet out at Frying Pan Shoals to 3-3.5 feet nearshore. Southerly winds 10-15 kt should continue overnight with perhaps some isolated showers developing after midnight. No significant changes from the previous forecast. Discussion from 300 PM follows... Southerly winds to continue through the period as large area of high pressure remains centered well offshore. SWAN seemed a bit underdone on seas forecast so went with a blend of WNA and continuity. This yields a continuation of fairly widespread 4 ft seas early on with a minimal decrease as one heads to the near shore regions. By tomorrow a small nearshore/offshore range may open up. SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/... As of 300 PM Monday...Southerly flow will continue through the period as the Bermuda High remains the dominant surface feature. Weak gradient will keep wind speeds around 10 kt through the period with seas around 3 ft Tue night into Wed dropping to 2 to 3 ft later Wed and Wed night. LONG TERM /THURSDAY THROUGH SATURDAY/... As of 300 PM Monday...A cold front will drop south through the waters Thurs into early Fri. This front will not produce any great northerly surge as the air mass change will be minimal. Southerly flow ahead of the front will veer around and then turn to the N-NE behind the front late Thurs into early Fri. A minimal NE surge behind it will push seas up from 2 to 4 ft on Thurs to 3 to 5 on Fri. By Sat, the winds will diminish but will veer to an easterly direction which will maintain basically 2 to 4 ft with some 5 fters mixed in. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...TRA NEAR TERM...TRA SHORT TERM...III LONG TERM...RGZ AVIATION...TRA MARINE...
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
615 PM CDT Mon Oct 9 2017 .SYNOPSIS... Issued at 330 PM CDT Mon Oct 9 2017 H5 analysis this morning had a strong shortwave over eastern Utah with 50 to 80 meter Ht falls noted from western Colorado into northern New Mexico. Upstream of this feature, 100 to 120 meter rises were noted from southern Idaho into northern Nevada. East of the trough, swrly flow aloft extended into New England. The remnants of TS Nate were located over western PA while a massive high was located across the eastern atlantic. Off the coast of western Canada, a shortwave was located in the northeastern Gulf of Alaska with some 100+ meter falls over northern British Columbia. Across western and north central Nebraska, light rain continued across the central and eastern Sandhills in association with an area of mid level frontogenesis in advance of the disturbance over western Colorado. Some wet snowflakes mixed in earlier this morning, across the sandhills and western Nebraska. Although the threat for snow has ended, a cold, wet, raw day continues with temperatures in the 40s. && .SHORT TERM...(This evening through Tuesday) Issued at 330 PM CDT Mon Oct 9 2017 This evening... Main forecast challenge continues to deal with the potent mid level low/shortwave crossing the central Plains. Slowly taper PoP west to east, mainly along and ahead of the main H7 fgen band. As of 20z, RAP mesoanalysis and radar trends suggest the band lining up generally from LBF to ONL. Precip rates have dropped and temps held steady enough to support all rain. Removed all PoP except corners of Frontier, Custer, and Wheeler counties by 06z, which is a couple hours slower than RAP and HRRR guidance. NAM forecast soundings keep some lower/mid level moisture near the WFO GID border through then. Overnight... Clearing sky continues across the panhandle and western Sandhills with lightening northwest winds as the H5 low pushes eastward across KS. Trended min temps toward the cold MET and MAV guidance, especially west of OGA to VTN. Farther east, the stratus will be relatively slow to exit due to proximity of the low and weak fgen across eastern Neb. Lower confidence for freezing temps Frontier to Holt counties and made little change to previous forecast lows there. However, temperatures and near surface moisture will definitely support frost development CWA wide. Updated the existing freeze headlines for all zones as lows range from near 20F invof Pine Ridge to near 33F far east. Tuesday... Mainly quiet day with large scale subsidence behind the low and lighter winds from a relaxed pressure gradient. Weak temp advection at H85 results in below normal temps in the mid to upper 50s. Return flow from a sfc high to switch winds to southerly later in the day. .LONG TERM...