Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/07/19

Area Forecast Discussion
National Weather Service La Crosse WI
1000 PM CST Wed Nov 6 2019 .SHORT TERM...(This evening through Thursday) Issued at 235 PM CST Wed Nov 6 2019 A secondary band of light snow is working east/southeast across northern Iowa and southwest Minnesota. This band of snow is being forced by moderate frontogenesis in the 1000-700 mb layer along with lift under the right entrance region of the 300 mb jet. The RAP has been consistent in maintaining the strength of the frontogenesis until showing some weakening late this afternoon into the evening along with slipping it southeast of the area. Until this occurs, there will be enough forcing for some light snow across northeast Iowa into southwest Wisconsin with minor accumulations of less than a half inch expected. Looking upstream, this snow is reducing the visibility to about a mile a times and the current timing would impact the evening commute. As of now, not planning to issue an advisory for this snow, but will likely issue a special weather statement to highlight the possibility of some slippery roads and lower visibilities during the commute. After this band of light snow, an area of high pressure will build in from the northwest and remain over the region through Thursday. Skies are expected to clear out overnight and with the fresh snow cover, low temperatures in the single digits will be possible west of the Mississippi River where skies should be clear the longest. The colder start will also hold down temperatures some Thursday with highs only in the lower to middle 20s. .LONG TERM...(Thursday night through Wednesday) Issued at 235 PM CST Wed Nov 6 2019 High pressure will be scooting overhead Thursday night, which should make for a chilly night in the single digits for most of the area, especially where somewhat fresh snow cover remains. A few of the typical cold locations in central WI could even dip below zero by Friday morning. Mid level RH/clouds look to be on the increase from the west Friday morning which could limit just how far temperatures in western portions of the area can drop depending on how soon any clouds arrive. Southerly return flow Friday into Saturday will allow things to slowly warm up, with highs approaching 40 by Saturday. There could be some light precipitation Sat. afternoon associated with a clipper dropping southeast across northern MN, and again Sunday as a cold front pushes through the area. That aforementioned cold front will put an end to the "mild" weather, with much colder air moving in behind it for early week. Highs will drop from the 30s on Sunday to the teens/low 20s by Monday as 850 mb temperatures drop to near - 20C. This would be more than 2 standard anomalies below normal, so very cold for this time of year indeed (hello, winter). High pressure looks to stay in control Monday and Tuesday, with some moderation in temperatures possible by mid week. && .AVIATION...(For the 06Z TAFS through 06Z Thursday night) Issued at 1000 PM CST Wed Nov 6 2019 Cigs: SKC/SCT conditions tonight through the better part of Thu with some increasing clouds for Fri ahead of an upper level shortwave. WX/vsby: No impacts currently expected. Winds: west northwest through the period. Should start to swing to the south overnight Thu as a high pressure ridge moves across the area. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...None. MN...None. IA...None. && $$ SHORT TERM...04 LONG TERM...Lee AVIATION...Rieck
Area Forecast Discussion
National Weather Service Caribou ME
932 PM EST Wed Nov 6 2019 .SYNOPSIS... High pressure builds south of the state tonight. Low pressure will develop near the coast of Maine on Thursday and track northeast across the Gulf of St. Lawrence by Friday evening. Canadian high pressure is expected to build in from the west into Saturday and then slide offshore Saturday night. A cold front will cross the area Sunday night and will be followed by high pressure Monday. && .NEAR TERM /THROUGH THURSDAY/... 9:32 PM Update: A clear sky across most of the FA. High and mid level clouds are seen on satellite pictures moving into far western portions of the area. Clouds will be on the increase from the west overnight. The air mass is very dry per the 00z KCAR sounding with a PWAT of only 0.15". A little bit of light snow may develop toward daybreak along and near the western Maine/Quebec border and into parts of the North Woods. Made some minor adjustments for tonight based on the latest observations, satellite pictures, and near term models. Previous discussion: Clouds will dissipate after sunset w/some clearing and temps to drop some more through the late evening. The RAP and GEM show the high pres ridge to shift to the east overnight w/clouds increasing in association of some weak WAA. There is jet streak noted by the model guidance at the 850-700mb layer of 35-45 kts pushing into the area by daybreak Thursday. This feature combined w/the weak WAA might be enough to trigger some light snow to break out by 09-12z timeframe, Therefore, adjusted the precip chances to account for this setup. Not expecting any accumulation by morning. Temps will drop off early tonight w/the clearing and winds letting up. Thinking here is that temps will level off later tonight w/the weak WAA and increasing clouds moving in. The 12Z GEM and ADJLAV appeared to fit well w/this trend. There is better agreement among guidance this afternoon showing a deepening of the coastal low pressure farther to the east, and after exiting the adjacent waters. The vorticity maxima currently over Alberta and Saskatchewan that will act as the trigger for cyclogenesis will likely round the base of the 500mb longwave trough after its axis is over Maine, leading to a neutrally tilted trough over the CWA. The result is a weaker low pressure, more progressive system, and lower QPF/snow amounts. Temperatures at the onset of precipitation tomorrow morning will be well above freezing across the south and near or just above freezing across the north. Precipitation will briefly start as rain or a mix for many, before wet-bulbing occurs and the rain/snow line sinks southward along I-95 between Houlton and Bangor. && .SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/... A cold front will form along the developing low pressure and move through the CWA tomorrow night, transitioning precipitation to a brief period of snow across the south. Around the same time, the aforementioned shortwave will arrive and enhance precipitation along the surface front. The highest QPF amounts are along the coast, which will still be on the eastern side of the trough axis when the shortwave arrives. Low pressure will begin to deepen and move northeast over Nova Scotia and towards Newfoundland Friday. Advection of colder, drier air and positioning of the best dynamics to our east will end widespread precipitation. Decreased PoPs and transitioned stratiform wording to showers after 12z Friday. NW flow, lingering low level moisture, and perhaps a weak deformation zone to the west of the low will probably favor at least some snow shower activity, but current thinking is coverage will be limited and the 12z NAM is too aggressive with QPF. