Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/22/19

Area Forecast Discussion
National Weather Service La Crosse WI
1040 PM CDT Mon Oct 21 2019 .SHORT TERM...(This evening through Tuesday) Issued at 332 PM CDT Mon Oct 21 2019 At 3 PM, a deepening surface low was located over the Twin Cities. CAPES have climbed up to 750 J/kg across northeast Iowa, southeast Minnesota, and west-central and north-central Wisconsin. In addition, the RAP has wind shear climbing up to 45 knots across northeast Iowa and southeast Minnesota late this afternoon and early evening. In addition, the NST parameter moves into northeast Iowa and southeast Minnesota just ahead of the deformation band. While it is not the most favorable severe weather setup, it is something that should be watched closely between 21.23z to 22.03z. From late tonight into Tuesday, the BUFKIT soundings continue to show that we will mix up to 800 mb. In addition, the 950 to 850 mb lapse rates will climb above 8 C/km. This will result in sustained winds of 20 to 30 mph with wind gusts up to 45 mph. Due to this, a Wind Advisory is in effect from 4 AM to 7 PM Tuesday west of the Mississippi River and from 7 AM to 7 PM Tuesday south of Interstate 94 in western Wisconsin. .LONG TERM...(Tuesday night through Monday) Issued at 332 PM CDT Mon Oct 21 2019 From Wednesday into Wednesday evening, a low pressure system will move quickly east southeast across Iowa. This system will produce light rain along and south of Interstate 90. This rain may briefly mix with some snow in the morning and evening, but no accumulations are expected. Rainfall amounts will be up to a tenth of an inch. The next chance of rain looks to be on Sunday, but confidence is really low due to a wide range of solutions. && .AVIATION...(For the 06Z TAFS through 06Z Tuesday night) Issued at 1040 PM CDT Mon Oct 21 2019 MVFR conditions have returned to many areas, along with periods of showers, as low pressure is gradually working its way across the region. As that low passes, winds will rapidly increase from the west, sustained at 15-25 knots with gusts of 35-40 knots for both LSE and RST, perhaps even briefly stronger at times. Strong gusts and occasional showers will then hang tight through much of the day Tuesday, with showers departing through the afternoon and winds gradually subsiding into the evening, though MVFR ceilings are likely to remain for much of the TAF period, briefly even down to IFR levels at RST through 08Z before the wind shift occurs. && .CLIMATE... Issued at 332 PM CDT Mon Oct 21 2019 Both La Crosse and Rochester are very close to setting daily precipitation records for October 21st. La Crosse has received 1.56 inches, so far. Their record is 1.60 inches in 2009. Rochester has received 1.33 inches, so far. Their record is 1.57 inches in 2009. The La Crosse precipitation total climbed above 40 inches (40.40 inches) for the year. This is the 13th time that this has occurred since 1873. The last 4 years are among the 14 wettest (2016 - wettest, 2017 - 14th wettest, and 2018 - 5th wettest). The Rochester precipitation total climbed above 50 inches (50.87 inches) for the first time in a calendar year. 8 out of the 15 wettest years at Rochester have occurred since 2004. All 5 of the wettest years have occurred since 2007. && .ARX WATCHES/WARNINGS/ADVISORIES... WI...Wind Advisory from 7 AM to 7 PM CDT Tuesday for WIZ032>034- 041>044-053>055-061. MN...Wind Advisory from 4 AM to 7 PM CDT Tuesday for MNZ079-086>088- 094>096. IA...Wind Advisory from 4 AM to 7 PM CDT Tuesday for IAZ008>011-018- 019-029-030. && $$ SHORT TERM...Boyne LONG TERM...Boyne AVIATION...Lawrence CLIMATE...Boyne
Area Forecast Discussion
National Weather Service Charleston SC
916 PM EDT Mon Oct 21 2019 .SYNOPSIS... A cold front will approach from the west late tonight and move off the coast late Tuesday. High pressure will rebuild Tuesday night through Thursday before another storm system potentially moves in Friday or Saturday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... 22/00z surface analysis shows the warm front is propagating slowly north and was located near the Florida/Georgia border north of Jacksonville. Intensifying warm air advection/isentropic assent has been producing an area of showers and even a few tstms from Brunswick up into the Georgia coastal waters. Mesonet observation show as much as 0.5-1.5 inches of rain has fallen across parts of McIntosh County over the past few hours with even higher amounts observed near Brunswick. Have adjusted pops up along the Georgia and far southern South Carolina coasts were current radar trends. Also adjusted overnight lows up a degree or two for many areas with temperatures expected to hold steady and/or slowly rise overnight as the warm front lifts north. Still think there is a non-zero risk for an isolated tornado across mainly the lower South Carolina coast. See the discussion from earlier this evening for additional information on that threat. Overall, the forecast is in good shape. 21/21z surface analysis placed a sharpening warm front across central Florida with weakening high pressure noted along the Carolina coast. The front will gradually lift north across Southeast South Carolina and Southeast Georgia tonight as the high moves offshore and a cold front approaches from the west. Isentropic assent/warm air advection will slowly increase with time, first producing a large area of low/mid-level cloudiness advecting in from the south followed by isolated to scattered showers later. Most of the lift looks to remain rooted along the 305K surface for much of the night with more dynamic, deep-layered forcing associated with the upper trough to the west not arriving until after daybreak. Much of the high resolution guidance is similar in showing an area of convection developing over the coastal waters in the vicinity of the warm front and along the nose of the strongest warm air advection. With most of the lift being primary driven by warm air advection and not by strong, kinematic forcing, it is unclear how widespread this activity will become. The H3R and RAP are both not overly aggressive in the coverage of convection during the overnight period, so pops have been lowered by about 10% across the board to show this trend. The best chance for measurable rainfall looks to occur from the Savannah Metro Area north along the lower South Carolina, including the Charleston Metro Area. Short term soundings show weak instability developing in the vicinity of the warm front with as much as 50 kt of bulk shear. Although instability and forcing are weak, there looks to be enough to support at least a few tstms. There will be a non- zero chance for an isolated tornado after midnight mainly along the lower South Carolina coast where weak instability and shear will maximize along the northward propagating warm front. Noted the latest RAP SigTor values in this area are forecast to be around 1 unit. Nocturnal tornadoes can be especially deadly. An isolated damaging wind event can also not be completely ruled out. Temperatures tonight will exhibit an atypical thermal curve with values rising early Tuesday with the passage of the warm front. Lows will range from the mid 60s in the area bounded by I-26 and US-17 to the upper 60s-lower 70s elsewhere. Temperatures are forecast be in the lower-mid 70s by daybreak Tuesday. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/... Tuesday: The base of a deep eastern U.S. upper trough is forecast to shift through the Tennessee and Ohio Valley regions. A cold front at the surface is expected to move into our inland zones to near the I-95 corridor during the early afternoon hours. The window for potential destabilization ahead of the front appears to be short and rather limited due to the progressive nature of the front. Surface dew points are expected to fall after mid afternoon as the front shifts to the coast. Prior to fropa, forecast soundings along zones along and east of I-95 show surface based CAPEs 1000-1500 J/KG along with Pwats near 2 inches along with bulk shear of 30 kt and rather unidirectional deep layer flow by early afternoon. There appears to be a brief potential for isolated strong to severe tstms just ahead of the cold front over coastal SC, especially along the Charleston Tri-County in the 17Z-20Z time frame. The overall risk for severe weather otherwise looks rather low given the timing of the front into the I-95 corridor by 18Z. We maintained high chance POPs all areas as convective rains will likely remained scattered. Temps will be warm in the lower to mid 80s with frontal compression and periods of insolation. Wednesday and Thursday: High pressure and dry weather will return to the region. It will be cooler on Wednesday with highs in the mid 70s. We also lowered temps Wednesday night as strong radiational cooling likely to send temps into the mid to upper 40s northwest tier to near 50 at both Charleston and Savannah. Northeast flow on Thursday should keep afternoon temps in the mid 70s most areas once again with a few high clouds around and some increasing coastal stratocumulus south of the Savannah River. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... An upper level trough will develop to the west late in the week. A frontal system is expected to impact the area Friday into Sunday, likely bringing periods of showers though the heaviest rain may remain just inland. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... MVFR cigs will gradually fill in from the south this evening as a warm front sharpens over Florida. Cigs could briefly rise to VFR at KSAV with its passage around 08z, but at least periods of MVFR should persist. Isolated to scattered showers will accompany the warm front where isentropic assent will be present. At this time, activity looks too isolated/scattered to support any mention of reduced vsbys. Will carry VCSH at both sites. A more consolidated line of showers/tstms associated with a cold front will approach both KCHS and KSAV from the west late morning into the early afternoon Tuesday. Latest model trends suggest this activity will be weakening as it approaches. Will carry VFR conditions with -SHRA for now. The cold front should clear the terminals by mid-late afternoon. Extended Aviation Outlook: Brief restrictions possible ahead of a cold front Tuesday morning. VFR Tuesday night through Thursday. Increasing chances for low clouds late Thursday night through the weekend along with scattered showers. && .MARINE... Tonight: A warm front will lift north through the waters overnight, allowing winds to veer from the southeast to the south. Speeds are expected to remain well below Small Craft Advisory criteria, topping out in the 10 to 15 kt range. Seas will average 2-3 ft nearshore and 3-4 ft offshore. Tuesday through Friday: A cold front will move offshore late Tuesday with winds veering from southwest to northwest in the wake of the front. We expect a nice punch of cooler and drier air over the waters Tuesday night and this will result in surging and jetting offshore flow. We will likely need a Small Craft Advisory for GA waters 20-60 NM during this time before flow begins to subside on Wednesday. The near shore waters will see decent surging but it appears we may not reach SCA criteria for a substantial length of time. The surface high will build north of the waters mid to late week with moderate onshore flow continuing. Seas may increase to advisory levels next weekend due to persistent northeast fetch and an increasing pressure gradient. && .CHS WATCHES/WARNINGS/ADVISORIES... GA...None. SC...None. MARINE...None. && $$
Area Forecast Discussion
National Weather Service Quad Cities IA IL
826 PM CDT Mon Oct 21 2019 .UPDATE... Issued at 823 PM CDT Mon Oct 21 2019 With coordination with offices to the east and northeast, I am expanding the wind advisory through our Illinois counties east of the current product. This will run identically with the previous placement through 3 PM Tuesday. Otherwise, the light showers are already well handled by the low pops in our forecast. UPDATE Issued at 442 PM CDT Mon Oct 21 2019 Recent winds gusts on the leading edge of the cold advection over eastern Iowa, are resulting in some wind gusts to 45 mph, thus I have issued a quick update to start the wind advisory right now, as opposed to midnight. There may be a period where winds decrease a bit this evening, prior to shifting to the northwest later this evening and increasing for the long haul. ERVIN && .SYNOPSIS... Issued at 217 PM CDT Mon Oct 21 2019 This afternoon is quite a nice change (for the most part) from our dreary, overcast, stormy morning. As of 2 PM, temperatures ranged from 53 in Cedar Rapids, to 64 in Freeport under a mix of sun and clouds. Low pressure was centered not too far away over central Iowa, and was slowly moving northeast based on latest surface analysis. A few wind gusts near 40 MPH were common along and east of the Mississippi River, as a dry slot evident on WV imagery worked over the area and allowed winds aloft to mix down to the surface. Further west, wind gusts of 35-45 MPH were occurring in central and eastern Nebraska, with some peak gusts of 55-60 MPH seen as well! This low pressure, and wind, will be our primary concerns and challenges for the short term period. && .SHORT TERM...(This Evening through Tuesday) ISSUED AT 217 PM CDT Mon Oct 21 2019 Key Messages... 1) Strong winds expected across the area beginning this evening, lasting through Tuesday morning. 