(Tuesday night through Monday) Issued at 330 PM CDT Mon Oct 9 2017 Tuesday night through Thursday: Temperatures will be the main forecast challenge in the mid range periods. For Tuesday night, dry air will remain in place across the forecast area with overnight dew points in the mid to upper 20s. With light winds expected, see no reason why to trend temps down into the upper 20s across the forecast area. This was well below the superblend forecast which had lower to mid 30s for lows Tuesday night. By Wednesday the upper level pattern will transition to swrly which will develop a surface trough of low pressure along the front ranges of Colorado and Wyoming. Increased southerly winds will develop downstream of the trough across western and north central Nebraska. This will result in increased low level warm air advection leading to highs in the 60s. By Thursday, a shortwave trough of low pressure aloft will track along the Canadian/US border. This will force a cold front into the western Dakotas Thursday. South of the front, H85 temps will rise into the teens. This will equate to highs in the 70s which will be the warmest day of the forecast period. Thursday night through Monday: A cold front will push through the forecast area Thursday night with highs Friday ranging from the mid 50s in the north to the mid 60s in the south. Little if any, precipitation will accompany passage of the front as it will push into a fairly dry airmass. Better chances for precipitation will arrive Saturday into Saturday night as an upper level trough of low pressure approaches the central plains from the intermountain west. Thunderstorms will light up along the frontal boundary which will be oriented form southern Kansas into Iowa. West of this boundary, favorable mid level frontogenesis will lead to light precipitation in the post frontal environment across central and northern Nebraska Saturday into Saturday night. ATTM, will keep the highest pops confined to northern and eastern areas initially, transitioning to all areas Saturday night. The upper level trough will move east of the area Sunday morning with seasonal and dry conditions expected Sunday and Monday. Highs Sunday will be in the upper 50s to lower 60s, while highs Monday will be in the mid to upper 60s. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 615 PM CDT Mon Oct 9 2017 VFR is expected all areas tonight and Tuesday. Radar and satellite indicate an area of developing showers this evening. This area of rain was nearly stationary and falling from 7000 feet ceilings. The dry air will get deeper this evening and weaken the area of rain from west to east. Sfc high pressure will move overhead Tuesday. && .LBF WATCHES/WARNINGS/ADVISORIES... Hard Freeze Warning from midnight CDT /11 PM MDT/ tonight to 10 AM CDT /9 AM MDT/ Tuesday for NEZ004>006-008-009-022>027-035>037- 056>059-069-094. Freeze Warning from midnight tonight to 10 AM CDT Tuesday for NEZ007-010-028-029-038-070-071. && $$ SYNOPSIS...Buttler SHORT TERM...Snively LONG TERM...Buttler AVIATION...CDC
Area Forecast Discussion
National Weather Service Midland/Odessa TX
550 PM CDT Mon Oct 9 2017 .DISCUSSION... The latest Aviation Discussion is included below. && .AVIATION... A cold front near the Pecos River will pick up speed this evening as gusty, northerly winds increase to 20-25kt sustained, and gusts of 35kt or greater will be possible at all area terminals. Low clouds may move south into northern reaches of the forecast area overnight, but think dry air in place will aid in dissipating the clouds, and will go with VFR conditions tonight and during the day Tuesday. Northerly winds will decrease to 10-15kt late tonight, but may still be gusty through 10/15Z at some terminals. && .PREV DISCUSSION... /issued 325 PM CDT Mon Oct 9 2017/ Not many changes to the current forecast. WV shows the upper trough over SW CO/NW NM at 18, but the cold front ended up a little faster than previously advertised, and fropa`d KMAF right at 17Z, w/little fanfare other than establishing the high temp for the day. Fortunately, westerly downslope flow managed to pump the temp up to 86F before the front arrived. Unfortunately, there is little antecedent moisture in place for the front to interact with, and rain chances look slim-to-none for the short term. 12Z KMAF RAOB came in w/a PWAT of 0.37", or only 44% of normal. Dry air advection will continue thru at least late Tuesday night, when surface flow veers and return flow resumes. The cold front will slow due to diurnal heating this afternoon somewhere invof the Pecos River, then pick up speed after sunset. Pressure rises north of the front suggest a windy night ahead, w/minimal high gap winds thru KGDP. Model temp progs suggest nrn Lea will stay well-abv freezing, w/post-frontal winds to keep things mixed. Temperatures then begin a slow rebound Tue/Wed, w/thicknesses/temps topping out abv-normal by Thursday afternoon under increasingly SW flow aloft. Next chance of rain looks to be as soon as Friday night, when the GFS brings a