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... Departing system and NW wrap around winds will be replaced by amplifying ridge from west through the weekend. The ridge will bring dry conditions Saturday and Sat night ahead of another shortwave passing through Ontario. The amplification of the ridge over the east coast places a jet over the Great Lakes and Midwest, which keeps the center of the disturbance to the north. Ahead of this, southwest flow with WAA increases Sunday over Maine, bringing potentially the warmest temps of the week on Sunday. Depending on velocity of elongated cold front dropping through the eastern Great Lakes into the Northeast, Sunday night would follow a non-diurnal temp trend. Temperatures would then cool Monday and Monday night with front slowing off the Maine coast. This creates a large spread in possible temps across the CWA Monday, but high temps may show in the AM. As noted in previous forecasts, not much moisture accompanies the passage, and positive tilt of the trough would likely only offer the chance of light snow or rain showers. Through mid-week, discrepancy exists in guidance handling slow exit of the boundary. High pressure will move into the Northeast and eventually lift or push this boundary out of the region. Slight to chance PoPs will exist over the area through remainder of period with below normal temps forecast. && .AVIATION /02Z THURSDAY THROUGH MONDAY/... NEAR TERM: VFR overnight. Conditions are expected to deteriorate across the northern terminals on Thursday to MVFR w/periods of IFR by the afternoon in snow. MVFR/IFR to hit KBGR and KBHB by Thursday afternoon in rain. SHORT TERM: Thursday: CIGs and VIS will start VFR and transition to IFR and LIFR in rain and snow Thursday afternoon. The rain/snow line is expected to set up around or just south of HUL and move southward Thursday night. Light south winds expected to start Thursday, then winds shift north to northeast Thursday night. Friday: Winds turn northwest and increase, gusting to 20 knots or greater. CIGs improve to MVFR and VFR, but VIS reductions will remain possible in snow showers. Friday Night Sat Night: VFR with WNW winds shifting W, gusts 15-25 kt possible. Winds will slacken to around 10 kts Saturday becoming SW and 10-20 kts at BHB. Sunday Sunday Night: VFR with MVFR possible in snow showers at northern TAF sites. SW winds 10-20 kts Monday: Snow and rain showers will taper with MVFR possible in heavier showers. Winds SW shifting W, gusts increasing to 15-25 kts. && .MARINE... NEAR TERM: The wind continues to diminish this evening and the seas continue to slowly subside. The wind and seas are expected to remain below small craft advisory levels into Thursday morning with a few gusts to 25 knots possible in the afternoon. SHORT TERM: The wind slackens Thursday night, and again building above 25kts Friday. A few gusts near Gale are possible Friday night. Waves will be slow to react, building from 2-4 Thursday to 4-6 Friday evening and overnight with offshore flow. These winds will calm into Saturday morning with winds 2-4 feet through Sat night. Winds and waves will again increase Sunday near SCA criteria. Waves in coastal ocean zones will approach 5-7 feet. Winds and waves remain elevated through Sunday night, subsiding into Monday. Early week will need to be monitored for changes as there is uncertainty regarding passage of a cold front Monday. && .CAR WATCHES/WARNINGS/ADVISORIES... ME...None. MARINE...None. && $$ Near Term...CB/Hewitt Short Term...Strauser Long Term...Cornwell Aviation...CB/Hewitt/Strauser Marine...CB/Hewitt/Strauser
Area Forecast Discussion
National Weather Service Des Moines IA
553 PM CST Wed Nov 6 2019 ...Updated for Current Weather Trends and 00z Aviation Discussion... .UPDATE... Issued at 553 PM CST Wed Nov 6 2019 Have pulled the snow farther south by about a county or so than original given progression of light snow toward I-80. The snow area has been moving east-southeastward at around 15 knots, but should begin to dissipate through the evening hours. The high resolution WRF-ARW seemed to be handling current trends the best and to a lesser degree the RAP and HRRR. Overall, only expecting a tenth or two of accumulation if that south of Highway 30 this evening before low level dry air in cross sections surges southward and brings the snow to an end. While road and bridge temperatures are in the middle 30s or higher, these of course will be falling through the night. Overall impacts should be low, but one area of concern is the melting snow on bridges currently may refreeze as the air and bridge temperatures lower overnight. Remainder of the forecast remains on track at this time. && .DISCUSSION.../Tonight through Wednesday/ Issued at 309 PM CST Wed Nov 6 2019 A cold front pushed through most of Iowa as of 2 PM and will exit the far southeast by 5 PM. Aloft, we have a shortwave that is pushing into northern Iowa and will make it`s way across the Upper Midwest tonight. Forcing with this wave is a little stronger than expected and according to cross sections, occurred within the dendritic growth zone in a nearly saturated layer. This resulted in occasional moderate to heavy snow north with visibilities of a quarter to three quarters of a mile at times. At this time road temps were just above freezing with bridges just below. Road cams showed wet to slushy roads where the heavier snow briefly fell. Due to the short duration of the heavier snow and the transient nature of the snow in general, I opted to handle impacts with a Special Weather Statement. As the shortwave passes and the forcing with it shifts east this evening, the snow is expected to sink towards