2) Wrap-around rain showers tonight with light amounts expected. Challenging forecast with differences primarily in the wind speeds and gusts amongst guidance. Surface low pressure will continue to slowly move north through the day, with strengthening expected to continue as the 500 hPa low deepens further with continued CVA across the region. With the deepening, the pressure gradient is expected to tighten on the back side of the low, leading to an increase of southwest to west winds tonight. Several CAMs including the HRRR and the RAP have remained consistent with very windy conditions across the area for tonight. However, they have also remained consistent with initializing around 5-10 kts too high from current obs, which is likely having impacts on forecast winds later in the period. However, global models and CAMs are in agreement of winds around 925-850 hPa near 45-55 kts passing across the area tonight and Tuesday morning. As clouds and moisture build in behind the departing surface low, expecting the environment to not decouple too much from the boundary layer, which will help support some mixing of winds to the surface. BUFKIT sounding profiles are also in agreement with this scenario. After collaboration with surrounding offices, have decided to issue a wind advisory for all of eastern Iowa and portions of northwest Illinois. Potential exists for sustained winds of 25-30 MPH, with frequent gusts to 45 MPH at times late tonight and Tuesday morning. In addition, there will be scattered rain showers and pockets of drizzle as moisture interacts with lift in the vort maxes wrapping around the upper level low, which may allow additional mixing of winds. This may lead to brief periods of higher gusts. Winds will begin to decrease Tuesday afternoon as the low pressure moves north of Lake Superior and the pressure gradient relaxes. Surface ridging will approach from the west, keeping our weather dry and quiet through the early portion of the long term period. .LONG TERM...(Tuesday Night through Monday) ISSUED AT 217 PM CDT Mon Oct 21 2019 Overall, relatively dry weather is expected through next weekend, with continued below normal temperatures. Tuesday night, winds will continue to diminish as the area is between systems; with the low moving even further off to the NE and the next quick moving clipper system approaching from the NW. Wednesday into Thursday, the clipper-type system will sweep across the area bringing locations along and north of I-80 mainly a slight chance for some showers. The best chance at measurable rain; 30 pops; is along Highway 20 from Independence to Manchester. Thursday, models have shifted a system SE, taking it up the OH Valley region. It does still clip our east and southeast counties with some low/20-30 chance pops. Dry conditions will prevail elsewhere. Thursday night into Friday, skies will be clearing out from NW to SE with nearly calm winds. Lows in the upper 20s and low 30s look to be on track; with the coldest values over the NW half of the CWA. High pressure will keep things quiet Friday and Saturday with continued below normal temps. Some moderation in temperatures is expected Sunday into next Monday, as a low in Manitoba brings a cold front SE into the region. In the same timeframe, some models show a southern system lifting into the mid Mississippi Valley region. For now, there is a slight chance for rain in the forecast for Saturday night through the first half of Sunday. Needless to say, confidence is low at this time. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening) ISSUED AT 611 PM CDT Mon Oct 21 2019 MVFR cigs will sweep back into the region around the 02-04Z window tonight, from west to east, and with that, winds will switch from southwest at 20 to 35 kts to west northwest at 25 to 40 kts. This strong wind and MVFR cig around 1200 to 2000 ft will continue through Tuesday afternoon. && .HYDROLOGY... Issued at 1225 PM CDT Mon Oct 21 2019 River levels continue to recede today. Rainfall amounts were generally under a half inch with just two reports near an inch. Relatively dry conditions are anticipated over the next week. The Pecatonica at Freeport fell out of flood this morning and is expected to hold steady through Friday just under flood stage. On the Rock River, Moline will fall below flood stage this afternoon, while Joslin will continue to slowly fall. Routed flow on the Mississippi River may push the Dubuque railroad gage to near flood stage late this week. South of the Quad Cities, levels will continue to recede for the next 2 to 3 days, before leveling off and possibly rising slightly late this week and into next week. && .DVN WATCHES/WARNINGS/ADVISORIES... IA...Wind Advisory until 3 PM CDT Tuesday for Benton-Buchanan-Cedar- Clinton-Delaware-Des Moines-Dubuque-Henry IA-Iowa-Jackson- Jefferson-Johnson-Jones-Keokuk-Lee-Linn-Louisa-Muscatine- Scott-Van Buren-Washington. IL...Wind Advisory until 3 PM CDT Tuesday for Bureau-Carroll- Henderson-Henry IL-Jo Daviess-Mercer-Putnam-Rock Island- Stephenson-Whiteside. MO...NONE. && $$ UPDATE...Ervin SYNOPSIS...Speck SHORT TERM...Speck LONG TERM...14 AVIATION...Ervin HYDROLOGY...14
Area Forecast Discussion...CORRECTED
National Weather Service Green Bay WI
1059 PM CDT Mon Oct 21 2019 Updated aviation portion for 06Z TAF issuance and new information added to update section .UPDATE... Issued at 959 PM CDT Mon Oct 21 2019 Have allowed the Lakeshore Flood Advisory to expire. Winds have turned south to southwest and diminished, so strong onshore flow has ended. As a result, water levels have already dropped about a foot, and continue to fall. Calls to local sheriff departments indicated that flooding conditions had improved in most areas, though at least minor flooding was likely still occurring in localized areas near the bay. A lack of recent on site reports made it difficult to fully assess the situation, but meteorological conditions suggested continued improvement should occur. UPDATE Issued at 700 PM CDT Mon Oct 21 2019 The wind advisory for Door county will be allowed to expire, as winds have dropped well below advisory criteria. Isolated thunderstorms will continue over far northern WI, where MUCAPE was around 400 j/kg within the nose of the dry slot. Will update the forecast to extend a slight chance of storms for a couple more hours. An area of locally dense marine fog was lifting up the Lake Michigan shoreline. Models show this moving out of the area by around 02z or shortly thereafter, so will just handle with Marine Weather Statements on the lake and Special Weather Statements for the shoreline areas. Will be calling around to determine whether or not coastal flooding is still occurring this evening. Water levels have come down a bit since they peaked earlier in the day, and winds are turning southerly, so conditions are expected to gradually improve. The current Lakeshore Flood Advisory is in effect until 10 pm. && .SHORT TERM...Tonight and Tuesday Issued at 252 PM CDT Mon Oct 21 2019 The latest RAP analysis and satellite/radar imagery show a strong area of low pressure along the western Wisconsin and Minnesota border early this afternoon. Moderate to briefly heavy rain continues to move northeast across much of Wisconsin. The strongest showers have been bringing down isolated strong gusty winds in the 40 to 50 mph range mainly over the Fox