shortwave into the area, under the RR quadrant of a 250mb jet. Chances continue thru the weekend, w/models bringing in a strong cold front Sunday. Models are wildly out of sync by Friday night, so details will change as the weekend nears. Temps should fall blo-normal Sun/Mon. && .PRELIMINARY POINT TEMPS/POPS... Big Spring 46 65 47 76 / 0 0 0 0 Carlsbad 44 65 45 76 / 0 0 0 0 Dryden 56 70 56 73 / 10 0 0 0 Fort Stockton 50 67 51 79 / 0 0 0 0 Guadalupe Pass 42 59 46 73 / 0 0 0 0 Hobbs 40 64 44 73 / 0 0 0 0 Marfa 44 70 44 77 / 0 0 0 0 Midland Intl Airport 46 65 48 75 / 0 0 0 0 Odessa 46 65 48 74 / 0 0 0 0 Wink 47 66 49 75 / 0 0 0 0 && .MAF WATCHES/WARNINGS/ADVISORIES... NM...None. TX...High Wind Warning from 9 PM this evening to 9 AM MDT Tuesday for Guadalupe Mountains. && $$ 99/99/
Area Forecast Discussion
National Weather Service Marquette MI
631 PM EDT Mon Oct 9 2017 .SHORT TERM...(This evening through Tuesday) Issued at 402 PM EDT MON OCT 9 2017 WV imagery and RAP analysis indicated a sw flow aloft across the Upper Great Lakes between a broad ridge centered over the western Atlantic and a trough from Hudson Bay through the nrn plains into the cntrl Rockies. 800-600 mb fgen from ern Nebraska into MN supported an area of light rain into sw MN and mainly just mid clouds farther ne toward wrn Lake Superior. At the surface, Northerly anticyclonic flow prevailed over the nrn Great Lakes as high pressure over the plains builds toward the area. stronger CAA into the west has kept temps in the lower 50s while readings had climbed to around 60 to the lower 60s over the rest of the cwa. Tonight, With continued CAA and 850 mb temps falling to around -2C expect lake clouds (water temps around 14C) to spread into the north. With the interior west will closer to the sfc high, expect temps to drop into the upper 20s while lake modification and clouds keep readings in the upper 30s near the Lake and over much of the north and east. Tuesday, High pressure will continue to build into the area bringing another mostly sunny day. However, with 850 mb temps near 0C, temps will remain in the lower to mid 50s. .LONG TERM...(Tuesday night through Monday) Issued at 336 PM EDT MON OCT 9 2017 Overall, a warming trend is on the way through the end of the work week with temperatures climbing 5 to 10 degrees above normal. Precipitation chances look scarce, but chances will increase towards the end of the week and for the weekend. Tuesday night through Wednesday, a quick moving shortwave will track across the lower Great Lakes. The main forcing associated with the shortwave looks to remain just south of the area; however, have maintained a slight chance for showers across the far south central as a few showers may make it up into southern Menominee county, especially early Wednesday morning. Otherwise, skies will become mostly sunny, giving way to another beautiful, seasonable fall day across much of the area. Wednesday night through Friday, return flow out ahead of an approaching cold front will promote a warm up through the end of the work week. Temperatures will climb into the mid to upper 60s. Thursday, the warmest areas look to be in locations across the northern portions Upper Michigan where downslope southerly flow will aid in warming. We could see a few scattered showers on Thursday, but with so much dry air aloft opted to leave mentions for the time being. Much of the day on Friday should stay dry as the deeper moisture along the advancing cold front and better upper-level jet dynamics do not arrive until later in the day. Therefore, towards the end of the day through Friday night chances for showers will increase as the cold front pushes east across Upper Michigan. By Saturday, the above mentioned cold front is progged to gradually slow its southward progression as shortwave energy begins to lift across the region. This will allow for moisture to lift back northward through the weekend and a broad area of low pressure develops along the baroclinic zone. There are some rather large discrepancies among the GFS and ECMWF in regards to the timing and strength of this impulse, which will impact what locations will see better chances for precipitation. The GFS is trending further south and much faster with the system; whereas, the ECMWF is a bit further north with a more wound up system. Certainly looks like some locations across the Western Great Lakes region may see moderate to heavy rain; however, with it still being a ways out in the forecast, the details will certainty be fine-tuned as the week progresses. Next week it looks like upper-level ridging will build back across the central CONUS and eventually transition over the Great Lakes region, which should promote another warming trend next week. However, this will all depend on how quickly the main upper-level trough digs east of the region. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 631 PM EDT MON OCT 9 2017 VFR conditions will continue through the forecast period. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 402 PM EDT MON OCT 9 2017 Cold advection in a nw flow and decreased stability/better mixing could result in some wind gusts to 25 knots tonight, especially over the east half of Lake Superior. Otherwise, expect winds 20kt or less through Friday as high pressure generally dominates through the period. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...JLB LONG TERM...Ritzman AVIATION...07 MARINE...JLB