the I-80 corridor but with the lack forcing, and a deeper dry layer near the surface in southern Iowa we shouldn`t see much more than flurries south of highway 30 and the further south from highway 30 you go, then less chance for this there will be. High pressure moves in overnight pushing in a lot of dry air. We should see clearing skies overnight and cold temps moving in. The wind will stay up between 10-15kts so temps while quite cold...will not bottom out to as cold as they could be. Still we are going with single digits far north where the snow fell to mid 20s south. We will remain cold and dry through Thursday night. On Friday the surface high shifts east and weak warm advection returns to the west/southwest third of the state by late in the day which will not help temps much but they should be at least a few degrees warmer than Thursday west. Strong warm advection will take place late Friday night/Saturday...which will give us the warmest day that we have seen in awhile and that we will see again for awhile. On Sunday, a push of cold air will follow a strong cold front pushing through the state leading to some very cold air settling into Iowa. It is not out of the question to see some record or near record cold high temperatures Monday and Tuesday. I did drop highs a couple more degrees on these days. By Wednesday the arctic high shifts to the east allowing for some return flow over the western half or so of the state and slightly moderating temps. && .AVIATION.../For the 00Z TAFS through 00Z Thursday evening/ Issued at 553 PM CST Wed Nov 6 2019 Area of light snow was pushing east-southeastward causing widespread MVFR or IFR restrictions over the northern terminals. The snow will soon reach DSM and bring a period of MVFR restrictions. Overall, snow will end this evening as low level dry air arrives with the sky becoming clear and conditions returning to VFR through the end of the period. Winds from the north will remain brisk overnight before decreasing some by tomorrow morning. && .DMX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Ansorge DISCUSSION...FAB AVIATION...Ansorge
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
512 PM CST Wed Nov 6 2019 .AVIATION... VFR conditions are currently prevailing across the area at the present time, but ceilings should lower back into MVFR and eventually IFR categories overnight. Before then, there could be an isolated shower or storm northwest of DRT, but any possible activity should remain northwest of the terminal. The main focus of this TAF period will be the continuing low clouds through the period and the passage of a cold front around 18z tomorrow afternoon. While there could be an isolated shower ahead of the front, should see much higher chances along and behind the front in the afternoon and evening hours. Overall chances for thunderstorms are low and will just mention VCTS with prevailing -SHRA for the FROPA and will have no mention of thunder in the evening hours. Conditions should slowly improve towards the end of the 24-30 hour period with ceilings possibly lifting into MVFR categories. North winds behind the front will be in the 18-30 knot range. && .PREV DISCUSSION... /ISSUED 240 PM CST Wed Nov 6 2019/ SHORT TERM (Tonight through Thursday Night)... Current weather pattern across the CONUS is defined by largely zonal west to east flow across much of the country. A closed low is parked near the CA/AZ/Mexico border, with west southwesterly flow at the mid and upper levels sending moisture from the Pacific into the mid to upper levels of South Central Texas with breezy southeasterly winds at the surface. Temperatures this afternoon have exceeded expectations for many locations, especially where cloud cover has been less than anticipated (primarily across the Coastal Plains - sitting at 85 in Kenedy right now). High temps today should range from the mid 70s across the Hill Country to the low to mid 80s elsewhere under partly to mostly cloudy skies with a decent southeasterly breeze at the surface. Tonight will remain generally mild (lows to the mid to upper 60s) with mostly cloudy to even overcast skies (cloud cover increasing throughout the night). Some patchy fog will be possible toward sunrise. The overnight period should stay dry, although the HRRR seems to indicate a chance for an MCS across the Hill Country in the early morning hours of Thursday (other models do not corroborate this). Attention then turns to the cold front tomorrow. Models are in fairly good agreement that the cold front will be entering the northern portions of the CWA (northern Val Verde through northern Burnet counties) by late Thursday morning, and completely through the entire region by mid to late afternoon Thursday. Winds will shift to northerly behind the front, with sustained winds increasing to 15 to 20 mph with some gusts up to 30 to 35 mph tomorrow afternoon through early Friday morning. Temperatures will drop in wake of the front, so high temperatures tomorrow will vary considerably from north to south, with the Hill Country maxing out in the upper 60s by late morning before the cold front passes, while the southern portions of the region should see high temps in the upper 70s to near 80 degrees. Models vary in how they handle precipitation with the front. There will likely be some sort of line (or broken line) of showers and isolated thunderstorms along and ahead of the front, but models vary on the robustness of this line. Behind the front, fairly high PoPs will persist as decent moisture will still in place and some decent ascent over the cooler surface airmass should produce scattered to widespread stratiform rain. Rain should come to an end by Friday morning (possible some showers lingering into the afternoon hours across the far southeastern counties). Total rainfall amounts should generally range from quarter of an inch to half an inch of rain, with higher amounts up to an inch or so possible across the Coastal Plains. As per usual, there could be isolated higher (or lower) amounts. Low temperatures on Thursday night/Friday morning are expected to remain above freezing, with lows bottoming out in the upper 30s to mid to upper 40s. LONG TERM (Friday through Wednesday)... Cloud cover and cold air advection will keep us chilly on Friday, with highs only in the mid 50s expected for all of South-Central Texas. Cloud cover will persist through the overnight period, so once again temperatures Saturday morning are