Valley and Lakeshore. Gale force gusts are also occurring over the Bay and Lakeshore, with reports of high water occurring along the shoreline near Suamico. Given the current winds, no change to the ongoing wind advisory or lakeshore flooding headlines. Not out of the question that an isolated rumble of thunder could occur as well south of Hwy 29. Meanwhile, the dry slot is pushing into southwest Wisconsin with partial clearing ongoing. Additional showers and a few thunderstorms are also occurring within the comma head of the cyclone over western Iowa and far eastern Nebraska. As this cyclone moves across the region over the next 24 hours, forecast concerns include precip trends and strong wind potential. Tonight...Low pressure will lift northeast across far northwest Wisconsin and western Lake Superior. Showers will continue to rapidly lift northeast ahead of the dry slot and clear far northern Wisconsin and Door County early this evening. The strongest winds look to occur just ahead of the dry slot within the heaviest showers, so winds should subside somewhat as the showers exit and winds shift to the southwest. A lull in the precip should then persist until early overnight. Then deeper moisture will return beneath the comma head overnight and bring widespread light rain and drizzle to the region. As cold advection moves in, winds may increase again towards day break, mainly over eastern WI. Low temps mainly ranging through the 40s. Tuesday...The upper cyclone will continue to lift north across the Upper Peninsula and Lake Superior. Progged soundings are quite moisture-laden through the day, with saturation extending up through 700 mb. This should result in periods of light rain and drizzle. Weak cold advection will continue which should serve to steepen low level lapse rates up to 900 or 875 mb, where winds are projected to reach into the 35 to 40 kt range. As a result, could see wind gusts of 35 to 40 mph, mainly over central and northeast WI where the pressure gradient will be tighter. Blustery highs ranging from the mid 40s to near 50. .LONG TERM...Tuesday Night Through Monday Issued at 252 PM CDT Mon Oct 21 2019 Showers will diminishing Tuesday night as the upper low moves off towards Hudson`s Bay. A few snowflakes could mix in with the rain Tuesday night but it`s not cold enough aloft for anything more than that. A Clipper system could bring some light rain or snow to east central Wisconsin Wednesday afternoon and evening, but the bulk of it should stay to our south. Otherwise generally dry and cooler than normal weather expected for the middle and end of the week with northwest upper flow and surface high pressure passing by to our south. && .AVIATION...for 06Z TAF Issuance Issued at 959 PM CDT Mon Oct 21 2019 Wrap-around showers with a low pressure system will overspread the region from west to east overnight, along with lowering ceilings and vsbys (MVFR/IFR). Showers and IFR/MVFR flight conditions will continue through most of the day on Tuesday, though some improvement should be noted in the late afternoon and evening as showers gradually taper off. Winds will diminish a little tonight before turning west and increasing again on Tuesday. Westerly gusts will reach 30 to 35 knots in central and east central WI during the afternoon and early evening. LLWS should gradually taper off overnight. && .MARINE... Issued at 252 PM CDT Mon Oct 21 2019 A strong low pressure system will passing through the area tonight and Tuesday. Ahead of the low, wind gusts will peak this afternoon in the 35 to 40 kt range, before subsiding somewhat this evening. After winds veer to the southwest, winds are expected to increase again late tonight into Tuesday. Gusts in the 35 to 40 kt range appear likely from late tonight into Tuesday evening. Wind gusts will be approaching gale force through Tuesday night. As a result, have extended the gale warning for the Bay until 00z Wednesday. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE.........Kieckbusch SHORT TERM.....MPC LONG TERM......RDM AVIATION.......Kieckbusch MARINE.........MPC
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1041 PM EDT Mon Oct 21 2019 .SYNOPSIS... Rain will be widespread and perhaps heavy at times ahead of a cold front which will cross Tennessee tonight and our area on Tuesday. Cool and dry high pressure will settle in for Wednesday and Thursday as an unsettled weather pattern returns for the weekend and to start next week. && .NEAR TERM /THROUGH TUESDAY/... As of 1035 PM EDT: Pre-frontal showers have survived into the extreme southern Appalachians late this evening, but no thunder or lightning has. With LAPS sbCAPE values now quite stable across the region, anticipate mainly increasing coverage of the showers through the overnight hours with the arrival of the cold front. It does not appear as if the eastern escarpment low clouds/fog have worsened in coverage or intensity this evening, so the SPS should suffice in lieu of any dense fog advisories since mixing will increase with the precipitation and the improving southerly flow. As a surface wave forms along the passing front along and east of the Blue Ridge early Tuesday, modest surface-based instability could return from the south ahead of the boundary. Isolated thunder chances will thus ramp back up east of the Blue Ridge and then peak in the scattered range across the piedmont from late morning into the early afternoon hours. The RAP now features sbCAPE values rebounding to around 1000 J/kg south/east of Charlotte by Noon, and this is the part of the forecast area that will see the best chance of isolated severe weather with the fropa as deep-layer bulk shear values exceed 50kt. Anticipate the surface cold front moving east of the I-77 corridor around 18Z, with rapid drying and gusty westerly winds expected behind the boundary. Temperatures will remain well above climo throughout the period. && .SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/... As of 210 PM EDT Monday: Quiet weather is on tap for the short term. The longwave trough responsible for pushing the cold front through the area will rapidly lift northeast away from the region through Wednesday with broad southwest flow aloft taking over in its wake. Breezy west to northwest winds behind the trough will continue to usher in cooler air with a 1025 mb surface high building into the region late Wednesday and lingering into Thursday. This will support sunny skies with winds becoming light by Wednesday evening. Winds will probably be just strong enough to preclude frost development in all but possibly the most sheltered mountain valleys late Tuesday night into early Wednesday morning. Good radiational cooling conditions (clear skies, light winds and low dewpoints) will likely support fairly widespread frost with isolated freeze conditions for the mountains into the North Carolina foothills Wednesday night with patchy frost possibly extending into the North Carolina Piedmont, especially north of I-40. Highs Wednesday and Thursday will be near if not slightly below normal despite sunny skies with highs in the 60s to near 70. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... As of 145 PM EDT Monday: Starting with Thursday evening with dry conditions as surface high pressure departs the East Coast. On the 500mb pattern Thursday night a broad trough covers the mid section of the nation. As this trough moves east, moisture will advect up from the Gulf of Mexico setting the stage for a prolonged period of considerable clouds and periods of rain. Timing is quite different between the GFS and ECMWF. The GFS has the rain arriving from Georgia very early Friday and widespread moderate to at times heavy rain Friday night and Saturday morning. The GFS has high pressure passing across late in the weekend as the front lingers across Florida and moisture returning early in the week. The EC maintains dry weather until late Saturday for the western mountains with low pressure crossing Oklahoma Saturday night then Missouri on Sunday. The EC has the bulk of the rain crossing Tennessee on Sunday and the NC mountains getting good rain Sunday night. The EC keeps the weather unsettled next week as another low pressure approaches from the west. The bulk of that rain does not arrive until late in the week. With vast differences in the models at least they do agree in a general sense that our weather will be unsettled in this forecast period. Temperatures close to seasonal normals with the warmer day on Monday. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/... At KCLT and elsewhere: Ceilings and visibility across the region should begin a steady fall from the west through late evening as low level moisture continues to get reinforced by southerly flow ahead of an approaching cold front. Anticipate a downward trend into lower MVFR around midnight, then solid IFR overnight, with KCLT taking the longest to reach IFR after 09Z. Showers will also steadily spread back into the area from the west, but the thunder potential is quite limited given the lack of instability. The thunder potential will steadily increase east of the mountains, however, as a wave forms along the passing cold front, with scattered thunder chances developing across the foothills 12Z to 16Z, and thunder chances peaking around KCLT after noon. IFR cigs should persist until fropa, with rapid improvement from the west through the afternoon hours. Increasing SE then SW flow ahead of the front will turn sharply westerly with fropa, and gusty as well. Outlook: VFR conditions will develop through Thursday as high pressure builds into the area. The next storm system will approach the area on Friday. Confidence Table... 02-08Z 08-14Z 14-20Z 20-00Z KCLT High 97% High 87% Med 77% High 100% KGSP High 80% Med 71% Med 73% High 100% KAVL High 81% High 80% High 83% High 100% KHKY Med 78% Med 76% Med 65% High 100% KGMU Med 75% Med 75% Med 77% High 100% KAND High 86% Med 68% High 91% 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: && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && $$ SYNOPSIS...DEO NEAR TERM...HG SHORT TERM...Munroe LONG TERM...DEO AVIATION...HG
Area Forecast Discussion
National Weather Service Huntsville AL
932 PM CDT Mon Oct 21 2019 .NEAR TERM...(Rest of tonight) Issued at 932 PM CDT Mon Oct 21 2019 Although a "main" area of showers has moved well east of the region as of an hour or so ago, more have formed, over east central Mississippi, moving NNE east across northern Alabama and adjacent southern middle Tennessee. These showers appeared to be developing, partially in response to greater upglide in the 295-300K region, and forcing associated with a cold front gradually approaching from the west. This hard to find front per surface analysis appears to just east of the Mississippi River, about from Memphis to Greenville MS. Clouds from the 10.3-3.9 micron low cloud/fog view and night microphysics would suggest the front could be along a line of lower clouds just east of the big river. Short term forecasts from various models all indicate this boundary should begin moving more quickly to the east in the late evening and overnight. Timing from the HRRR and RAP suggests it should be east of NE Alabama in the 3-5 AM timeframe. Will make appropriate adjustments to the grids and end shower activity over our area by 5 AM. Wind should become westerly in the late evening, then WNW in the 3-7 mph range. This and drier air filtering in from the west should help keep fog formation minimized. Low temperatures in the upper 40s western areas to lower 50s east (and near large bodies of water) look good at this time. .SHORT TERM...(Tuesday through Wednesday) Issued at 307 PM CDT Mon Oct 21 2019 The overall pattern should continue to improve going into the Tue/Wed time frame, as a strong dome of high pressure out of the srn Plains builds ewd into much of the region. Overall temps are xpcted to be near seasonal thru mid week, with afternoon highs both Tue/Wed in the upper 60s/near 70F and lows Tue night in the lower 40s/around 40F. .LONG TERM...(Wednesday night through Sunday) Issued at 307 PM CDT Mon Oct 21 2019 High pressure will then move east of the mid TN Valley going into the end of the work week, with a slight warming trend developing on Thu. The focus then shifts towards the upcoming weekend period, with the latter half of the global models pointing to the next storm system/wx maker developing over the wrn Gulf region/states. Subtle differences remain with a couple of these global models in the Fri thru Sun time frame. Nevertheless, a potent upper trough axis should dig well into the Gulf region, with a sfc low developing along the wrn Gulf states. This sfc low looks to translate NE thru the cntrl Gulf states, but appears to remain just south of the local area. For now, this looks to maintain any precip associated with this next wx system as all showers for the cntrl TN Valley thru Sun. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 656 PM CDT Mon Oct 21 2019 The last of the showers preceding an approaching cold front were moving over the KMSL terminal, and should reach KHSV in the next hour or two. Afterward, the cold front which per radar and surface observations was nearing the far NW of Alabama should move across the central Tennessee Valley tonight. Shower activity will end after the front passes to the east. Despite moisture from recent rains, winds should remain up sufficiently to keep fog formation minimized. Light SE-S winds should become SW after the front passes, then become W-NW towards daybreak Tue. Westerly winds should increase into the 10-20kt range by the late morning and early afternoon. && .HUN WATCHES/WARNINGS/ADVISORIES... AL...NONE. TN...NONE. && $$ NEAR TERM...RSB SHORT TERM...09 LONG TERM...09 AVIATION...RSB For more information please visit our website at
Area Forecast Discussion
National Weather Service Lincoln IL