Area Forecast Discussion
National Weather Service Norman OK
458 PM CDT Mon Oct 9 2017 .DISCUSSION... The October 10-11, 2017 00 UTC TAF discussion follows: && .AVIATION... Post-frontal stratus (currently across northwest Oklahoma), 1500-2500 ft AGL, will spread southeastward through most terminals this evening. The exception might be KLAW and KSPS; stratus may stay north of these terminals. Stratus is expected to dissipate from west to east tomorrow morning, which will lead to VFR conditions. Otherwise, gusty, post-frontal north-northwest winds are expected to continue through the TAF period. Mahale && .PREV DISCUSSION... /issued 244 PM CDT Mon Oct 9 2017/ DISCUSSION... Severe thunderstorm and strong surface wind potential through tonight are the main concerns. No significant changes were made to the previous forecast. AT 230 pm, a surface low was located just north of Medford, Oklahoma with a cold front extending south from the low to near Chickasha, Oklahoma to Waurika, Oklahoma. The low and front will continue to push eastward in the next several hours. Severe thunderstorm potential for the rest of this afternoon and evening has not changed since the 1111 AM AFD update. Still appears first development of storms will occur near the front and surface low, probably not far from I-35 between Guthrie and Blackwell in the 4 to 6 pm time frame as the cap erodes. Additional storms may form near the front farther south after 6 pm, though the cap will be stronger there. Any storms will likely begin as supercells with very large hail as the main hazard as they move northeast. Still not sure about storm coverage/evolution late this afternoon and evening. HRRR runs have overall been depicting isolated to scattered storms forming and occurring well east of I-35 across eastern Oklahoma after 5 pm, while the 12 UTC ARW/NMM models have been depicting higher storm coverage as far west as I-35 with storms organizing into a line 5 to 8 pm. The sparse storm scenario would support a very large hail and slightly higher tornado potential while the line of organized storms scenario would support a higher damaging wind and heavy rainfall threat. Severe storm potential should diminish after midnight tonight with weakening instability. However, went ahead and added low chances for storms (20%) after midnight tonight southeast of I-44 where some HRRR runs hinted that mid level moisture and instability may be sufficient to support some weaker high based showers/storms. Light rain showers may form and occur across mainly northern Oklahoma tonight, north of a Cheyenne to Perry line, closer to the mid/upper low. Kept rain chances in the 20-50% range to account for this activity with the highest chances near Buffalo, Oklahoma after midnight. Low level temperature model profiles appeared to be too warm for any snowflakes at the ground. Any rainfall should remain light and under 0.25". Surface winds will increase in the cold air behind the cold front tonight. For now, think most gusts will stay below 40 mph and thus, below Wind Advisory criteria. Believe the strongest gusts will occur across the northwest half of Oklahoma where the surface gradient will be strongest and where more cloud cover will limit radiational cooling and promote stronger low level mixing. Much cooler air will move into the area tonight. Went towards the colder side of guidance lows in many locations, mainly in the upper 30s in northwestern Oklahoma to around 50 near Durant. Tuesday, much cooler conditions will occur. Some light lingering rain showers may occur during the morning hours across the area, particularly near and north of the Oklahoma/Kansas state line. Skies will clear west to east as the mid/upper low moves northeastward and away from the Southern Plains. Highs will struggle to get out of the 50s in many locations. Temperatures will average 15-20F below average. Tuesday night into Wednesday morning, frost and perhaps a light freeze may be possible in some locations, mainly rural low lying areas across the western and northern part of Oklahoma. Clear skies, light