expected to remain above freezing, with overnight/early morning lows in the low to upper 40s. Mostly cloudy skies and northerly winds continue through Saturday as well, although we are expected to warm up into the mid 60s on Saturday afternoon. Winds shift back to the southeast by Sunday, bringing moisture back into South-Central Texas. Mostly cloudy skies are expected to continue, however, with high temperatures around 70 degrees. By late Sunday into Monday, an arctic blast is expected to overtake much of the US thanks to a potent mid to upper level low and accompanying trough. This is expected to send a strong cold front through the region sometime during the day on Monday. This will bring another chance for showers and thunderstorms to the region, especially for areas along and east of the Interstate 35 corridor. It will also bring in another round of strong northerly winds behind the front, as well as much cooler temperatures and drier air. Another freeze seems quite possible early Tuesday morning for the Hill Country. High temperatures for Tuesday afternoon are expected to be in the mid 40s to low 50s, with another freeze expected overnight Tuesday into Wednesday morning, with the coverage of this freeze expanding to everywhere except for the Rio Grande Plains. Cold temperatures will continue into Wednesday afternoon, with highs expected to only reach the low to mid 50s. && .PRELIMINARY POINT TEMPS/POPS... Austin Camp Mabry 65 72 44 56 43 / 10 80 60 10 - Austin Bergstrom Intl Airport 65 72 44 56 42 / - 80 60 10 - New Braunfels Muni Airport 66 74 44 55 44 / - 80 60 10 - Burnet Muni Airport 63 68 40 54 40 / 10 80 60 10 0 Del Rio Intl Airport 69 77 46 57 49 / 10 70 60 10 10 Georgetown Muni Airport 64 70 42 55 40 / - 80 60 10 0 Hondo Muni Airport 68 76 45 57 46 / - 80 60 10 - San Marcos Muni Airport 65 73 43 56 42 / - 80 60 10 - La Grange - Fayette Regional 63 75 47 57 43 / - 80 60 20 - San Antonio Intl Airport 67 75 45 56 47 / - 80 60 10 - Stinson Muni Airport 68 78 47 56 47 / - 80 60 10 - && .EWX WATCHES/WARNINGS/ADVISORIES... None. && $$ Aviation...Hampshire Short-Term/Long-Term...05
Area Forecast Discussion
National Weather Service Wichita KS
940 PM CST Wed Nov 6 2019 .UPDATE... Issued at 937 PM CST Wed Nov 6 2019 Updated to decrease precip chances. Have been updating to decrease precip chances over the last few hours mainly based on trends. After looking upstream, also feel that drizzle chances are decreasing as ceilings over northern KS/Nebraska are mostly above IFR levels with no visibility restrictions. Feel that surge of dry air will offset the cold advection and keep ceilings and possible drizzle chances on the low side. So trimmed the northern extent of precip and only left for the last row or two of our counties. && .SHORT TERM...(This evening through Saturday night) Issued at 343 PM CST Wed Nov 6 2019 By mid-afternoon today, a cold front is progressing south through the forecast area. Behind this front, much colder air will be ushered into the area beginning this evening and overnight tonight as northerly wind speeds increase. Increasing moisture south of the front along with some marginal instability has produced a few isolated thunderstorms in northern Oklahoma this afternoon. Over the next few hours, a few of these scattered showers with possible thunder may make it as far north as southern/southeast Kansas. However, continue to think that the bulk of the activity will remain south of the Oklahoma border. As the evening progresses and the front continues to progress southward, low clouds and drizzle will overspread much of south central and southeast Kansas. RAP forecast soundings and low-level moisture profiles suggest that a few brief snow flurries or some brief freezing drizzle will be possible up in central Kansas and quickly move south on the back edge of the departing precipitation. Overall, however, agree with the previous forecasts that this would be rather brief and thus impacts minimized with little or no accumulation expected. Biggest change with this forecast issuance was timing adjustments. Think around or just after sunrise tomorrow all precipitation will be out of the forecast area to the south and east. This will make way for clear skies tomorrow but much cooler than normal temperatures. Afternoon highs could struggle to reach the 40 degree mark in some locations of central Kansas. By Friday, as surface high pressure slides across the Northern Plains and into the Middle Mississippi Valley, very dry air will be advected into the region. Highs will remain well below normal but will be about 7-10 degrees warmer than Thursday. As the surface ridge continues to trek eastward across the Middle Mississippi and Ohio Valley on Friday, winds will flip back around to blow out of the south as the pressure gradient tightens. As a result, much warmer temperatures on Saturday are expected with highs reaching into the 70s at some places. Increasingly, models have trended warmer for Sunday over the past couple of days, so continue to go with a "middle of the road" approach for Sunday`s highs with temps near-normal. .LONG TERM...(Sunday through Wednesday) Issued at 343 PM CST Wed Nov 6 2019 A major change will come Monday and Tuesday to start the work week, however. A few light snow showers will be possible late Sunday or early Monday with the passage of the next cold front. Other than a possible dusting, not much if any accumulation is to be expected with this light/low-impact precipitation. However, the main highlight of this period by far will be the MUCH colder temperatures. With standard anomaly values approaching 3+ standard deviations below the mean, a significant cool down is expected with on Monday in the 30s and early morning lows on Tuesday dropping in the 10-15 degree range. After analyzing model certainty tools and various guidance, these lows on Tuesday reflect a significant downward trend from the previous forecast. This will be something to watch over the next several days. Although record lows for November 12 are quite low in the single digits at all climate sites, Tuesday lows could approach those values or at least get close. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 534 PM CST Wed Nov 6 2019 Aviation concerns will be low clouds behind a strong cold front along with scattered showers and storms over far southern KS. Strong cold front currently stretches from near KEMP to just north of KICT and is continuing to quickly push south. South of the front, scattered showers and storms have been affecting mainly areas just south of the KS-OK border, with some of it clipping far se KS. This activity is developing in an area of 850-700mb moisture transport. Pockets of MVFR ceilings are likely behind the front as colder air continues to spill south, but feel confident we are not looking at IFR conditions. Also not out of the question to see some areas of drizzle develop as low layers continue to saturate, but these areas look to be few and far between. Ceilings will quickly lift Thu morning as dry air continues to move-in, allowing VFR ceilings for most sites a couple hours after sunrise. && .FIRE WEATHER... Issued at 343 PM CST Wed Nov 6 2019 Gradually warming temperatures and low humidity in a much drier air mass may lend to very high grassland fire danger across portions of central Kansas Friday afternoon. Otherwise, intermittent high grassland fire danger is expected over the next week or so. && .PRELIMINARY POINT TEMPS/POPS... Wichita-KICT 31 42 24 51 / 20 10 0 0 Hutchinson 29 41 22 52 / 10 0 0 0 Newton 28 40 22 50 / 10 10 0 0 ElDorado 30 40 24 49 / 20 10 0 0 Winfield-KWLD 33 42 25 49 / 40 20 0 0 Russell 25 40 23 58 / 10 0 0 0 Great Bend 26 40 22 57 / 10 10 0 0 Salina 27 40 22 54 / 10 0 0 0 McPherson 28 40 21 51 / 10 0 0 0 Coffeyville 36 43 24 50 / 60 30 0 0 Chanute 33 41 23 48 / 30 10 0 0 Iola 32 40 22 48 / 20 10 0 0 Parsons-KPPF 34 42 24 49 / 50 20 0 0 && .ICT WATCHES/WARNINGS/ADVISORIES... None. && $$ UPDATE...RBL SHORT TERM...TAV LONG TERM...TAV AVIATION...RBL FIRE WEATHER...TAV
Area Forecast Discussion
National Weather Service Lincoln IL
800 PM CST Wed Nov 6 2019 .SYNOPSIS... Issued at 800 PM CST Wed Nov 6 2019 A cold front will continue to push south across central and southeast Illinois tonight. Isolated showers or a mix of light rain and light snow will be possible as the boundary moves through central Illinois tonight. More widespread rain will impact southeast Illinois tonight and Thursday morning, which may mix with snow before ending. Skies will quickly become sunny from northwest to southeast on Thursday, though temperatures will be significantly cooler, with highs only in the 30s. && .UPDATE... Issued at 800 PM CST Wed Nov 6 2019 Radar shows the cold front about to go through Jacksonville and Lincoln, and recently passing Bloomington. Winds quickly increasing to around 15-20 mph behind the front, but were near 5 mph ahead of it. Latest HRRR guidance brings the front to near I-70 by midnight. Initial batch of showers ahead of the front has largely moved into Indiana, though a surge of precipitation with the upper wave entering the lower Ohio Valley should move into southeast Illinois after midnight. Further north, evening sounding from our office showing a fair amount of dry air above 800 mb, and forecast soundings only show some modest increase over the next several hours. Precipitation with the northern wave has been across northern Illinois and into central Iowa, largely tracking east. Rain/snow mix still possible, before diminishing after 2-3 am. Forecast was recently updated to address the PoP trends, including increasing them south of I-70 Monday morning. Changes also were made to add areas of fog near and south of I-70 this evening, and to update the timing of the wind shift. && .SHORT TERM...(This evening through Thursday) ISSUED AT 240 PM CST Wed Nov 6 2019 A weak frontal boundary will move across the area tonight and bring increasing clouds and small chances of precip. In the north, some of the precip could be a mix of rain and snow, while areas to the south will see all rain. As the boundary moves across southeast Illinois, cooler air will also move into the area, with the precip becoming a mix or rain and snow. Rainfall amounts through tomorrow will remain well below one quarter of an inch, and snowfall should remain less then a couple of tenths. Overnight lows will generally be below freezing, except for southeast Illinois where temps will only drop into the middle 30s. Chilly conditions are expected tomorrow with temps in the mid 30s to lower 40s. .LONG TERM...(Thursday night through Wednesday) ISSUED AT 240 PM CST Wed Nov 6 2019 With the mid level ridge still remaining over the western US into the weekend and the beginning of next week, northwest flow/troughiness will continue across the central and eastern parts of the US. This means cold and relatively dry weather conditions will be the rule through the Long Term period. So, two cold high pressure areas are forecast to move into the area through the period. The first one will arrive lat Thursday afternoon into the evening hours. This cold high pressure will sit over the area through the first part of the weekend. The second high pressure area will move into the area at the beginning of next week. In between, a boundary will move through the area Sunday night through Monday. Dry weather is again expected with this weekend boundary, however pops will be in the slight to isolated category. This second high pressure area will also bring dry weather to central IL through the middle of the week. Temps will be cold through the period, with coldest temps expected with the second high pressure area next week. Overnight lows Monday and Tue night will be in the teens most areas, while afternoon highs on Tuesday will be below freezing. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 520 PM CST Wed Nov 6 2019 Cold front is seen on radar between KGBG/KPIA, and is progged to pass KPIA by 00Z and KSPI-KCMI in the 02-03Z time frame. Been seeing some lower MVFR ceilings becoming widespread ahead of the front over the last couple hours, and this trend will continue well into the night. Further north, am expecting ceilings to drop below 3,000 feet by about 03Z, but the MVFR conditions should be of a shorter duration. As the front passes, winds will quickly shift to the north and start to gust to around 20 knots, which will last a good portion of the night. While some light rain or snow showers are possible behind the front, they currently do not look to be a significant issue. Ceilings expected to rise to around 3000 feet between 08-12Z and skies should clear out by 18Z Thursday. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Geelhart SYNOPSIS...Geelhart SHORT TERM...Auten LONG TERM...Auten AVIATION...Geelhart
Area Forecast Discussion
National Weather Service Marquette MI