859 PM CDT Mon Oct 21 2019 .SYNOPSIS... Issued at 225 PM CDT Mon Oct 21 2019 A strong low pressure to our northwest will result in breezy conditions across central Illinois through Tuesday. Temperatures will cool off some on Tuesday, but a brief warming trend is on tap for Wednesday. && .UPDATE... Issued at 859 PM CDT Mon Oct 21 2019 01z/8pm surface analysis shows a cold front extending from just east of Paris to near Olney. A fine-line of showers has developed along/ahead of the front across west-central Indiana, so have added 20 PoPs to the far SE KILX CWA for the next 2 hours before the front crosses the Wabash River into Indiana. Behind the front, gusty southwesterly winds have brought much cooler air into the region with current temps in the lower to middle 50s. The strong winds that were observed earlier today have subsided somewhat: however, another surge of momentum is noted upstream across Iowa where winds have once again increased substantially. This momentum will track across north-central Illinois late tonight into Tuesday morning, producing wind gusts of 40-45mph along/north of a Macomb to Minonk line. Further southeast, winds will gradually increase as well...with gusts of 30-35mph by morning. && .SHORT TERM...(This evening through Tuesday) ISSUED AT 225 PM CDT Mon Oct 21 2019 Most of the showers are off to our east early this afternoon, with the back edge generally along the I-57 corridor. This should be out of the CWA over the next couple hours, and will plan on going with a dry forecast tonight. Surface and upper low are starting to become vertically stacked, with the next round of wraparound clouds edging into far western Illinois. Clear slot is helping to mix down some of the stronger winds aloft, and 35-40 mph gusts are becoming common again within it (gust to 45 mph was noted at Peoria at 1 pm). The gusts over the southeast half of the CWA should fade somewhat with sunset, but continue northwest overnight with the closer proximity to the low. Gusts will pick up again on Tuesday, but Bufkit momentum transfer suggests they should stay below advisory criteria as the low pulls further northeast toward Lake Superior. .LONG TERM...(Tuesday night through Monday) ISSUED AT 225 PM CDT Mon Oct 21 2019 As the upper low lifts into Ontario, the overall upper level pattern becomes more of a broad trough over the central U.S., with a digging shortwave over the Plains on Wednesday. This will lead to a couple cool days across the area later in the week. Main cold front is progged to move through Wednesday night. Bulk of the precipitation appears to be post-frontal, as an upper low cuts off over the Texas panhandle later on Thursday. Will go with 30% PoP`s Thursday afternoon and evening over much of the area, though latest European and GFS models would suggest the areas south of I-72 with more of a risk. While colder air will be spilling into the area Thursday night, currently looks like the precip should end before any potential changeover to snow. While brief ridging takes place early in the weekend, some model differences are evident. Longer range models have not changed from earlier runs, with the European ejecting the upper low into south central Illinois by Sunday morning, while the GFS and Canadian models gradually wash it out and keeps us dry. The European solution remains more of an anomaly, so low PoP`s remain warranted at this point. However, the models are in more of an agreement with a surge of cold air next week, though beyond the current forecast period. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 643 PM CDT Mon Oct 21 2019 Patchy mid-level clouds have spread across locations along/west of I-55 early this evening: however, the main aviation weather concerns are the strong winds and MVFR clouds currently poised upstream across Iowa. HRRR cloud height progs suggest these lower clouds will spill across north-central Illinois late tonight into Tuesday morning. Based on latest projections, have lowered ceilings to MVFR at KPIA by 11z and at KBMI by 12z. Further southeast at the remaining terminals, have only mentioned scattered low clouds. The MVFR ceilings will quickly lift north of KPIA/KBMI by midday...followed by clearing skies during the afternoon. W/SW winds will remain strong through the entire period...with gusts of around 25kt tonight and 25-30kt on Tuesday. && .ILX WATCHES/WARNINGS/ADVISORIES... NONE. && $$ UPDATE...Barnes SYNOPSIS...Geelhart SHORT TERM...Geelhart LONG TERM...Geelhart AVIATION...Barnes
Area Forecast Discussion
National Weather Service North Platte NE
701 PM CDT Mon Oct 21 2019 .SHORT TERM...(This evening through Tuesday night) Issued at 351 PM CDT Mon Oct 21 2019 Impacts/Highlights and Confidence: Main highlight revolves around the high wind headline. Strong northwesterly winds will continue rest of today with wind gusts 30-60 mph with peak gusts 50-60 mph generally along and east of highway 83 to the I-80 corridor through 7 PM CDT. Winds will subside this evening with peak gusts thereafter up to 50 mph across eastern parts of north central NE decreasing to 30-40 mph after midnight. HRRR ensemble supports peak gusts 40-50 kts through 00Z as seen via 50th percentile with the signal then shifting to eastern SD and northeast NE after 00Z. Thus confidence moderate-high with the wind gust forecast. Chance for rain and possible snow/mix tomorrow night. Confidence is low-moderate given transient forcing that weakens in time and for overall precip coverage. Any mix/snow should be limited to northwestern NE. Discussion: Latest water vapor imagery shows a deep upper low centered roughly over far northwest IA and far southwest MN with cyclonic flow affecting much of the CONUS. Latest radar display shows swaths of weak returns across north central NE with very light rain and drizzle being reported under 1-3 kft ceilings. The mid-level closed upper low will evolve and lift north across Lake Superior by early Tuesday night into Ontario. Else, mesoanalysis shows surface low positioned over the east central MN/WI border with a cold front extending through southwest WI south across central IL. Meanwhile, a decent gradient/synoptic wind environment has been in place over the Sandhills and central-north central NE with high winds continuing to be reported as of 2-3 PM CDT with gusts exceeding 58 mph. Recent BUFKIT soundings show mean mixed-layer winds peaking 43-47 kts at KLBF, KTIF, and KBBW with winds at the top of the mixed- layer up to 60 kts. Decent potential remains for high winds to mix down to the surface and be realized, even though mean mixed-layer winds are not greater than 50 kts. Especially as gusts continue to be reported. Latest thinking is window of high winds will now span through 7 PM CDT. Apparent strong surface gradient overhead has evolved slower to the northeast than expected. Gusts should start to subside early this evening as mixing decreases nonetheless. Further, winds aloft start decreasing as well at 925 and 850 hPa. However, elevated winds will continue overnight with sustained winds 10-30 mph, highest across north central NEB, as the surface low evolves to far northeast WI and the MN Arrowhead region tonight. Up next, a weak disturbance in the cyclonic flow will move across the Northern High Plains to NEB tomorrow night. This will coincide with a weak surface low that evolves southeastward with it. There are slight chances for precip across northern NEB tomorrow night, mainly after midnight. This is associated with lower tropospheric frontal forcing, however, it wanes across the area as it evolves southward thus chances confined to the north of the CWA. .LONG TERM...