surface winds, and a surface high will promote excellent radiational cooling. Generally preferred the colder side of guidance lows. Wednesday through next Monday, a pronounced warming trend will occur through at least early Saturday before a cold front moves through the area. Highs in the 80s and possibly lower 90s may occur Friday and Saturday. Low chances for showers and storms may return with the cold front passage Saturday into Sunday, though confidence remains low. Cooler weather will likely occur by Monday. MBS && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 45 59 40 68 / 10 10 0 0 Hobart OK 42 62 39 69 / 10 10 0 0 Wichita Falls TX 46 64 41 70 / 10 10 0 0 Gage OK 39 59 34 70 / 30 10 0 0 Ponca City OK 47 55 36 67 / 50 20 0 0 Durant OK 51 67 43 74 / 40 10 0 0 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && $$ 30/10/10
Area Forecast Discussion
National Weather Service Raleigh NC
1025 PM EDT Mon Oct 9 2017 .SYNOPSIS... A surface trough will remain nearly stationary over central NC through mid week, with a large high pressure located in the western Atlantic. && .NEAR TERM /THROUGH TONIGHT/... As of 1025 PM Monday... There is not much going on as far as the radar is concerning this evening. The GFS and some of the high resolution short term models were not verifying well, even with all the record PW`s, high dew points, and temperatures associated with the tropical-like air mass in place. Still looking for a trigger for later tonight upstream. There is some hope in that there is a vorticity max upstream over upstate SC and the HRRR and GFS indicate a large area of showers will develop over NE GA into western NC, then spread NE remaining mainly west of RDU, courtesy of a mid level vorticity maximum. There is just not enough agreement in the near term models to support that wet solution. Given lower confidence in the models given the current data - we will lower POP to slight chance east, low chance west overnight. Lows should be very close persistence, but just a bit lower than this mornings record high minimums in the 70s, but still at record values in the lower to mid 70s, with some breaks in the overcast. See the climate section below for the daily records. Fog may be more of an issue in the south and east, given the breaks in the overcast, light winds, and high surface moisture. Stratus should be more of an issue in the west, given the extensive mid clouds now - and the lack of clearing expected for total saturation at the surface. && .SHORT TERM /TUESDAY AND TUESDAY NIGHT/... As of 335 PM Monday... Expect status quo, with very little change in the overall pattern, as the weak surface trough stays just to the N and W of the forecast area. PW remains anomalously high (over 200% of normal) with low level flow holding from the S and SW, so scattered showers will be possible at almost any time. The aforementioned perturbation will translate NNW into VA Tue morning, as the mid level ridge continues to build across the Gulf States/Southeast/Carolinas, and this may result in just enough weak subsidence to limit shower development, particularly across the southeastern CWA, closer to the mid level ridge axis. Models all agree on good rainfall coverage Tue, shifting northward Tue night, although these large scale models may be overblown with gridscale precip. For now will go with 50-60% pops Tue, dropping gradually to 30-40% north and 20-30% south Tue night, all below statistical guidance pops. Skies should start off cloudy with areas of fog/stratus Tue morning, followed by at least partial sunshine in most places in the afternoon before clouds fill back in with heating. More fog and stratus appear likely Tue night with a warm and humid air mass and light winds. Above normal highs 81-87 and lows 71-76. -GIH && .LONG TERM /WEDNESDAY THROUGH MONDAY/... As of 245 PM EDT Monday... Airmass over the area will remain very moist Wednesday, but begin to dry out as a mid level short wave moving across the Great Lakes tamps down the amplitude of the subtropical ridge along the southern Atlantic Coast. Resulting westerly flow will dry us out from the mid levels downward and force the subtropical ridge to retrograde southwest through late week. A weak backdoor front associated with the short wave will settle south, slowing as it becomes oriented more parallel to the mid level flow, through later Thursday. As a result, expect at least scattered convection on Wednesday, with PoPs diminishing through Thursday as the frontal zone lingers in the southeast with drier air filtering in behind it. Highs both Wednesday and Thursday will reach upper 70s across the north to low and mid 80s in the south. Forcing will be very weak Friday and Saturday, but we don`t dry out completely, with precipitable