1020 PM EST Wed Nov 6 2019 .UPDATE... Issued at 1019 PM EST WED NOV 6 2019 While LES will be on the increase off Lake Superior overnight/Thu morning under deepening moisture profile/rising inversion and modest forcing from shortwave, the main focus will be on development of a dominant LES band tied to Lake Nipigon preconditioning. Conditions look very favorable for intense snowfall rates (2-3in/hr) in this band which will organize later tonight and then continue thru much of the day on Thu as winds veer northerly across the e half of Lake Superior. Lake induced equilibrium levels will increase to upwards of 16kft with DGZ well placed in the convective layer to boost snow- to-water ratios. HRRR runs over the last several hrs of have been showing the dominant band tied to Lake Nipigon developing into Alger County in roughly the 09-12z time frame then shifting w to either far eastern Marquette County or far western Alger County Thu morning where it remains nearly stationary into the aftn hrs. Nearly stationary aspect results in hvy pcpn/snowfall. 00Z HRRR paints 1.20 inches of liquid pcpn over far eastern Marquette County (just e of Harvey down thru Skandia/Carlshend) which could easily translate to at least 18 inches of snow. Quick perusal of incoming 00z models shows a lack of agreement on degree of veering winds over the lake and thus where the dominant snow band will stream onshore most persistently. NAM indicates western Alger County (roughly w of Munising) and the NMM roughly Munising/Shingleton. The ARW is much more aggressive with veering winds over eastern Lake Superior and would drive hvy LES thru western Alger County and into much of northern and eastern Marquette County. Even outside of this main dominant band, LES bands will contain mdt/hvy snowfall. A warning may be needed somewhere in the n central given the excellent conditions for hvy LES, but the rather localized hvy snow and uncertainty in placement of heaviest snowfall precludes issuance at this time. Envision this being a situation where warning issuance or special messaging will be needed once the band takes shape, and there is better confidence in eventual placement of where the band will become nearly stationary. Out w, localized heavier LES will also develop overnight/Thu morning over western Upper MI, and some isolated advy level snow accumulations may occur. Will be adding Marquette County to the advy for Thu since there is at least high enough confidence of the eastern part of the county being impacted by decent snow (e of Harvey). Advy for Delta and/or southern Schoolcraft may be needed at some point as significant snowfall from the dominant band will stream well inland. && .SHORT TERM...(This evening through Thursday) Issued at 355 PM EST WED NOV 6 2019 Big story this afternoon, evening and into tomorrow will be lake effect snow. The flow will follow the expected wind shift, initially being WNW to W, shifting to northwest tonight with the southward approach of east to west oriented shortwave, then northerly early tomorrow morning in the east as a high builds into the central Plains. The NW flow will continue for the Keweenaw and western counties tomorrow. The the lake effect bands will follow the wind shift so the traditional W, WSW, NW, and N belts should expect snow through the next 24hrs. Beginning with the westerly to northwesterly flow, many of the models are picking up on the wind shift in the next couple hours. Little to no 1000-850mb low level shear, persistent moisture flux thanks to our healthy Lake Superior skin/850 temp delta T near 20C, lift through the DGZ and inversion heights increasing to ~8k ft AGL, we can expect persistent bands this afternoon. After the wind shift to the NW, some models are picking up on slight lowering of the inversion closer to 5k ft AGL, but this is more likely the models resolving breaks in the snow bands themselves. NW flow should persist through the overnight hours. By tomorrow morning, model consensus is that the flow will shift in the eastern counties to be from the north. With this wind shift, models are picking up on increased surface convergence and an impressive amount of lift through the DGZ. The corresponding inversion height increases over 10k are believable. Some models, for example the GFS, has the inversion height upwards of 13k ft. There is disagreement on exact placement of the enhancement and the CAMS are responding with subtle disagreements on the placement of the persistent stronger bands of snow. There does appear to be a westward trend of some of the stronger bands into Marquette County, with a gradual eastward movement of the bands through the day tomorrow. Previous forecasts of 10+ inches were dialed back some in northern Alger and Schoolcraft counties due to this eastward shift and less focused QPF, but some isolated areas of 12+ inches across the region are not out of the question. If the bands become more organized, there is the potential for the snow bands to make it into southern Schoolcraft and Delta counties and the current forecast has the northeast corner of Delta approaching 6-8 inches. Snow ratios across the board tomorrow hover close to 20:1 using a blend of models and methods. Continued the high end advisory for the eastern counties through 0z Thursday night but if the models come into more agreement on the placement of when and where they`ll setup, the advisory may end up upgraded to a warning. Temperatures tonight will likely dip into the mid-teens in the traditional cold spots closer to the WI/MI border. The lakes will moderate lows, but only a little. Expect lows in the 20s closer to the shoreline. Tomorrow, a colder airmass then the past couple of days will move in, and keep temperatures below freezing across the region. The eastern counties will be warmest, closer to 30F, but the inland western ares will struggle into the mid 20s. With the colder airmass digging south, expect gustier winds over Lake Superior that could kick wave heights upwards of 9ft along Alger County. There is the potential for some minor beach erosion in some spots. .LONG TERM...