(Wednesday through Monday) Issued at 351 PM CDT Mon Oct 21 2019 Impacts/Highlights and Confidence: Moderate winds Wednesday along with cooling conditions with highs Thursday about 10-15 degrees below seasonable normals. Warm up then occurs with highs swinging up to 10-15 degrees above-normal Saturday. Saturday poses potential for elevated fire weather conditions given the synoptic setup/ridge breakdown and low afternoon humidity already forecast. Winds look to be the limiting factor but will continue to monitor moderate confidence at this time in this time frame. Discussion: Generally, large-scale troughing will continue to affect the region through Thursday night until mid-level ridge builds east out of the eastern North Pacific Thursday with mid- level height rises spreading across the area Friday as the ridge extends from CA across the Northern High Plains. Next upper-level trough breaks the ridge down Friday night-Saturday. The upper ridge sets the region up for a warm-up ahead of the next frontal system on Saturday. This sets up the potential for low chances for precipitation Saturday night-Monday. However, Friday and beyond, differences in phase and amplitude are starting to become apparent in the synoptic pattern thus confidence starts to decrease as we go further in time. Sunday-Monday looks to hold potential for unsettled conditions as the upper-trough evolves south and east. && .AVIATION...(For the 00Z TAFS through 00Z Tuesday evening) Issued at 701 PM CDT Mon Oct 21 2019 Strong winds will gradually diminish overnight with clear skies prevailing. Some low level wind shear is possible tonight as the low level level jet increases. Surface winds increase once again on Tuesday with gusts up to 25 to 30 knots. Otherwise, dry conditions will continue through Tuesday. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...ET LONG TERM...ET AVIATION...Kulik
Area Forecast Discussion
National Weather Service Tallahassee FL
834 PM EDT Mon Oct 21 2019 .UPDATE... Isolated showers ahead of the main line of rain and storms have dissipated. The line of rain and storms is moving through South Central Alabama and the Florida Panhandle currently. Lightning has been mainly along the coast. Strong to severe storms are still possible in the Florida Counties mainly near the coast. && .PREV DISCUSSION [729 PM EDT]... .NEAR TERM [Through Tonight]... At 18 UTC surface analysis showed the cold front moving into the Mid South, generally along a line from near Little Rock, AR to Houston, TX. The MCS across Srn MS and Coastal Louisiana has weakened over the last couple of hours, but model data suggests this area of convection will likely restrengthen in the next couple of hours as it encounters a more unstable airmass to the east. Observational data over the last hour from the 18 UTC upper air launch at Slidell, LA shows strong winds >45kt above 850 mb, and as these more favorable wind fields move toward our region, expect the severe threat to increase throughout the evening hours and into the overnight. After sunset, a line of thunderstorms should move into the area from the west. As discussed, the potential is present for a severe weather event overnight, especially south of the I-10 corridor. Southerly flow off of the Gulf of Mexico will advect dew point temperatures >70, and with temperatures in the low 70`s, LCL`s will be extremely low. Forecast hodographs suggest that a veered wind profile will exist; thus, with SRH values near 200 m^2/s^2 and cape values over 1500 J/kg in the southern portion of the CWA, there is certainly the potential for a couple of tornadoes. Damaging wind will also be a concern given that dcape values will be around 800 J/kg. Additionally, the increased instability for this time of year will allow for not only strong updrafts, but storms which will maintain themselves well into the night time hours. The line of thunderstorms will weaken towards the eastern portion of the CWA, and it should mostly clear out by the end of the near term period. Only a few updates were made this cycle to the inherited near term grids. The last few runs of the HRRR along with radar trends suggest the convective activity is moving a little faster than depicted in other numerical guidance, thus have maintained the faster progression of the storms through our region. .SHORT TERM [Tuesday Through Wednesday Night]... The aforementioned cold front will make its complete passage by Tues evening. Highest chances for showers/storms will therefore be in our eastern CWA as the front moves through. Some of the storms may be strong to severe - evident in SPC`s Day 2 Convective Outlook for Tues showing a marginal risk for severe weather east of PCB, MAI, and ABY (General Thunder, elsewhere) as of 1730z. Thereafter, high pressure temporarily builds in the front`s wake, making for fair weather conditions Wed and Thurs with northerly winds veering to northeasterly at 5-10 knots. This will bring in a cool airmass, keeping high temperatures in the 70s and lows in the upper 40s/low 50s (dewpoints in the 40s on Wed). .LONG TERM [Thursday Through Monday]... A somewhat uncertain synoptic pattern develops this weekend. Generally, a positively-tilted trough digs down the SW CONUS, producing deep-layer southeasterly flow over our area. The ECMWF solution cuts off an upper-level low over New Mexico and Texas, then propagates it northeast along the Ohio-Tennessee Valley. A front attached to this cutoff low approaches our area around Sun but there are indications that it may stall. Both the GFS and ECMWF also show Gulf moisture moving ashore by the east-to-southeast flow from high pressure. This may enhance convergence along the approaching frontal boundary. Therefore an active, wet pattern is anticipated for the remainder of the forecast period. The expected increase in showers/storms and cloud cover should keep high temperatures in the 70s (lows in the 60s). .AVIATION... [Through 00Z Wednesday] Rain is moving in from the west tonight ahead of a cold front. The best chance for thunder will be at ECP. Isolated showers are likely ahead of the main batch of rain. Conditions will deteriorate overnight with the best chance of fog at ABY and VLD with IFR CIGs expected. Elsewhere MVFR CIGs are likely but patchy IFR conditions are possible. The cold