water remaining from 1 to 1.5 inches. The surface front will be stalled along the coast with weak high pressure trying to build down the east coast. We also remain basically directly beneath the subtropical ridge axis, so expect only scattered convection driven by diurnal heating. Highs Friday will be our coolest of the extended period, and above normal, from 75 to 80. Highs will creep up as the airmass modifies while we await an airmass change (which could come in the form of a decent frontal passage as early as next Tuesday) - from upper 70s to lower 80s Saturday to 80 to 85 Sunday and Monday. Mins through the period will be mostly in the low to mid 60s. && .AVIATION /00Z TUESDAY THROUGH SUNDAY/... As of 755 PM Monday... 24-Hour TAF period: A few showers still linger across Central NC, however coverage is very isolated. Expect more showers and isolated storms to develop and move over the region overnight, though there is low confidence on if/when they would impact any given terminal. Regardless, there is still high confidence that sub VFR cigs and visbys will develop at all terminals, starting as early as 02Z and lasting into the morning hours Tuesday. Expect mainly MVFR/IFR cigs and visbys, however both could drop into the LIFR range between 10Z and 13Z. An additional round of showers and storms is expected during the aft/eve Tuesday, with the usual reduced cigs and visbys if/where they occur. -KC Looking ahead: There is a high probability of poor aviation conditions developing after 00z Wed (Tue evening), lasting through Wed morning, perhaps improving to MVFR or VFR by Wed afternoon, then falling again to IFR Wed night/Thu morning as we stay in a moist and somewhat volatile air mass. MVFR conditions are expected to dominate through late in the week, although some models are predicting passage of a backdoor cold front southward through the area Fri, which would bring drier and less warm/humid air into the area. Confidence in the details of late-week aviation conditions is lower than usual. -GIH && .CLIMATE... Record high minimums for October 10: RDU: 68 (set in 1959) GSO: 67 (set in 1913) FAY: 72 (set in 1959) && .RAH WATCHES/WARNINGS/ADVISORIES... None. $$ SYNOPSIS...Badgett NEAR TERM...Badgett SHORT TERM...Hartfield LONG TERM...mlm AVIATION...KC/Hartfield CLIMATE...Hartfield
Area Forecast Discussion
National Weather Service Blacksburg VA
1143 PM EDT Mon Oct 9 2017 .SYNOPSIS... A front stalled over NC will slowly lift north into Virginia Tuesday. Low pressure and a cold front then moves east into the mountains by Wednesday evening then off the coast Thursday. High pressure builds in from the northeast late in the week. && .NEAR TERM /THROUGH TUESDAY/... As of 1140 PM EDT Monday... Showers have been hard pressed in developing and moving north into the area this evening, so adjusted pops down to account for this leaning toward a HRRR trend. Otherwise, fog will form although clouds increasing may limit extent of fog in terms of how dense it gets. Previous discussion from early evening... Forecast is in pretty good shape overall. Did increase coverage of fog somewhat for the overnight period further south and east as stalled frontal zone in the vicinity of the central Carolinas returns northward as a warm front. Still some question per 18z guidance on how low visibilities become in fog but at this point dense fog does not look likely attm. Should see eventual lower and thickening of ceilings from south to north mainly after midnight, with better radiational cooling to the north. Any showers appear likely to hold off in NW NC/upper NC Piedmont counties until at least 10 pm. Relatively warm and muggy night for early October standards with lows in the mid 60s to low 70s and dewpoints running only a couple degrees lower than projected lows. Previous near-term discussion issued at 250 PM Monday follows... Weak boundary moves south and stalls over North Carolina this evening. Weak impulses riding along this boundary within southwest flow aloft will bring this boundary back into the area as a warm front overnight into Tuesday. Behind this initial boundary today is a weak surface ridge. As the warm front lifts north, it will glide over this ridge creating rain, low clouds and fog tonight. Precipitation likely to move across NW North Carolina after midnight, then advance to the hwy 460 corridor through Tuesday morning. This front will move north of 460 during the afternoon. PWATS will remain above normal even with the passing of a frontal boundary today. Environment becomes tropical with the passing of the warm front tonight and Tuesday with PWATS ranging from 1.70 to 2.00 inches by the afternoon. Short waves riding along the boundary and saturated atmosphere will bring a quarter to a half inch (0.25 to 0.50) of rain to the area over the next 24 hours. Given that this is a warm front with extensive amounts of cloudiness, instabilities may not be realized for thunderstorms activity. Can not rule out a few breaks across the piedmont in the afternoon, therefore will include a slight chance for thunderstorms in the weather grids. Expecting some clearing this evening as surface ridge moves over the area. With the ground being wet and saturated low levels, areas of locally dense fog is possible. The area of concern will be north of hwy 460 where surface ridge is more established and far enough away from stalled boundary`s debris clouds. Overnight lows will remain muggy with readings from the mid 60s to low 70s. With the expectations of rain advancing north over a surface ridge through the day, Tuesday highs may warm into the upper 70s to lower 80s. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 215 PM EDT Monday... Tuesday night low pressure will be over Illinois with front stalled from the low across Kentucky and Virginia. By Wednesday the low is over Ohio and a warm front has moved north into northern Virginia. The associated cold front will cross through the Mid Atlantic region by Wednesday evening. Staying close to the timing and placement of the fronts off the 12Z GFS. Amount of heating will be the driving factor for the coverage and strength of thunderstorms. Shear and low level convergence will already be in place. With any decent amount of sun Convective Available Potential Energy could be up to 1500 J/Kg. Highest rainfall totals will be north of the region more in line with where the better dynamics will be tracking. High pressure begins wedging south behind the low pressure system on Thursday. Air mass coming in with the high has slightly lower 850MB temperatures over the region and drier air above 700 MB Thursday. Lower level for the most part stay moist with east to southeast wind. Models showing isentropic lift around 300K with good eastern upslope flow on Thursday night. && .LONG TERM /FRIDAY THROUGH MONDAY/... As of 215 PM EDT Monday... Wedge fully entrenched with persistent east to southeast surface and low level winds on Friday. By Saturday the center of the high will be over Virginia. Will keep clouds and add some light upslope rain in the forecast for Friday. As this high moves offshore Saturday night and Sunday winds turn back around to the southwest. This will put the region in the warm sector ahead of an approaching cold front. Will have showers and thunderstorms in the forecast for Sunday through Monday along and ahead of the cold front. A strong cold front on the horizon for Monday. Much cooler and drier air advertised by the models behind the front. Temperatures will be above normal through Sunday. && .AVIATION /04Z TUESDAY THROUGH SATURDAY/... As of 727 PM EDT Monday... SCT-BKN VFR stratocumulus ceilings initially in post-frontal regime with quasistationary front now stalled over the Carolinas. Aforementioned stalled front will lift back northward as a weak warm front after 04z. This will bring a degradation in flight categories from MVFR to IFR ceilings and areas of patchy fog, with intervals of showers along and south of Route 460 and particularly near Route 58 through sunrise. Fog is likely pretty much anywhere given anomalously humid conditions for Fall, along with the significant rainfall experienced yesterday. Visibilities in fog may be closer to LIFR or even VLIFR north and northwest of the Blue Ridge (north of Roanoke) where radiational cooling may be somewhat greater than further south. Any showers should be light and not be the primary restrictive element. Winds initially southwest 3-6 kts trending light and variable as boundary settles into the region overnight into early Tuesday. Warm front drifts slowly northeast during the day on Tuesday, with periods of showers and MVFR/IFR ceilings with VFR visibility. May even be a thunderstorm but confidence is too low on development to include in the TAF attm. Ceilings should become VFR at Lewisburg and Bluefield late, but MVFR to IFR ceilings likely elsewhere. Medium to high confidence in winds. Low to medium confidence on visibilities in fog, medium confidence on ceilings. Extended Aviation Discussion... Low pressure in the Ohio Valley spreads a cold front into the region on Wednesday into Wednesday night, bringing showers and thunderstorms. A cold-air damming/wedge regime then ensues behind this feature Thursday into Friday with significantly degraded aviation conditions possible in this period from lower ceilings, fog or stratus. Improvement to VFR for Saturday. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...RCS/WP NEAR TERM...AL/RCS/WP SHORT TERM...AMS LONG TERM...AMS AVIATION...AL/RCS