(Thursday night through Wednesday) Issued at 355 PM EST WED NOV 6 2019 Temperatures look to remain well below normal through the first portion of November as an eastern CONUS trough remains in place. A brief reprieve, although still blo normal, will move in Friday afternoon, with SW flowing pushing temperatures back near 30 for Friday and into the 30s for Saturday. As a trough pushes across Upper Michigan on Saturday night, arctic air will funnel in behind the trough and associated cold front. A return to mostly NW flow will return Sunday afternoon into the middle of next week with LES chances persisting. On Thursday night, high pressure will build in the Northern Plains as the pressure gradient relaxes with moderate height rises. With the exception of the Keweenaw, expecting PoPs to fall off through the evening into Friday morning. Winds will become more from the SW with WAA at 850 mb and temps climbing through Friday. Models still suggest 1 to 2 inches across the western portions of the W to NW lake effect snow belts, with 2 to 3 inches across the east from Munising to Grand Marais. Temperatures will continue to climb through early in the afternoon on Saturday. May seem some -shsn through the night on Friday as WAA and some weak isentropic lift move across Upper Michigan. Wouldn`t amount to much more than an inch or so, but there is still the chance. High temperatures may climb into the mid-30s by Saturday afternoon, before models suggest a trough and associated cold front to pass through with CAA and associated height falls. This will mark the return of some LES in the NW wind lake-effect snow belts. The cold front on Saturday evening will be associated with another shot of extended cold air throughout the Northern Plains and Great Lakes region. Anomalously cold air for early November will fill in behind this cold front with 850 mb temps falling between -20C and - 22C. This will lead for a greater chance of LES downwind of Lake Superior through the rest of the forecast period as winds are predominately expected to remain northwesterly with some periods of more northerly. With continued cold air filling in through Monday, Monday night may bring the chance at record lows, or at least approaching zero degrees. Cloud cover will remain key for some of these low temperatures, as persistent LES and clouds down wind of the lake may act as a blanket for some. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 705 PM EST WED NOV 6 2019 Deepening moisture profile and passage of a disturbance will lead to increasing lake effect shsn thru Thu morning. NW low-level winds will favor KIWD/KCMX for the shsn. As is typical for lake effect, conditions will be quite variable, likely varying btwn IFR and VFR with MVFR generally prevailing. At KSAW, downslope nature of the wind should allow VFR conditions to prevail thru the night with only some -shsn/flurries at times. Thu morning, winds may veer toward the n just enough for heavier shsn to possibly reach the terminal, but confidence right now is too low to include any significant vis reductions. MVFR cigs should develop at KSAW prior to sunrise. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 355 PM EST WED NOV 6 2019 Generally winds have been w-wnw through the day tonight between 20 and 30 knots with occasional reports of gusts near 35 knots of some of the higher platforms. The winds will shift to northwest tonight and the persistent 20 to 30 knots is expected to continue. Wind gusts at or around gale force will be possible, especially at bridge or anemometer level of some of the higher platforms. This will continue through the night and into tomorrow, but the winds over the eastern lake will shift more northerly and gradually weaken going into Thursday evening. Lake effect snow bands are expected to follow the wind direction, and in more persistent and organized bands, expect visibilities to temporarily drop below 1nm, especially tomorrow in the eastern lake where more impressive bands are expected. Building high pressure on Friday into Saturday will relax winds below 20 knots through Sunday morning. Behind a strong cold front Saturday evening, NW winds will pick up with gusts between 30 and 35 knots. There still remains a chance for prevailing gales, but will need to monitor for changes in the forecast moving forward. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... Winter Weather Advisory until 7 PM EST Thursday for MIZ006-007- 085. Winter Weather Advisory from 7 AM to 7 PM EST Thursday for MIZ005. Lake Superior... None. Lake Michigan... None. && $$ UPDATE...Rolfson SHORT TERM...JP LONG TERM...JAW AVIATION...Rolfson MARINE...JAW
...Updated Aviation Forecast Discussion...

.DISCUSSION... Issued at 322 PM CST Wed Nov 6 2019 Forecast Summary: With northwesterly mid level flow remaining over the Plains at least through the beginning of next week, reinforcing surges of cold air will be the primary forecast concern. A fairly dry atmosphere will lead to only minimal and transient precipitation chances. Tonight through Thursday: Arctic cold front had pushed through eastern Nebraska and southwest Iowa as of early afternoon. Sharply colder temperatures were advecting in behind the front on north winds gusting over 25 mph. Temperatures had climbed into the 50s in southeast Nebraska and southwest Iowa before low clouds and cold advection knocked them back down into the 30s and 40s. Also, light snow was noted across southeast South Dakota, working into northeast Nebraska, in area of enhanced lift under right entrance region of 150kt upper level jet. HRRR was the first mesoscale model to show light snow in our area this afternoon, and the RAP was beginning to catch on. While the most concentrated snows will be north of our area, could see up to an inch of snow in far northeast Nebraska before lift translates east this evening. Then, 1040mb high pressure is forecast to settle into the region later tonight through Thursday night, with airmass characterized by 850 temps as cold as 15C below. 850 temps started today at 12Z around 7C at Omaha, and are forecast to drop almost 15C by Thursday morning. Core of surface high pressure will be overhead during the day Thursday leading to very little mixing and cold temperatures. Lows Thursday morning should fall back into the teens most areas, with highs in the afternoon struggling back into the 30s. Thursday night through Saturday: A warming trend is in the offing to end the work week. High pressure slides east Thursday night allowing return southerly flow to overspread the region. Meanwhile, lowering pressure in the Northern Plains ahead of approaching strong mid level shortwave trough will enhance southerly flow Friday, with winds turning to a more favorable-to-warming southwesterly component by Saturday. 