front will move through by tomorrow afternoon. VFR conditions will return by noon tomorrow (mid to late morning at DHN and ECP). .MARINE... Boating conditions are at near-cautionary levels ahead of an approaching cold front to begin the work week, with southerly winds at 10-15 knots. Seas will generally be 2-3 ft (isolated 4 and 5). Strong-to-severe thunderstorms will be possible Mon evening with gusty winds being the main hazard. A few waterspouts may spin up as well. As the front moves through on Tues, winds will veer southwest to northwest at around 10 knots. By midweek, winds shift to northerly around 20 knots, possibly necessitating Small Craft Advisories for Wed. Winds and seas relax somewhat from Thurs, onward at 10-15 knots out of the east-to-northeast. .FIRE WEATHER... Drier air will move in behind a cold front tomorrow. Relative humidity will remain above the critical threshold. Patchy fog is likely in the early morning hours. There are no fire weather concerns. .HYDROLOGY... A wet pattern for the bulk of this forecast period should provide much-needed rain to our area. Expected rainfall amounts from the first front are around a quarter-inch areawide. However, it is uncertain how much we will receive when the second frontal system and Gulf moisture arrive this weekend. Given the moderate-to- severe drought dating back to September and low river/stream levels, there are no flooding concerns at the moment. Potential flood threats will be re-evaluated as confidence increases in the synoptic pattern evolution later this week. .SPOTTER INFORMATION STATEMENT... Spotter activation is not requested. However, spotters are always encouraged to safely report significant weather conditions when they occur by calling the office or tweeting us @NWSTallahassee. && .PRELIMINARY POINT TEMPS/POPS... Tallahassee 71 80 52 74 54 / 60 60 0 0 0 Panama City 70 78 54 73 57 / 80 50 0 0 0 Dothan 65 74 48 70 50 / 70 30 0 0 0 Albany 69 77 51 71 52 / 60 50 0 0 0 Valdosta 70 81 52 73 54 / 40 70 0 0 0 Cross City 72 85 56 77 59 / 30 70 10 0 0 Apalachicola 73 80 56 73 60 / 70 60 0 0 0 && .TAE WATCHES/WARNINGS/ADVISORIES... FL...High Rip Current Risk until 2 AM EDT /1 AM CDT/ Tuesday for Coastal Bay-Coastal Franklin-Coastal Gulf-South Walton. GA...None. AL...None. GM...None. && $$ UPDATE...McD NEAR TERM...Godsey SHORT TERM...IG LONG TERM...IG AVIATION...McD MARINE...IG FIRE WEATHER...McD HYDROLOGY...IG
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
825 PM EDT Mon Oct 21 2019 .UPDATE... 00Z water vapor and H4 RAP analysis show a highly amplified upper level pattern in place over the conus this evening. The main feature is a deep but progressive trough that has dug all the way down to the northern Gulf coast. This trough is supporting a strong area of occluded low pressure centered over the upper midwest. An elongated frontal system extends from this system down through the Ohio/TN valleys and then into the north-central Gulf of Mexico. A large area of showers/storms has been steadily moving along the northern Gulf coast and through the deep south ahead of this front this afternoon/early evening. However, this energy is about to run up against a strong and stubborn area of upper level ridging extending from the Bahamas...across south Florida...and into the SE Gulf of Mexico. Global guidance in good agreement that this ridge will win the battle and significantly hold back the upper level synoptic support by the time the lower level frontal system makes it down into the west-central Florida. For the rest of the evening...the warm front that has been slowly migrating northward across the region today is currently analyzed up toward the Florida Big Bend area...and still forcing a few shallow showers that have been occasionally moving onshore into Levy County. These showers will likely persist for another couple of hours before the warm front lifts further north...taking the lower level focus for lift with it. The remainder of the overnight looks to be mostly dry for our the showers/storms off to our NW slow in their forward progress and weaken. Generally light winds overnight...thin passing clouds...and still saturated soils will likely result in patchy late night fog in the normally fog prone locations away from the coast. Temperatures will remain well above normal (mainly 70s) for the second half of October as our region stays within the thermal ridge ahead of the approaching front. Tuesday...The low level front will continue to make slow progress into the region...reaching the Nature Coast counties during the afternoon. Aloft...the energy forcing all the storms to our NW this evening will shear out quickly to the northeast around the periphery of the aforementioned upper ridge...with barely any height falls / synoptic lift arriving over our heads. The lower level frontal focus will be essentially be the only lifting mechanism...keeping the shower activity unorganized and generally light as it moves into the northern counties. The weakening trend will only continue as the front progresses southward...and not expecting much (if any) shower activity as one moves southward from the I-4 corridor. The front itself will likely make it through to south Florida by the mid-evening hours...but at this point we should see it stall. With the front to the south, we should manage to get a 1-2 day period of drier air across much of our region, but it will be short-lived as moisture quickly returns during the end of the week as the next frontal system dips into the deep south. && .AVIATION (22/00z THROUGH 23/06z)... VFR conditions prevail across west-central and southwest Florida this evening. Earlier shower activity has weakened and shifted north of the terminals. Winds will be light overnight...with thin cloud cover...allowing for some patchy fog to develop over the still saturated soils. KLAL/KPGD will see best chance of a period of MVFR BR between 08-12Z. After any early fog lifts...mainly VFR conditions expected for the Tuesday. A few showers are forecast ahead of an approaching front, however, coverage will not be high, and will decrease as one moves southward from the I-4 corridor. Southwest winds 8-11kts during the day will shift NW and then north in the wake of the front during the evening hours. && .MARINE... Winds through Tuesday morning hold south to southwesterly around 10 knots. A cold front will push through from northwest to southeast Tuesday afternoon and evening shifting winds briefly to a northwesterly direction and then northeasterly Tuesday night. Winds pick up behind the front to between 15 and 20 knots with rougher seas. Winds then shift more easterly for Thursday, but remain elevated around 15 knots. && .Preliminary Point Temps/PoPs... TPA 76 88 68 82 / 10 20 10 10 FMY 76 89 74 87 / 0 10 10 30 GIF 74 90 69 83 / 10 20 10 0 SRQ 76 88 70 86 / 10 20 10 10 BKV 73 88 64 81 / 10 30 10 0 SPG 78 88 70 84 / 10 20 10 10 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ Mroczka