850 temps swing back to the positive side of 0C by Friday morning, and increase into the 10 to 15C range by Saturday afternoon. Thus we should see pronounced warming beginning Friday when highs approach 50 after morning lows in the 20s. Highs Saturday could top 60 in most of our area given the added compressional warming component of southwest winds under an already mild atmosphere. Saturday night through Wednesday: The roller coaster of temperatures takes a huge plunge early next week. Another strong cold front is slated into the area later Saturday night. However the airmass behind this system is even colder than today`s, with 850 temps dropping into the 15 to 20C below range on Monday. A 1045mb surface high is forecast to settle over the region by Monday night before retreating Tuesday night. Given the degree of this arctic airmass, we will likely see morning highs on Sunday with falling afternoon temperatures, then highs only in the 20s Monday and Tuesday. Lows are likely to bottom out in the teens Sunday night and single digits Monday night. Some moderation of temps is expected Wednesday as southerly flow returns, but still well below normal. The best chance for any light snow during this period is Sunday night and Monday when the strongest cold advection is occurring and deeper dendritic temperature regime is overhead. However moisture is lacking, so any snow should remain fairly light. && .AVIATION...(For the 00Z TAFS through 00Z Thursday evening) Issued at 609 PM CST Wed Nov 6 2019 MVFR ceilings of 020-030 are forecast at KOFK and KOMA through 03Z. After 03Z, ceilings should gradually lift to SCT250 by 12Z. Ceilings at KLNK will be VFR through the period, with ceilings also improving to SCT250 by 12Z. Wind gusts at KLNK of 20 to 30 knots are expected to diminish after 03Z with prevailing wind speeds of 12 to 14 knots. && .OAX WATCHES/WARNINGS/ADVISORIES... NE...None. IA...None. && $$ DISCUSSION...Dergan AVIATION...Smith
Area Forecast Discussion
National Weather Service Shreveport LA
919 PM CST Wed Nov 6 2019 .UPDATE... Widespread showers and a few thunderstorms continue to spread east and northeast across the Middle Red River Valley of extreme Northeast Texas, Southeast Oklahoma and Southwest Arkansas. 00z NAM output in good agreement with HRRR and HREF output suggesting that this activity should not come much further south overnight, remaining near or northwest of the I-30 Corridor. For this reason, have removed pop mention closer to the I-20 Corridor for the remainder of the night. Also slowed the southward progression of the large rain shield through much of the morning hours on Thursday, cutting pops back to slight chance variety mainly across Northern Louisiana until the afternoon hours. Changes to temps were minor overnight and through the day Thursday. Updated zone package already sent...13. && .PREV DISCUSSION... /issued 509 PM CST Wed Nov 6 2019/ AVIATION... VFR conditions currently prevailing across all our terminal locations and those conditions should continue into the late evening and most of the overnight hours. Convection currently northwest of the I-30 Corridor should remain north and west of our northern and western most terminal locations through at least 07/12z. Beyond 12z, introduced prevailing VCSH across our northern and western most terminals with prevailing -SHRA from 15-18z and beyond. Further east, including our LFK/SHV/ELD and MLU terminals, did not introduce VCSH until closer to 18z. Frontal boundary will push through our terminal airspace ahead of this precipitation with most of this activity being post frontal. Ceilings will fall rapidly along and in the wake of the cold frontal passage with at least MVFR ceilings and VSBYS along with -SHRA overspreading the region through much of the late morning and afternoon hours on Thursday. 13 && .PRELIMINARY POINT TEMPS/POPS... SHV 59 61 38 51 / 10 80 50 10 MLU 60 62 35 50 / 0 80 60 10 DEQ 60 60 32 52 / 80 90 20 0 TXK 59 60 34 49 / 30 90 30 0 ELD 56 58 32 49 / 10 80 30 0 TYR 61 62 39 53 / 10 80 30 10 GGG 60 62 38 51 / 10 80 50 10 LFK 64 64 43 55 / 0 70 60 10 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 13/13
Area Forecast Discussion
National Weather Service Tucson AZ
301 PM MST Wed Nov 6 2019 .SYNOPSIS...Scattered showers and thunderstorms especially east of Tucson into this evening. Some strong thunderstorms may also occur this evening. Otherwise, expect dry conditions briefly before isolated thunderstorms return Friday into Saturday east to south of Tucson. Dry conditions will then prevail across much of the area early next week. && .DISCUSSION...The weather system that brought morning showers and thunderstorms, some with moderate rain and small hail, continued to pass through Arizona this afternoon. Most of the shower and thunderstorm activity was isolated in nature and confined to Cochise, Graham and Greenlee counties this afternoon. The latest HRRR model solution showed this activity shifting farther east this evening as the system weakens more and tracks over east-central Arizona. Thereafter, models showed a ridge of high pressure aloft building along the West Coast with a weak upper low undercutting the ridge near northern Baja. This upper low was forecast to brush the far southeast corner of Arizona Friday into Saturday with the possibility of a few showers or thunderstorms there. Otherwise, dry weather can be anticipated elsewhere Thursday through next week. Daily high temperatures will remain a few degrees above normal through the forecast period. && .AVIATION...Valid through 08/00Z. Scattered -TSRA/-SHRA mainly east of KTUS this afternoon and evening. Brief wind gusts to 45 kts may occur this afternoon with the strongest TSRA. Otherwise, cloud decks generally 8k-12k ft MSL into Thursday morning. Surface wind will be variable in direction mostly under 12 kts aside from potentially stronger thunderstorms gusts. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...There will be a slight chance of showers and thunderstorms east of Tucson this evening, with scattered showers and thunderstorms are expected overnight. Dry conditions will then prevail across much of the area Thursday into next Monday. The exception is late Friday night into Saturday when a few showers may occur mostly across southern and eastern Cochise County. 20-foot winds will generally be under 15 mph through early next week, except for some locally gusty east winds on Friday. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && $$ Visit us on Facebook...Twitter...YouTube...and at